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Another story about global warming causing volcanoes…
124 Comments
Maybe Not. If you consider the WUWT “reference pages”, there isn’t any attempt to quantify volcanic activity which is a significant factor Climate.
Including plate tectonics and volcanic activity is logical as it can directly impacts climate and weather patterns for years.
Tall ask I guess but here are a few links to some of the event monitoring:
– Threat monitoring (note Long Valley Caldra): http://volcanoes.usgs.gov/observatories/calvo/
– Earthquakes: http://earthquake.usgs.gov/earthquakes/map/#%7B%22feed%22%3A%221day_m25%22%2C%22search%22%3Anull%2C%22sort%22%3A%22newest%22%2C%22basemap%22%3A%22grayscale%22%2C%22autoUpdate%22%3Atrue%2C%22restrictListToMap%22%3Atrue%2C%22timeZone%22%3A%22local%22%2C%22mapposition%22%3A%5B%5B-60.93043220292333%2C-279.140625%5D%2C%5B83.31873282163234%2C79.1015625%5D%5D%2C%22overlays%22%3A%7B%22plates%22%3Atrue%7D%2C%22viewModes%22%3A%7B%22list%22%3Atrue%2C%22map%22%3Atrue%2C%22settings%22%3Afalse%2C%22help%22%3Afalse%7D%7D
The link between climate change and volcanism is still poorly understood. Many volcanoes do not seem to have been affected by it. Nor is it a particularly pressing concern today, even though we face an ice-free future. It can take thousands of years after the glaciers melt for volcanic activity to rise.
Where is going to be “ice-free” in the “future”?
I think the operative phrase here is “is still poorly understood”…
If they don’t understand what is going on, how in the world can they model it (OK, rand(n)…)…
Why don’t they just be truthful and say “please send more money”…ok, expecting the truth is a bit of a stretch….
Reminds me of a joke my Dad told me when I was in college (probably only half-joking…)
Son: No mon, no fun, your Son….
Dad: Too bad, so sad, your Dad…
October 2, 2014 5:39 am
What’s the deal with people not living in reality.
It’s the Sun, Reconstructed TSI chart and world volcanic activity match up don’t you think??
http://lasp.colorado.edu/lisird/tsi/historical_tsi.html
http://iceagenow.info/2012/04/volcanic-activity-increasing/
BTW how do you post pictures, I have nobtabs to do so, thanks.
October 2, 2014 5:41 am
I like the idea that the end of the ice age was “generally quite favourable” to human life. What aspects were less favourable? The lack of ice at the equator for drinkies, perhaps? This article seems science-free, with its words like “bizarre”, “strange”, “brutish”, and the concept of ice being “heavy”! I also wonder where the author got the idea that Antarctica is losing 4b tons of ice annually?
Peter, I imagine the sea level rise must have made some groups of people move away from rising waters. When I look at today´s bathymetry I wonder if we may not find archeological ruins a few meters inland from where the beaches used to be? A sea level rise like they had must have been the origin of the Flood stories?
October 2, 2014 5:41 am
It doesn’t matter, what if volcanos, earthquakes, extinctions, migrations, deaths, sea level changes, heat, cold, floods, drought, hurricanes and tornados are all made “worse” by global warming. Global warming / climate change is natural until the A appears in front of it.
Stop accepting the bogus implied link to man, it gives the alarmists undeserved credibility. Events, however tragic, that have a natural cause are irrelevant to this debate.
Make these fools state explicitly that the cause is AGW – then ask them how they know.
October 2, 2014 5:45 am
Ice sheets are heavy. Each year, Antarctica’s loses around 40 billion metric tons of ice.
Does anyone know how much of that ice loss was CAUSED by volcanic activity?
Discovery – Jun 9, 2014
Hidden Volcanoes Melt Antarctic Glaciers from Below
Antarctica is a land of ice. But dive below the West Antarctic Ice Sheet, and you’ll find fire as well, in the form of subglacial volcanoes.
