Earthquakes and climate change

[GeoffBeacon]

In the blurb about Bill McGuire's book it says

An astonishing transformation over the last 20,000 years has seen our planet flip from a frigid wasteland into the temperate world upon which our civilisation has grown and thrived. This most dynamic episode in Earth history saw the crust bouncing and bending in response to the melting of the great ice sheets and the filling of the ocean basins; triggering earthquakes, spawning tsunamis and provoking a lively response from the world’s volcanoes. Now there are signs that human-induced climate change is encouraging the sleeping giant beneath our feet to stir once again.

Waking the Giant: How a changing climate triggers earthquakes, tsunamis, and volcanoes
http://www.billmcguire.co.uk/books/waking-the-giant.html

What do we think? Will unloading the polar regions of hundreds of billions of tonnes of ice each year have much of an effect on the Earth's crust soon?

[Lewis C]

Geoff - a couple of points worth mentioning -

Beside his teaching work, Prof McGuire is the director of Aeon Benfield Hazard Research Centre, and his expertise is of a caliber that he runs the vulcanism risk assessment desk for Munich Re, which is one of the largest global re-insurance corporations (who provide insurance to insurers).

Munich Re has built a unique global data-base of 'natural' catastrophes since the early '70s which very clearly shows the rising trend of severe earthquake and volcano events. That trend is not as steep as those for meteorological impacts over the period, but it is very significant.

The continued melting and uneven redistribution of over a trillion tonnes of land-ice per year would thus have consequences that our architecture simply was not built to face.

Regards,

Lewis

[Laurent]

I don't know you but I have a bad feeling, it seems to me we have an increase in tectonic activity around the globe. Not sure if it is normal or not !
We can use this unuse thread to collect the informations on tectonic activity
Recently there was :
A new island near Pakistan
A new island near Fukushima
Etna is growing in intensity
Yellow stone activity is increasing
Some volanoes in Antartica also ...

[wili]

A clever fellow that goes by "prokaryotes" is more or less obsessed with the idea that for various reasons GW may trigger increased tectonic activity. I can't recall whether he is on these threads, but he frequents RC and has his own very good blog (which is mostly about climate science in general--a very impressive collection of sources, that):http://climatestate.com/

I'll see if I can track down one of his posts on this issue in particular.

It seems to me that SLR, in particular, must have some effect on pressure on tectonic plates at some point.

ETA: Here is the particular part of his site where he has collected some relevant videos: http://climatestate.com/category/climate-science/geosphere/geomorphology/

(He used to have a lot of links to actual research papers, but I can't seem to find those on his site anymore.)

(By the way, do you have a link for "A new island near Fukushima"? Do you mean the 'island' of floating debris??)

[Laurent]

I like the posts of Prokaryotes on the blog !
My concern is not only the sea level rise but the building of energy in the oceans !
The climat is a balance between the sun energy and the earth energy, if we put a blanket over the earth the heat will certainly accumulate inside the earth because it cannot escape anymore as it did ! It should take time thought !
http://www.telegraph.co.uk/earth/earthvideo/10464479/Volcano-raises-new-island-off-coast-of-Japan.html

[Shared Humanity]

I have to believe that the melting ice sheets (Greenland and Antarctic) and the subsequent lifting of the earth's crust underneath would trigger a great deal of tectonic activity.

[ccgwebmaster]

I have to believe that the melting ice sheets (Greenland and Antarctic) and the subsequent lifting of the earth's crust underneath would trigger a great deal of tectonic activity.

Or at least some - if memory serves not yet a dominant effect (but it struck me it could potentially effectively fast-forward a certain amount of activity that was in the pipeline anyway). I seem to recall the Wikipedia article was pretty good:

http://en.wikipedia.org/wiki/Post-glacial_rebound

And a little bit in the media - Bill McGuide in the Guardian:

http://www.theguardian.com/environment/2012/feb/26/why-climate-change-shake-earth

This one I recall reading - more of the same but has a bit of a stab at a number:

http://www.theguardian.com/science/2007/aug/07/disasters

The link was most obvious following the retreat of the glaciers around 18,000 years ago, after which sea levels jumped back up to where they are today, triggering a 300% increase in explosive volcanic activity in the Mediterranean in doing so.

With apologies if I duplicated any of those links, I have a vague recollection of posting one or two things about this somewhere back in the distant mists of a year or so ago...

[Laurent]

Scientists find records of rare 'earthquake lights'
http://www.usatoday.com/story/news/nation/2014/01/02/earthquake-lights-rare-phenomenon/4255097/

[AbruptSLR]

I like the following quote from Bill McGuire's book:

"Twenty thousand years ago, Iceland was entirely covered by a layer of ice that averaged close to a kilometer in thickness.  Around 15-16,000 year ago, planetary warming triggered rapid melting of the glaciers, reducing the load acting on the volcanoes beneath and on the underlying asthenosphere.  By 12,000 years ago unloading was sufficiently advanced to trigger a spectacular response.  Over a period of 1500 years or so, the volcanic eruption rate jumped by between 30 and 50 times, before falling back to today's level.  This volcanic rejuvenation was in part a reflection of the release of magma held ready and waiting, within and beneath the volcanoes themselves, but mainly testament to a huge increase in the supply of fresh magma from deeper within the Earth.  Such was the load reduction due to the rapid loss of ice mass, that the depressed lithosphere quickly bounced back by as much as half a kilometer, dramatically reducing the pressures in the asthenosphere and triggering a 30-fold jump in magma production."

