Study suggests a sea level climate feedback loop in the mid-ocean ridge system regulates ice ages

Icy ebb and flow influenced by hydrothermal activity
Release of magma from beneath earth’s crust plays significant role in earth’s climate


The last million years of Earth’s history was dominated by the cyclic advance and retreat of ice sheets over large swaths of North America. During cold glacial intervals, ice sheets reached as far south as Long Island and Indiana, while during warm interglacial periods the ice rapidly retreated to Greenland. It has long been known that ice ages occur every 40,000 years or so, but the cause of rapid transition between glacial and interglacial periods has remained a mystery.

While conventional wisdom says that this icy ebb and flow is an interaction between the world’s oceans, the ice itself, and the earth’s atmosphere, an article appearing in the Jan. 28, 2016 issue of the journal Science sheds new light on the role that the earth itself may play in this climatological ballet.

David Lund of the Department of Marine Sciences at the University of Connecticut and his colleagues have studied hydrothermal activity along the mid-ocean ridge system — the longest mountain range in the world which extends some 37,000 miles along the ocean floor. Their research suggests that the release of hot molten rock, or magma, from beneath the earth’s crust in response to changes in sea level plays a significant role in the earth’s climate. This change is attributed to the release of heat and carbon dioxide (CO2) into the deep ocean.

Lund says, “Mid-ocean range magmatism — the release of molten rock through volcanic vents or fissures — is driven by seafloor spreading and decompression melting of the upper mantle” — the partially molten layer just beneath the earth’s crust.

“This activity is controlled by the rate of pressure release at any given location. There’s clear evidence that when ice sheets grow, sea level lowers and significant pressure is taken off the ocean ridges. This causes melting in the mantle, which should in turn promote the release of heat and carbon into the oceans — and that’s when glacial termination begins — meaning the ice starts to melt. Then, sea levels begin to rise, pressure on the ridges increases, and magmatic activity decreases.”

Well-documented sedimentary records from the East Pacific Rise (EPR) — a mid-ocean ridge extending roughly from Antarctica to the Gulf of California — show evidence of enhanced hydrothermal activity during the last two glacial terminations, the last of which took place about 15,000 years ago.

According to Lund, the southern East Pacific rise (SEPR) has the fastest spreading rate and the highest magmatic budget of any ridge in the global mid-ocean ridge system. Due to its elevated magmatism, the SEPR has over 50 known active vent sites.

He says, “The coincidence in timing between hydrothermal maxima and glacial terminations implies that there may be a direct causal relationship between hydrothermal activity and deglaciation … Our results support the hypothesis that enhanced ridge magmatism, hydrothermal output, and perhaps mantle CO2 flux acts as a negative feedback on ice-sheet size … ”

In this study, core samples from both sides of the ridge axis were analyzed and included radiocarbon and oxygen isotopic analyses of microscopic shells to provide age control for each core. Major and trace element concentrations were determined using x-ray florescence and inductively coupled plasma mass spectrometry.

The EPR results establish the timing of hydrothermal anomalies, an essential prerequisite for determining whether ridge magmatism can act as a negative feedback on ice-sheet size.


[Update by Willis] The underlying paper in Science magazine, “Enhanced East Pacific Rise hydrothermal activity during the last two glacial terminations”, is paywalled here. From the magazine:

Searching sediment for climate signals

Sediments on the ocean floor may provide clues about the interplay between ice ages and mid-ocean ridge magma production. Lund et al. present well-dated and detailed sediment records from hydrothermal activity along the East Pacific Rise. The sediments show changes in metal fluxes that are tied to the past two glaciations. Ice age changes in sea level alter magma production, which is manifested by changes in hydrothermal systems. The apparent increase in hydrothermal activity at the East Pacific Rise around the past two glacial terminations suggests some role in moderating the size of ice sheets.

Science, this issue p. 478


Mid-ocean ridge magmatism is driven by seafloor spreading and decompression melting of the upper mantle. Melt production is apparently modulated by glacial-interglacial changes in sea level, raising the possibility that magmatic flux acts as a negative feedback on ice-sheet size. The timing of melt variability is poorly constrained, however, precluding a clear link between ridge magmatism and Pleistocene climate transitions. Here we present well-dated sedimentary records from the East Pacific Rise that show evidence of enhanced hydrothermal activity during the last two glacial terminations. We suggest that glacial maxima and lowering of sea level caused anomalous melting in the upper mantle and that the subsequent magmatic anomalies promoted deglaciation through the release of mantle heat and carbon at mid-ocean ridges.

And here is one of their figures, with the original caption:

metal flux at spreading sites

Fig. 4
Normalized metal fluxes at 11°S compared with EPR bathymetry.
The hydrothermal time series are from the eastern (magenta) and western (black) flanks of the EPR and include (A) Fe flux, (B) Mn flux, and (C) As flux. We normalized each record by subtracting the mean and dividing by the standard deviation of each time series to facilitate comparison between cores with different mean metal concentrations. The results include both discrete samples (thin lines) and time series smoothed with a 20-ky-wide Gaussian window (thick lines) to approximate the resolution of the bathymetry compilation at 17°S (gray lines) (4). Fluxes from 0 to 40 ky are based on the results from Fig. 2; the interval from 40 to 200 ky B.P. is based on results shown in Fig. 3.

292 thoughts on “Study suggests a sea level climate feedback loop in the mid-ocean ridge system regulates ice ages

    • Not necessarily.
      Milankovic hypothesis is fine, except it is not the insolation forcing, it is change in the gravitational forces flexing the earth’s crust; causing tectonic plates movement to accelerate and decelerate. More here

      The red bands corresponding to interglacial periods indicate rapid magma flow in the expanding sea floor, while green-ish bands (the glaciation periods) suggest very slow expansion.

      • That would imply that the release of pressure from the ice sheets melting adds to magma release in the rifting zones. Wouldn’t the release of the extra continental weight as the ice sheets melt also temporarily release side to side pressure at the rifts?

      • Hi doc, nice to hear from you.
        There is a more than a bit of difference between normal summer/winter and the Milankovic cycles max/min summer insolation ratios. Remember reading somewhere that Milankovic cycle min is equivalent 2-3 extra cloudy days.

      • @ goldminor
        By magnifying part of this image of MAR it is possible to count 20-25 distinct sections.on each side of the of the current rift line. During the last 2.6 million years or so in the Quaternary period, ice ages have occurred with about 100 Kyr periodicity.

      • Leif, Murray Salby has shown that temperature OWNS the time rate of change of CO2 as Roe shows 65N insolation owns the time rate of change in ice volume. The time rate of changes operate on one physical process and at short time scale, while the overall trends in CO2, temperature, and ice respond to many physical processes at many different time scales.

      • At a minimum, it shows there is an elephant in the room. We can twiddle with the time derivative of ice volume and find this effect marginalized should the elephant stir.

        Even within the Pleistocene there is a downward trend in temperature not accounted for in Roe.

      • Murray Salby has shown that temperature…
        In science, the word ‘shown’ usually means that the finding is generally accepted by most scientists. It would be more correct to say that “Murray Salby claims that temperature …”

      • Fair enough. Not defending Salby’s conclusions, but his work with the time derivative correlation of temperature and CO2 is not contested. Ferdinand agrees.

        The fundamental issue with orbital explanations seems to be that they have no trend beyond the longest~410 kyr known period, but the planet clearly does.

      • Slide 7 Zachos 50,000,000 years. Apparent in more detail here:

        You probably ascribe the general cooling trend to tectonic changes. I am not convinced.

        Above is the isthmus at Panama 10 million years ago according to Christopher Scotese’s base maps. I have plotted the vectors of the corners of Colorado since the Permian. It can be seen that the isthmus is very constricted 10 million years ago and the direction North america has been headed is not conducive to the isthmus having been substantially open any time considerably before.

        In the bigger picture there have been five well known glacial episodes since the Proterozoic and they have occurred in every imaginable configuration of continents.

      • Doc, that is an interesting article, I will read bits of it, one at the time.
        However, I am disappointed that the word ‘tectonic’ is excluded.
        Sun warms the land and the oceans, ocean currents move the heat around the globe shaping the climate change, while the continents with the oceans and their currents were and are shaped by tectonics.
        Hence one could say that next to the sun, tectonics is the most senior partner in any consideration of the climate change.

      • You are misusing the word ‘tectonics’. What you should have said is ‘distribution of land masses’. Tectonics is used to describe the dynamic process that shapes the land [and ocean] masses, while the resulting distribution is the result which is largely static on time scales we care about.

      • Leif writes

        Milankovitch is doing fine:

        Its because of strongly stated beliefs like this that I, for one, cant take much of what you say seriously. Milankovitch is far from fine. It may be the best lead we have for ice age climate change but it is far from compelling.

        For example from your quoted paper

        while the convergence of atmospheric and oceanic heat fluxes plays a large role in wintertime climates, summertime climates in continental interiors are much more strongly controlled by the local radiation balance [e.g., Peixoto and Oort, 1992]. Thus there are strong physical grounds, supported by model studies [e.g., Felzer et al., 1995], for expecting a direct response of summertime temperatures, and hence of ice-sheet ablation rates

        Hinges on the unsupported assumption that the snow melts during the warmer summers and isn’t fully replaced during the colder winters that go along with the orbital changes. Pleixoto and Oort wrote a book in 1992 proposing this and it doesn’t even appear to be a peer reviewed paper.

        FYI, You give the impression of certainty where there is none and it damages your credibility (with me at any rate)

      • Hmmm… Am I missing something? If I understand it, Lund, et al, says that magmatism should increase during glaciations. But Vukcevic says that it decreases.

        Lund: “…evidence of enhanced hydrothermal activity during the last two glacial terminations. We suggest that glacial maxima and lowering of sea level caused anomalous melting in the upper mantle…”

        Vukcevic: “The red bands corresponding to interglacial periods indicate rapid magma flow in the expanding sea floor, while green-ish bands (the glaciation periods) suggest very slow expansion. They are of similar width despite the fact that interglacials are by an order of magnitude shorter than the ice ages.”

      • I have not looked globally but Mid Atlantic Ridge (in the N. Atlantic section ( above illustration’s location) during last 25 years has been in it’s most active state since early 1700s, so ‘magmatism’ in that area correlates directly with temperatures.

      • Correlation is not causation, especially not for such a short length of time in such a limited area.
        It also correlated with the price of a US postage stamp.

    • There’s no reason to assume that both theories don’t play into this. It doesn’t have to be one or the other. This recent study certainly adds a positive-feedback loop into the works.

      • I agree with Paul. Best not to pick one theory and diss the rest, that’s what got us into the greenhouse warming debacle.

      • Yes, but it’s negative feedback, with a long delay, not positive feedback.

        Lund thinks that it works like this:

        Cold -> glaciations -> falling sea-level -> increased magmatism -> heat & CO2 release -> less cold -> deglaciation

        That’s negative feedback. We think of negative feedback as stabilizing a system and attenuating other effects, which is generally true, but In feedback systems delays in negative feedback classically have the potential to cause oscillation. So Lund’s hypothesis is not preposterous.

        But the synchronism with Milankovitch cycles suggests that, as you said, both mechanisms could have roles in the glaciation/deglaciation cycles.

  1. It has long been known that ice ages occur every 40,000 years or so, but the cause of rapid transition between glacial and interglacial periods has remained a mystery.

    Wrong, glacial/interglacial timing was ~40,000 years (obliquity cycle) between 3 and 1 million years ago, up to the mid Pleistocene revolution (MPR), after which the timing changed to about 100,000 years (eccentricity cycle).

    This is just another study from the “Milankovich is a scary east European name so lets trash his theory” department. They’re quite nice when you get to know them – no need to be scared.

    It has however been suggested that when glaciation reaches its maximum, weight of ice on the tectonic plates could trigger an interglacial. This would have to happen while retaining the Milankovich timing though.

  2. Total geofantasy! Doesn’t explain the D/O abrupt oscillations nor the global synchroniety of climate changes. Dispersal of heat in ocean water from a linear source is also a major probem.

      • Marcus: This study shows that the rate of magma outflow from the mid-ocean ridges correlates with rate of sea level rise and ice sheet melting during the last two glacial terminations. One could cause the other, or it could be coincidence. Since I am not knowledgeable in this area, I would love to read the considered opinion of someone like Don, who is a distinguished earth scientist.

      • Thanks, Rud. I don’t find the mechanism of glacial termination plausible either. However, the correlation should be explained somehow. I was thinking that maybe the redistribution of the weight during deglaciation would squeeze out some magma, not the other way around.

      • I mention this just for the sake of conversation, since people have asked what could possibly cause such a correlation, as that seeming to exist between magma outflows and ice ages/interglacials.
        It has been noted as well that periods of low solar activity seem to be correlated with a increase in volcanism, and perhaps seismic activity as well. Without going all Electric Universe here, there are those electric currents which encircle the Earth, the so called Birkeland currents, and also currents associated with earthquakes, although my initial understanding of those back in my college geology days was that these were piezoelectric effects related to compression or decompression of rocks. But Telluric currents are different than those I think.
        Considering how little seems to be known about how such phenomenon as red sprites and blue jets and gamma radiation which emanate from some thunderstorms, I would hazard a guess that much remains undiscovered regarding the interaction between the sun, the Earth, electric currents, and geologic activity.

      • PS: And anything else which will be known to scientists of the future, but is unknown or elucidated as of now.
        Note that people have always thought that about everything to be discovered has been, and it is only details that are missing.
        I doubt that will be seen, far in the future, to cease to be true as of the past few decades.

      • I’m not convinced that ocean floor magma flux is even quantifiable, much less precisely correlative with numerous, abrupt, short term climate and glacial oscillations. Then there is the problem of trying to heat something like 300 million cubic miles of ocean water with a narrow, linear source. Forget about adding CO2 to the atmosphere–warming always precedes CO2 increase so adding CO2 isn’t a factor here. Then there is the problem of how you could produce synchronous warming and glaciations in both hemispheres with a linear heat source in one hemisphere. Then there is the problem of ……………………

      • Thanks for your insight, Don.

        Regarding the time lag of CO2 vs temperature in the ice core records, I honestly think nobody knows for sure, there are too many untestable assumptions built into this analysis.

