Guest post by Steven Goddard
Scientific American has reported that global warming may cause an increase in volcanic eruptions, due to increased magma formation at lower pressures as glaciers melt.
This caught my attention because I used to work as a volcano researcher and igneous petrologist.
That report said that about 10 percent of Iceland’s biggest ice cap, Vatnajokull, has melted since 1890 and the land nearby was rising about 25 millimetres (0.98 inch) a year, bringing shifts in geological stresses.
They estimated that the thaw had led to the formation of 1.4 cubic km (0.3 cubic mile) of magma deep below ground over the past century.
At high pressures such as under an ice cap, they reckon that rocks cannot expand to turn into liquid magma even if they are hot enough. “As the ice melts the rock can melt because the pressure decreases,” she said. Sigmundsson said that monitoring of the Vatnajokull volcano since 2008 suggested that the 2008 estimate for magma generation was “probably a minimum estimate. It can be somewhat larger.”
Interesting theory, but does it work quantitatively? Magmas, as with most solids, do show a direct relationship between the melting point and pressure. As the pressure increases, so does the melting point. (Ice is a noticeable exception to this, and shows an inverse relationship. The reason that people can ice skate is because the pressure under the blade creates a thin later of melted ice which lubricates the surface.
Below is a phase diagram of a basaltic magma similar to that found in Iceland, showing the relationship between temperature and pressure. The melting temperature does decrease at lower pressures. From 100 km depth to 0 km the melting point drops about 300°C. That is about 3°C / km. Ice is about one third as dense as basaltic magma, so the loss of 1 km of ice lowers the melting point by about 1C, or less than 0.1%.
More precisely, this study from the Carnegie Geophysical Institute did an empirical measurement of the relationship for one basaltic mineral – diposide. They found the relationship to be
Tm = 1391.5 + 0.01297 * P
Where Tm is the melting point in degrees C and P is the pressure in atmospheres. One atmosphere pressure is equal to about 10 metres of ice, so one additional metre of ice increases the melting point by about 0.0013°C. The loss of 100 metres of ice would therefore lower the melting point by about one tenth of a degree. The thickest ice in Iceland is only 500 meters thick, so complete loss of all ice would only alter the melting point by about 0.5°C, or less than 0.05%.
The geothermal gradient of the earth is typically about 40°C per km, so a 0.5°C change in temperature is equivalent to a depth change of about 20 metres. Near mid-ocean ridges this gradient is steeper, so the equivalent depth change in Iceland would be less than 20 metres. Is it credible that a 0.5°C decrease in the melting point could stimulate excess volcanic activity? Short answer – no. Volcanic activity is caused by magma rising to the surface, not glaciers melting. However, the loss of the glaciers would reduce the amount of steam and ash generated. Ash is formed when magma is cooled and fractured by steam. So the loss of the glaciers would reduce the size of the steam/ash cloud and make the Iceland volcanoes behave more like Hawaii volcanoes.
In short, the loss of all ice in Iceland would make the volcanoes less destructive.
BTW – On Al Gore’s planet, the geothermal gradient is much higher, with core temperatures averaging millions of degrees.
http://www.youtube.com/watch?v=ag2AWst3Qv4
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In 2000 the Guardian said the largest glacier would be gone in 5 years – it hasn’t changed much in 10 years.
For an examination of Iceland climate data, volcanoes and glaciers, including the Guardian’s old claim, see:
http://www.appinsys.com/globalwarming/RS_Iceland.htm
Which is the source (and cause) of these hot spots?:
http://weather.unisys.com/surface/sst_anom.html
A US volcano with a clear “political spin”(clearly a subversive “tea bagger”) emitting tons of CO2 , a “civil desobedience” of EPA regulations?:
http://volcanoes.usgs.gov/lvo/activity/monitoring/co2.php
If you see the following images you´ll find them sinful:
Plasma and volcanoes: http://geoplasma.spaces.live.com/blog/cns!C00F2616F39D0B2B!152.entry
@Steve Goddard,
The ice-skating question has been an interesting area of popular physics research over the last century or more. Michael Faraday, Lord Kelvin, and J. Willard Gibbs, three of the biggest names in the history of Physics, were actively involved with this question, and experimentally proved the “pressure-melt” hypothesis wrong. Modern research has confirmed Faraday’s hypothesis of a liquid “pre-melt” layer on top of the ice, which is what permits skating (and skiing, for that matter) down to about -30 C. There are MRI images, X-ray diffraction patterns, and AFM (Atomic Force Microscopy) images that absolutely confirm this hypothesis.