If such behavior were to occur in the West Antarctic Ice Sheet, WAIS, (where there are numerous volcanoes and faults and a very thin crust), then the world would experience a significant increase in the rate of SLR.

[Laurent]

Volcanic mayhem drove major burst of evolution
http://www.newscientist.com/article/mg22129522.600-volcanic-mayhem-drove-major-burst-of-evolution.html?cmpid=RSS|NSNS|2012-GLOBAL|environment#.Utp9CaFKHUJ

[Laurent]

Prehistoric North Sea 'Atlantis' hit by 5m tsunami
http://www.bbc.com/news/science-environment-27224243

[Haldir]

I don't know you but I have a bad feeling, it seems to me we have an increase in tectonic activity around the globe. Not sure if it is normal or not !

I recently did an analysis on this because we had had several 7+ quakes in April 2014. I concluded, as I have in the past, that no matter how you slice the data there has been no increase in quakes. I can try to post some data/charts if there is an interest. I think we just hear about more of them now due to the Internet, 24/7 media, etc.

[Laurent]

California Hit With Earthquake Of 6.0 Magnitude
http://www.huffingtonpost.com/2014/08/24/california-earthquake_n_5703959.html

That one doesn't seem to be linked to an earthquake...
Mysterious, Giant Half-Mile-Long Crack Splits Ground In Mexico
http://www.huffingtonpost.com/2014/08/22/giant-crack-in-mexico-video_n_5699362.html

[Laurent]

Earth's tectonic plates have doubled their speed
http://www.newscientist.com/article/mg22329843.000-earths-tectonic-plates-have-doubled-their-speed.html?cmpid=RSS|NSNS|2012-GLOBAL|environment#.VADi-FFJzlc

will that have an effect on climat (more water in the crust than thought) ? Don't know !

[Laurent]

Magnitude-6 Earthquake Hits Northern Pakistan
http://www.huffingtonpost.com/2014/08/31/northern-pakistan-earthquake_n_5743866.html?utm_hp_ref=green&ir=Green

[F.Tnioli]

I don't know you but I have a bad feeling, it seems to me we have an increase in tectonic activity around the globe. Not sure if it is normal or not !

I recently did an analysis on this because we had had several 7+ quakes in April 2014. I concluded, as I have in the past, that no matter how you slice the data there has been no increase in quakes. I can try to post some data/charts if there is an interest. I think we just hear about more of them now due to the Internet, 24/7 media, etc.

There is interest. I have it. Please post data, and please briefly define your conclusions from it.

No offense, but a person who did just a single post expressing disagreement - often gets an extra bit of doubt. But the main reason to ask is, of course, that i am definitely interested in tectonics in the world which has - as being reported in this here topic, - has its continental plates moving twice faster than before. And i thank you in advance for any data you would possibly present, too.

edit: 1 week later, no response to the above... Accordingly, my doubts grow to the point of discarding Haldir's opinion. Sad.

[Laurent]

Sentinel radar satellite tracks continued Napa slip after quake
http://www.bbc.com/news/science-environment-30510268

[Laurent]

Maps: Oklahoma’s earthquake problem is getting worse
http://www.washingtonpost.com/news/energy-environment/wp/2015/02/03/maps-oklahomas-earthquake-problem-is-getting-worse/

[ghoti]

Also note that the quakes have been "moving" north and there are now frequent quakes in Kansas just north of the Oklahoma border or close enough to the border that the closest town used by the USGS to report them is in Kansas. I'd bet you could follow the spread of wells northward to match this.

[dorlomin]

"Extraordinary claims require extraordinary evidence"
A quote from a book is rather ordinary evidence. The vast bulk of the worlds seismic zones are very far from ice sheets. 

[GeoffBeacon]

Dolormin

I haven't seen any work (but I haven't been looking) that shows a reliable increase in global seismic activity yet but why use the "extraordinary claims" epithet here.  More seismic activity is expected as the changing loads from ice and water squeeze the Earth round the equator and relax it at the poles.

And what was your point in saying "The vast bulk of the worlds seismic zones are very far from ice sheets"? ccgwebmaster posted this link earlier http://www.theguardian.com/science/2007/aug/07/disasters

The link was most obvious following the retreat of the glaciers around 18,000 years ago, after which sea levels jumped back up to where they are today, triggering a 300% increase in explosive volcanic activity in the Mediterranean in doing so.