      • I think the proportion of the volume of the ocean to the volume of new sea floor material which is exuded throughout the world is relevant.
        As has been noted, the specific heat of mafic sea floor magma is low compared to the seawater which cools it, and the total amount of new sea floor crust which forms in a year is only about a cubic mile or so. Even if this were to double or more, it is a tiny volume compared to the volume of the ocean which is given by Don K as 300 million cubic miles.
        Yes, the magma is hot, but the proportion is miniscule.

    • Don…………….love your work, but you lost me when you cited ‘nor the global synchroniety of climate changes’. I don’t know if you are referring to Natural Climate Change or Global Warming Climate Change.

      • Since the study said “sedimentary records from the East Pacific Rise (EPR) — a mid-ocean ridge extending roughly from Antarctica to the Gulf of California — show evidence of enhanced hydrothermal activity during the last two glacial terminations, the last of which took place about 15,000 years ago,” I took Don’s comment to mean climate change 15,000 years ago at the latest and that the change in climate didn’t spread out from the East Pacific.

    • Don Easterbrook,

      Total geofantasy! Doesn’t explain the D/O abrupt oscillations nor the global synchroniety of climate changes.

      Why does it need to?

  3. There has been a mid-Atlantic Ocean ridge for almost 150 million years now and a north Atlantic one for 55 million years now. Why would it have only started 1 million years ago.

    • Bill, the midocean ridges run back to the earliest times of the planet. The Atlantic Ocean began to appear about 150 MYA, but that is just the Atlantic and its mid-Atlantic Ridge. The Great Rift Valley is another spreading zone that runs up through east Africa, the Red Sea and Jordan Valley. If you have ever stood on the western side of the Jordan Valley looking across the Sea of Galilee or on the cliffs west and above the Dead Sea looking east toward Syria or Jordan, you were looking from one continent to another.

      The continents have been banging around, crashing together and rifting apart almost since the planet formed. Once a global ocean came into existence (more than three billion years ago), crust with continental-type chemistry and mineralogy also begins to appear. The cause is the subduction of water-saturated sediments, which react under increasing heat and pressure to produce newer, lighter minerals typical of the granitic rocks that compose most continents. These float on the mantle. Marine crust consists of heavier basaltic rock that resembles the original planetary crust. Marine crust is much thinner than continental crust – ca one sixth as thick as the thickness continental crust. This page:

      includes some maps of the planet during the Paleozoic and illustrates the locations, motion, and changes of continental crust during that period.

  4. This “study” contains so many errors and false assumptions, that it would take almost entire book just to list them all. I wonder which peers reviewed this monstrosity.

    • the longest mountain range in the world which extends some 37,000 miles along the ocean floor ….Isn’t the Earth’s circumference only 20,000 miles? How does that work?

      • Well we can start with this:
        “The last million years of Earth’s history was dominated by the cyclic advance and retreat of ice sheets over large swaths of North America. During cold glacial intervals, ice sheets reached as far south as Long Island and Indiana, while during warm interglacial periods the ice rapidly retreated to Greenland. It has long been known that ice ages occur every 40,000 years or so, but the cause of rapid transition between glacial and interglacial periods has remained a mystery.”

        1) For the last million years, the alleged “ice ages” which are really periods of glaciation with an ICE AGE, have lasted for about 100,000 years each – not “40,000 years or so.”
        2) What mystery? These phases of cooling and warming coincide almost exactly within the Milankovitch cycles scheme.
        3) All the rest….

      • FJS, your first point is correct, but the second is at least incomplete. As you state, deglaciations occur roughly every 100,000 years, but the cycle is not that regular. Northern hemisphere insolation maxima occur every 20-25,000 years. It seems each deglaciation coincides with such a maximum, but not vice versa. The debate as to why this is so is ongoing.

    • it looks more like a feedback mechanism than the driver.

      In addition the Fe pulse from such activity could have a further pulse of impact due CO2 removal from the ocean surface due to photosynthesis but variably delayed due to location and currents.

      interesting at any level but in my mind not the key to climate cycles.

  5. Lots to speculate and I don’t think we have not the beginning of a hint why the 100ky cycle started one million years ago. But it has never fit into the Milankovitch cycles so it’s an earth cycle, not climate cycle. But blaming it on the ice ages is a bit far fetched.

    The 100ky cycles in the benthic foraminifera and the Antarctic ice cores can be explanained by somtehing else than basin effect (Shackleton hypothesis) and global temperature and the is a lot more to it.

    • The planet has been cooling off for 15 million years. At some point the ice ages had to become deeper and longer.

      • I understand the total fixation on the “ice ages” until you realize that mammoths (and horses and aurochs and antilopes) were walking around on northernmost Siberia during the “coldest” phase of the Last Glacial Maximum, (google Jarkov, Yukagir, Fishhook mammoth) and they were very abundant too in the Yukon slightly before the LGM but well in the lowest isotope values. Then you realize that we have to do our homework ALL over again, to start of with the interpretation of the isotopes.

        Could it be that the Stilostomella extinction event was directly caused by the transition from the 41K world to the 100k world? SomewhereAROUND 1.5Ma. I think so. Earth just entered a whle new phase there. It’s just a coincidence that’s only one million years ago.

        It’s all clear to me now. That would include the cause of the African Humid periods.

      • Northeastern Siberia and inland Alaska (not Yukon) were too dry for glaciers to accumulate so they were steppes during glaciations. Not odd at all that mammoths and horses and saiga antelope lived there, since they were/are adapted to cold steppe habitat. However no aurochses, they were forest beasts, though there were Steppe Bison.

      • TTY–

        Even if too dry for ice sheet buildup, Arctic ocean coastal plain during glaciation would have been even colder than today. Woolly mammoths are pachyderms. They require an abundant supply of vegetation of the type that doesn’t grow on permafrost. That theory needs work.


      • We know perfectly well what those mammoths ate from the stomach contents of deep-frozen cadavers in Siberia, and yes, they were grazers and yes, they ate plants that grew on permafrost.

      • Thanks TTY, for Helmens et al 2007 That’s very useful. Challenging people really helps to find applicable references. :-) Anyway, I’d still like to focus on the 30Ka interval, where also fennoscandian ice was at minimum. It’s also interesting to note that there are similar radiocarbon bulk dates from the sediments of the Pingualuit crater in Quebec, supposedly way down buried in the Laurentide ice sheet (albeit not undisputed). There is however an IRSL date of 70ka

        Also from my ref, Hubberten et al 2004, check out fig 6 page 1339 about the Karginian / Mid Weichselian having warmer summers than today ( )

        The point is not that there wasn’t an ice age nor a cold Last Glacial Maximum, however if you make a snapshot of the world at say 35 ka, sometimes before the LGM then the ice sheets are at their minimums, and temperatures are comparable to the Holocene. However the explanations of the various proxies require them to be way down. Hence things do not add up at all. So I wonder how many generations it will take to accept that we do not understand the proxies correctly.

      • Great graphic. Might be hilarious to plot 65N insolation across that. Particularly as it has no trend. No known orbital parameter does. As you say, trend matters.

      • The sea-level curve from Red Sea salinity (which is probably the most reliable) suggests that ice volume (above current volume) 30-40 000 years ago was about half of the LGM volume, so I expect that the Laurentide Ice-sheet was considerably reduced too.

        The warm summers during the Karginsk interval (=MIS 3) in Siberia have been well-known for a long time, but were a local phenomenon. Siberian geologists even used to count Karginsk as a full interglacial. However in other parts of the World the climate was considerably colder than today. In southern Norway for example, which I know well, the fossil flora and fauna indicates conditions similar to Novaya Zemlya or Svalbard today, i. e. more than 10 degrees colder than at present.

      • TTY,

        I appreciate that Southern Norway was appreciable colder than Siberia during MIS-3, considering the close ice field remnants of the Mid Weichselian advance. Those remnants are rather closely confined here:

        However that does not imply that the rest of the world was considerably colder. I did show the considerations of the Pingualuit crater in North Quebec, the abundant megafauna in NW America, the gall wasps in the tar pits of RachoLaBrea and the lack of glaciation in the southern hemisphere. And since the balancing of benthic foram isotopes for the oceanic basin effect (and sea evels for that matter) required hypothetic huge ice sheets on Siberia (Bintanja et al 2002 QI 95-96, 11-23) obviously there is something wrong with the assumption with the shackleton hypothesis. It’s to be predicted that the difference between the 65N Isolation graph and the LR04 Benthic stack (Lisiecky and Raymo 2005) gives a good indication of Mid Atlantic Rdige volcanic activity cycles.

      • tty January 30, 2016 at 2:37 am–

        Yes, we know what they ate:

        “Food at various stages of digestion has been found in the intestines of several woolly mammoths, giving a good picture of their diet. Woolly mammoths sustained themselves on plant food, mainly grass and sedges, which were supplemented with herbaceous plants, flowering plants, shrubs, mosses, and tree matter.”

        But, do we know that what they ate grew on permafrost? Trees do not grow on today’s Arctic coastal plains, but you assert that they did during a much drier and colder climate?

        Perhaps the climate during the time of the mammoths wasn’t what we think it was.


    • One million years ago the ice-age cycles increase in duration from around 40,000 years to about 100,000 years. At the same time the average temperature of the planet’s surface decreases. At the same time the spread between interglacial and glacial temperatures increases several fold.

      At the beginning of the Neogene (Miocene, Pliocene, Pleistocene, and Holocene) North and South America are separated by sea ways. where southern Mexico and the Isthmus of Panama are.

      The opening closes in the Pliocene. The Mediterranean becomes an immense, dry basin, with grasslands, salt flats and the most spectacular water falls on the planet. It stays that way for quite a while.

      What this new hypothesis explains is the “shape” of the cooling and warming patterns. The interglacials are marked by increased heat flow. The ice sheets melt, and the planet warms. Then a new gradual cooling begins as the liquified magma in the mantle begins to cool, a much slower process than the melt would have been. They do seem to have empirical evidence in sediment records that matches what you might expect. If this pattern were to constructively feed back into the Milankovitch cycle, it would explain a great deal.

      • At the same time the average temperature of the planet’s surface decreases. At the same time the spread between interglacial and glacial temperatures increases several fold.

        That is an assumption based on the isotope ratios in benthic foraminafera. You might be interested to see what changes in seawaters pCO2 and pCa2+ may do to the isotope ratio’s in foraminifera shells. Also with the new eruptions going on, might there be a reason to assume that seawater pCa2+ and PCO2 might not have been all that constant?

        The opening closes in the Pliocene.
        Another hypothesis that has been challenged.

      • The isotope ratio in marine environments mostly reflects the amount of glacial ice not temperature per se.
        However the temperature changes between interglacials and glacials are extremely well documented by a large number of proxies including (but not limited to):
        Ice core isotope ratios
        Mg/Ca ratios
        Pollen Analysis
        Fossil/Relict Permafrost

        “Another hypothesis that has been challenged.”

        But not successfully.

      • Say we are at glacial max, and the temp then rises to current interglacial temps.
        How long will it take for two miles of ice to melt?

      • “How long will it take for two miles of ice to melt?”

        About 7,000 years. Actually glacial maximum was about 20,000 years ago, but interglacial temperatures and rapid melting only started about 15,000 years ago while the Laurentide ice-sheet was all gone about 8,000 years ago. Notice that more than half of those 7,000 years was during fully interglacial climate significantly warmer than today. The smaller North European ice-sheet lasted about 1500 years less.

      • TTY In response to your proxies. Consider the period 40k-30k between Heinrich Events 4 and 3, I challange you to find any positive proof of large ice sheets which are not present today. A few references:

        Yet all your proxies were close to the most extreme values at the LGM.

        Proxies are an inherent affirming the consequent fallacy. A causes B we see B hence it was A causing it, overviewing that C and D also cause B. Or building ice sheets (which weren’t there at that period) do increase the d18O of benthic foraminiferam by the bassin effect. Lack of CO2 dissolved in water also increases the d18O. So what was it? If there were no ice sheets, it wasn’t the basin effect of Shackleton 1967

      • “TTY In response to your proxies. Consider the period 40k-30k between Heinrich Events 4 and 3, I challange you to find any positive proof of large ice sheets which are not present today.”

        The Northern European Ice-sheet which I am most familiar with was certainly much reduced during this interval, but it was certainly not absent. Check for example the Sokli profile in northern Finland. Sokli was briefly just outside the glaciated area at this time:

        Also sea-level was much lower than at present so large ice-sheets certainly existed somewhere. The Baltic for example was never salt between MIS 5 and MIS 1.

      • Leftturnandre:
        It is difficult to reconstruct the extent of continental glaciation before the LGM since each glaciation removes most evidence of the previous one, consequently it is difficult to verify the ocean record on land. However it can be done, at least in outline. I recommend that you read the following:

        Northern Europe:

        North America

      • “About 7,000 years.”

        Thank you.
        That is a long time.
        During that time, albedo presumably remained high, and yet melting commenced and continued. Ditto the affect of the increased altitude and radiative properties of ice at the top of the ice sheet on what precipitation type dominated.
        It is a puzzle. Hard to imagine there is an explanation that isolates one single parameter as the “cause”.

        Separately: I wonder…did the ice sheet press the continental surface down low enough that it was below sea level, possibly causing the ocean to get up under the ice and have it float off?

      • “I wonder…did the ice sheet press the continental surface down low enough that it was below sea level, possibly causing the ocean to get up under the ice and have it float off?”

        Yes. This mechanism almost certainly speeded up the breakup of the ice over Hudson Bay once the Hudson Strait opened up.

  6. In my currently suspicious and cynical state of mind, I suspect this will morph into an explanation for “the pause” or the upcoming cold period.

  7. Ice age temperature proxies demonstrate rapid surface atmosphere warming, and slow jagged surface atmosphere cooling. Seems to me this has to do with simple physics. A calm ocean will layer up and spread that top warmest layer like an oil slick, leading to rapid evaporation and heat exchange from the ocean into the atmosphere, which should also add greenhouse gasses keeping everything wet and toasty and preventing solar recharge. Eventually there would be no more heat left in the oceans. This would eventually dry the air, clear the skies, and kick up with wind. Clear sky windy conditions would lead to a somewhat jagged step down to an ocean full of warmth (with occasional heat exchange but mostly heat absorption) but an atmosphere left out in the cold. Orbital mechanics (and its many variations) could explain the somewhat uneven cycle that causes a normally noisy uptake/discharge system that on a mini scale also has quick upticks in temp followed by jagged steps down, to swing much higher and lower.