Now, a new study finds that these subglacial volcanoes and other geothermal “hotspots” are contributing to the melting of Thwaites Glacier, a major river of ice that flows into Antarctica’s Pine Island Bay. Areas of the glacier that sit near geologic features thought to be volcanic are melting faster than regions farther away from hotspots, said Dustin Schroeder, the study’s lead author and a geophysicist at the University of Texas at Austin.
http://news.discovery.com/earth/global-warming/hidden-volcanoes-melt-antarctic-glaciers-from-below-140609.htm
======================
National Geographic – November 18, 2013
The new volcano’s discovery was accidental. In January 2010, scientists set up a series of seismometers, or earthquake detectors, on Marie Byrd Land, a highland region of West Antarctica.
http://news.nationalgeographic.com/news/2013/13/131118-antarctica-volcano-earthquakes-erupt-sea-level-rise-science/
October 2, 2014 5:49 am
There is a volcanic field in Germany which seems to erupt after the ice-load is lifted. The East Eifel volcanic field
Laacher see erupted with a VEI 6.0; 12,900 years ago (interesting Younger Dryas-type date) which formed a large caldera lake.
http://www.volcanodiscovery.com/laacher_see.html
http://esys.org/rev_info/Deutschland/laachsee-luftbild-hq.jpg
No the Laacher See erupted about 200 varve years or tree-ring years before the onset of the Younger Dryas.
http://www.ingentaconnect.com/content/ap/qr/2002/00000058/00000003/art02379
Also there wasn’t any ice sheet nowhere near the Laacher see. You’d have to go as far north as central Sweden for that. I’m trying to fgure out if the periodic active Eiffel periods do keep pace with the glacial/interglacial cycles. It could be.
Also interesting why the Volcaism in the Massif Central in France seem to have the same cycles, maybe.
Oh and one of the more important volcanic traces are found in the ice cores of Greenland.
October 2, 2014 6:03 am
As I had posted on WUWT a few years ago, I wonder whether the quiet sun, such as we are now experiencing, does not somehow trigger a higher level of volcanism. No, I offer no ideas how this could be causation rather than correlation (even if it IS correlation), but that’s my story and I’m stickin’ to it. Maybe we could call it the Madman Theory. : )
October 2, 2014 6:11 am
Increase in solar wind speed and energy over the weekend and Japanese volcano erupts, more activity in Iceland, eruption in Russia and earthquake in Indonesia. Coincidence? Of course admitting that the sun does this just leads you along the path of what else it can affect and the collapse of the CO2 myth.
October 2, 2014 6:18 am
Sweden is still rebounding from the last ice age at a couple of mm per year. So considering the lag following a major melt that happened 10k to 14k years ago, the most recent melting will take a time to have an affect? According to the PIOMAS Ice Volume trend Arctic sea ice is down about 10,000 cu K which is a cube about 13 miles on each side. That’s not very big and as this is sea ice there is no (none, zero) actual weight loss. What about land ice? If I’m correct all recent volcanoes have gone off whether covered in ice or not.
The most significant geological events would be the 2004 Sumatra–Andaman earthquake and the 2011 Great East Japan Earthquake. According to Wikipedia:
The japan earthquake “triggered powerful tsunami waves that reached heights of up to 40.5 metres (133 ft) in Miyako in Tōhoku’s Iwate Prefecture,[16][17] and which, in the Sendai area, travelled up to 10 km (6 mi) inland.[18] The earthquake moved Honshu (the main island of Japan) 2.4 m (8 ft) east and shifted the Earth on its axis by estimates of between 10 cm (4 in) and 25 cm (10 in),[19][20][21] and generated sound waves detected by the low-orbiting GOCE satellite”
The Indian Ocean earthquake struck “with a magnitude of Mw 9.1–9.3, it is the third largest earthquake ever recorded on a seismograph. The earthquake had the longest duration of faulting ever observed, between 8.3 and 10 minutes. It caused the entire planet to vibrate as much as 1 centimetre (0.4 inches)[9] and triggered other earthquakes as far away as Alaska.”
These events will have set up the potential for new geological events simply because large parts of the planet have moved around, and not by mm but metres. I find it hard to picture how recent ‘loss’ of ice can compete with these events and make any impression on plate tectonics, as the bulk of ice ‘loss’ happened 14,000 years ago.
October 2, 2014 6:26 am
Their logic defies logic. To me their example of heavier ice would compress the earth’s surface. This downward force creates higher pressure in the magma.
The sheets are so heavy, in fact, that as they grow, they cause the Earth’s crust to bend — like a plank of wood when placed under weight. This is what really happens (according to my theory) when an ice sheet builds up and get’s so heavy, the crust’s downward push builds up pressure in the magma. This downward flexing can lead to a increase in stress in the underlying magma, which, as my theory goes, makes it easier for magma to find weak spots in the earth’s surface, thus creating more volcanic eruptions. The pressurized magma has to go somewhere. (Hey, I have theories too, where’s my grant money?).