Sorry about the use of the term myth, but what do you call something that’s taught in textbooks as truth, but is clearly either extremely oversimplified, or just outright wrong? There has been clear, compelling research (with actual data and methodology published, see above) showing that it’s NOT pressure melt that causes a water film to form under ice skates allowing ice skating to occur. Rosenberg’s article is the definitive summary on this, and the incontrovertible, factual evidence is that the maximum pressure generated by skates on ice is about 470 atm, enough to depress freezing point by ony about 3.5C, which would make skating impossible below that temperatures without the liquid “pre-melt” layer on top of the ice. The pre-melt layer is what makes it so slippery walking on ice with leather-soled dress shoes (check NHL coaches), too, and allows the puck to slide.
I’m not trying to be obnoxious or belligerent here. You stumbled on a field I happen to know very well from my own research and teaching. I was just trying to set you straight. I’ve heard it said that no good deed goes unpunished and I may be experiencing just that…
Your analogy has nothing really to do with your main point, which is excellent. Holding on to an analogy that is clearly false only hurts your credibility, something I would rather not see happen, since I agree with your position on the glaciers and volcanos.
Please read the Rosenberg article and just change the analogy. I would have sent both replies by email had I known how. I hope the public exchange hasn’t hardened you into an unreasonable defense of your position.
Sincerely and respectfully.
Nice comment Mike Odin! I was thinking that too , the socialist banking “reforms” have really hurt a lot of people, I think it was the first leg of the plan that includes the AGW/ CO2 scam to reduce us all to serfdom (as my last name is Edwards I will not go back there)
Its getting more ridiculous!
Just caught a report on CTV (Canadian) in which the reporter explained that this volcano will keep erupting until the ice around it melts!!!
Seems this intrepid reporter has discovered a previously unknown cause and effect relationship that is bound to have profound implications.
By 2050 or 2030 or 2100 or whenever, when the world is 7 or 2 or 12 degrees warmer and all the ice is gone and Manhattan is a marine park, we won’t have to worry about volcanoes.
LOL.
Sorry for being redundant but Scientific American revealed itself as a purveyor of politicized junk science with their concerted and unprecedented attack on Bjorn Lomborg’s book The Skeptical Environmentalist a few years back.
They are the kind of publication Mann and Jones approve of.
Don’t know about the ice skate thing. I always had four pairs. two pairs of speed skates, (width about 1.5mm & flat ground with a whetstone), one pair hockey skates hand ground to be almost knife edged for extreme stuff, (Never slipped sideways unless I leant over so much the boot lifted the blade off the ice, groove almost half width of blade), & one pair hockey skates shallow ground for more general use.
The deep ground blades were the slowest although that may in part be due to heavy ‘rocker’ grind where the lengthwise profile was like a rocking chair rocker.. I’m inclined to think the popular explanation is incorrect.