    • Pamela, I think the warming-cooling pattern matches the pressure-release liquifaction followed by gradual cooling solidification quite well. One of the curiousities in the Green Ice Core data is that during the last glacial epoch, the temperature and ice accumulation are positively correlated on the ice cap. However, during the Holocene, the temperature and accumulation are negatively correlated. That is true throughout the entire Holocene. The planet has cooled while the ice on Greenland’s ice cap has increased.

  8. “[When] significant pressure is taken off the ocean ridges. This causes melting in the mantle…” Totally beyond me. The authors are shooting for an Oscar.

    • Consider a phase diagram. Above a specific temperature but below a specific pressure the minerals that compose basaltic rock are liquid. If the pressure of the water over the thin marine crust is essentially just enough to keep the rock in the upper mantle solid, and that pressure is gradually reduced as ice-sheet growth pulls water out of the oceans, the pressure reduces to a point where the phase change happens abruptly. Like pulling the rocker off a pressure cooker, the material is suddenly under less pressure and changes phase. That would be the abrupt warming at the end of glacial. The ice sheets melt and ocean basin fill. The pressure increases to above the phase change point and the melt begins gradually to recrystallize, leading into the long slow cooling of the next glacial epoch. If this is paired with changes in the external energy budget due to synchronising with the Milankovitch cycle, it could “explain” a great deal. Of course, whether or not it is true is different.

      • Yes, nice, but I don’t buy it. Assuming the maximally molten state coincides with the maximal magma outflow, then I would expect both to precede the maximum rate of ice melting, not to coincide with it.

      • This might seem like a completely dumb question (probably is).

        But why the heck would the core or the mantle or crust give a hoot about ANYTHING that lies above it.

        The gravitational field inside the shell, due to the shell, is zero.

        The pressure on those liquid rocks depends only on what material is underneath it; not what is on top of it.

        The gravity at the center of the earth (due to the earth) is zero.


      • The gravitational field goes to zero at the Earths center, but the pressure sure as hell doesn’t. By your reasoning the pressure in e. g. an oxygen tube should go to zero when it is launched into orbit. It doesn’t.

      • Everything feels the weight of everything above it, no? But at depth, it seems to me after considering G.E. Smith’s comment, the pressure is reduced by the gravity of the material above it…but pressure increases as we go down in the ocean column.
        Hmm…a conundrum.

      • If we could dig a tube right through the Earth, from say Perth to Philadelphia, running right through the center of the Earth (close enough for climate science), and it was open to the atmosphere at each end and encased by a magic force field which kept everything out including heat, what would the air pressure be at the exact gravitational center of the tube?
        Speaking of pay grades…I need a raise from Exxon for all this work here!

      • Duster, that makes sense up to a point. I’m not arguing but why would the abrupt phase change only work one way? Why isn’t the crystallisation of the melt just as abrupt?

      • Indeed great summary of now this might work. A very elegant theory …. I remember during my undergrad single hons geology course at St. Andrews learning about mantle plumes and decompression melting (Dr. Donaldson). Not sure if a 15 bar pressure reduction would do much but this theory certainly has elegance. Milankovitch never seemed to quite fit … At leadt not universally. Also worth thinking about the effect on ocean temps and the cooling rate once the extrusion has stalled. Very nicely explains the rapid deglaciations but slow reglaciation. Indeed our natural current state is a glaciated planet punctuated by these magma induced hiatae.

        At the very least this is a great example of how we dont know everything. No such thing as settled science.

      • george e. smith January 29, 2016 at 2:48 pm

        An object on the surface of the earth is “pulled on” by all the mass between it and the center of the Earth, and by all the mass out to the surface on the other side of the Earth. An object at depth is pulled on by all the mass below it down to the center, and by all the mass on the other side of the center, except now the matter above it is pulling back the other way. The net effect is a reduction in the weight that object exerts on lower levels. The force an object would exert upon lower levels would gradually lessen as its depth increased, finally falling to zero at the center. Only at the center would mass above be equal in all directions, and all of that mass would be pulled toward the center. Thus pressure increases with depth, with max pressure at the very center.


      • Duster: How about considering the phase change that would occur, and the heat energy involved in that change? I have not seen before a discussion of the mantle or a portion of it near the surface change from liquid to solid and the energy involved.

        For example what is the energy involved in cooling a kg of granite from liquid to solid (enthalpy of fusion), and add that to the specific heat of granite to get the total energy released.

        From a famous open encyclopedia: “Silicon has a heat of fusion of 50.21 kJ/mol. 50 kW of power can supply the energy required to melt about 100 kg of silicon in one hour, after it is brought to the melting point temperature:”

        50 kW = 50kJ/s = 180000kJ/h

        180000kJ/h * (1 mol Si)/50.21kJ * 28gSi/(mol Si) * 1kgSi/1000gSi = 100.4kg/h

        Specific heat of granite is 0.79. So… cool a few cubic km of granite from 1600 to 4 degrees C. What is the heat released?

      • Here is a rough number:

        Heat contributed to the oceans by the cooling of 10 cu km of SiO (substitute for basalt) from 1600 to 4 degrees C, and the solidification from the liquid to a solid state:

        Cp = 0.79 J/g*K x 1596 Deg x 2900 kg/m^3 x 1×10^9 m^3/km^3 x 10 km^3
        = 3.66 x 10^19 Joules
        Heat of fusion = 1,792.8 J/g*K x 1600 Deg x 2900 kg/m^3 x 1×10^9 m^3/km^3 x 10 km^3
        = 5.199 x 10^19 Joules
        Total 8,86 x 10^19 Joules

        For granite (density 2.65) the total is 8,1 x 10^19 Joules

        The selection of 10 cu km is arbitrary. Adjust according to the actual volume emerging from the ocean ridges.

    • Changes of state can be inhibited by pressure; when the pressure is relieved, the change of state takes place.

    • Menicholas: “If we could dig a tube right through the Earth, from say Perth to Philadelphia, running right through the center of the Earth (close enough for climate science), and it was open to the atmosphere at each end and encased by a magic force field which kept everything out including heat, what would the air pressure be at the exact gravitational center of the tube?”

      By 60 km down you’d have liquid air at a pressure of over 750 atmospheres and a density of around 0.87. From there it’s 0.96 atmospheres per meter for the next 3000km, 0.7 atm/m at 4000km, falling off to zero at 6400km. Ball park: 5 million bars. –AGF

  9. Well, if you assume a constant amount of water on Earth, the sea level drops (less pressure over the ocean bottoms) will lead to more pressure over the land (ice builds on the continents).

    So does one cancel out the other? Does the mantle under the land get squished out? There has to be a lot of future grants required to figure these out.

    And if the sea level drops 300′ on an average depth of 8,000′ does that really take that much pressure off the ocean floor? 7,700′ of water is still exerts a lot of pressure.

      • Density of water changes with temperature, but not a whole lot. So assume density of water is 62.4 lb per cubic ft.

        Pressure at 8,000 ft = p = 62.4 lb/cu ft x 8000 ft x 1sq foot/144 inches sq inches.= 3,467 psi. Adding one atm of pressure (14.7 psi) gives 3,481 psi

        Pressure at 7,700 ft. = (62.4 x 7700)/144 +14.7 = 3,351 psi.

    • “Does the mantle under the land get squished out?”

      Certainly. It gets “squished out” and forms a “forebulge” several hundred meters high and a couple of thousand kilometers wide all around the ice-sheet. Once the ice melts the material flows slowly back. It is still going on after 12,000 years. This is main reason why the Atlantic coast south of New York is slowly sinking, while to the north it is slowly rising.

    • “And if the sea level drops 300′ on an average depth of 8,000′ does that really take that much pressure off the ocean floor? 7,700′ of water is still exerts a lot of pressure.”

      It does seem to me that moving 10^16 (10,000,000,000,000,000) metric tons of water from the high latitude glaciers to the ocean might alter the stresses on the spreading zones a bit — not just vertical stresses, but lateral stresses as well. Where does 10^16 come from? Off the back of a 3×5 index card here in my hand. 3×10^6 square km of ice 3 km thick x 9×10^6 tonnes per km^3. I’m sure that the actual number is much different, but there really does seem to be an impressive amount of mass being shifted during a deglaciation.

      (Does anyone have a real number for the amount of mass shifted in the past 20000 years?)

      • Good question, Don. Since the ocean dropped by about 300 feet, I’d estimate the weight moved at 90 metres deep * 3.6e+14 sq. metres ocean = 3.3e+16 cubic metres, and about the same amount of tonnes.


      • There is good evidence that the pressure changes during glaciation/deglaciation affects volcanic activity both in glaciated areas (like Iceland) and well outside them (like the Eifel and Auvergne volcanic fields in Europe).

  10. Assuming this is true, “Well-documented sedimentary records from the East Pacific Rise (EPR) — a mid-ocean ridge extending roughly from Antarctica to the Gulf of California — show evidence of enhanced hydrothermal activity during the last two glacial terminations, the last of which took place about 15,000 years ago.” then it seems likely that the amount of magmatism is a feedback that kicks in during de-glaciation and glaciation. It may not be a feedback of great importance.

    • Interesting idea. It is conceptually possible that isostatic rebound as ice is lost could cause an increase in volcanism. In which case Lund’s new observations might be right but he has inverted cause and effect. But I would have thought that possibly true more along subduction zones at (continental) plate edges rather than the deep seafloor spreading rift system. Since isostatic rebound is by definition a continental crust thingy. You offload a ship and it floats higher in the water, also.

      • If subduction speeds up, does not rifting have to increase as the ocean crust is pulled from the spreading center more quickly?

      • Good question. We dunno (provisional title of my next ebook, for which this thread might provide one essay if I can ever get motivated to start writing another ebook again). We got the plates, we got their rough motions. We have not got their net net, or their motion drivers. That geological scientific revolution only began in the late 1960’s despite Alfred Weggoner’s convincing 1912 paper and 1916 book. Wrote about his hisnp continental drift theory as the first of three big recognition examples in that chapter of The Arts of Truth.

      • Seems like the more one contemplates, (-plates, get it? OK, I’ll stop.) the more factors one might see having some effect, whether small, medium, or tiny. But if all these things are occurring at the same time, perhaps they all add up to some sort of feedback impactful enough to cause glacial to give way to interglacial.

        I recall reading about “continental drift” as a young lad, and it immediately made sense to me, even then.
        (I see the way that any talk of continental drift was scorned by the geologic establishment, to the point of a person being drummed out of the profession if they appeared to be propounding it…all the way into the fifties…as a good analogy to climate science in the 21st century.)

        How anyone could look at the obvious fit of the coastlines, and matching fossils in matching strata on both sides of the Atlantic ocean, and discard that these landmasses were once joined. Lack of a known mechanism caused people to disbelieve what was obvious to a child.

      • “Lund’s new observations might be right but he has inverted cause and effect.”

        That’s what I conclude, but I can’t think why anyone should care what I conclude.

      • “How anyone could look at the obvious fit of the coastlines, and matching fossils in matching strata on both sides of the Atlantic ocean, and discard that these landmasses were once joined. Lack of a known mechanism caused people to disbelieve what was obvious to a child.”

        M. Having gone to school before continents were allowed to move, let me answer that. If you hust look at a map, the fit between South America and Africa while intriguing isn’t all that great and the fossils and stratigraphy of both continents weren’t all that well known in the early 20th Century. Neither was ocean topography all that clear before the WW-II advances in sonar were applied to marine research in the 1950s. Land bridges were a popular explanation for fossil fauna similarities where such were acknowledged and we still us them — quite possibly correctly now — to explain, for example, the ancient interchanges of faunas between North America and Eurasia. In addition, continental drift not only couldn’t be explained, it appeared to defy physics since it required masses of relatively light continental rock to somehow plow through denser ocean basalts. It never really crossed anyone’s mind that the continental rock might be permanent but the ocean basalts might be transient.

        (There were, BTW, a bunch of less well known geological problems that continental drift has resolved and a few that it hasn’t and that everyone seems to have agreed to ignore).

      • The coastlines are a pretty close match, even if one does not use the continental shelf margins which lie offshore under deep water. And not just Africa and South America, but the Southeast coastline of North America as well.
        Of course, “close match” is a matter of opinion to some degree, when loosely stated.
        My opinion and yours seem to differ on this Don.

        As far as how well such things as matching strata and fossils may or may not have been known, I think enough was known for Koppen, to postulate the idea a few decades before it was presented more formally by Wegener (who was Koppen’s son in law). But the idea had been presented many times before over hundreds of years in one form or another, going all the way back at least to Abraham Ortelius.

        In any case, much accumulating evidence was ignored in a systematic and most unscientific manner during the intervening years. One can deny it or paper it over, but learned people, particularly so-called experts, are often wrong, and spectacularly so, and are often quite pusillanimous in their assessment and denunciations of those who challenge the orthodoxy.
        As I and others have long noted, the history of science is literally a compendium of overturned paradigms and ideas. Scientists are human beings like everyone else, with the same failings and frailties of thought and action, and often have more than a little egotistical belief in their own infallibility.

      • M: “The coastlines are a pretty close match, even if one does not use the continental shelf margins which lie offshore under deep water.” Yes although the further one gets from the African Byte, the less good the fit. — largely I think because Mercator projections distort shapes some and the distortion is a function of latitude. Think stretchy jigsaw pieces.

        “And not just Africa and South America, but the Southeast coastline of North America as well.” Not really. And if you tried to do the piecework on the US SouthEast coastline back in the early 20th century, you’d find some substantial chunks of Real Estate – Cuba, Santo Domingo, Puerto Rico, etc in quite inconvenient places. There’s a great set of paleomaps at Well worth investigating if you’re interested in tracing continental drift back through time.

        One thing I would agree with you on was that the behavior of many geologists toward the notion of continental drift was utterly appalling. But once they were confronted with strong evidence in the form of good ocean floor maps from advanced sonar and the presence of magnetic stripes parallel to the spreading zones from sensitive magnetometers, most came around pretty quickly.

        And to their credit, many, not all, of them actually learned something from the experience. Geologists — unlike climate scientists — seem relatively tolerant of unconventional theories like Thomas Gold’s “Deep Oil” as long as the theories aren’t totally incredible.