There are actual studies on just that theoretical base, JP. I say actual, because they were aimed at understanding apparent Pleistocene subglacial vulcanism in British Columbia….as evidenced by fresh pillow lavas found where there is dry land today. The story goes that the sheer weight of more than a kilometer of ice exploited pre-existing weaknesses. Nary a bleat about climate change, back then….just good old geologists seeking to explain an interesting phenomenon that, as it happens, was not model-generated.
I´m going to speculate way out in lala land, based on my knowledge of rock mechanics and fluid dynamics. However, I am not an expert on magma fluid dynamics or vulcanism…….
Putting an ice load over a continent does reduce the load over the ocean basin (it removes the water mass). This means the rocks under the ocean basin see a tiny stress reduction (about 187 psi or 13 atmospheres). The new ice load will cause a very slow moving pressure pulse from under the continent towards the ocean basin. We have equations to estimate the pulse travel time, but I don´t have the information on the rock viscosities in a particular area, so let´s just say it must move incredibly slow and take thousands of years.
The key is to look at that 187 psi static load reduction over the ocean basin WHEN THE ICE FORMS as the trigger to charge magma chambers near the surface because the stress near the surface has dropped. These chambers charge up with slightly hotter and much lower viscosity material.
The inverse process should take place when the ice load is removed. The water shifts from ice to liquid, moves over the ocean basin, increases stresses over the sea floor by about 187 psi. This happens quickly, before the horizontal pressure transient caused by the initial ice load can move very far into the ocean basin. The initial ice stress load must be getting picked up by rock compressibility and the bending of the continental plate, which allows the non ice covered area to move upwards a little bit).
So let´s keep theorizing…..if the water increases the earth field stress by 187 psi, and the load is transmitted to a lava chamber located near the surface, which has been slightly recharged by warmer, lighter and lower viscosity material, then the outcome may be a swarm of volcanic eruptions.
Note that the magma chamber doesn´t have to be located near an area where the ice load was imposed then removed. The load which causes magma chamber pressure pulses is a slow reduction in stress as the ice forms, and faster stress increases when the ice melts and the water moves to increase sea level.
I bet this was already described in a scientific journal, but since this isn´t my field I never read about it nor gave it much thought. This means I have absolutely no pride and can take criticism over this idea rather easily.
Now moving on to the effect of volcanic eruptions, I understand it´s a mixed bag. They add CO2 to the air, but they also can cause climate cooling when aerosols reach the upper atmosphere?
October 2, 2014 7:10 am
The article begins with the question as to why there is so much volcanic activity lately (not sure that it is, but anyway .. .), and then precedes to talk about a period 19,000 years ago when massive ice sheets where melting fast.
Comparing conditions in the past when mile thick ice sheets were depressing the Earth’s crust with today’s largely ice free world is bizarre. But then I guess climate science has a logic all of its own.
Vince, it´s not necessarily “climate science” as such. I looked at it as an interesting rock mechanics exercise. Given enough time and some help I could probably put together a coupled model (coupling rock stress field with the magma flows) to show how it could be possible for the Greenland, North American and Scandinavian glaciers impact the frequency of volcanic eruptions in Iceland. On the other hand maybe such a model would prove there´s no way they could do so. And I bet somebody already prepared such a model.
October 2, 2014 7:12 am
I’m under the impression that some scientists are suggesting that Ice moves the tectonic plates!
Ice is the lighter and less dense stuff that sits on top of the earths crust or lithosphere, the weight of Ice on the tectonic plates and the upper mantle is negligible, the crust alone is up to 100 km thick and the deepest glacier is only about 2.5 kilometers thick, for every square km of Ice there is potentially up to 100 square km of crust below it, there is no contest over what moves what, and as a mater of fact, the thinest part of earths crust is on the ocean floor, therefor glaciers and the polar ice caps are mostly on the thickest parts of earths crust, cutting their way through mountains and volcanically active areas etc..
Another fact, Ice floats above earths crust and it’s weight is distributed, balanced and is constantly moving and spreading around, behaving as a fluid on geological timescales compared to the earths crust and upper mantle.
Magma may look and behave like a liquid tho it’s a lot heavier and denser than Ice.
But I have noticed there is nothing as dense as these “Anthropogenic global warming/climate change” claims, except maybe the science and people behind them.
