Icy ebb and flow influenced by hydrothermal activity
Release of magma from beneath earth’s crust plays significant role in earth’s climate
From the UNIVERSITY OF CONNECTICUT
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
Abstract
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:
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.
Milanković must be rolling in his grave right now.
Why? Is his graveyard seismically active?
Milankovitch rules!
http://math.ucr.edu/home/baez/glacial/glacial.pdf
Is that a show..?
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
http://judithcurry.com/2015/07/13/the-siddhartha-heuristic/#comment-717949
http://www.vukcevic.talktalk.net/IG.jpg
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?
Nonsense, The tidal forces are much too small. Milankovitch is doing fine:
http://www.leif.org/EOS/2006GL027817-Milankovitch.pdf
“the available records support a direct, zero-lag, antiphased relationship between the rate of change of global ice volume and summertime insolation in the northern high latitudes.”
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.
What has that to do with the Milankovitch Cycles?
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.
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
I don’t know what you are referring to, check out slide 5 of
http://www.leif.org/research/Climate-Change-My-View.pdf
and educate me.
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.
I have no pre-conceived opinion on this, considering the uncertainties involved.
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
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
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.”
Hi daveburton
The image I linked to is showing gravity and not magnetic anomaly.
“Magmatism” not “magnetism.” (I misread it the first time, too.)
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.
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.
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.
As an earth scientist yourself, what do you make of the time correlation between ice sheet melt / sea level change and magma flux?
… Well Ummmmm.., Northern sea ice melts will cause .o7 mm of SLR per year ! What is your point ??
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.
Not much. See extensive comments just posted below.
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.
MP, interesting observation. See my comment to BobG downthread.
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.
Thanks, Menicholas. You’re right, of course – we all carry some pretty recent physics in our pockets in the form of USB keys for example.
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.
I was referring to pre-1945 climate changes where human emissions could not be a factor.
Don Easterbrook,
Why does it need to?
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:
http://palaeos.com/paleozoic/paleozoic.htm
includes some maps of the planet during the Paleozoic and illustrates the locations, motion, and changes of continental crust during that period.
Because that’s when the ice ages started.
Good point, Bill. Also, AFAIK land volcanoes also become active during cooling periods.
See the picto-chart w partial list of eruptions: http://sierrafoothillcommentary.com/2016/01/06/volcanos-and-climate-change/
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?
It doesn’t follow a geodesic? Look at Google Earth.
It has forks and turns and such.
21,600 nautical miles, around the equator, or one a minute. At 1852 metres per NM you can metricate that as easily as I could.
g
http://www.whoi.edu/cms/images/Tivey_vent_map_en_84868.jpg
The Earth’s circumference is about 24,900 miles.
It’s easy to remember because 1000 miles is about one time zone. There are 24 time zones, and at the equator one time zone is just over 1000 miles east-west (about 1040 miles), and at my NC latitude it’s just under 1000 miles (about 840 miles).
You haven’t bothered to mention any.
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.
Anthony, pls correct the caption on the first image.
Sydlexia’s a tibch!
Indeed! Waht’s a mid-ceaon ridge?
[Write in the middle of the cea,on the floor of the ocean. .mod]
loL….oops, got that backwards
… Look at that squirrel way over there !
You’d have to ask the YouTube video maker. It is actually wrong on YouTube. Kind of kills the credibility of a nice instruction video is you spell the title wrong (I did that on a poster once…never put a title on a poster after being up for 36 hours!)
Sose dylsexia !
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.
http://s28.postimg.org/srndawlf1/CO2_and_Temp_Last_15_Mys.png
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.