      • Certainly there are/were discrepancies, as would be expected after tens of millions of years of erosion, deposition, igneous intrusions, island building events (including much if not all of Florida I think), and other processes that would distort the shape and placement of coastlines. And I think many if not all of these processes were well known to occur even back in Wegener’s time and beyond.
        Compared to what one might expect of a fit of random shapes, such as inverting the continents and then trying to fit them together, or fitting together the east coast of Africa with the west coast of North America, the fit is far from what could ever occur by random chance. Anyway, that is just my opinion.

        I appreciate your responses to my comments.
        As well as Dr. Istvan’s.

  11. Oh shitie….a 40-60K shave of the glacial period length…in one single go….please do not scratch the surface any deeper…..won’t be pleasant to the “intellectuals”… .and very deary indeed. :)


  12. [quote] “Then, sea levels begin to rise, pressure on the ridges increases, and magmatic activity decreases.”

    Using the average depth of the ocean at 12,000ft, the average pressure at the bottom of the ocean is about 5000psi [34,000 kPa]. Considering the range of ocean level change between glacial and interglacial times is about 400ft, this is equal to a change of about 200psi [1300 kPa] at the bottom of the ocean, or only 0.04% of the total pressure. I personally don’t see this as a major driver in release or non-release of Magma, considering the earths mantel has much higher pressures than this (the deeper you go). Like popping a zit, squeezed from below. They don’t pop when you go on an airplane.

    • But that’s not the entire reason why this mechanism could exist. Isostatic adjustment of the crust from the repositioning of mass on the surface may be important.

      When mass accumulates on the continents and the poles, those areas are pushed down into the mantle, and the mid ocean ridge would be a likely place for any mantle material to be pushed out from the displacement.

      • Sure, but that this not what the quote says. [quote] “meaning the ice starts to melt. Then, sea levels begin to rise, pressure on the ridges increases, and magmatic activity decreases.” This is only a change of 400ft of sea level to induce pressure change.

        Your logic is the inverse of what they are saying. As the sea level begins to drop, and ice sheets begin to increase, magma pressure increases on the ridges from all the ice pushing down on the landmass (or something like that). Like my zit analogy. Your theory makes more sense IMO,

      • Would not both happen at once, each contributing? Add possible increased subduction and the consequent increased pulling away of oceanic crust from the spreading center…

  13. Lund published different evidence to support his theory last year in Science (timing of the parallel rift ridges, a model of how lower sea levels might increase magma melting and rift volcanism). Was criticized for being very poorly time constrained, and for models that purport to show differences in seafloor magma production from lower sea water pressure when termination onset sea level is ~120 meters below present and oceans average 3700 meters deep. His model claimed that a (120/3700) 3.2% difference in pressure significantly changes mid ocean rift volcanism. Maybe not in reality. So his new paper analyzes better time constrained rift core samples that purport to show increased hydrothermal venting at the last two glacial terminations. Paper is paywalled, but two observations. 1. Hydrothermal venting is not per se related to increased magmatic vulcanism. It is seawater circulating in the faults arising in the new basalts as they cool, and does not arise everywhere equally. You have to search for ‘smokers’. 2. Even if Lund has the timing of increased venting correct, it is a correlation, not a causation.

    I am quite doubtful of Lund’s hypothesis for two very different but rather fundamental reasons.
    1. Enormous ocean thermal capacity. Yes, the global seafloor rift system is 80,000km long by an average 10km wide. That is a heating surface of 800,000km2. The oceans have a total surface of 362 million km2, most of it deep beyond continental shelves. I did not bother to look up the exact surface proportion of deep ocean. There are ~1.35 billion km3 of seawater, average depth 3.7km. The rift ridges are directly heating roughly 0.002 or about 0.2% of the ocean floor. Seawater has ~10x the heat capacity of iron, one of the two main constituents of basaltic magma (the other is lower heat capacity silica). The magma volume that actually happens in say 10000 years for fast spreading ridges (low scarps just a few hundred meters high), ‘fast’ spreading being 2.5 cm/year, or 25000 cm in 10000 years, or 0.25km, at a scarp height of maybe 300 meters, or 0.3km, is a fast spreading rift magma volume of maybe (0.25km w *1km l * 0.3km h) 0.075 km3. The exposed rift magma is ~1000C (actual solidification point at seafloor), a 0.075 km3 per km2 intrusion could raise the direct overlying 1 km3 water column 0.075km3*(1000/100) ~0.75C . But the adjacent bottom water will dilute that thermalization to about (0.75C *0.002) 0.00015C. De minimus. The ocean bottoms are observationally an isothermal 0-3C despite seafloor spreading. Just not enough volcanic heat given really big, really deep oceans. Put differently without calcs, ocean heat capacity is why all sorts of tube worms, clams, shrimp, crab live directly adjacent to black smokers spewing mineral laden water at 700C, feeding off those minerals in water that is 0-3C. Google any number of really cool images, and extrapolate to Lund’s thesis.
    2. Basaltic eruptions are CO2 poor, so mid ocean rift volcanism cannot trigger glacial termination via elevated CO2, either. (AND, the ice cores show CO2 rise lags termination temperature rise by about 800 years in the four previous termination events. Observational fail.) It is andesic magmas from subduction zones that are CO2 rich. That is because these zones are recycling crustal sedimentary carbonates into magma rather than drawing up mafic mantle magma. Without subduction zone carbonate recycling, it is estimated that photosynthesis and then life would cease in less than 2.5 million years, at CO2 ppm about 150. Cause the calcification carbon sink never stops until marine life does. Thousands of feet of limestone and dolomite rock strata once on ocean floors are just biologically sunk CO2.

    • Your explanation is too sciencey for us rubes. Could you convert No. 1 to equivalent atom bomb explosions per second? -kidding

    • RH,

      I read somewhere that the average rift and subduction rates move at about the same speed as your fingernails grow. That makes it easy to visualize.

      Not too sciency, but I couldn’t figure out how to convert it into Olympic-sized swimming pools.

    • Thanks, ristvan. I was going to put up a comment on those lines but without all the detailed calculations. Like you say, the amount of heat released into the ocean is not enough to make any noticeable difference to ocean temperature and hence to climate or to ice. The amount of CO2 released would be puny, and anyway CO2 cannot be the driver of temperature on those time scales. See in

      • Mike Jonas

        I gave it a shot – see above; got about 8 x 10^18 Joules per cu km of magma ejected into the ocean. I have no idea what the volume involved is. My suspicion is that the amount of heat is considerable. Almost half of it is from cooling and more than half is from solidification (heat of fusion). If the annual total eruption is 100 cu km on 40,000 km of fractures. It is 8 to 9 x 10^20 J for 2.5m depth cooler over the affected area (say, 1 km wide). Adjust accordingly. Obviously volcanic eruptions add more depth on a smaller area.

        (Someone please check my work).

        We need the total volume of volcanic eruptions and extrusions on earth, both above and below water. Multiply by 8 x 10^18 J/km^3.

      • Sources I have seen give an annual total for new sea floor crust at 3-4 cubic kilometers, or just around 1 cubic mile. Currently.

      • Menicholas

        Then the heat from new ocean floor is about 2.5 x 10^19 J per annum. That is a lot more than I heard about before. Also remember that hot smokers turn over the entire volume of the oceans about every 100m years. which is about 140 cubic kilometers per year. What are the temperatures involved? A few hundred degrees? At 300 degrees it is 1.26 x 10^19 Joules of additional heat. Then there is the leakage of heat through the entire floor surface from general cooling of the Earth. The total is claimed elsewhere to be 2 x 10^13 which is nothing.

        What surprises me is that this heat is adding up to a very large value: 3.75 x 10^19 Joules. This is far more than the ‘nuclear heat’ from the Earth’s core by a factor of 10,000 I think. It is 7.5% equal to of all the energy used by humankind in a year.
        Calculated from the poorly written caption at:

    • The submarine geothermal effect need not affect ALL the ocean to affect global climate. Correct me if I am wrong, but I believe tropical Pacific warming events ultimately affect the globe. Recently, there was a big blob of warm water off Oregon/BC, coinciding with a major submarine volcanic eruption. This blob of warm water would be a mere blip in comparison with the entire Pacific, but nevertheless, remained a localized, significant warm water event. So what I suggest is that not all submarine volcanic events are equal.

      • That was a bit confused. What I mean is, submarine, geothermal heat can (likely) affect surface temperatures in a localized manner, even if such heat does not change the bulk temperature of the deep ocean basins, due to localized convection. If such an event happened in a fortuitous location, e.g. where El Ninos are born, or near Norway, then global climate would be affected, even if the deep ocean temperature did not change much. Such a consequence would not be expected from a geothermal event of similar scale near the Falkland Islands. So bulk ocean heating is not required. Just fortuitous localized ones.

      • Does it seem possible that a convective bubble of warmer water could ascend through several miles of ocean, ocean which is far cooler that the bubble of rising water, and retain its heat and hence make it anywhere near the surface.
        Seems very unlikely.
        The amount of heat per unit time is too small, the ocean is too deep and too cold at depth, the conductive properties of water to great, and likely turbulence is also too much to allow such.
        Picture spitting in the ocean to warm it, or farting in a gale storm to stink out your neighbors in an adjoining state.

      • @Menicholas – But it did happen, and just recently, off Oregon/BC. The blob is indeed linked to a submarine volcano. I think the issue it whether the convective bubble rises with laminar or chaotic flow.

  14. The problem with this study, like many climate studies, is they focus on one factor and try to attribute it to the big picture, but in reality the big picture inherently includes all variables. The glacial cycle is caused by the culmination of all relevant factors, and that’s why not one factor, i.e. Milankovitch Cycle, completely explains the it.

  15. It’s an interesting analysis, although I greatly doubt their CO2 hypothesis for a couple of reasons. From their conclusion, quoted without elision, just split by subject:

    Our results support the hypothesis that enhanced ridge magmatism, hydrothermal output, and perhaps mantle CO2 flux act as a negative feedback on ice-sheet size (1, 4). Although the modern carbon output from ridges is small (0.02 to 0.2 Pg C/year) (24), the flux probably increased as a result of sea-level modulation.

    I dislike the word “probably” in conclusions. In addition, even an order of magnitude increase would only put the output at 0.2 to 2 petagrams (Pg, which is the term the scientific purists use for Gt, gigatonnes.) In terms of CO2 changes, it’s a difference that wouldn’t make much difference.

    Suppose the CO2 emitted is increased by 2 gigatonnes per year. Approximately half of that gets sequestered by increases in natural sinks. This means that the equilibrium atmospheric level will be the point where the additional amount sequestered is equal to the whole 2 Gt/year. To do that, the atmospheric level needs to increase by a total of 4 gigatonnes, which is about 2 ppmv … like I said, a difference that makes little difference.

    They continue:

    Carbon sources at off-axis locations, backarc basins, and island arcs may also amplify the mid-ocean ridge signal (2).

    Yes, they may. However, the main CO2 signal is so small that such incremental additions don’t change the picture.

    The long melt-migration times for carbon-rich melts may lead to considerable differences in timing between hydrothermal and carbon-flux variations, however (25).

    Mmm … seems like they are into speculation there.

    Another mechanism whereby magmatic variations may influence climate is the hydrothermal heat flux itself. Enhanced geothermal heat flux should warm and destabilize the deep ocean (26), with excess heat emerging along isopycnals into the surface Southern Ocean (26, 27). Temperatures in the deep eastern tropical Pacific and Antarctica peaked during each of the last two glacial terminations (28), consistent with the timing of enhanced EPR hydrothermal activity.

    Now that, on the other hand, is an interesting suggestion. I regret that they made no attempt to quantify those changes, however. My experience as a lifelong seaman is that the ocean is stupendously huge. However, the underlying paper (26) is open-access here, most interesting.

    Always more to learn,


    • Willis,,thanks for digging while I was calculating for the comment upthread. Read your linked ref 26. Color me intrigued but underwhelmed for several reasons. First sea water bouyancy is salinity as well as temperature driven. Second, a few tenths of a degree difference are not going to set up significant convective cells. Your Tstorms operate on about +29C to -40C. Third, oceanographic studies seem to confirm that the major deep ocean circulation patterns are driven by seasonal thermohaline circulation channeled by seafloor topography: the simple fact that freezing sea water exudes brine, so the sea ice is (relatively) freshwater. And this happens at about -1.8C, so the water at the ocean bottom is maybe 0-3C even after absorbing all that geothermal heat (which must be emerging in some quantity such as the paper suggests). And that very cold saltwater stays at the bottom until ‘flushed up’ by the thermohaline circulation always pushing from ‘behind’ against the seafloor topography. Which changes over geologic time thanks to plate tectonics. There is a theory (Deffeyes, Princeton geologist emeritus) that thr present ice ages were inaugurated by closure of the Isthmus of Panama. The largest waterfall in the world presently invisibly exits the Arctic Ocean into the Atlantic each winter. Invisible, since deep under the sea surface. Isn’t Mother Nature grand?

    • I find the CO2 problematic too. Lowered sea levels would also tend to release increased CO2 from clathrates and there are immense volumes in the Arctic, the North Sea, and along the eastern seaboard that could be expected to change phase. But atmospheric CO2 seems to follow temperature so that doesn’t hold. There definitely would be an increase in CO2 released from volcanism, but the evidence over the entire Phanerozoic is that non-biological sources of carbon emission cannot keep up with biological sinks. That alone shoots down CO2 as a significant climate moderator.

      • M, in almost all cases (never say never) nope. Read essay Ice that Burns in you know whose most recent ebook.
        Not only is no methane time bomb possible, our ability to extract methane from clathrate is also close to zero. Hint. Mud clathrate (most) isn’t sand clathrate ( little). A simple consequence of how methanogens form biogenic methane clathrate in the first place. Thermogenic plus abiogenic is probably less than 10% of total methane clathrate (but we dunno for sure). You probably would enjoy that illustrated essay. Explains a lot of science in a few illustrated paragraphs.

      • Yes, thank you.
        I actually know this Rud, and was going to go into that in my reply to Duster. I merely meant to inquire if he meant to say methane from clathrates instead of CO2 from clathrates? As far as I know clathrates are methane and water.
        I also recall that the timeline of clathrates in recent literature went form an interesting look at ice that burns, to a possible huge and nearly inexhaustible fuel supply, to a possible Earth scorching explosion as it all might release at once if pressure was to drop precipitously and thus turn the entire atmosphere in a air fuel mixture which was then ignited by lightning, to this being pretty much impossible, to the stuff being not likely as a fuel source, and this was just an interesting curiosity as originally revealed.
        Clathrate is of course very problematic for deep sea oil exploration and production, which the whole world was given a lesson on after the Macondo blowout and subsequent containment efforts.
        But I did thought I disremembered recently that some country was engaging in an effort to try and exploit this as a fuel source. Perhaps it was Japan?