[solartim27]

http://earthsky.org/earth/undersea-volcanic-pulses-might-trigger-climate-swings
Snippet from the article:

Some scientists think volcanoes might act in concert with the well-known Milankovitch cycles – repeating changes in the shape of Earth’s solar orbit, and the tilt and direction of our world’s axis — to produce suddenly seesawing hot and cold periods. The major one is a 100,000-year cycle in which the planet’s orbit around the sun changes from more or less an annual circle into an ellipse that annually brings it closer or farther from the sun.

Recent ice ages seem to build up through most of this 100,000-year cycle; but then things suddenly warm back up near the orbit’s peak eccentricity. The causes are not clear.

Enter volcanoes. Researchers have suggested that as icecaps build on land, pressure on underlying volcanoes also builds, and eruptions are suppressed. But when warming somehow starts and the ice begins melting, pressure lets up, and eruptions surge. They belch CO2 that produces more warming, which melts more ice, which creates a self-feeding effect that tips the planet suddenly into a warm period.

[Gray-Wolf]

Surely there is some kind of 'balance' in this system? While ice sheets are forming mega tonnages of sea water are placed onto land so reducing pressure over ocean volcanic peaks/ridges in the ocean basins ( whilst increasing pressure over land based systems?) so the suppression on land is balanced by increases in activity in the ocean basins?

[Laurent]

If Earth never had life, continents would be smaller
http://news.sciencemag.org/earth/2015/04/if-earth-never-had-life-continents-would-be-smaller

VIENNA—It may seem counterintuitive, but life on Earth, even with all the messy erosion it creates, keeps continents growing. Presenting here this week at the annual meeting of the European Geosciences Union, researchers say it's the erosion itself that makes the difference in continental size. Plant life, for example, can root its way through rock, breaking rocks into sediment. The sediments, like milk-dunked cookies, carry liquid water in their pores, which allows more water to be recycled back into Earth’s mantle. If not enough water is present in the mantle about 100 to 200 km deep to keep things flowing, continental production decreases. The authors built a planetary evolution model to show how these processes relate and found that if continental weathering and erosion rates decreased, at first the continents would remain large. But over time, if life never evolved on Earth, not enough water would make its way to the mantle to help produce more continental crust, and whatever continents there were would then shrink. Now, continents cover 40% of the planet. Without life, that coverage would shrink to 30%. In a more extreme case, if life never existed, the continents might only cover 10% of Earth. When it comes to a habitable planet, life even plays a role in building the habitats.

Climate change will certainly change that...

[foolhardycougar]

There are some deadliest earthquake hit the ground in the past here are some
1 Shensi, China, Jan. 23, 1556
Magnitude about 8, about 830,000 deaths.
2 Tangshan, China, July 27, 1976 Magnitude 7.5
3  Aleppo, Syria, Aug. 9, 1138
Magnitude not known, about 230,000 deaths
4  Sumatra, Indonesia, Dec. 26, 2004
Magnitude 9.1, 227,898 deaths
5 Haiti, Jan 12, 2010
Magnitude 7.0 222,570 people killed
And many more the researchers found one thing in common is that these are not just earthquakes they also have change atmospheric temperature to a certain point. The reason would be the change in Tectonic plate architecture and driving changes in earths elliptical movements around the sun.

[folke_kelm]

I did read through the whole thread now and i have to say, that there are many many misunderstandings and wrongconclusions here.
Please folks, ask geologists about earthquakes and volcanism.
Now it is coincidental that i am geologist, so i am able to provide some facts here.

1. You have to collect the facts about the number of earthquakes and volcanic eruptions.
There are certainly NOT more earthquakes now than for several decades ago. There are very slightly more volcanic eruptions than in the 80ies or 90ies, but well within the natural variability, and consider that 80ies and 90ies have been very low in activity.
You will find the statistics at usgs.gov

2. Munich Re has very good statistics about natural disasters. When you analyse these numbers you will see a rise in costs for all hazards, but Earthquakes and volcanic eruptions are very well correlated with increasing numbers of humans in the risk zones. For climatic risks there is no such correlation, it is much more random, but rising much steeper.

3. Please consider the pressure difference between release due to melting ice caps. the effect of rising sea level is 1013 hektopascal for each 10 m rise. The effect of melting an ice cap is at least 50 times this amount, dependend of how thick the ice cap is. The effect of melting ice caps is very localized meanwhile the effect of sea level rise is dissipated over the whole ocean. Triggering eruptions at deep sea ridges due to sea level fall is very very unlikely, triggering eruptions due to pressure release from ice cap removal is very possible because melting rocks is a function of temperature and pressure (and chemical composition of the rock and fluids), the warmer it is the more melt, the lower the pressure is the more melt you get.

4 according the movement of crustal plates (posted by Laurent august 29 2014) i have not read anything that could verify this claim. The link Laurent provides compares te movement over a time span of 2 Billion years, this has nothing to do with times that span over the whole ice age and it is only one paper.

5 According the quakes in Oregon, moving northward, has again nothing to do with climate change, these quakes are very likely related to injection of fluids into the upper crust for fracking.