October 2, 2014 7:21 am
By their logic, anything connected to a glacier can be connected to AGW. It doesnt have to make any sense. isostasy has been studied and published about for over 100 years.
Alarmists are far more interested in making connections back to Kevin Bacon than discussing the science behind the papers.
October 2, 2014 7:22 am
We know about many past volcanic eruptions because of the ash that ends up on the earth’s surface tens to hundreds (or even thousands) of miles away. Suppose volcanoes were erupting under the glacial ice as often as they do after the glaciers melt. For large glaciers, the ash would tend to stay underneath the ice, never making it up into the atmosphere to be spread around for later detection. Then, after things cool down, the slowly moving glaciers would grind away the local evidence — freshly hardened lava, etc. — that an eruption occurred underneath it. This is ironic considering that stuff deposited on top of glaciers can be detected hundreds of thousands of years later inside ice cores, whereas stuff deposited underneath glaciers slowly gets ground and mixed with other debris until there’s nothing recognizable to detect. Consequently, less evidence of past volcanic eruptions during glacial periods, leading to the hypothesis that volcanic eruptions increased after the glaciers melted.
“For large glaciers, the ash would tend to stay underneath the ice, never making it up into the atmosphere to be spread around for later detection.”
It sure does. It is called “móberg” in Icelandic and it is very characteristic. Read all about it:
http://is.wikipedia.org/wiki/M%C3%B3berg_(jar%C3%B0fr%C3%A6%C3%B0i)
I thought I would check your assertion “We are not in a notably active volcanic period.” and it seems you may be right.
2010
The event was as breathtaking as it was disruptive, but does it signify something far more serious? Are volcanic eruptions on the rise?
Not according to Lee Siebert, director of the Smithsonian Global Volcanism Program (GVP). Charged with documenting, analyzing and disseminating information about Earth’s active volcanoes, the GVP boasts 40 years of data to indicate it’s business as usual under the crust.
“If you plot data from the last 200 years, there’s a clear increase in the number of eruptions over time,” Siebert said, “but that’s not a function of the actual number of eruptions but rather due to reporting effects.”
Specifically, the GVP found that the increase in volcanic eruptions paralleled the rise in global population. It paralleled human encroachment of volcanic areas and improvements in communication technologies.
http://news.discovery.com/earth/global-warming/are-volcanic-eruptions-increasing.htm
So just like with tornadoes etc. better detection more eyes in more / new areas.
October 2, 2014 7:54 am
Actually the last 20 years have been notable for a remarkably low level of volcanism. Not a single major eruption since Pinatubo in 1991.
However it is true that there seems to be a certain degree of linkage between activity in some volcano fields and nearby glaciation. Not very surprising really, since glaciation causes large scale flows of subsurface material because of isostatic effects.
For example it seems that the Eifel volcanic field in Germany is influenced by glaciation, and possibly also the Auvergne field in France and the Campi Flegrei field in Italy.
In Iceland things are more complicated. On the whole it seems that there is more volcanism during interglacials, but there are volcanos that have only erupted during glaciations, others that are mostly active in interglacials and some that don’t seem to care.
October 2, 2014 8:00 am
So “A 2009 study, for example, concluded that between 12,000 and 7,000 years ago, the global level of volcanic activity rose by up to six times. Around the same period the rate of volcanic activity in Iceland soared to at least 30 times today’s level.”
That should have stop warming in its track no?
October 2, 2014 8:10 am
In all seriousness,
Which hemisphere (north or south) has the greatest annual change in ice+snow mass that is supported by land?
In this question, we ignore the changes in sea ice. Ice displaces it’s weight of water, so there is no change in mass by the melting of sea-ice. So we ignore the floating ice in the Arctic and the much larger Antarctic perimeter. The Arctic has annual snow-cover over millions of km^2 across Siberia, Scandinavia, North America and Greenland and it all melts. In Antarctica, there is annual snow accumulation, but how much of it melts or sublimes during the year? A significant percentage of Antarctica ice is lost annually in the flow of glaciers, but this ought to be at a semi-constant rate over the year. Glaciers thousands of feet thick will still flow some during the dead of winter.
I suspect, purely from an annual crustal loading-unloading, the northern hemisphere has the greatest change.
This is mostly an academic question. When it comes to flexure of the earth’s crust, annual changes in the ice and snow loading at hemisphere scales pale in comparison to the semi-diurnal Earth Tides that can raise or lower a give point of the earth by 0.5 meters.