      • Yes, Japan spent over a decade engineering an experimental ship (depressurization method ) to experiment for ~1 week of production on their Nankai Trough sand deposit of methane clathrate. Unless the production cost comes in under $16 per, they will import LNG instead. So far, no word on the result. Since has been near two years, my guess is they have failed economically.

      • Cannot blame them for trying I suppose. Has to be the biggest economy in the world with little or no natural energy deposits. Unless you count geothermal, and hydroelectric.

  16. Well maybe… Or maybe the magma is always just responding to sea level rise. Wouldn’t it take an awful lot of magma to change the ocean temperature significantly? And haven’t I read that water in the deep trenches do not mix with water higher up? Seems silly to me.

      • M, Actually not. Google. A spreading rift is obviously a rift valley. But the extruding magma tends to cool on the valley sides. The slower the spread, the higher the resulting rift valley edge escarpments become from magma pile up. The faster the spread, the lower the rift edge escarpments. This is well documented ‘new’ geology. Highest regards.

      • No. There is a ridge on either side of the rift valley. Parallel. So sharp is termed an escarpment. Its height depends on how fast the rift valley spreads. Faster means lower. You can even intuit why, as magma cools and solidifies on contact with seawater. The slower that process goes, the higher the magma escarpments eventually become. So faster spreading means lower escarpment height.
        Isn’t nature grand and often counterintuitive?

      • Yup, it sure iln.
        I studied this stuff in college, and before and ever since, just for fun. Was not really seeking a degree to start with.
        (I shall have to remember to use more precise language here.)
        I have wondered how the ridges give way to nice (relatively) flat sea floor as the spreading proceeds?
        In any case, upon further thought, does it seem as though the oceanic plate might not really be a solid monolithic plate after all? Of does it become so after it cools and departs from the spreading center?

  17. “Hillier & Watts (2007) surveyed 201,055 submarine volcanoes estimating that a total of 3,477,403 submarine volcanoes exist worldwide. According to the observations of Batiza (1982), we may infer that at least 4% of seamounts are active volcanoes. We can expect a higher percentage in the case of the count taken by Hillier & Watts (2007) because it includes smaller, younger seamounts; a higher proportion of which will be active. Nevertheless, in the spirit of caution and based on our minimum inference of 4% seamount activity from Batiza’s observations, I estimate 139,096 active submarine volcanoes worldwide. If we are to assume, in the absence of other emission figures for mid oceanic plate volcanoes, that Kilauea is a typical mid oceanic plate volcano with a typical mid oceanic emission of 870 KtCpa (Kerrick, 2001), then we might estimate a total submarine volcanogenic CO2 output of 121 GtCpa. Even if we assume, as Kerrick (2001) and Gerlach (1991) did, that we’ve only noticed the most significant outgassing and curb our estimate accordingly, we still have 24.2 GtCpa of submarine volcanic origin.”

    • I thinking the rising plume of material which has given rise to the Hawaiian island chain, and leads all the way back to Midway before changing direction and continuing for another very long distance, is quite a large hotspot as undersea volcanoes go. I doubt it is any sort of average, but rather on the very high side.

      • I strongly agree. Remember that the “Big Island” is actually the highest mountain on Earth. rising well over 10,000 meters above it’s surroundings. It is most definitely not an average volcano.

  18. The mid-ocean ridge is under several miles of water. During an ice age sea levels drop by 100 to 200 feet.
    That doesn’t seem like enough of a pressure change to cause what they are postulating.

    • For mantle rock the partial derivative of temperature with respect to pressure at constant entropy is about 10K per GPa of pressure. The variation of pressure corresponding to 200 feet of water is about 700kPa or 0.7MPa or 0.0007 GPa; which equates to 0.007K. In other words the decompression leads to a temperature change so small only climate change scientists are able to see it as significant. Unless the rocks are already very near melting, I can’t see how this would affect much of anything.

    • “During an ice age sea levels drop by 100 to 200 feet.”

      At glacial maximum the drop is more like 400 feet, though 200 feet may be a reasonable average over the whole 100,000 year glaciation.

    • I seem to recall that there was some question as to what causes the spreading centers and subduction. Is the upwelling at the spreading centers pushed the oceanic crust so hard it has no where to go but under the adjacent continental plate, or is the subducting plate pulling the crust apart at the spreading center?

      Seems likely there is some sort of chicken and egg relationship, and besides there are spreading centers with no subduction occurring on the other end of the plate…like in the Atlantic. How are the North American plate and the adjacent oceanic crust in the Atlantic connected, or are they not connected? Is the oceanic plate pushing North America? North American is six times thicker than the Oceanic plate behind it, so it would seem more likely that the continent is pulling the oceanic plate. Hmm…issues with both.

      And is rifting that causes continents to split to begin with due to upwelling mantle material, or due to other forces putting the continental plate under tension, which then splits and induces upwelling?

      And did I understand correctly that all of this is based on a study of one spreading center?

      • “I seem to recall that there was some question as to what causes the spreading centers and subduction. Is the upwelling at the spreading centers pushed the oceanic crust so hard it has no where to go but under the adjacent continental plate, or is the subducting plate pulling the crust apart at the spreading center?”

        M. Think of a pot of boiling, roiling water. Are the “billows” being pushed up or sucked down? I think the answer is neither or maybe both depending on what sort of mental model you want to use. What’s happening is that the whole pot is subject to turbulent flow as large amounts of water vapor tries to find it’s way out. Why not bubbles as will occur from CO2 outgassing before boiling starts? I have no idea. But anyway, I think the movement of continental plates is probably a similar phenomenon on a much grander and much slower scale. The rocks we see are just scuzz on the surface created when the surface material on the pot freezes as it is roiling around.

      • Heavy, man.
        So that is like a ton per square foot?
        Which is the weight of the air column above it?
        So, how much less weight is on that acre when the barometer drops during a hurricane, than when it is under high pressure?
        Surprised the ocean does not just fly up into the storm from the release of pressure.

    • The ocean is around 4 miles or so deep, or around 20,000 feet. Which makes any number you care to quote about 200 feet, about 1% as big as the number for the whole water column.

      • The average depth is actually about 12,000 feet, so the c. 400 feet drop at glacial maximum is about 3,3 %. However the average depth of the mid-ocean ridges is only about 8,000 feet, so there the drop is about 5 %. Not a negligible amount.

      • Aah. Thank you for the correction.
        I wonder what mechanism could cause a sudden surge in magma upwelling though, since the water is removed from the ocean and added to the continents over a long period of time…although less time for the melting apparently.
        And how to explain such as the Younger Dryas, under this particular hypothesis?

        In any case, I have decided some time ago that one cannot get a horse sense of matters cosmic or geological by considering our impression of the size of the numbers involved.

  19. I don’t know about the ridge system being a major source of CO2 in the oceans, but its input of H+ helps maintain ocean pH. Rivers carry bicarbonate and carbonate to the ocean, and there must be a mechanism that prevents the oceans from becoming increasingly alkaline over time. H+ ion released in the mid-ocean ridge system probably supplies that mechanism.

    Even as hot as the water around the “smokers” is, it is not a particularly large input of heat in the overall energy budget for the oceans. The ridge system provides maybe a third of overall heat flow.

    • a mechanism that prevents the oceans from becoming increasingly alkaline over time

      well since a lot of that is from chalk and limestone – fossil sea creatures – I would have though t there is a fairly obvious mechanism…

  20. “when ice sheets grow, sea level lowers and significant pressure is taken off the ocean ridges. This causes melting in the mantle, which should in turn promote the release of heat and carbon into the oceans”
    So… ice causes the heat???
    Too dumb for words…

  21. I wonder about oceans: it seems that the water covering most of our planet goes down into the crust, too. If I’m wrong, there’d better not be a plug…

    Since the oceans must go into the crust, just like a river extends well below a riverbed, then what holds it up?

    The answer (maybe; I’ll defer to Willis on this) must be that as the oceans extend downward, at some point they become steam due to temperatures increasing with depth. I know pressure is involved, but it gets pretty hot down there.

    It’s steam that is holding up the oceans. Otherwise, the water would all drain to the center of the earth…

    I forgot where I was going with this. But there it is.

    • Not steam. The temperature and pressure place the water in the super critical regime. Its a high density fluid.

      • Gravity. When you throw a rock in water, it does not float. It is denser than water (mantle rock, about 5 times denser.)

      • Are you asking what supports the fluid above? The pressure in the fluid is sufficient to support the fluid above.This is the reason for the hydrostatic gradient in any fluid. Did I understand your question correctly?

    • DbS, clever. You forgot nothing.
      There is a fascinating emerging branch of basic geology trying to figure out what water (in the form of ultrasupercritical steam and other stuff I do not understand) does to Earth’s lithosphere. Impacts seismology, mantle composition theories, mineral formation theories. We have only just reached diamond anvil technology to start to explore in the lab extreme pressure/temperture hydrated mineral formation. As an amateur rock hound, I enjoy spending evenings reading up on the frontiers of geology and minerology. Mantle water stuff is the equivalent of an Apollo space program. Less well funded, of course.

    • So, maybe the steam escapes from the surface of the ocean and forms them hurricanes, the lower pressure from the ‘cane pulls the oceans up, which allows more steam to escape, forming more hurricanes.

      Anyway, under the crust, DB, in your analogy the continents are like the mop wringer of the ocean sediments?
      I have wondered what happens to seamounts and such when the reach a subduction zone?
      Do they get scraped off, or sucked in and under?

  22. Not long after the team from UCSB and Scripps did one of their Alvin deep dive studies of the EPR Black Smokers, I and a few others went to check out some CO2 wells near Brawley, which is in the area where the EPR is under the Colorado Delta, just south of the Salton Sea. There is definitely CO2 coming out of the Mid-Ocean Ridges.

      • I thought that area was an extension of the San Andreas fault system, and is thus more of a strike slip, or transform fault.
        I could be wrong, but is not the Baja peninsula riding on the Pacific plate along with everything else west of the San Andreas, and moving roughly north-northwest?

    • I think that’s a bit tricky James. Yes, the East Pacific rift zone does meander up that way. But the land on both sides is continental rock with the west side being moved off in the general direction of Tokyo along the San Andreas fault system. So you really don’t know if the CO2 in the Imperial Valley is bubbling up from the mantle or is somehow being liberated from sediment beds. I believe that either is possible .

  23. I look forward to more input from Geologists,
    People tend to overlook the fact that we are sitting on a ball of fire that cracks open every now and then and releases a lot of heat into the system.
    Blow up a party balloon to about 1ft diameter and see the thickness of the rubber skin, that’s about the thickness of the Earths Crust.
    What has the most Influence on Earths surface temperature, core temperature,CO2, or the Sun?
    Food for thought.

    • Diameter of earth is about 8000 miles, thickness of crust, about 30 miles = 266/1

      Diameter of balloon 1 ft or 12 inches. Cannot find a source readily for inflated toy balloon wall thickness, but I think it must be in the ballpark of a sheet of paper, or perhaps thinner.
      A ream of typing paper is about two inches (off the top of my head), and is 480-500 sheets, so one inch is about 250 sheets of paper, twelve inches is about 3000 sheets or 3000/1

      Check: Metric, one foot is 2.54 x 12 30.84 centimeters or 308.4 millimeters, sheet of paper listed as 0.05 to 0.1 millimeters or about 3000/1 to 6000/1

      Nope. Seemed off at first glance.

    • I once calculated the relative size of all the oil ever extracted from the Earth, and the Earth.
      I came up with a number for oil of about the volume of a large mountain, and compared to the Earth, this relative size is about the same relative sizes of a cue ball and the worlds largest bacteria, roughly speaking.

    • DI, I owe an apology. If one uses thickness of ocean crust, and my estimate of balloon equaling sheet of paper is off, and it is really more like two to five sheets, the numbers match up pretty well.
      So Solly!

    • Largest current influence on Earths surface temp?

      a) Sun
      b) C02
      c) Earth core
      d) Data interpretation
      e) none of the above

  24. If it involves an interaction of suspension or solution between the gaseous and liquid portions of the planet’s atmosphere, isn’t it ALL “climate”? Since when was water not part of the climate?

  25. This is an important part of it. There are phases from warm to cool every century on avg every 25-30yrs. We are in cooling now after warming 1981-2011 then cooling 1950-80.There are small yet more drastic cooling/warming every 2-400 years then there are times of Great Lakes forming or Palm Trees growing on a Tropical Arctic ice free Ocean year round. We are nearing a mini ice age where Atlanta has climate of Syracuse in 2020s but it starts with the Sun. The Sun is doing its thing right now. The Atlantic Ocean is very important per once things show up on earth & can change in an instant as in weeks not years. Good article but as always; whattsupwiththat has great articles on climate. I suggest it for everyone I know.

  26. Ridiculous stuff! This new ‘theory’ doesn’t even begin to explain why all Ice Ages start very suddenly like some turned on that hot thing in the sky that is yellow during the day and voila: the ice melts. Then this fades away again and the ice returns.

  27. The trick to solving holistic problems is to summarize all of the observations and let the observations lead to the correct solution.

    There must be a physical explanation for everything that is observed, increased volcanic activity, sudden changes to the geomagnetic field, and cyclic abrupt climate change.

    See below for other anomalous observations. Solar cycle changes is the primary driver of all the changes. The sun is significantly different than the standard model. The sun cyclically changes in manners which we believe is not possible. There are hundreds of astronomical observations to support that assertion and dozens of solar system observations that also support that assertion. The observations in question are sufficient to definitively solve the problem.

    The increase in volcanic eruptions and the increase in plate tectonics is due to electric charge movement due to changes in the sun from the ionosphere into the core of the planet which is the reason why the geomagnetic field intensity is now dropping at 5%/decade (starting in the mid 1990s) where it was before dropping at 5%/century.