All evidence we have according earth quakes an volcanism shows only one effect which is likely to happen, that is increasing volcanism as fast as the pressure is sufficent low to induce melting in a locally existent magma chamber, so it is a very localised process. You can not take Iceland as a reference because it is a very unique localisation with mantle hot spot directly under two intersecting plate boundaries, one as a mid ocean ridge and under thin ocean crust.
The magnitude of pressure release induced volcanism in iceland will certainly noy happen at any location  in Greenland and Antarctica.

[crandles]

What about

And many more the researchers found one thing in common is that these are not just earthquakes they also have change atmospheric temperature to a certain point. The reason would be the change in Tectonic plate architecture and driving changes in earths elliptical movements around the sun.

Change atmospheric temperature? Certainly, but the reason would be sulphates thrown up into stratosphere reflecting incoming sunlight.

"change in Tectonic plate architecture and driving changes in earths elliptical movements around the sun" seems unlikely to me. Toba estimated at 2800 km^3 of eruptive material sounds like a lot but when you compare to 4/3*pi*6371^3 km^3 is it enough to change any sort of wobble in Earth's movements to a measurable amount? Perhaps a tiny fraction of a second change in length of day but even if you change speed of rotation this will affect length of daytime and length of nighttime so that over a year you still get the same ratio (marginally more daytime as sun is bigger than earth). I am less clear about size of any effect on eccentricity, axial tilt, and precession but would presume that any effects on climate would be similarly minuscule such that it would be impossible to detect.

[wili]

More Fatal Earthquakes to Come, Warn Climate Change Scientists

http://www.newsweek.com/nepal-earthquake-could-have-been-manmade-disaster-climate-change-brings-326017.html

“There’s a volcano in Alaska, Pavlov, that only erupts during the autumn and winter. The 10cm or 15cm rise in sea level during the winter months, when low pressure comes over, is enough to bend the crust and squeeze magma out. That’s an example of how tiny a change you need,” he said.

Meanwhile, geologists modelling the effect of retreating ice sheets in the northern hemisphere predict more volcanic activity as pressure is released on fault lines. McGuire points to three eruptions in five years in Iceland – “You can’t say that’s statistical proof but … it makes you think.”

[folke_kelm]

Wili,

the article you provided in your link is a good example for really really bad journalism.
it is full of factual mistakes, wrong conclusions and sensational overdrifts. A reader with knowledge about Geology will clearly notice, that the author does not have the slightest clue abut what he is writing about and that Bill McGuire did not correct the mistakes preprint.

We have to be cautious about attributing climate change to every disaster in the world, especially in regard to this earthquake in the Himalaya. Every Geologist know, that the region is prone to big Earthquakes and this one really was awaited. Climate change is not at all necessary for it to happen.

Regarding the volcano Pawlow, it is McGuires own private hypothesis that a rise of sea level of 10cm will result in eruption. The change is due to change in atmospheric pressure and he does not account to the weight of the atmosphere.
The most important mechanism to trigger eruptions is not increase in pressure to "squeeze out" Magma, but pressure release to induce melt and generating of magma.

[wili]

Thanks for the feedback. So what does explain the pattern of eruptions at Pawlow?

Also, if I can pester you a bit further: It would be helpful if you could point me to a source that would show that influence of CC on seismic activity is unlikely so I could use it elsewhere to point out erroneous beliefs.

[folke_kelm]

Mt Pavlov, 22 eruptions since 1950. Eruptions only during autumn and winter is simply a lie. Look here for example: http://www.volcanodiscovery.com/alaska/pavlov/

regarding influence of climate change to seismicity, it is clearly shown, that huge pressure differences due to removal of ice shields trigger seismic events and volcanism. I will dig a little into the litterature, but be aware of, that there is very little available with "there is no effect". You will have to find rebuttals of papers which show an effect.

Regarding triggering of earthquakes due to increased rainfall it is much more likely that this effect depends on groundwater invading into deeper layers and lubricating these faultlines, if at all. This effect is shown to work if you look at the earthquakes due to fracking in USA.

[ritter]

Regarding triggering of earthquakes due to increased rainfall it is much more likely that this effect depends on groundwater invading into deeper layers and lubricating these faultlines, if at all. This effect is shown to work if you look at the earthquakes due to fracking in USA.

Or injecting water into steam fields to generate geothermal power.

[AbruptSLR]

The linked article discusses the link between increased seismic activity and increasing climate change:

http://www.newsweek.com/nepal-earthquake-could-have-been-manmade-disaster-climate-change-brings-326017.html

[folke_kelm]

ASLR,

This article is shown already some posts earlier in this thread and i wrote some comments about it. IN simple words, this is absolutely bullsh......
many factual errors and some sorry, there is no other word for it...lies.

[AbruptSLR]

ASLR,

This article is shown already some posts earlier in this thread and i wrote some comments about it. IN simple words, this is absolutely bullsh......
many factual errors and some sorry, there is no other word for it...lies.