October 2, 2014 8:34 am
I recall that the so-called scientists who were spewing global warming babble tried to deny that volcanic activity was increasing. Now they have to agree with sensible scientist that said it was increasing. However, they still try to use warning as the culprit. Perhaps they should take note on the Sun’s effect on Earth’s volcanoes and even the Earth’s own magnetic influence.
October 2, 2014 8:37 am
I am quite prepared to believe that Katla might have erupted again were it not for the overlying ice. I believe that one day that ice might melt, kaboom. What I have trouble believing is that we can link significant quantities of that ice melting with anthropogenic CO2 released.
Editor
October 2, 2014 10:06 am
Um, something like 70% of all volcanoes are under the ocean… and we only figured this out recently. Just how can anyone know how active they ALL were 50,000 years ago, or more?
Also, just how much does ice flexing explain the volcanoes of California ( subduction zone with little ice) or on Tropical Islands…. (Indonesia anyone? Toba? Krakatao?))
I smell a load of bunk.
FWIW, I ran into a different paper that ascribed the changes to core vs crust displacement due to wobbly orbits / tides from major planet gravity….
Yep,
http://ww2.iers.org/IERS/EN/Science/EarthRotation/EarthRotation.html
There was probably a short lived Venus + Jupiter related perturbation in early January this year. One day we may be able to compute n-body mechanics from first principles and appreciate tidal forces throughout bodies of varying density in three dimensions. Who knows, we might even grasp the true nature of gravity and its relation to energy and mass.
Till then we’ll just have to drink bunk cocktail: snake-oil from normally distributed statisticians with an pinch of 95% salt and a faded paper umbrella decorated with black swans,
One day we may be able to compute n-body mechanics from first principles and appreciate tidal forces throughout bodies of varying density in three dimensions.
I don’t believe we would have accurate planetary ephemerides if we didn’t do that already using spherical harmonics for various bodies up to whatever order suits your application.
October 2, 2014 10:15 am
This is ridiculous because it completely ignores the length of geologic time. Water can and does allow for extra fluidity and expansion of molten rock, overburden does need to be released, but these things move with plasticity on a timeline of millions of years and only moving quickly (as we see on the surface) when they are at standard pressure/temperature.
These people are looking at modern geologic activity like it was caused yesterday (in geologic terms). This is dramatically closer to Christian catastrophism on a 6000 year time line than geology.
October 2, 2014 10:17 am
Reblogged this on CraigM350 and commented:
“The link between climate change and volcanism is still poorly understood”
But if we can blame it on ‘carbon pollution’ we’ll speculate anyway.
Reminds me of the contortions Jo Abbas twisted herself into trying to link climate change to the Kobe earthquake.
October 2, 2014 11:13 am
Don Andersen and James Natland a professor emeritus at the University of Miamidescribe their analysis about the roots of volcanism online in the september 8 issue of the Proceedings of the National Academy of Sciences . In essence it apostulates , the engine behind earth interior processes is not heat from the interior , but cooling of the planets surface . The paper is titled Mantle updrafts and mechanisms of oceanic volcanism , To put it briefly increased volcanism is caused by a cooling of the earth surface .
Absolute balderdash..
On shorter timescales, outgassing from volcanic activity can cool the earths surface, there is absolutely no effect from ice sheets or cooling on the surface of earths crust which can effect the interior processes of this planet.
“Over geologic time, the inner core grows as the whole Earth cools.“
This process takes place over millions of years as the entire earth cools, not just the surface
October 2, 2014 11:59 am
The link between climate change and volcanism is still poorly understood
Not that will stop the alarmists jumping all over this claim has ‘proof’ or stop the authors grant hunting of the back of this idea. While such everything and its dog is down to AGW studies are seen ,its clear there is still much money in the area . We will know even academia has dumped ‘the cause’ , once all we see are real studies , which ironical may have real value, as there is no longer any easy cash to be had pimping AGW.
October 2, 2014 3:43 pm
One of the assertions made by Ronald D Voisin refrenced in this article:
http://wattsupwiththat.com/2014/09/24/an-engineers-questions-regarding-holocene-climate-change/
and discussed in his full paper, which is linked at the end of his article, is an increase of volcanic activity at the start/end of glaciation/interglacial caused by what he terms the ‘startup’ and ‘blowout’ of the geo core reactor. Put simply, when the core reactor becomes more active (end of glaciation beginning of an interglacial) more heat gets pumped into the mantle, which causes thermal expansion which in turn causes more movement of magma towards the crust. When the core reactor becomes less active less heat gets pumped into the mantle, which causes thermal contraction and ‘chaotic’ magma movement, even greater than at ‘startup’ due to the less viscous nature the mantle at that point. Thus, his hypothesis expects increased volcanic activity at both the beginning and end of an interglacial.