    Does every one remember the Northern Hemisphere burn marks (eight locations two different continents at different latitudes) that coincide in time with the Younger Dryas abrupt cooling event? (See below for details as to what the YD event was.) There must be an explanation as to what caused the burn marks, why there is a geomagnetic excursion at that time, and why the planet abruptly cooled for 1200 years. The charge movement cause the abrupt change to the geomagnetic field which in turn causes the cooling. The geomagnetic field in the liquid core in time integrates the surface based charge change which explain the duration of the cooling.

    Large volcanic eruptions correlate with deep solar magnetic cycle minimums. There is an increase in volcanic eruptions when the solar magnetic cycle slows down and again when the solar cycle restarts. We have already experience the increase in volcanic activity and earthquake activity that is associated with the slowdown of the solar cycle (2010 for example there was a threefold increase in volcanic activity in Indonesia.)

    We are going to have a chance to watch the mechanisms live. We are going to first experience Dansgaard-Oeschger cooling and then when the solar magnetic cycle restarts Heinrich event type cooling. Very, very large volcanic eruption correlate with the restart of the solar magnetic cycle.
    This paper is not asking the correct questions. Volcanic eruptions only result in cooling for a couple of years. What physical change causes there to be suddenly an increase in volcanic activity all over the earth (i.e. both hemisphere)? Magma chambers are change due to local conditions. There is no current mechanism that would suddenly cause there to be an increase in volcanic activity all over the planet.

    The abrupt cooling events are followed by sustained cold periods of hundreds of years. The Younger Dryas abrupt cooling event which occurred 11,900 years ago at which time the planet went from interglacial warm to glacial cold and the cold period lasted for 1200 years.

    Volcanic eruptions cannot and do not cause the planet to cool and stay cold. The restart of the solar magnetic cycle causes geomagnetic excursions which is the reason for the hundreds of years of cooling. It is the mechanism that causes there to a geomagnetic excursion (massive movement of electrical charge for the ionosphere to the earth’s surface that both cause geomagnetic excursions and large volcanic eruptions.

    Analyzing data from our optical dust logger, we find that volcanic ash layers from the Siple Dome (Antarctica) borehole are simultaneous (with >99% rejection of the null hypothesis) with the onset of millennium-timescale cooling recorded at Greenland Ice Sheet Project 2 (GISP2; Greenland). These data are the best evidence yet for a causal connection between volcanism and millennial climate change and lead to possibilities of a direct causal relationship. Evidence has been accumulating for decades that volcanic eruptions can perturb climate and possibly affect it on long timescales and that volcanism may respond to climate change. If rapid climate change can induce volcanism, this result could be further evidence of a southern-lead North–South climate asynchrony. Alternatively, a volcanic-forcing viewpoint is of particular interest because of the high correlation and relative timing of the events, and it may involve a scenario in which volcanic ash and sulfate abruptly increase the soluble iron in large surface areas of the nutrient-limited Southern Ocean, stimulate growth of phytoplankton, which enhance volcanic effects on planetary albedo and the global carbon cycle, and trigger northern millennial cooling. Large global temperature swings could be limited by feedback within the volcano–climate system.

    The government has raised alert levels of 21 other volcanoes to the second- and third- highest levels in the last two months because they have shown an increase in activity, said Syamsul Rizal, a state volcanologist, said monday. Many of those are already rumbling and belching out heavy black ash.

    “We can say this is quite extraordinary, about 20 at the same time,” Swantika said. “We have to keep an eye on those mountains. … But I cannot say or predict which will erupt. What we can do is monitor patterns.”

    Geologist Brent McInnes said as he hadn’t seen the raw data but would find such a rash of volcanic activity significant.

    “If it’s true that there are over 20 volcanos demonstrating increased levels of seismic activity, then that is something we should pay attention to,” said McInnes, a professor at Australia’s Curtin University who has done extensive volcanic research in Indonesia.

    He said such an increase could indicate “maybe there is a major plate restructuring going on, and that would be significant.”

    We don’t always get lightning [when a volcano erupts],” said Steve McNutt, research professor of volcano seismology at the University of Alaska, Fairbanks, who was involved in the project. “And that’s one of the things we’re trying to figure out.”

    What caused an abrupt change to the geomagnetic field cyclically in the past (the geomagnetic field excursion) is what caused five geologically separated (different magma chambers, same location on the planet, same island) volcanoes to erupt simultaneously and to capture a geomagnetic excursion. Do you see why it is anomalous that five geologically separate volcanoes would erupt at the same time and also capture the rare geomagnetic excursion?

    Geomagnetic excursion captured by multiple volcanoes in a monogenetic field
    Five monogenetic volcanoes within the Quaternary Auckland volcanic field are shown to have recorded a virtually identical but anomalous paleomagnetic direction (mean inclination and declination of 61.7° and 351.0°, respectively), consistent with the capture of a geomagnetic excursion. Based on documented rates of change of paleomagnetic field direction during excursions this implies that the volcanoes may have all formed within a period of only 50–100 years or less. These temporally linked volcanoes are widespread throughout the field and appear not to be structurally related. However, the general paradigm for the reawakening of monogenetic fields is that only a single new volcano or group of closely spaced vents is created, typically at intervals of several hundred years or more. </blockquote

    • The restart of the solar magnetic cycle causes geomagnetic excursions which is the reason for the hundreds of years of cooling
      More nonsense. Go play with Vuk.

      • Leif your beliefs are independent of the observations. Everything that I have stated in this forum is supported by observations. For you it is unimaginable that the sun is physically different than your beliefs.

        Sun spots and solar coronal holes are currently disappearing. The pathetic effort to prop up the sunspot number will only highlight the abrupt end, the interruption, to the solar cycle. There is a race going as to which will be the first announcement the end of global warming or the interruption to the solar cycle.

        Why has the geomagnetic field intensity decrease suddenly change in the mid 1990’s. In the 1990’s the drop in the increase in the geomagnetic increase by a factor of 10 from 5%/century to 5%/decade? What is the physical reason for the sudden change to the geomagnetic field intensity? Note geomagnetic field abrupt changes correlate with abrupt climate change. The mechanism reason is the geomagnetic field blocks GCR. When the geomagnetic field has multiple poles there is cooling at the new pole locations which are now in low latitude regions due to the increase GCR which causes increased cloud cover.

        The sudden unexplained drop in the geomagnetic field intensity is the reason why the Europeans spent $300 million dollars to launch three specialized satellites (SWARM) to monitor the entire geomagnetic field with laboratory accuracy.

        The geomagnetic field intensity has now dropped 10%. The speed in the drop the geomagnetic field intensity is 10% faster than a core based change can cause even if there was mechanism that could suddenly cause massive widespread change in the liquid core of the planet starting in the mid 1990s.

        ..the relationship between climate, the Sun and the geomagnetic field could be more complex than previously imagined. And the previous points allow the possibility for some connection between the geomagnetic field and climate over these time scales.

        Geomagnetic polarity reversals and excursions in the Quaternary correlate well with interglacial-to-glacial transitions and glacial maxima.

        The peculiar solar cycle 24 – where do we stand?
        Solar cycle 24 has been very weak so far. It was preceded by an extremely quiet and long solar minimum. Data from the solar interior, the solar surface and the heliosphere all show that cycle 24 began from an unusual minimum and is unlike the cycles that preceded it. We begin this review of where solar cycle 24 stands today with a look at the antecedents of this cycle, and examine why the minimum preceding the cycle is considered peculiar (§ 2). We then examine in § 3 whether we missed early signs that the cycle could be unusual. § 4 describes where cycle 24 is at today.…than-expected/

        Earth’s magnetic field, which protects the planet from huge blasts of deadly solar radiation, has been weakening over the past six months, according to data collected by a European Space Agency (ESA) satellite array called Swarm. While changes in magnetic field strength are part of this normal flipping cycle, data from Swarm have shown the field is starting to weaken faster than in the past. Previously, researchers estimated the field was weakening about 5 percent per century, but the new data revealed the field is actually weakening at 5 percent per decade, or 10 times faster than thought. As such, rather than the full flip occurring in about 2,000 years, (William: In less than 50 years not in 2000 years) as was predicted, the new data suggest it could happen sooner. Floberghagen hopes that more data from Swarm will shed light on why the field is weakening faster now.

        Response to Comment on “Are there connections between Earth’s magnetic field and climate?, Earth Planet. Sci. Lett., 253, 328–339, 2007” by Bard, E., and Delaygue, M., Earth Planet. Sci. Lett., in press, 2007

        Also, we wish to recall that evidence of a correlation between archeomagnetic jerks and
        cooling events (in a region extending from the eastern North Atlantic to the Middle East) now covers a period of 5 millenia and involves 10 events (see f.i. Figure 1 of Gallet and Genevey, 2007). The climatic record uses a combination of results from Bond et al (2001), history of Swiss glaciers (Holzhauser et al, 2005) and historical accounts reviewed by Le Roy Ladurie (2004). Recent high-resolution paleomagnetic records (e.g. Snowball and Sandgren, 2004; St-Onge et al., 2003) and global geomagnetic field modeling (Korte and Constable, 2006) support the idea that part of the centennial-scale fluctuations in 14C production may have been influenced by previously unmodeled rapid dipole field variations. In any case, the relationship between climate, the Sun and the geomagnetic field could be more complex than previously imagined. And the previous points allow the possibility for some connection between the geomagnetic field and
        climate over these time scales.

        Reduced solar activity as a trigger for the start of the Younger Dryas?
        We discuss the possibility that an abrupt reduction in solar irradiance (William: The sun causes what is observed when the solar cycle restarts) triggered the start of the Younger Dryas and we argue that this is indeed supported by three observations: (1) the abrupt and strong increase in residual 14C at the start of the Younger Dryas that seems to be too sharp to be caused by ocean circulation changes alone, (2) the Younger Dryas being part of an & 2500 year quasi-cycle * also found in the 14C record* that is supposedly of solar origin, (3) the registration of the Younger Dryas in geological records in the tropics and the mid-latitudes of the Southern Hemisphere.

        Estimates for the increase in 14C at the start of the YD all demonstrate a strong and rapid rise: 40-70 percent within 300 years (Goslar et al., 1995), 30-60 percent/percent in 70 years (BjoK rck et al., 1996), 50-80 percent/percent 200 years (Hughen et al., 1998) and 70 percent/percent in 200 years (Hajdas et al., 1998). This change is apparently the largest increase of atmospheric 14C known from late glacial and Holocene records (Goslar et al., 1995). Hajdas et al. (1998) used this sharp increase of atmospheric 14C at the onset of the YD as a tool for time correlation between sites.

        The effect of changes in the Earth’s moment of inertia during glaciation on geomagnetic polarity excursions and reversals: Implications for Quaternary chronology

        Geomagnetic polarity reversals and excursions in the Quaternary correlate well with interglacial-to-glacial transitions and glacial maxima. It is suggested that this relationship results from interactions between the Earth’s mantle and core that accompany decreases in the Earth’s moment of inertia during ice accumulation, which weaken the geomagnetic field in order to
        try to counter the decrease in differential rotation between the mantle and inner core that is being
        forced. In the Late Pleistocene, geomagnetic excursions directly correlate with brief phases of rapid ice growth that accompany falls in global sea-level, notably during the Younger Dryas stage, Dansgaard–Oeschger interstadials 5 and 10 that precede the rapid melting events during Heinrich events H3 and H4, and during the transitions between oxygen isotope stages 5c-5b, and 5e-5d. It is proposed that similar relationships between instabilities in climate and the geomagnetic field also typefied the Middle Pleistocene. As a result of the transfer of some of the mass of the oceans into polar ice sheets, the climate instabilities that initiate these rapid ice accumulations redistribute angular momentum and rotational kinetic energy between the Earth’s mantle and inner core. These changes weaken the Earth’s magnetic field, facilitating geomagnetic excursions and also causing enhanced production of cosmogenic nuclides, including 14C. The subsequent phases of rapid ice melting, Heinrich events, reverse this effect: strengthening the field. This explanation, of forcing of geomagnetic excursions by climate instabilities, provides a natural explanation for why, during the Middle-Late Pleistocene, excursions have been numerous but none has developed into a polarity reversal: the characteristic duration of the climate instabilities is too short.

      • A progressive thinking scientist (a rare creature indeed) could be interested in fact that the Earth’s CAM oscillates synchronised in periodicity and the phase with sunspot cycles

        What might be the solar system’s clockwork driving both?

      • Hi doc
        You are stating the obvious “[nor the amplitude]” .
        the Earth’s core and the sun’s convective zone have vastly different properties, and since one is unlikely to be driving the other, but available data indicate degree of similarity in the bi-decadal oscillations (unlikely to be a coincidence), a progressive thinking scientist (a rare creature indeed) could be asking: what might be the solar system’s clockwork at work here?

      • That is more like it, now you are getting interested.
        They don’t even know it exists unless they read my comments, which is extremely unlikely.
        J&B data is here:
        You can have a go at it, use ‘rough’ rather than intermediate or smoothed data.
        Method 1 easily reproduced by anyone: subtract 21 year moving average from the original data. Since you do not believe that there is fundamental difference between odd and even SSN cycles plot absolute so obtained value abs(x) against your new sunspot series, since I used the old one.
        Method 2 is more scientific approach: use suitable high pass filter (I used 6db down at 40 years fourth-order zero-phase shift Butterworth, front and back 20 year padded).
        There are some (non-essential) differences in result between two methods, also for a good reason the first and the last 10 years are discarded in both methods.

        p.s. I don’t do science; I am interested in a lesser knowns.

      • I don’t do science
        That is clear as day. BTW, the decadal changes in dLOD/dt since 1962 are not in phase with sunspot cycles:

        and more BTW: There is a strong 5.9-year variation in CAM.

      • Now you are sidestepping your responsibility (as possible progressive thinking scientist) to reproduce and verify what was discussed.
        As you well know the LOD’s oscillations are affected by multiplicity of causes, the Earth’s core electromagnetic coupling is not only but it is the major one.

        “and more BTW: There is a strong 5.9-year variation in CAM”

        Absolutely, 5.93 years is Jupiter’s abs(perihelion – aphelion – perihelion) periodicity
        progressive thinking scientist might ask: why?

      • Now you are sidestepping your responsibility (as possible progressive thinking scientist) to reproduce and verify what was discussed.
        Pseudo-science does not deserve to be discussed, only to be dismissed.
        Good scientists are not ‘progressive thinking’, but are conservative and do not jump on hare-brained schemes. And, as you said, what you do it not science.
        There is no doubt that there are decadal and intra-decadal changes in the CAM, but there is no evidence that those are in any way connected to whatever clockwork you postulate.