SR
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
https://www.researchgate.net/publication/251546286_New_insights_into_Late_Pleistocene_glacial_and_postglacial_history_of_northernmost_Ungava_Canada_from_Pingualuit_Crater_Lake_sediments
Also from my ref, Hubberten et al 2004, check out fig 6 page 1339 about the Karginian / Mid Weichselian having warmer summers than today ( http://epic.awi.de/9052/1/Hub2004a.pdf )
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.
http://www.personal.soton.ac.uk/ejr/Rohling-papers/2003-Siddall%20et%20al%202003%20Red%20Sea%20sea%20level%20Nature.pdf
http://www.personal.soton.ac.uk/ejr/Rohling-papers/2008-Rohling%20et%20al%20MIS3%20synchro%20Paleoceanography.pdf
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: http://www.ngu.no/upload/Publikasjoner/Bulletin/Bulletin450.pdf
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:
From https://en.wikipedia.org/wiki/Woolly_mammoth:
“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.
SR
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.
http://palaeos.com/cenozoic/neogene.html
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. http://www.pnas.org/content/112/19/6110.abstract
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
Alkenone
TEX86
Mg/Ca ratios
Pollen Analysis
Chironomids
Carabids
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:
http://epic.awi.de/9052/1/Hub2004a.pdf
http://www.tc.gov.yk.ca/publications/ice_age_klondike_2011.pdf
http://www.sciencedirect.com/science/article/pii/0033589476900478
http://www.sciencedaily.com/releases/2015/11/151109153810.htm
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:
http://www.geologinenseura.fi/bulletin/Volume79/Helmens_etal_2007.pdf
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:
http://www.ngu.no/upload/publikasjoner/Special%20publication/SP13_s79-144.pdf
North America
http://noblegas.berkeley.edu/~balcs/pubs/Balco_Geology_2010.pdf
http://www.geo.oregonstate.edu/files/geo/Royetal-GSAB-2004.pdf
https://www.researchgate.net/publication/251469625_Chronology_and_Extent_of_Late_Cenozoic_Ice_Sheets_in_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.
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.
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.
Warmer air hold more moisture, and so more of the sea can be transported to the top of an ice sheet in a given amount of time.
Might be as simple as the ratio of rain in the summer months to snow.
And maybe Greenland was in the “snow shadow” of the North American ice sheet?
look carefully though, they say “…perhaps CO2 mantle flux…”. Looks like they didn’t really want to say that CO2 had a major role. I’ll bet the reviewers made them add that.
Yes I noticed that ultimately it was the fizz wot dunn it. The ice ages just came along for the ride.
*laughs so hard milk comes out of nose…and was not even drinking any milk*
This a separate paper from the one by Tolstoy?
Yes. But they are both studying the same east pacific spreading ridge.
I think my post went into a black hole.
[Nothing in the queue. .mod]
Ah. There it is.
“[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.
Nice!
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.
G
Could you please provide a link? Ice, for example, melts under pressure.
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.
SR
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
Thank you!
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.
Quick, we need a model!
I’m available….but no nude pics unless you Photoshop the truss & zimmer frame out !!
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.
w.
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).
Thanks Willis. I like your numbers better than mine. I’m surprised they are so close actually.
I’ve added a link to the underlying paper to the head post. It is here.
w.
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.
M, very nice summary of my essay on same.
“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.
http://cosscience1.pbworks.com/f/1248192657/Module10-001.gif
http://cosscience1.pbworks.com/f/1248192659/Module10-002.gif
http://www.proprofs.com/quiz-school/user_upload/ckeditor/continental%20drift%20cartoon.gif
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 http://www.scotese.com/earth.htm. 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.
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. 🙂
cheers
[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…
If it was a big juicy whitehead just about to pop anyway it might.
You mean 4%. Quite a lot.
As I wrote last year, there’s good reason to believe crustal expansion and contraction is the root cause for this cycle:
The Caterpillar theory of tectonic plate movement – it’s just simple physics.
http://scottishsceptic.co.uk/wp-content/uploads/2015/06/I-_see_no_caterpillar_scr.png
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
Plus many. But I cannot do SkS math. Cook and Kidz are far above my pay grade. Also 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.
Whose fingernails are we talking about here?
Ours, or theirs:
http://25.media.tumblr.com/tumblr_mbf6nna4ki1rr7wnno1_500.jpg
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 http://wattsupwiththat.com/2015/07/31/the-mathematics-of-carbon-dioxide-part-3/
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:
http://www3.epa.gov/climatechange/science/indicators/oceans/ocean-heat.html
Tectonics and climate natural variability
http://www.vukcevic.talktalk.net/NA-NV.gif
Sorry but a graph without units is just taking up space.