"There are none so blind as those who refuse to see."

[sidd]

I agree with Mr. folke_kelm : the evidence for climate caused seismic destabilization in the Nepal earthquake is weak at best.

[AbruptSLR]

I agree with Mr. folke_kelm : the evidence for climate caused seismic destabilization in the Nepal earthquake is weak at best.

I concur that not currently credible to point to any particular seismic event (and maybe in particular to the Nepal earthquake) and to say that it is clearly related to climate change.  Also, I concur that the Newsweek article that I linked to contains numerous examples of poor journalism and is clearly not a peer reviewed technical paper.  Nevertheless, if one wishes to focus on the trees, one will remain blind to the forest; and it appears clear to me that climate change related changes in SLR, groundwater levels, de-glaciation, and probably precipitation events, will gradually increase seismic activity with continued global warming.  I have read McGuires' work and he findings (in their original bodies of work and not in a popular news article) are scientifically sound (with appropriate disclaimers & acknowledgement of uncertainties).

Thus will I am not prepared to sift through the misconceptions from the reasonable projections on this topic; in general terms it is clear to me that the topic of this thread is merited.

[sidd]

Another important point is pointed out by Mr. folke_kelm:
"The most important mechanism to trigger eruptions is not increase in pressure to "squeeze out" Magma, but pressure release to induce melt and generating of magma."

To first approximation, SLR loads the crust globally, but deglaciation unloads locally, thus look for this effect under the major ice sheets. We already see Austfonna rumble in Iceland, i wonder about Erebus down south. That is a sulfur generating thing, i seem to remember.

[folke_kelm]

ASLR,

" the topic of this thread is merited. "

Yes it is, but one has to be very carefull not to attribute climate change to processes where we know that there are other much more obvious reasons.
Every volcanic eruption and every earthquake has its own reasons and its own conditions and we have to think twice before we attribute climate change to it.
The role of fluids to geodynamic process is known and in parts we understand it. It is clearly not as simple as it is described in this tread. Fluids as water may increase seismicity as you see in Oregon, but they are able to decrease it too, it depends on local circumstances wether they generate quakes or wether they induce aseismic slip on faults, thus PREVENTING earthquakes or diminishing it.
Articles like this one give a very oversimplified (wrong) picture and discredit science. They create distrust in science and this makes me sad if not to say angry.

[Tor Bejnar]

Most of the 3+ earthquakes in Oklahoma (and many in other fracking localities) can be credited with an anthropomorphic global warming association (and many of the smaller ones, too). The pumped fluids that cause the earthquakes are waste from (mostly) oil and gas extraction processes, and those petroleum products are mostly burned (some escapes into the air, some are used as lubricants or asphalt, etc.), increasing atmospheric CO₂. Increasing atmospheric CO₂, or course, is the driving force for global warming (the current bout, and every previous one, too, only previous bouts weren't anthropomorphic in nature).

There are little earthquakes associated with rockfalls and icefalls.  Climate change has an influence on these, too.

Most of this thread, of course, has to do with processes that change crustal stresses that inhibit or support fault movements and volcanic eruptions. 

[AbruptSLR]

ASLR,

" the topic of this thread is merited. "

Yes it is, but one has to be very carefull not to attribute climate change to processes where we know that there are other much more obvious reasons.
Every volcanic eruption and every earthquake has its own reasons and its own conditions and we have to think twice before we attribute climate change to it.
The role of fluids to geodynamic process is known and in parts we understand it. It is clearly not as simple as it is described in this tread. Fluids as water may increase seismicity as you see in Oregon, but they are able to decrease it too, it depends on local circumstances wether they generate quakes or wether they induce aseismic slip on faults, thus PREVENTING earthquakes or diminishing it.
Articles like this one give a very oversimplified (wrong) picture and discredit science. They create distrust in science and this makes me sad if not to say angry.

folke_kelm,

While I concur with your points, and it would be nice if everyone on Earth was more rigorous & responsible; they are not (which to a large degree explains the underpinning of anthropogenic climate change).  Nevertheless, the Earth Systems are going to do what they are going to do, in response to the forcing that mankind is subjecting it to, even if you manage to prove that some articles are partly wrong and contain some unnecessary alarmism.

I suspect that your sadness/anger has more to do with the social competition between different social groups for control over the common pursue, an the various inaccuracies of different articles.  As I doubt that any policymakers are going to change any of their actions based on any concern whatsoever about increasing seismic activity associated with increasing climate change; I suspect that if you wait patiently, policymakers won't spend any more money than if you are upset; & I am sure that the truth about Earthquakes & climate change will evenly become more obvious to everyone.

Best,
ASLR

[AbruptSLR]

The following links lead to some older articles about the link between seismic activity & climate change:

http://www.worldwatch.org/node/4388

http://www.carbonbrief.org/blog/2012/06/can-climate-change-cause-earthquakes/

http://www.theguardian.com/environment/2012/feb/26/why-climate-change-shake-earth

[Timothy Astin]

ASLR

The Carbon Brief article you link is a balanced piece. It essentially supports folke_kelm's arguments.