      • Earth’s core electromagnetic coupling is not only but it is the major one
        This is nonsense, as there is no such coupling. The field at the surface is simply the core field seen at a distance of 3000 km.

      • Doc
        You are making a wrong assumption. Electromagnetic coupling is between the liquid core and the conductive mantle; they happen to sit next to each other.

        Science is not about outright rejection (that’s religion’s job) science is about collecting data, investigating, probing, reproducing and verifying whatever might be in there.
        It might go against what we know, or what we think we know, nature doesn’t care about anyone’s views or opinions, it just do what it comes to it naturally.

      • Electromagnetic coupling is between the liquid core and the conductive mantle; they happen to sit next to each other.
        This is correct [although you in the past maintained that it was with the surface field or the magnetosphere or the sun or Jupiter or …], but the coupling is weak as the mantle is not that conductive compared to the core, and is not the dominant one.

        nature doesn’t care about anyone’s views or opinions, it just do what it comes to it naturally
        And hence nature does not care about your opinion.

      • “And hence nature does not care about your opinion.”
        But reverse is true, I do respect nature’s ‘opinion’ despite the fact that I hardly understand any of it.
        See you some time again, by then I’ll update the graph with your SSN numbers.

    • Prior to the Vema discovering the Mid-Atlantic Ridge, and subsequently the Glomar Challenger mapping and dating sea floor sediments in relation to the ridge, and the light this shed on sea floor spreading and a mechanism for plate tectonics, it was inconceivable to many highly expert geologists that continents could move relative to one another. In spite of much independent evidence that they apparently had done so.
      I do not know if the current state of knowledge of solar dynamics, what might be called the orthodox view, is accurate or not but…well…I think there is circumstantial evidence that the output and magnetic activity of the sun may vary over time scales which may not be very well understood.
      These are of course separate topics, and one idea does not give any indication of the veracity of the other, but it does highlight how easy it is to be very well informed and yet overlook important evidence.

  28. A potential test for this dubious hypothesis would be to identify increased magma activity the further south one observed the East Pacific Rise, since sea level change was a function of arc distance from the center of the northern ice mass: the weight of ice shifted the entire lithosphere southward relative to the hydrosphere, enhancing the southern sea level change. In other words, the northern ice mass moved the solid earth’s center of gravity. –AGF

  29. It would be interesting to compare the somewhat quantifiable positive albedo feedback of ice sheets to the supposed negative negative feedback proposed here, or to compare the direct heat of magma activity with theoretical effects of outgassing GHGs (which of course follow the T rise in the cores). After all, it’s not the actual heat our engines produce that brings on doom, but the CO2 they produce. Is that a valid analogy or not? –AGF

  30. I’ve added the following graphic and original caption from the study to the head post:

    Fig. 4
    Normalized metal fluxes at 11°S compared with EPR bathymetry.

    The hydrothermal time series are from the eastern (magenta) and western (black) flanks of the EPR and include (A) Fe flux, (B) Mn flux, and (C) As flux. We normalized each record by subtracting the mean and dividing by the standard deviation of each time series to facilitate comparison between cores with different mean metal concentrations. The results include both discrete samples (thin lines) and time series smoothed with a 20-ky-wide Gaussian window (thick lines) to approximate the resolution of the bathymetry compilation at 17°S (gray lines) (4). Fluxes from 0 to 40 ky are based on the results from Fig. 2; the interval from 40 to 200 ky B.P. is based on results shown in Fig. 3.

    • “We normalized each record by subtracting the mean and dividing by the standard deviation …” Willis, this is more your cup of tea: How do we determine a standard deviation of a varying quantity?

  31. Two beach boxes just sold in Melbourne for $280 thou each ,I’m told the Australian doomsayer Flannery has also in the last few years bought a beach front house .

  32. You mean it’s hot down there? Surely not. If that were true climate scientists would be buzzing about it constantly. In reality, they can’t change that subject fast enough.

    It’s rather like when you mention that centuries of min/max temps are not the same as centuries of temps. Nobody argues, because the subject would kill the game. So the subject gets changed, and even the most scholarly types go on talking of “temperatures” when they are actually talking about min/max records.

    The two great subject changers: the heat below, and the clouds above.

  33. Why do we get switching between galcial and interglacial? The overall context as explained by Bill Illis above is that the earth’s climate has been steadily cooling for 15 million years. And 3 million years ago this cooling reached a level to initiate the glacial period we are now in.

    However such transitions are rarely tidy and clean cut. We are in a transition period of oscillation between deep glaciation and interglacial. These two states represent “attractors”, that is, islands of stability in a chaotic dynamic system. Sometimes at the transition between one state and another, due to a slow change in a system’s overall state – e.g. our 15 million years of slow cooling – there is a period of switching between two states.

    A nice way to illustrate this is the classic demonstration of the switch between laminar and turbulent flow of water from a tap (faucet). As shown here:

    Here the flow rate has vern finely adjusted to be right on the transition between laminar (weak flow) and turbulent (stronger flow, tap fully open). If you look carefully you can see little jumps as the system tries to jump from one state to the other. This is actually not difficult to do – depending on what sort of faucet you have.

    That us where our climate is now. Finely balanced between glacial and interglacial. So – I hear you ask – what about ole Milankovich? We’re just coming to him (and of course Kroll). Consider this state of fine balance between two states. In this state a tiny external forcing can tip the system from one state to another. Now the Milankovich forcings are, and aleays have been, acting on the earth. However it is only during slow transition between non glacial and glacial, when the system is sufficiently finely balanced between the two states / attractors, that the very weak Milankovich forcing manifests a pacing role on the earth’s climate. Thus as the system switches between glacial and interglacial, it does so at a Milankovich frequency, reflecting its delicately poised condition.

    Of course, there is not just one Milankovich frequency but several. Thus as glaciation gradually deepens, one million years ago at the mid Pleistocene revolution the system switched from being driven by the obliquity cycle of 41 kyrs to something resembling the eccentricity cycle of 100 kyrs. This makes it a highly interesting example of a system in quasistable transition switching between alternative external periodic forcings.

    In future if the secular trend continues there will be an eventual transition to permanent glaciation with no interglacials. It is interesting to speculate if all the previous deep glaciations e.g. the Cryogenian, 700 mya, also began – and ended – with such transitional periods of glacial-interglacial oscillation.

  34. For all the elegant (and doubtless meritworthy) theories put forward to explain climate variation, is science collectively not at risk of missing a possibly obvious point i.e. that the theories advanced (and the data underpinning them) need not be either (i) “the” driver of climate variation, nor (ii) necessarily competing or contradictory.

    Is it not just conceivable that each new theory based on each new dataset/observation might in fact complement other theories and datasets? Might they not all be inter-connected at any number of levels over time?

    We are groping for explanations for climate variation in a fog of ignorance – we see certain things apparently clearly standing out in the fog (as we see features standing above a real fog).

    Those that see those things first are tempted to trumpet “their discovery” as “the” answer that will dispel the fog of ignorance. But almost always they are not.

    In science, should we not proceed as a sailing master does when enveloped by fog? Noting a feature, then another, and another, checking and verifying what the features are, and proceeding very cautiously, trying to form a mental image of the coastline?

  35. When all is said and done, if this study were true then in order to stop global warming we must first increase global warming to melt more ice to increase the pressure on the ridges to decrease the magmatic activity which will bring us out of this warming period. What to do, what to do.

    • What to do?
      We need to build a large thermostatic looking control and place it in the UN building in New York and call it ET.
      The world’s UN delegates could spend endless hours debating where to set the ET(earth’s thermostat) thereby looking useful AND appearing to save the world as well.
      Oh wait…….

  36. I’ve heard it said that the cause of El nino is volcanic activity emanating around solomon ridge. any validity or disproof for this? seems plausible.

      • thanks for taking the time,
        you said below “Volcanic eruptions of the area are most likely not a direct cause”.
        I would be interested in understanding why this would not be the case. an irregular heating event emanating from an ill-measured(?) volcanic region seems to be the obvious candidate for the source of heating. by “not a direct cause” do you mean something else such as magnetic fields causing volcanics which in turn generates El nino heating events?

    • EM, I would suggest you read Bob Tasdales work on ENSO if you want to understand it. He is quite clear. And nothing to do with undersea volcanos.

      • Mr. Tisdale does a great work on ENSO and PDO, but I am not convinced by his ENSO originating hypothesis.
        The area is one of world’s tectonically most complex.

        Volcanic eruptions of the area are most likely not a direct cause, but I am suggested they are a numerical proxy (see red line in my link further above at 8:13 am), for a possible mechanism that I am not in position to satisfactory explain.

  37. As I have stated, it is unimaginable to many that our sun could be significantly different than the standard model. I get that.

    For that reason I am waiting till there is in your face evidence that the solar cycle has been interrupted and that the planet is abruptly cooling to present in detail, in a manner that can be understood by a general audience, the solution to the puzzles.

    It is a fact that there are hundreds of astronomical observations (paradoxes that do make sense – such as the alignment of quasars that are billions of light years apart and ‘strings’/’web’/’lattice’ of galaxies and quasars, and alignment of dwarf galaxies in a plane rather than distributed in a sphere about the large galaxies – concerning ever pillar of cosmological theory) that support the assertion that our sun, the stars in the galaxies, and quasars are significantly different than the standard models. The difference concerns what happens when very massive bodies collapse, the physics of massive objects.

    What forms when a very massive object collapses, determined based on hundreds of observations in peer reviewed papers, which are identified as anomalies and paradoxes, is an active object that changes with time. The theoretical hairless black ‘hole’ theory that was developed at the turn of the last century is not correct, based on observations.

    How the sun is different than the standard model explains how the recent change to the sun caused the earth’s geomagnetic field intensity drop, to increased from a drop of 5%/century to a drop of 5%/decade starting in the 1990’s. Note a drop of 5%/decade is not possible for any liquid core change. There is no mechanism to sudden cause massive changes of liquid movement in the earth’s core and even if there was, a back emf is generated in the liquid core that resists fast field changes.

    The current unexplained observed changes to the sun has happened before and is the reason, the physical cause as to why the earth’s climate was changed cyclically in the past, sometimes abruptly with a very, very large change (unimaginable large and rapid). There is a physical reason, a physical cause for what is observed in the paleo climatic record and the paleo geomagnetic record. The immense forcing change that causes what has happened in the past is the sun.

    Greenland Ice Sheet Temperatures Last 100,000 years

    It is interesting that the Dansgaard/Oescheger events which have characteristic period of 1470 years have continued throughout the Holocene interglacial period. As there are cosmogenic isotope changes that are concurrent with all of the Dansgaard/Oescheger events (also referred to a Bond events named after Gerald Bond who tracked 23 of the cycles) and the Heinrich events it is obvious a specific solar cycle change is causing what is observed.

    The last super large abrupt climate change was the ‘Younger Dryas’ abrupt climate change event. The YD abrupt climate change event occurred 11,900 years ago at which the time the planet went from interglacial warm to glacial cold with 70% of the cooling occurring in less than a decade and with the cooling period lasting for 1200 years – with a change that is capable of and does terminate an interglacial period. The YD abrupt climate change event is cyclically, not a one of event.

    Spooky Alignment of Quasars Across Billions of Light-years

    “The first odd thing we noticed was that some of the quasars’ rotation axes were aligned with each other — despite the fact that these quasars are separated by billions of light-years,” said Hutsemékers.

    The team then went further and looked to see if the rotation axes were linked, not just to each other, but also to the structure of the Universe on large scales at that time.

    When astronomers look at the distribution of galaxies on scales of billions of light-years they find that they are not evenly distributed.

    They form a cosmic web of filaments and clumps around huge voids where galaxies are scarce. This intriguing and beautiful arrangement of material is known as large-scale structure.
    Alignment of quasar polarizations with large-scale structures, September 23, 2014

    Mysterious dance of dwarf galaxies may force a cosmic rethink
    The discovery that many small galaxies throughout the universe do not ‘swarm’ around larger ones like bees do but ‘dance’ in orderly disc-shaped orbits is a challenge to our understanding of how the universe formed and evolved. The researchers believe the answer may be hidden in some currently unknown physical process that governs how gas flows in the universe, although, as yet, there is no obvious mechanism that can guide dwarf galaxies into narrow planes.

    Velocity anti-correlation of diametrically opposed galaxy satellites in the low-redshift Universe

  38. Can we clear up an issue I have of using the term “ice age” to refer to a glacial period? The term ice age properly refers to the at least 5 snowball Earth periods when the planet was uber cold. These million’s of years of snowball Earth, more or less, conditions are theorized to be at least partially caused by plate tectonics leading to million’s of years long term changes in solar insolation and climate patterns. These changes are irregular and do not have an obvious typical pattern, partly due to the gross measurement systems used to detect these snowball Earth periods. However, it is thought they generally cycle with an abrupt rise to warmth followed by a slow jagged descent.

    During these major ice ages, there are more regular periods of glacial and interglacial climate patterns that have a sudden rise to warmth followed by a slow jagged decay to cold. We are presently in an ice age and are experiencing glacial and interglacial conditions. The most prominent theory is that these more regular oscillating periods are triggered by orbital mechanics.

    I believe the study posted above is referring not to ice ages but to glaciation periods and interglacial periods. The rift theory will have to compete with the orbital mechanics theory. And I believe it falls short of replacing it.

    For an easy read about the differences between ice ages and glacial/interglacial periods see the following:

    • The next time you will attempt to redefine a peer review :-)

      Seriously, Britannica and Wikipedia differ on this one. Should we ask Her Majesty, or the Supreme Court, or Comrade Xi, to decide?

      • Scientists have recorded five (at least) significant ice ages: the Huronian (2.4-2.1 billion years ago), Cryogenian (850-635 million years ago), Andean-Saharan (460-430 mya), Karoo (360-260 mya) and Quaternary (2.6 mya-present).

        In our present Quaternary ice age, there have been about a dozen or so major glaciations interspersed with interglacials. The most recent glaciation period is often referred to informally as the “Ice Age,” which peaked about 18,000 years ago. We are in the present warm interglacial Holocene which started about 12,000 years ago.

        I guess Hollywood decided that “Glacial” just doesn’t roll off the tongue like “Ice Age” does.