DaveE.
link from USGS site (http://earthquake.usgs.gov/earthquakes/world/?regionID=58)
Geology and geodynamics of Iceland
R.G. Trønnes, Nordic volcanological Institute, University of Iceland
http://www2.norvol.hi.is/Apps/WebObjects/HI.woa/1/swdocument/1006551/Introduction+to+Geology+and+geodynamics+of+Iceland+-+Reidar+Tršnnes.pdf
page 9: Crustal thickness under Vatnajökull is approximatly 40 km.
page 7: Earthquake patterns
After reading all of the theories (er, hypotheses) expressed above about why ice skates work, I tried my own experiment using an ice cube taken from the tray under the ice-maker in my refrigerator. (They no longer look like cubes, but that’s immaterial — lets call it an ice polygon, or I-P for short.) So I laid my I-P on its side atop a multi-folded-up paper towel to insulate it from the Formica counter-top and applied the back side of a stainless-steel dinner knife pressing down as hard as I could.
In less than a minute, the back of the blade had formed a deep groove in my I-P, and I thought maybe the ice-skaters had it right — all it took was some heavy pressure on a thin blade. But then I thought I should not have used a knife at room temperature and should repeat the experiment after cold-soaking my knife in the ice-maker tray.
About an hour later, I retrieved the knife but it was too cold to hold and I had to wrap it in several layers of paper toweling before I could press the back of the blade once again on a new frigid piece of I-P. But this time, pressing as hard as I could, there was no groove formed under the back of the blade. So I turned the knife over and applied pressure using the sharp blade. Still hardly a groove could be formed!
From results of this experiment I concluded that ice-skating works better if the blade is slightly warmer than the ice, and I presume it will be so as the skater’s blades travel through the ambient air following each stroke. It is also possible that AGW would benefit this process, but so would GW that is non-A.
Just The Facts (08:46:28) :
We should also come up with a plan and resources to help our farming sector to rapidly adjust to a sudden change in climate.
Absolutely. And last, but not least, we should stop the crazy projects to turn food into fuel, especially US corn ethanol, which has a questionable net effect on climate gases anyway.
Just The Facts (21:15:14) :
“Looking at the picture of the venting volcano above it seems clear that volcanic activity is a driver of climate change that we must take very seriously. While we don’t know when, it is just a matter of time before a very large volcanic eruption, or possibly a cluster of big ones, causes an episode of rapid cooling like the year without summer:
http://en.wikipedia.org/wiki/Year_Without_a_Summer
We are very unprepared for this type scenario. Shouldn’t we be diverting some of our limited resources, including some of our good climate scientists, over to researching and preparing for an inevitable rapid catastrophic volcanic cooling episode? Solar panels aren’t going to be much help when millions of people are starving to death due to crop failures…
REPLY
“They” already have that covered. /Sarc
Beginning in 1973, policy changes promoted by Nixon Secretary of Agriculture Earl Butz deregulated the corn market. He dismantled supply management policies, selling off government storage bins used as food security reserves…. Butz and agribusiness giant, Cargill, along with the Farm Bureau argued that farm prices crashing would be a positive because they would be remedied by more exports and new uses such as ethanol and corn sweeteners. The 1996 Freedom to Farm Act [written by Cargill VP Dan Amstutz] represented the culmination of this “free market” ideology by calling for the elimination, over 7 years, of all price floors and grain reserves.” http://www.nffc.net/Learn/Fact%20Sheets/King%20Corn%20Fact%20Sheet.pdf
Here are the results
“In summary, we have record low grain inventories globally as we move into a new crop year. We have demand growing strongly. Which means that going forward even small crop failures are going to drive grain prices to record levels. As an investor, we continue to find these long term trends..very attractive.” Food shortfalls predicted: 2008
“Recently there have been increased calls for the development of a U.S. or international grain reserve to provide priority access to food supplies for Humanitarian needs. The National Grain and Feed Association (NGFA) and the North American Export Grain Association (NAEGA) strongly advise against this concept”
July 22, 2008 letter to President Bush
Riots from Haiti to Bangladesh to Egypt over the soaring costs of basic foods have brought the issue to a boiling point and catapulted it to the forefront of the world’s attention, …
“The finance ministers were in shock, almost in panic this weekend,” he said on CNN’s “American Morning,” in a reference to top economic officials who gathered in Washington. “There are riots all over the world in the poor countries … ” April 14, 2008 – Riots, instability spread as food prices skyrocket
“May 1, 2008 … Today, says USDA Undersecretary Mark Keenum, “Our cupboard is bare.” U.S. government food surpluses have evaporated….. “
Surplus U.S. food supplies dry up – USA TODAY
Ten corporations are busy consolidation a strangle hold on the world food supply. The bogus “Food Safety Bills” here in the USA were supposed to finish wiping out independent farming in the USA. One bill would even “regulate” home veggie gardens!