(page 13 of 20)
It might easily be so that the gravitationally precipitated “start-up” of a previously “blown-out” core geo-reactor is geologically observed to be a smooth and rapid function, as observed. Once the process begins in nascent form it might likely proceed uninterrupted and very quickly as a relatively high viscosity / low-fluid dynamics situation is transformed to a lower viscosity / higher fluid dynamics one. Only after a geologically short delay would accumulated heat and enhanced reaction kinetics give rise to more vigorous, violent and
susceptible activity (as the reactor continues to grow in size).
On the other side, the “blow-out” of this now enlarged and highly energetic reactor is likely to be far more chaotic with its high fluid dynamics. It might be a staged process wherein an initial chaotic external fluid flow scatters one now-giant reactor into a few large spatial components that individually continue to be large enough to be highly reactive. This external fluid flow already had to be very hot to be so dynamic as to enter the central core. This then slows the overall kinetics but possibly only partially. The variously sized reactor sub-components might then likely experience their own chaotic, incoherent shut-downs (dispersions) and occasional restarts as gravitational influences begin to act on these large (now randomly displaced) spatial components of the original reactor. Consequently the whole of the shutdown process might be geologically step-staged over time, as observed, and the asymmetry of large amplitude temperature swings may well be consistent with the overall hypothesis presented herein. (It appears obvious to consider that these asymmetries are fundamental to the primary driver itself and not some artifact of other less influential drivers.)
Ryan October 2, 2014 at 4:53 pm
Are you referring to Ronald Ronald D Voisin’s article? If so, you exhibit serious misunderstanding. He is talking about the core and mantle of the the earth, warming and cooling, becoming more and less viscous in response to fission reactions that cause the core to expand and contract depending on how vigorous the reactions run over time. He is not talking about the small changes in surface temperatures caused by seasonal variations.
October 2, 2014 10:11 pm
“A 2009 study, for example, concluded that between 12,000 and 7,000 years ago, the global level of volcanic activity rose by up to six times. Around the same period the rate of volcanic activity in Iceland soared to at least 30 times today’s level.”
Speculation. No volcanologist during that time. The Sumerians had yet to invent writing.
“when an ice sheet melts, and its mass is removed, the crust springs back. This upward flexing can lead to a drop in stress in the underlying rocks, which, the theory goes, makes it easier for magma to reach the surface and feed volcanic eruptions.”
The ice sheet is in Antarctica. The volcano is in Japan. Look at the world map to see how far the magma has to travel. Gravitational force is vertical. Magma has to travel horizontally. Don’t make sense. Another attempt to blame everything to climate change.
October 2, 2014 11:13 pm
What better way to scare people than to claim that volcanoes will go off if you drive your SUV. Next it will be earthquakes and tsunamis.
Believe it or not I have actually experienced this kind of claim in my working life. When trying to access a remote village in the 3rd world, green NGOs told the locals that tsunamis could come if any development was allowed. So we weren’t allowed in.
I don´t think this is the intent. A link between the ice age cycles and volcano activity is within the realm of possibility. However, we are now in an interglacial period, the ice over North America disappeared many years ago, so it has nothing to do with humanity burning fossil fuels or making cement.
I see this is as an interesting scientific puzzle we could try to solve. And it has nothing to do with anthropogenic global warming or whatever Obama was worried about before Ebola hit Dallas (I assume he´s focused on a more real danger at this point?).
Link between ice ages and volcanic eruptions is an interesting possibility. However, the mechanism proposed is contrary to known geophysics. Magma is a fluid that is almost incompressible. Large ice mass depresses the crust and increases the pressure on magma. Melting the ice inflates the crust and reduces the pressure on magma. You need high magma pressure for volcanic eruption. Melting of ice sheets has opposite effect.
A more sensible mechanism is ice mass covers the craters of volcanoes preventing eruptions. But this is contrary to the claim of more eruptions 12,000 to 7,000 years ago. There should be more today since craters are no longer covered with ice.