The link between earthquakes and volcanic eruptions and climate change is via localised land-ice sheet removal over Greenland and parts of Antarctica.

The link is by pressure release, which can a) locally favour increased magma generation, and by b) isostatic uplift locally increasing earthquakes, almost all of which will be small.

It also draws out how much Prof Bill McGuire overhyped his book on the links, and when challenged retreated to geological othodoxy.


Geological othodoxy is that the incidence of very large earthquakes will continue to be caused overwhelmingly by earth tectonic motions independent of climate change.  The Nepal earthquake is a good example of this.  The epicentre was at about 15km depth. Somew geologists called this "shallow" but only when considering a crustal thickness locally of about 70km. The epicentre was far too deep to be affected by hydrology. And there has been a geological insignificant change in ice-loading in the region in the last 200 years to be a significant contributory factor.  Even if (when?) all the regional Himalayan mountain glaciers disappear, the decrease in ice-loading will be a very small factor for earthquakes compared to the lateral plate tectonic motions in the region.

[folke_kelm]

15 km is indeed a shallow quake, there are quakes generated in the mantle layer more than 100 km deep.
McGuire has his own hypotheses about climate change and geological phenomena like earthquakes, volcanic eruptions and landslides, reaching much longer than the links we do know well.
Climate change does create landslides. It is very much able to cause melt of hot rock, it is able to generate quakes due to unloading and isostatic rebound. All that is well known and monitored in places where it is dangerous for people. If you look at places like Sweden (where i live), Norway (ok, prone to landslides) or Finland you will not see much of this McGuire predictes, and remember, the past is our window into the future.
McGuire does not reach long in the geological society, he is not taken serious in this case (In other cases he is much well renowned as serious scientist). Because of this he writes a book. This strategy is not unknown for scientists with strong ego (other examples are Henrik Svensmark or Ian Plimer (geologist too).
I ordered his book in the library and did a first reading. My conclusions are, that he attributes climate change to phenomena where it is not suitable. It is a reading about catastrophes which would have occured anyway, which always have occured in earth history. Submarine landslides like the storegga landslide in Norway will happen, climate change or not, simply because the continental shelf is unstable, it has ever been and will ever be. The history of sedimentology is full of turbidity currents witnessing about it.
We do not need sensationalistic books or newspaperarticles, we need facts and backup in the scientific litterature. We all are called to educate, especially if we have scientific education and access to papers. We have to get the facts right, to sort the wheat from the chaff.
There is so much more to be concerned about in the field of climate change than these tiny parts McGuire writes about. It is a pity that they make it to the newspapers and bookshelfs. They do it only because the story sells.

[AbruptSLR]

Timothy Astin & folke_kelm,

Unfortunately, I do not have time to parse the questions of what is appropriate behavior for well qualified scientists like James Hansen & Bill McGuire, when writing in the non-peer reviewed literature about the possible risks associated with the "fat-tailed" pdf for climate change.  Thus I will only briefly touch on the following extract from the 2012 Carbon Brief article, which confirms that at that time Bill McGuire was stating his opinion that sea level rise, SLR, by 2100 would be in the 1 to 2m range, while the high end IPCC AR4 SLR projection was on the order of 0.65 to 0.7m.  Since 2012 the IPCC increased their SLR projections by about 50% to now have a high range of about 0.98m; however, the US NOAA Dec 2012 SLR guidance advises that design for a coastal power plant should use 2m of SLR by 2100.  In this regards, it appears to me that Bill McGuire's opinion about possible anthropogenic driven SLR levels by 2100 were much more realistic than the AR4 scientists who choose (intentionally) to err on the side of least drama to the extent as to endanger the general public.  It will be interesting to see how much AR6 increases its SLR rise projections above the AR5 projections.

Both of your posts seem to down play the significance of SLR on future tectonic activity; however, I assure you that 2m of SLR by 2100 is a massive weight redistribution around the world and will definitely impact entire tectonic plate action.

Furthermore, regarding the Nepal event; while it is true that it is currently not feasible to say whether any individual seismic event was or was not influence by anthropogenic behavior, the attached figure shows the GRACE satellite mass change observations from 2003 to 2010; which shows over 3cm of equivalent water height mass differences over the entire Indian Subcontinent in this timeframe alone (& I assure you that the indicated tend has accelerated since 2010), and Nepal is in-between the Northern Plains of India where the groundwater levels have been severely decreased due to extensive pumping (water mining), while some portions of the Tibet have received unusually high snowfall while other portions have experience unusually high de-glaciation.  All of this change in water mass distribution around Nepal has a strong probability of being related to anthropogenic activity and by theory should have an impact on seismic activity in Nepal.