Years are on the x axis, Dave, and the correlation is in the timing. Interesting but not convincing..
One interesting correlation is that the two trends come together shortly after or right at the end of the last 2 GMs. Will this happen again after the end of the next GM?
graph updated
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.
They have nailed down the role of mid-ceaon ridges in cie age termination splendidly.
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.
Excellent point.
Why focus on either/or causation?
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:
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:
Yes, they may. However, the main CO2 signal is so small that such incremental additions don’t change the picture.
Mmm … seems like they are into speculation there.
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,
w.
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?
You have some very informative comments today, Thanks!
Yep, siphoning all the volcanic sea floor sludge up into Denmark straits during periods of high activity, then eroding the sediment during periods of low activity, modulating the AMOC, tectonics driven natural variability
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.
Methane from clathrates?
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.
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.
Just to be clear, spreading centers are ridges…subduction zones are trenches.
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.
So mid ocean ridge is a misnomer? I had not realized that. I stand corrected.
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?
Like the prospective title of my next ‘sciency’ maybe ebook if I can ever get going, DUNNO. Regards. Rud
Very plausible.
“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.”
http://principia-scientific.org/volcanic-carbon-dioxide.html/
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.
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.
200 feet of water is 100psi (about) or 7 tons of pressure for every square foot, or 300,000 tons per acre.
I dunno, but that sounds kinda big.
Air pressure (STP) is about 43,000 tons per acre. That sounds kinda big, too. But we don’t implode.
Heavy, man.
Heavy.
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.
http://biomesfirst11.wikispaces.com/file/view/Open_Ocean_Depth_Map.jpg/262119524/Open_Ocean_Depth_Map.jpg
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.
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…
Interesting. It warrants a lot more data collection from other ridge systems.
“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…
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.
Thanks, Kevin. So then what holds up the 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?
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.
That’s because that area is a subduction zone not a mid ocean ridge.
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 .
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
In absolute, instantaneous terms, (a).
Changing a) to insolation would make more sense
If Gates and Menicholas agree, it must be a).
Either that, or the Devil has just got himself a pair of ice-skates.
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?
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.
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.
The hot yellow thing!
Although I have to say it looks distinctly whitish to my admittedly untrained eye.
Never mind the tectonics, It has to be the all-powerful CO2!
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.)
http://www.nbcnews.com/id/39934297/ns/world_news-asiapacific/#.VRe6PGctGUl
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.
http://www.pnas.org/content/101/17/6341.full#otherarticles
http://www.msnbc.msn.com/id/39934297/ns/world_news-asiapacific/
http://news.nationalgeographic.com/news/2009/04/photogalleries/volcano-lightning-pictures/
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?
http://www.agu.org/pubs/crossref/2006/2006GL027284.shtml
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.
http://iopscience.iop.org/1742-6596/440/1/012001/pdf/1742-6596_440_1_012001.pdf
http://www.scientificamerican.com/ar…than-expected/
http://geosci.uchicago.edu/~rtp1/BardPapers/responseCourtillotEPSL07.pdf
https://www.rug.nl/research/portal/files/6661387/2000QuatIntRenssen.pdf
http://www.iisc.ernet.in/currsci/apr252003/1105.pdf
solar coronal holes are currently disappearing
hardly: http://services.swpc.noaa.gov/images/animations/GOES-15-CS-PTHNA-0.4/latest.png
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
http://www.vukcevic.talktalk.net/J-V.gif
What might be the solar system’s clockwork driving both?
It is clear from your graphs that the phase is not the same [nor the amplitude].
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?
Very likely a coincidence. What do Jackson and Bloxham say about this? Perhaps they are not ‘progressive thinking scientists’ …
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: http://sbc.oma.be/data1.html
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.
http://www.vukcevic.talktalk.net/E-CAM.gif
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:
http://www.leif.org/research/Changing-LOD.png
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 electromagn