If you want the real story behind the how the CED deliberately has been wiping out independent farmers in the USA and exporting the techniques to other countries check out
History, HACCP and the Food Safety Con Job It is very well researched.
RE: pwl (06:02:18) : [Eyjafjallajokull]
For the Microsoft Voices Sam or Anna:
a’ya vill lev vich’k
seems to give results that approximate your audio file.
RE: Espen (15:30:48) : “… we should stop the crazy projects to turn food into fuel,”
If we ever have a major killing famine develop, such as might be caused by a major eruption of the Yellowstone Supervolcano, I think we could very well be forced into a desperate crash program to turn fuel [coal] into food.
As of a couple of weeks, ago, we had over 7 Billion Bushels of Field Corn in Storage. Corn was selling for $3.50/bu, or just a touch over $0.06/lb.
None of the food situations around the world in 2008 could, even remotely, be connected to Field Corn grown in the U.S.
Shame on you, Gail.
Hello…..?
Doesn’t this ‘story’ then serve as yet another example of NEGATIVE FEEDBACK that the IPCC et al failed to account for in their models?
Herewith more on our WeatherAction long range forecast of ongoing Volcano impacts on European airspace.
FLIGHT PROBLEMS LIKELY TO CONTINUE TO 26th APRIL WARN LONG RANGE FORECASTERS
Piers Corbyn of WeatherAction long range Weather, Climate & solar impact forecasters warns their long range European wind maps & predictions of likely solar effects on Iceland volcano spell ongoing trouble for airspace
http://bit.ly/cPh4YT
Kum Dollison (17:55:49) :
As of a couple of weeks, ago, we had over 7 Billion Bushels of Field Corn in Storage. Corn was selling for $3.50/bu, or just a touch over $0.06/lb.
None of the food situations around the world in 2008 could, even remotely, be connected to Field Corn grown in the U.S.
Shame on you, Gail.
REPLY:
I did not want to get into the LONG explanation but here goes.
These are the key points:
July 26, 2002: Report Finds Fundamental Flaws in WTO’s Agreement on Agriculture: “Institute for Agriculture and Trade Policy report argues that the Agreement on Agriculture fails to account for agri-business’ monopoly over global agricultural trade.” http://www.socialfunds.com/news/article.cgi/891.html
2002 Effect of policies on farmers in USA and Mexico: Between 1995 and 2000, the prices US farmers receive for corn declined 33 percent, 42 percent for wheat, and 34 percent for soybeans. No wonder that since NAFTA went into effect 33,000 small farmers in the US have gone out of business— more than six times the pre-NAFTA rate. In Mexico, the price farmers receive for corn has plummeted 45 percent At least 1.5 million farmers have left their land. 900,000 people leave Mexico’s land every year, a U.N. program says. According to a study by Jose Romero and Alicia Puyana carried out for the federal government of Mexico, between 1992 and 2002, the number of agricultural households fell an astounding 75% – from 2.3 million to 575, 000 http://www.globalexchange.org/campaigns/ftaa/topten.html
INDIA:
Farmer suicides in India: Now the full toll—surely among the largest sustained waves of suicides in human history—is becoming apparent. And as Sainath emphasizes, these numbers still underestimate the disaster, since women farmers are excluded from the official statistics… It is important that the figure of 150,000 farm suicides is a bottom line estimate…. “Overall,” says Professor Nagaraj, “there exists since the mid-90s, an acute agrarian crisis. That’s across the country. In the Big Four and some other states, specific factors compound the problem…. Cultivation costs have shot up in these high input zones, with some inputs seeing cost hikes of several hundred per cent… Meanwhile, prices have crashed, as in the case of cotton, due to massive U.S.-EU subsidies to their growers. All due to price rigging with the tightening grip of large corporations over the trade in agricultural commodities.” http://alternatives-international.net/article1394.html