Extract from the 2012 Carbon Brief Article: "McGuire told us in an email:

"We are currently on a high-end emissions scenario track and prospects for getting off this any time soon look pretty bleak [...]. These scenarios are Met Office Hadley Centre scenarios that build in carbon feedbacks, and are - in my opinion - very realistic. In relation to sea level, the consensus now is that a 1 - 2m rise is most likely by 2100."

McGuire is also clearly coming from a particular viewpoint:

"The language used in scientific papers is always careful, but released from the constraints of peer-reviewed journals we are able to express our thoughts in a more personal manner - as James Hansen in the US has done so effectively. My personal opinion is that climate change will be catastrophic - even without any geological response."

Perhaps it's not that surprising that book authors will try and make their work sound exciting. But there are no end of newspapers willing to pounce on catastrophic visions of the future in order to perpetuate the 'it's an apocalypse/it isn't happening' see-saw that makes up the worst end of climate reporting.

McGuire is not shying away from discussing high-end scenarios, which is fair enough. But in our view he should make clear that this is what he is doing, and also more carefully communicate the uncertainty in his work. After all, it appears to be decidedly early days for this research."

While I do concur that most seismic activity is still natural in origin, and the influence of climate change is still on the "fat right-tail" end of the seismic hazard pdf; nevertheless, I believe that it is a mistake to think that society is safe from the potential impacts of abrupt climate change.

Best,
ASLR

[folke_kelm]

ASLR

I think we agree at least in your conclusion: " I believe that it is a mistake to think that society is safe from the potential impacts of abrupt climate change."

But i advise you to do your own calculations. What pressure difference will a sea level change or change of ground water level of 3 cm, 50cm or 1m, 10m create at the depth of shallow or medium deep earthquakes and could these pressuere differences possibly have some influence on the stress field in subductions zones or transform faults?
When you do this calculation you will see it is a very very tiny effect.
Then do the same calculation for an ice shield of 1000 m thickness. This is a totally different story.

I do not downplay any risk of climate change and every time, when i discuss climate change and sea level rise with my colleagues i tend to ask, what we missed, because Paleo sea level shows us, that there must be a missing factor (This is Hansens point of view and i am convinced he is right on this point, we have a huge risk to have 2m at 2100). However i oppose strongly genarealisations.
Risks for slides, quakes and eruptions are strongly located risks with very local factors to have influence on them. I strongly disagree with McGuire about the general seismic risk of sea level rise, i do nat at all disagree with him about the sea level rise itself.
If someone is able to show me a convincing model how sea level rise may contribute to a general risk of seismicity, not only at points where ice sheets are removed, then i will clearly change my mind, but so long no one has provided a mechanism, so long all is pure speculation.
Please understand me right, there are colleagues who are working with risk assessment of landslides in the Alps due to climate change. There is a well understood mechanism and there have already been slides due to warming. But, this is local and well understood.
Every location with risks has its own preconditions where climate change might or might not play a role. Generalisation here might be fatal in this respect that it disqualifies one in the perception of the people we have to target with our arguments.

[AbruptSLR]

ASLR

I think we agree at least in your conclusion: " I believe that it is a mistake to think that society is safe from the potential impacts of abrupt climate change."

But i advise you to do your own calculations. What pressure difference will a sea level change or change of ground water level of 3 cm, 50cm or 1m, 10m create at the depth of shallow or medium deep earthquakes and could these pressuere differences possibly have some influence on the stress field in subductions zones or transform faults?
When you do this calculation you will see it is a very very tiny effect.
Then do the same calculation for an ice shield of 1000 m thickness. This is a totally different story.

I do not downplay any risk of climate change and every time, when i discuss climate change and sea level rise with my colleagues i tend to ask, what we missed, because Paleo sea level shows us, that there must be a missing factor (This is Hansens point of view and i am convinced he is right on this point, we have a huge risk to have 2m at 2100). However i oppose strongly genarealisations.
Risks for slides, quakes and eruptions are strongly located risks with very local factors to have influence on them. I strongly disagree with McGuire about the general seismic risk of sea level rise, i do nat at all disagree with him about the sea level rise itself.
If someone is able to show me a convincing model how sea level rise may contribute to a general risk of seismicity, not only at points where ice sheets are removed, then i will clearly change my mind, but so long no one has provided a mechanism, so long all is pure speculation.
Please understand me right, there are colleagues who are working with risk assessment of landslides in the Alps due to climate change. There is a well understood mechanism and there have already been slides due to warming. But, this is local and well understood.
Every location with risks has its own preconditions where climate change might or might not play a role. Generalisation here might be fatal in this respect that it disqualifies one in the perception of the people we have to target with our arguments.

First, I would like to note that the figure of the Indian Subcontinent mass changes, in my last post, did not show changes in ground water elevation, but rather the water head change of equivalent ponded water height per year.  While this weight change may still be relatively small, it is still good to be accurate.  Also note that the groundwater table is down hundreds of feet in these worse areas (not just 10m).