        The reason I want to separate this vocabulary is that the epic ice ages are likely caused by continental positioning/repositioning, while the glacials are likely caused by orbital mechanics interacting with stable continental positions.

        There is a difference.

      • PG

        Do you know of any evidence that those previous major ice ages also began (and ended) with transitional periods of oscillation between glacial and interglacial?

      • If major ice age epochs were driven by tectonic plate movements, I would imagine a jagged response up and/or down towards ice or warmth. What that looked like in detail is not available compared to the last 400,000 years of ice-core evidenced Milanchovitch driven changes. Why? Because the evidence is in rock formations and age, not ice cores. Meaning that fine detail just isn’t available due to erosion of the rock data versus the preservation of ice-core data. That said, the following article includes that the smaller time spans of Milanchovitch cycles were active during epoch ice ages at least in part or at certain times.

      • Pamela

        Thanks – that’s a great reference.
        I guessed it would be a question of resolution, the Vostok etc. ice cores are quite special in that regard. Good day to you!

  39. To consider submarine geothermal influence we must consider many more features than just spreading ridges e,g, rift valleys, hydrothermal vents associated with transform faults, and the full range of volcanic styles including andesitic and silicic. We know that submarine large scale explosive eruptions do occur

    The average geothermal gradient is roughly 25 °C per km of depth. Within expansion zones this progressively increases to the point of being 100 c or more at 0 crust depth. We know these exist in the submarine environment e.g. the northern extension of the East African Rift Valley

    The paper here records a correlation. I do not expect that it proclaims that is has identified THE controlling mechanism. Early in my studies I was taught that progress in earth science involves “3 steps forward and 2 steps backward”. Fully accepting or rejecting a hypothesis is not the way forward. Record the observation and add it to the evidence. Fully eliminating evidence through thorough research is an important part of the process. It takes diligence and time. This is the way forward that will never be understood or adopted through the unfortunate vested interest of personal bias and politics of climate science

    Submarine geothermal energy input HAS to have an influence. The jury must stay out while we undertake the many years of research required to establish its influence in quantitive terms. Questions like “does submarine geothermal flux have a part to play in ENSO events?” are important

    One point regarding the proximal influence of heat within spreading ridges: The heat is most likely concentrated in fluids . This will ascend rapidly in the form of plumes

    One of Earth’s systems we know least about is submarine tectonics and volcanism

  40. Don Easterbrook
    Total geofantasy! Doesn’t explain the D/O abrupt oscillations
    nor the global synchroniety of climate changes.

    But albedo can explain both of them. Albedo can deliver orders of magnitude greater insolation absorption (feedbacks) than can CO2.


  41. “This activity is controlled by the rate of pressure release at any given location. There’s clear evidence that when ice sheets grow, sea level lowers and significant pressure is taken off the ocean ridges. This causes melting in the mantle, which should in turn promote the release of heat and carbon into the oceans …


    Not a new idea……
    This lot looked at whether they could find an association between water pressure/glaciation and magmatism along the Australian-Antarctic ridge.

    Conclusion…Maybe [more work needs to be done….quelle surprise]

  42. What I found interesting were the illustrations of the the Earth’s orbit relative to the Sun.
    This led me to consider another variable that might affect the periodicity of glaciations: the position of the Sun in our galaxy, and possibly even the position of our galaxy in the Universe.

  43. …and so, with having no surface water to speak of to maintain sealing pressure on underlying magma, Earths land masses must be boiling cauldrons of it……………….and where are those warm currents rising almost vertically from he deep?

  44. Doesn’t this more or less support the global warming science idea that extra CO2 can cause increases in global temp ?

  45. ren January 29, 2016 at 12:21 pm
    “Hillier & Watts (2007) surveyed 201,055 submarine volcanoes estimating that a total of 3,477,403 submarine volcanoes exist worldwide. According to the observations of Batiza (1982), we may infer that at least 4% of seamounts are active volcanoes. We can expect a higher percentage in the case of the count taken by Hillier & Watts (2007) because it includes smaller, younger seamounts; a higher proportion of which will be active.
    Good show, ren.

    More and more to find and learn about, concerning ocean hot pockets.

    Like this more recent article.

    Seafloor Vent System Helps Solve Mystery Of Earth Crust Heat Loss
    By Katherine Derla, Tech Times | January 5,

    The Earth’s heat loss from the planet’s crust baffled scientists for decades, until now. Scientists discovered a new class of hydrothermal vent system that could precisely explain previous global climate.

    A hydrothermal vent is an opening in the seafloor out of which flows mineral-rich water that has been heated by magma. The new seafloor vent system could clear up the long-standing debate between actual observations that the Earth’s crust is losing heat and the Earth’s theoretical cooling rate.

    The discovery was made by researchers from the University of Southampton and the National Oceanography Centre (NOC) in the United Kingdom. The research team used a combination of remotely operated vehicles and robot-subs to observe the vent system on the seafloor.

    “Theory has long predicted that there must be more cooling in certain locations on the Earth’s crust than we could account for using the known mechanisms and this new class of hydrothermal vent system may account for that difference,” said NOC geologist Bramley Murton, who supervised the research.

    Other hydrothermal vent systems use volcanic heat from magma chambers. The newly discovered hydrothermal vent system type makes use of hot rocks being pushed upward and toward the seabed by tectonic spreading centers, which are low-angle faults.

    The research team believes that the new hydrothermal vent system type can be found across the globe in various tectonic seafloor spreading locations. The new vent systems will shed new light on the Earth’s cooling mechanism, added Murton.

    The new hydrothermal vent system type was discovered during a Caribbean expedition at the Von Damm Vent Field. The driving process of the new vents is not completely understood, rendering them unaccounted for in existing scientific models that explain how chemistry and heat travel upward from the Earth’s crust.

    The new vents are also nearly invisible to the conventional techniques utilized in searching for hydrothermal vents. The research was published in the journal Nature Communications on Dec. 22, 2015.

    To measure the vent field, the team used sonar on an autonomous underwater vehicle, the Autosub6000, which then mapped the vent field. The team then sent a remotely operated vehicle (ROV) to the vents to collect mineral samples and hydrothermal fluids. The ROV’s multi-beam sonar was also utilized to produce a high-resolution map.

    An analysis of the samples proved both chemistry and minerals were different form the ones taken from other hydrothermal vents. The chimneys and mounds found in other vents are mostly made up of copper sulfides and iron, while on the Von Damm Vent Field, the 50-meter-tall (almost 165 feet) chimneys and mounds are largely made up of talc, a mineral rich in magnesium.

    “This research also means that ocean models of magnesium and calcium budgets will need to be updated and could lead to more accurate insights into the Earth’s past climate,” the researchers concluded.

    The complete article in Nature here.

    22 December 2015

    Talc-dominated seafloor deposits reveal a new class of hydrothermal system

    Matthew R. S. Hodgkinson, Alexander P. Webber, Stephen Roberts, Rachel A. Mills, Douglas P. Connelly & Bramley J. Murton

  46. Where the South Pacific Convergence Zone and Tropical Convergence Zone meet up there is sure alot of hydrothermal venting and Volcanic Activity.

    Deep-sea Vents and Volcanic Activity Discovered – 04/01/2016

    By the time of their return from a 28-day expedition onboard R/V Falkor in mid-December 2015, a team of scientists had more than doubled the number of known hydrothermal vent sites in the Mariana Back-arc region. This area, west of the Mariana Trench, is where plate spreading and submarine volcanism are concentrated. Several momentous findings were made, including the discovery of one of the deepest vents ever found plus volcanic activity.

    The team on R/V Falkor led by NOAA Pacific Marine Environmental Laboratory Cooperative Institute scientists Dr. Joe Resing from University of Washington and Dr. Bill Chadwick from Oregon State University, were able to increase the number of known hydrothermal vent sites in the Back-arc from three to seven by discovering four new areas of activity. One of these vents is amongst the deepest ever found from the 700 vent sites known globally. Only three other vents extend deeper than this newly-found vent, detected at a depth of 4,230 metres (13,900 feet).

    Another important outcome was the discovery of an extremely rare recently-erupted underwater lava field that is likely only a few months old. According to chief scientist Dr. Joseph Resing, this region probably experiences eruptions no more than once a century, making the 125m (400 feet) thick lava flows a very exceptional find. The scientists also observed cloudy warm water leaking through the still-cooling pillow lavas. At the return of AUV Sentry, imagery showed brand new lava flow on the sea floor.

    The multidisciplinary group used their Woods Hole Oceanographic Institution’s Autonomous Underwater Vehicle (AUV) Sentry, operated as part of the National Deep Submergence Facility. Multibeam sonar and chemical and optical sensors were also used to hunt for the new hydrothermal oases on a track that explored a 600km (400 mile) stretch of Pacific seafloor in the vicinity of the Marianas Trench Marine National Monument. This region, best known for including the ocean’s deepest depths, is also populated with active underwater volcanoes and unique deep-sea ecosystems that provide a rich environment for uniquely adapted species.

    The science team will return to this same Back-arc region one year from now to explore the newly-found hydrothermal vents with Schmidt Ocean Institute’s brand new 4,500m ROV. Armed with new maps of the recently discovered vents, the researchers will be able to better characterise the deep-sea ecosystems in and around the Mariana Trench Marine National Monument, exploring how vent species adapt to their unique chemical and geologic environment.

    All data obtained during the expedition are made publicly available by Schmidt Ocean Institute. Support for this expedition was provided by the NOAA Ocean Exploration and Research Programme and NOAA’s Pacific Island Regional Office.

    • It is beginning to look as if a major portion of ocean heat energy gain could be from cooling magma. The old figure for ocean turnover through the vents (10 years?) was 100m year to cycle the volume of the oceans. Suppose it is 20m instead. I calculated above the heat with a difference of 300 C. Suppose it is 1000, net. There is just a heck of a lot of heat coming into the water.

      The estimate above of 3-4 km^3 of new magma per year may be far too low. All these factors (according to my flawed calculations) are coming close to the total heat gained by the oceans. Wouldn’t it be amazing if it turned out there was no missing heat at all?

      Keep an eye on these:
      magma volume x cooling plus heat of fusion of the rocks
      vent flow, total, and delta T

      The ‘cooling’ of the core on the basis of heat slowly leaking out is tiny compared with the heat coming from these three.

  47. People need to understand the size and temperature of these undersea structures… the one structure called Godzilla is in our Blob zone off Oregon.

    So, one more for the road.

    The 40,000-Mile Volcano
    By WILLIAM J. BROAD JAN. 12, 2016

    Picture a volcano. Now imagine that its main vent extends in a line. Now imagine that this line is so long that it runs for more than 40,000 miles through the dark recesses of all the world’s oceans, girding the globe like the seams of a baseball.

    Welcome to one of the planet’s most obscure but important features, known rather prosaically as the midocean ridges. Though long enough to circle the moon more than six times, they receive little notice because they lie hidden in pitch darkness. Oceanographers stumbled on their volcanic nature in 1973. Ever since, costly expeditions have slowly explored the undersea world, which typically lies more than a mile down.

    The results can make the visions of Jules Verne seem rather tame.

    The ridges feature long rift valleys and, down their middles, giant fields of gushing hot springs that shed tons of minerals into icy seawater, slowly building eerie mounds and towers that can be rich in metals like gold and silver. One knobby tower in the Pacific Ocean, nicknamed Godzilla, grew 15 stories high. Thickets of snakelike tubeworms and other bizarre creatures often blanket the hot features, as do hungry prowlers such as spider crabs.

    The riot of life coexists with springs hot enough to melt lead or the plastic windows of mini submarines. With extreme care, humans and robots have measured temperatures as high as 780 degrees……

    ….A main question is to what extent the volcanism changes over time. The old idea was that the eruptions of oozing lava and related activity occurred at fairly steady rates. Now, studies hint at the existence of outbursts large enough to influence not only the character of the global sea but the planet’s temperature.

    Experts believe the activity may carry major repercussions because the oceanic ridges account for some 70 percent of the planet’s volcanic eruptions. By definition, that makes them enormous sources of heat and exotic minerals as well as such everyday gases as carbon dioxide, which all volcanoes emit.

    “It’s a whole new perspective on how the Earth works,” said Daniel J. Fornari, a senior scientist at the Woods Hole Oceanographic Institution on Cape Cod, Mass. “We’ve got our eyes and ears on a part of the seafloor that’s really dynamic.”

    The source of all of this activity is the slow churning of Earth’s molten interior, which continually rearranges the planet’s two dozen or so large crustal plates. The volcanic ridges mark the places where oceanic slabs slowly pull apart, giving molten rock and gases an escape route…..

    ….“Discovering the Deep,” published in May by Cambridge University Press, is filled with hundreds of images of alien creatures as well as volcanic towers belching clouds of superheated water rich in metals and minerals. It profiles more than a dozen hot spots around the globe, including those on the Juan de Fuca Ridge, home to Godzilla. Oceanographers, the book says, have discovered vast swarms of unusually sturdy microbes thriving in dark volcanic waters as hot as 250 degrees — hotter than most boiling water on land….

  48. This theory is nonsense !

    What has sea level risen across the interglacial ? 200 feet ? 300 feet ?

    The conversion is 2.31 feet per psi. So a 300 foot rise in sea level amounts to less than a 150 psi change in pressure at the oceans’ floor.

    Thinking of it another way is 33 feet beneath the surface of a body of water is one atmosphere. A 330 foot rise in sea level is an increase of 10 atmospheres, and an atmosphere is 14.7 psi.

    So a 330 foot rise in sea level would cause an increase of 147psi.

    So these BOZO’s are saying that a 150 psi change in pressure at the oceans’ floor is enough to dramatically change volcanism in the earth’s mantle ???


    But then, that’s what I guess can be expected from 2-3 decades of dumbed-down educational systems and Post-Normal Science.


  49. Oh, and before anyone gets cute here, including long-time posters and/or WUWT contributors, about the size of the water body or the weight of water, etc. :

    A column of water is a column of water ! It does not matter if the column is the diameter of a buret, or a swimming pool or a lake or a sea or the entire ocean !!! 2.31 feet per psi is the change in pressure with the height of water – PERIOD !

    So I reiterate : only an idiot would think that a 150 psi change on the earth’s surface could cause a cataclysmic change in the earth’s plate tectonics or its volcanism.

    Any geologists, PhD. level, care to comment on this specifically ?

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