http://www.counterpunch.org/sainath02122009.html
1986 Global commodity prices slumped in the mid eighties, triggering a five fold increase in farm subsidies in the USA and the EU subsidy to double. Pressure from commodity exporters inspired a decision to pursue Agricultural Policy reform at Uruguay round of GATT. It was lead by Under Secretary of Agriculture Dan Amstutz. http://books.google.com/books?id=0VyUe1kMc2wC&pg=PA68&lpg=PA68&dq=Daniel+Amstutz+Undersecretary+of+Agriculture,+1986&source=bl&ots=g_NvagIp9r&sig=iNU3jWVgC7LkAjkzuSQt6LyINfI&hl=en&ei=XF-gSavhGY-EtgeXjZz_DA&sa=X&oi=book_result&resnum=2&ct=result#PPA68,M1
Launched in 1986, the General Agreement on Tariffs & Trade (GATT) Uruguay Round of international trade talks has been dominated by a confrontation between the US and the EC over farm policy reform. Both sides proclaim their commitment to devising a GATT regime which will bring an end to the anarchy in world agricultural markets, yet neither is willing to address the underlying cause of the present malaise: structural over-production in their own farm sectors and the resulting accumulation of surpluses. The use of export subsidies to put these surpluses on to world markets caused developing countries severe trade and food security problems in the 1980s; and a Uruguay Round deal is unlikely to bring any relief. What it will do, however, is introduce new regulations which, enshrined in international trade law, will restrict the right of developing countries to manage their own food systems. Most importantly, the use of trade measures to control food imports and price support measures to promote staple food production could be severely constrained, or banned, by a ‘farm superpower’ GATT agreement. http://www.informaworld.com/smpp/content~content=a769339885~db=all
Trade Related Aspects of Intellectual Property Rights (TRIPS) introduction of intellectual property rules on plants, animals and seeds under WTO’s Agreement “could damage the livelihoods of these 1.4 billion farmers worldwide and undermine food sovereignty and food security ” Joint Communication from the African Group to the Council for Trade-Related Aspects of Intellectual Property Rights (2003) http://www.fao.org/docrep/007/y5714e/y5714e07.htm
U.S. Corn Trade
The United States is the world’s largest producer and exporter of corn. Corn grain exports represent a significant source of demand for U.S. producers and make the largest net contribution to the U.S. agricultural trade balance of all the agricultural commodities, indicating the importance of corn exports to the U.S. economy. On average, corn grain (excluding popcorn or sweet corn) accounted for approximately 11 percent of all U.S. agricultural exports by value during the 1990s. In 2008, due to record exports of corn and other feed grains, that share grew to over 12 percent of the U.S agricultural export value. http://www.ers.usda.gov/Briefing/corn/trade.htm
The manipulation of corn and grain by the grain traders has forced independent farmers out of business here in the USA and in other countries.Thanks to tax payer dollars Cargill et al buy US corn at under the cost of production in the USA and Europe and sell at a lower price in other countries. This has forced farmers out of business. When there is a short fall like in 2008 their are no local independents to meet the demand. Both Cargill and Monsanto posted record high earning in 2008.