Second, McGuire's book presents a clear example of the influence of the weight of the increase water (due to SLR) offshore of Los Angeles, California, to pry-open (ie to reduce the compressive stress normal to the fault) the strike-slip fault running through the LA basin; thereby increasing the risk of an earthquake due to the SLR (as you check the book out of the library take a look).  While this is only one location, there must be other comparable cases around the world, where seismic risk will increase due to SLR.

Third, do not forget that a 2m SLR by 2100 would redistribute weight around the world to the extent that the rotational axis of the Earth will tilt; which when combined with the current rapid change of the Earth's magnetic poles; could combine to temporarily cause increased tectonic activity between now and 2100.

Hopefully, Earth System Models will advance sufficiently in the next ten to twenty years to gain a clearer understanding of the implications of such considerations.

ASLR

[wili]

Yeah, I don't see how one can completely rule out such effects playing a role at some point.

But I'm mostly interested in the seismic effects on the lands under the major ice sheets (GIS, WAIS, EAIS) as these sheets loose more and more mass. Are those areas just not susceptible to earthquakes, or could we see increases in seismic activity there that could accelerate the destruction of those sheets--a sort of feedback?

[AbruptSLR]

wili,

Some of the considerations that you are interested in are addressed in the "Antarctic Tectonics" at the following link:

http://forum.arctic-sea-ice.net/index.php/topic,393.0.html

Furthermore, Reply #97 of the "Surge of WAIS Ice Mass Loss" thread at the following link discusses the Chen et al 2013 paper (see the linked free pdf) about how rapid glacial ice melting is driving Earth's rotational pole to the East (see the first three attached images); which, when coupled with the Moon's gravity results in changes to gravitational stresses on tectonic plates.

http://forum.arctic-sea-ice.net/index.php/topic,21.50.html

Chen, J.L., C.R. Wilson, J.C. Ries, B.D. Tapley, Rapid ice melting drives Earth's pole to the east, Geophys. Res. Lett., Vol. 40, 1-6, DOI: 10.1002/grl.50552, 2013

ftp://ftp.csr.utexas.edu/pub/ggfc/papers/grl50552.pdf

Also, the following paper by Chen et al 2014 shows that the yearly change in the groundwater depletion in Northwest India amounts to many gigatonnes per year (see the linked free pdf).

Chen, J.L., J. Li, Z.Z. Zhang, S.N. Ni, Long-Term Groundwater Variations in Northwest India From Satellite Gravity Measurements, Global and Planetary Change, Vol. 116, 130-138, doi: 10.1016/j.gloplacha.2014.02.007, 2014.

ftp://ftp.csr.utexas.edu/pub/ggfc/papers/2014GPC_NWI_Groundwater.pdf

See also:

http://www.csr.utexas.edu/personal/chen/publication.html

Best,
ASLR

[AbruptSLR]

Yeah, I don't see how one can completely rule out such effects playing a role at some point.

But I'm mostly interested in the seismic effects on the lands under the major ice sheets (GIS, WAIS, EAIS) as these sheets loose more and more mass. Are those areas just not susceptible to earthquakes, or could we see increases in seismic activity there that could accelerate the destruction of those sheets--a sort of feedback?

wili,

Especially see Reply #69 of the "Antarctic Tectonics" thread

http://forum.arctic-sea-ice.net/index.php/topic,393.50.html

The linked reference (and associated attached image) provides the first evident that remote earthquakes (i.e. Chile) can trigger icequakes in Anatarctica:


Zhigang Peng, Jacob I. Walter, Richard C. Aster, Andrew Nyblade, Douglas A. Wiens & Sridhar Anandakrishnan, (2014), "Antarctic icequakes triggered by the 2010 Maule earthquake in Chile", Nature Geoscience, doi:10.1038/ngeo2212


http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2212.html


Abstract: "Seismic waves from distant, large earthquakes can almost instantaneously trigger shallow micro-earthquakes and deep tectonic tremor as they pass through Earth’s crust. Such remotely triggered seismic activity mostly occurs in tectonically active regions. Triggered seismicity is generally considered to reflect shear failure on critically stressed fault planes and is thought to be driven by dynamic stress perturbations from both Love and Rayleigh types of surface seismic wave. Here we analyse seismic data from Antarctica in the six hours leading up to and following the 2010 Mw 8.8 Maule earthquake in Chile. We identify many high-frequency seismic signals during the passage of the Rayleigh waves generated by the Maule earthquake, and interpret them as small icequakes triggered by the Rayleigh waves. The source locations of these triggered icequakes are difficult to determine owing to sparse seismic network coverage, but the triggered events generate surface waves, so are probably formed by near-surface sources. Our observations are consistent with tensile fracturing of near-surface ice or other brittle fracture events caused by changes in volumetric strain as the high-amplitude Rayleigh waves passed through. We conclude that cryospheric systems can be sensitive to large distant earthquakes."

Also see:

http://www.cbsnews.com/news/distant-earthquake-triggers-icequake-in-antarctica/

But in the same Antarctic Tectonics folder also see Replies: #18-19, #28-29, #34-40; #48-65 and #69-72

Best,
ASLR