October 3, 2014 8:35 pm
NY Professor: Global Warming gave birth to ISIS
http://www.huffingtonpost.com/charles-b-strozier/how-climate-change-helped_b_5903170.html
http://dailycaller.com/2014/09/30/claim-global-warming-helped-create-isis/
October 4, 2014 12:10 am
@Dr. Strangelove 10/3 at 6:59 pm
There was a WUWT post in Dec. 20, 2012, “A link between climate, ice melt, and volcanic eruptions is found.” The main post idea was:
“In times of global warming, the glaciers are melting on the continents relatively quickly. At the same time the sea level rises. The weight on the continents decreases, while the weight on the oceanic tectonic plates increases. Thus, the stress changes within in the earth to open more routes for ascending magma” says Dr Jegen.
I don’t buy that idea. It is too indirect. But it caused a paradigm shift in my thinking. I could buy a link of volcanism caused by ice age cycles in that a drop in sea level would directly change the stresses on the flanks of thousands of volcanic islands.
When it comes to plausible mechanisms, however, I can make a very good case for climate induced volcanism
at the COLDESTinto the COLDER part of the ice age, not the warmest of the interglacial. Consider this….At the closest point,As it gets colder, we have ice sheets bearing down on the cratons of the world. Sea level isvery lowdropping until we have with beaches at the continental margins. Every volcanic island and seamount now has 100 m + of its once submerged skirt above water. The stresses on the flanks of these active / dormant / extinct volcanos is much higher than when formed. Large-run-out-landslides will become more frequent. Each one exposing the core of the volcanos to less overburden pressure inducing eruptions. Imagine the sloughing of the north slope of Mt. St. Helens causing its [explosive] eruption.
I can see this as a positive feedback loop. As sea level drops, volcanic islands are more likely to slough, inducing explosive eruptions throwing ash into the stratosphere. The earth cools, there are more severe winters, ice accumulates, dropping sea level further.
Originally in 2012, I focused on the coldest point of the cycle, but I realize now that the mechanism works all the while sea level falls. One island lets go at a 1 meter drop, another blows at 2 meters, still another at 5 meters. So this can help the process of sea level fall, but only if there is evidence of more volcanism during the cooling than during the more rapid warming and sea level rise.
From the National Post Is it volcano season? From Japan to Iceland, scientists probe the reasons why there are so many eruptions lately
Eruptions caused by climate change
In recent decades, it has become apparent that the consequences of planetary ice loss might not end with rising sea levels. Evidence has been building that in the past, periods of severe loss of glaciers were followed by a significant spike in volcanic activity.
Around 19,000 years ago, glaciation was at a peak. Much of Europe and North America was under ice. Then the climate warmed, and the glaciers began to recede. The effect on the planet was generally quite favourable for humankind. But, since the mid-1970s, a number of studies have suggested that, as the ice vanished, volcanic eruptions became much more frequent. A 2009 study, for example, concluded that between 12,000 and 7,000 years ago, the global level of volcanic activity rose by up to six times. Around the same period the rate of volcanic activity in Iceland soared to at least 30 times today’s level.
There is supporting evidence from continental Europe, North America and Antarctica that volcanic activity also increased after earlier deglaciation cycles. Bizarrely, then, volcanic activity seems — at least sometimes — to rise and fall with ice levels. But why? Again, this strange effect might come down to stress.
Eruptions cause by the melting of ice
Ice sheets are heavy. Each year, Antarctica’s loses around 40 billion metric tons of ice. The sheets are so heavy, in fact, that as they grow, they cause the Earth’s crust to bend — like a plank of wood when placed under weight. The corollary of this is that, when an ice sheet melts, and its mass is removed, the crust springs back. This upward flexing can lead to a drop in stress in the underlying rocks, which, the theory goes, makes it easier for magma to reach the surface and feed volcanic eruptions.
The link between climate change and volcanism is still poorly understood. Many volcanoes do not seem to have been affected by it. Nor is it a particularly pressing concern today, even though we face an ice-free future. It can take thousands of years after the glaciers melt for volcanic activity to rise.
Yet while it may not be an immediate hazard, this strange effect is a reminder that our planet can respond to change in unforeseen ways. Contrary to their brutish reputation, volcanoes are helping scientists understand just how sensitive our planet can be.
http://news.nationalpost.com/2014/09/30/is-it-volcano-season-from-japan-to-iceland-scientists-probe-the-reasons-why-there-are-so-many-eruptions-lately/
h/t to reader Cam_S