If you can make the statement you made I strongly suggest you find out what is happening to your food supply. As I stated above Nicole Johnson wrote a very well researched article (referances are about 1/2 the article) at http://www.opednews.com/articles/History-HACCP-and-the-Foo-by-Nicole-Johnson-090906-229.html
The food safety bills originated in the January 2005: Guide to good farming practices: This draft guide to good farming practices for animal production food safety was taken from the Report of the Meeting of the OIE Terrestrial Animal Health Standards Commission (Paris, 17-28 January 2005) http://www.oie.int/boutique/extrait/25berlingueri823836_0.pdf?PHPSESSID=64969a28688594daf57a7263f42fb1ce
The first try to make it law in the USA was the 2005 Bill: Safe and Secure Food Act http://www.govtrack.us/congress/billtext.xpd?bill=s109-1534
I have thirteen pages of similar references on the take over of the World Food supply if the above do not convince you.
How about June 2006 – The Global Diversity Treaty: Standard Material Transfer Agreement (SMTA) a standardized contract that will enable much easier access to crop diversity. [ germplasm for patenting] royalty payment (1.1% of sales) is paid only if product is unavailable for further breeding and research. funds will be devoted to conservation efforts. Translation: Bio-techs Corporations steal seed from third world farmers, patents it and pay money to Bioversity International http://www.bioversityinternational.org/publications/pdf/1144.pdf
Followed by April 2007 – Monsanto, Cargill and Maseca-ADM sign agreements to establish regional seed banks in the center and south of Mexico. http://www.counterpunch.org/ross11212007.html
Surely you’re joking, Mr. Freysteinn!
Iceland’s peachfuzz hoarfrost doesn’t weigh down the earth much. Some Icelandic egos seem to have reached the point of gravitational singularity, though. It might have something to do with all that press Jules Vernes gave them in Journey to the Center of the Earth. Things grow slowly on Iceland, including megalomania. They’ve got the elves, but the big fat man in the red suit is over in Greenland, where they have real ice, unlike Iceland’s semi-seasonal frost strata. Bah.
Piers Corbyn (20:22:50) :
I’ll be keeping an eye on your volcano forecasts, but I am extremely skeptical ……
Steve, how does the change in pressure from melting 500m of ice compare with moon tidal pull. Also,since the magma is already erupting below the ice, fracturing reaches the surface already. The ice would appear to be more vulnerable to the elevated geothermal temp below it than 1-2C air temp inc-
If you have something that has been strained almost to its breaking point, it seems to make sense that any sudden small stress increase may cross the line and trigger a cascading fracture. I note that many earthquakes seem to occur when the sun and the moon are in-line — full moon or dark of the moon. That is when earth is seeing its highest tidal stresses for any given two-week period.
When Mt. St. Helens was acting up I recall noticing that many of these eruptions seemed to occur just after an indicated high tide on the Puget Sound daily tide calendar.
GaryPearse (07:08:53) :
Tides are typically few feet, so I would imagine that the loss of 500 metres of ice would have a larger long term effect, though tides happen much more quickly.
Have a look at the Potential Temperature animation, in “Tropopause (NH)” on this site,
and see the blob of very warm air hit Iceland on the 13/14th April.
http://www.pa.op.dlr.de/arctic/index.html
Doug in Seattle (12:28:39) :
“Volcanism in Iceland is driven by oceanic plate spreading, not isostatic response to ice unloading (or fracturing in response to it). The magnitude of the extensional stresses associated with plate spreading, even on a local scale, such would be in pay in Iceland, simply dwarf those associated with the small amount of unloading that could be associated with ice loss in the past century”
Yes the fractures are already there and they spread repeatedly giving access to low pressure at the surface. A common phenomenon is the eruption below an ice sheet that gives a flat-topped, steep sided volcano know as a “tuya”. I recall a smart wag many years ago exclaiming that this is the origin of the phrase “What’s a Tuya?” meaning “What do you care about it?”
“lgl (10:39:55) :
Ulric Lyons (04:46:35) :
The eruptions are primarily due to temerature differentials, as with all eruptions. A very cool month or so followed by a strong uplift in temperature is what triggers volcanic activity.
I find it more likely that there is a common cause behind the two. Change of Earth’s rotation for instance.”
I don`t. LOD is also controlled by temperature change, not visa versa.