Will clathrate decomposition cause earthquakes and tsunamis? Can glaciers, or unstable landforms affected by them, be broken up using earthmovers, drains, or explosives to prevent sudden collapse?
A 2009/9/18 Alvia Gaskill <[email protected]>: > I finally understand that the at risk areas, including Newfoundland are at > risk from tsunamis generated from Greenland and Antarctica. The article > below and the previous one were ambiguous on this. There is also a > wraparound effect from tsunamis that was found for the Indonesian one in > 2004, so that while Chile, New Zealand and parts of Canada close to > Greenland would be the most likely impacted, a large enough one would affect > a far larger region. The example closest to home is that of the Blake > Ridge, an undersea formation off the coast of the Carolinas that has large > masses of mud and sediment on a slope. If an earthquake dislodged it, the > tsunami would reach the coast of NC in less than half an hour and Wash. DC > in a only a few hours. As the Blake Ridge is not associated with glaciers, > however, it would not be subject to the kinds of triggering mechanisms > discussed regarding Greenland and Antarctica. > > > ----- Original Message ----- From: "Alvia Gaskill" <[email protected]> > To: <[email protected]>; <[email protected]> > Cc: "Geoengineering" <[email protected]>; "Bill McGuire" > <[email protected]> > Sent: Friday, September 18, 2009 11:07 AM > Subject: [geo] Re: Colloquium report: hazards from global warming > > >> >> The only way that "frequent" volcanic eruptions could cause a warming >> effect >> is if enough CO2 were emitted to change the radiative balance of the >> atmosphere. As this is the Anthropocene and not the Cretaceous, I think >> that unlikely. I still fail to see the risk to or threat from Canadian >> Newfoundland as it has no glaciers and hasn't had any for 8,000 years. The >> use of stratospheric aerosols would have no impact on volcanic eruptions >> or >> earthquakes since it wouldn't increase the amount of ice significantly. >> You >> can't make up for hundreds of years of melting in a few. >> >> I am interested in Song's "experiments" supposedly demonstrating the >> potential of glacial earthquakes to cause tsunamis. Are these the results >> of models or are there field measurements to back them? Once again, my >> call >> for a comprehensive risk assessment of the structural stability of the ice >> sheets. Of course, since we don't seem to give a rip about the stability >> of >> bridges until there is a crack in a major part big enough to see from the >> highway (Oakland Bay Bridge) why am I not surprised no such study has been >> undertaken? And if we did find that a large crack was developing in the >> Greenland or Antarctic Ice Sheets, what would we do about it? This comes >> back to MacCracken's argument about waiting until it's too late to take >> action, my analogy of the patient with diabetes (wait until the heart >> attack >> for intervention) and society's requirement for a crisis before doing >> anything. You can't put the ice back on the ice sheet via enhanced >> precipitation and you sure as hell can't do it once it's floating in the >> water and NYC and London are destroyed. >> >> This just in. Man-made CO2 emissions will not be stabilized in the next >> five years. >> >> >> ----- Original Message ----- From: "Andrew Lockley" >> <[email protected]> >> To: <[email protected]> >> Cc: "Geoengineering" <[email protected]>; "Bill McGuire" >> <[email protected]> >> Sent: Thursday, September 17, 2009 9:02 PM >> Subject: [geo] Re: Colloquium report: hazards from global warming >> >> >>> >>> This raises interesting points about the limits of SRM geoengineering. >>> Perhaps the experts on the list could explain why frequent volcanic >>> eruptions cause a warming effect? Can we be sure that H2S >>> geoengineering techniques we propose cannot result in this 'blowback'? >>> >>> A >>> >>> 2009/9/17 John Nissen <[email protected]>: >>>> >>>> This is a press report on the first day of the Hazards Colloquium, >>>> organised >>>> by Bill McGuire, at UCL, London. >>>> >>>> http://planetark.org/wen/54708 >>>> >>>> Global Warming May Bring Tsunami And Quakes: Scientists >>>> >>>> Date: 17-Sep-09 >>>> Country: UK >>>> Author: Richard Meares >>>> >>>> LONDON - Quakes, volcanic eruptions, giant landslides and tsunamis may >>>> become more frequent as global warming changes the earth's crust, >>>> scientists >>>> said on Wednesday. >>>> >>>> Climate-linked geological changes may also trigger "methane burps," the >>>> release of a potent greenhouse gas, currently stored in solid form under >>>> melting permafrost and the seabed, in quantities greater than all the >>>> carbon >>>> dioxide (CO2) in our air today. >>>> >>>> "Climate change doesn't just affect the atmosphere and the oceans but >>>> the >>>> earth's crust as well. The whole earth is an interactive system," >>>> Professor >>>> Bill McGuire of University College London told Reuters, at the first >>>> major >>>> conference of scientists researching the changing climate's effects on >>>> geological hazards. >>>> >>>> "In the political community people are almost completely unaware of any >>>> geological aspects to climate change." >>>> >>>> The vulcanologists, seismologists, glaciologists, climatologists and >>>> landslide experts at the meeting have looked to the past to try to >>>> predict >>>> future changes, particularly to climate upheaval at the end of the last >>>> ice >>>> age, some 12,000 years ago. >>>> >>>> "When the ice is lost, the earth's crust bounces back up again and that >>>> triggers earthquakes, which trigger submarine landslides, which cause >>>> tsunamis," said McGuire, who organized the three-day conference. >>>> >>>> David Pyle of Oxford University said small changes in the mass of the >>>> earth's surface seems to affect volcanic activity in general, not just >>>> in >>>> places where ice receded after a cold spell. Weather patterns also seem >>>> to >>>> affect volcanic activity - not just the other way round, he told the >>>> conference. >>>> >>>> LONDON'S ASIAN SUNSET >>>> >>>> Behind him was a slide of a dazzlingly bright orange painting, "London >>>> sunset after Krakatau, 1883" - referring to a huge Asian volcanic >>>> eruption >>>> whose effects were seen and felt around the world. >>>> >>>> Volcanoes can spew vast amounts of ash, sulphur, carbon dioxide and >>>> water >>>> into the upper atmosphere, reflecting sunlight and sometimes cooling the >>>> earth for a couple of years. But too many eruptions, too close together, >>>> may >>>> have the opposite effect and quicken global warming, said U.S. >>>> vulcanologist >>>> Peter Ward. >>>> >>>> "Prior to man, the most abrupt climate change was initiated by >>>> volcanoes, >>>> but now man has taken over. Understanding why and how volcanoes did it >>>> will >>>> help man figure out what to do," he said. >>>> >>>> Speakers were careful to point out that many findings still amounted >>>> only >>>> to >>>> hypotheses, but said evidence appeared to be mounting that the world >>>> could >>>> be in for shocks on a vast scale. >>>> >>>> Tony Song of NASA's Jet Propulsion Laboratory in California warned of >>>> the >>>> vast power of recently discovered "glacial earthquakes" -- in which >>>> glacial >>>> ice mass crashes downwards like an enormous landslide. >>>> >>>> In the West Antarctic, ice piled more than one mile above sea level is >>>> being >>>> undermined in places by water seeping in underneath. >>>> >>>> "Our experiments show that glacial earthquakes can generate far more >>>> powerful tsunamis than undersea earthquakes with similar magnitude," >>>> said >>>> Song. >>>> >>>> "Several high-latitude regions, such as Chile, New Zealand and Canadian >>>> Newfoundland are particularly at risk." >>>> >>>> He said ice sheets appeared to be disintegrating much more rapidly than >>>> thought and said glacial earthquake tsunamis were "low-probability but >>>> high-risk." >>>> >>>> McGuire said the possible geological hazards were alarming enough, but >>>> just >>>> one small part of a scary picture if man-made CO2 emissions were not >>>> stabilized within around the next five years. >>>> >>>> "Added to all the rest of the mayhem and chaos, these things would just >>>> be >>>> the icing on the cake," he said. "Things would be so bad that the odd >>>> tsunami or eruption won't make much difference." >>>> >>>> > >>>> >>> >>> > >> >> >> >> > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
