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Unread 09-02-2011
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Default Rapid Deglaciation as an initiator of volcanic activity

http://dash.harvard.edu/bitstream/ha...pdf?sequence=1

Quote:
An evaluation of the historical record of volcanic eruptions shows that subaerial volcanism increases globally by two to six times above background levels between 12 ka and 7 ka, during the last deglaciation. Increased volcanism occurs in deglaciating regions. Causal mechanisms could include an increase in magma production owing to the mantle decompression caused by ablation of glaciers and ice caps or a more general pacing of when eruptions occur by the glacial variability.
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If such a large volcanic output of CO2 occurs, then volcanism forges a positive feedback between glacial variability and atmospheric CO2 concentrations: deglaciation increases volcanic eruptions, raises atmospheric CO2, and causes more deglaciation.
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Evidence has also accumulated that short-term changes in weather and environment influence volcanism: the subtle variations associated with Earth's tides (Johntson and Mauk, 1972; Hamilton, 1973; Sparks, 1981), daily variations in atmospheric pressure and temperature (Neuberg, 2000), seasonal changes in water storage (Saar and Manga, 2003; Mason et al., 2004), and other short-term changes in the environment (Kennett and Thunell, 1975; Rampino et al., 1979; Dzurisin, 1980) have all been implicated as influencing the timing of volcanic eruptions.
This implies the eath's crust is far more sensitive than I realised. The relationship between deglaciation and volcanic activity is not new
http://onlinelibrary.wiley.com/doi/1...ly+maintenance
Quote:
Volcanic activity on sub-Antarctic Marion Island is found to have occurred only during the interglacials. The present volcano distribution is associated with a radial and peripheral fault system, the location of which appears to be related to the former glacier distribution. An hypothesis is presented suggesting that the faulting is a result of deglaciation and that the specific location of the faults is due to the differential stresses occurring between ice-covered and ice-free areas during isostatic uplift. The faulting initiates volcanism due to the location of the island within a volcanic region.
It has been discussed before on Manpollo, but has it been included in the climate models? No, I cannot show how that could be done.

http://rsta.royalsocietypublishing.o...1919/2317.full
Potential for a hazardous geospheric response to projected future climate changes
B. McGuire*

Quote:
Periods of exceptional climate change in Earth history are associated with a dynamic response from the geosphere, involving enhanced levels of potentially hazardous geological and geomorphological activity. The response is expressed through the adjustment, modulation or triggering of a broad range of surface and crustal phenomena, including volcanic and seismic activity, submarine and subaerial landslides, tsunamis and landslide ‘splash’ waves, glacial outburst and rock-dam failure floods, debris flows and gas-hydrate destabilization. In relation to anthropogenic climate change, modelling studies and projection of current trends point towards increased risk in relation to a spectrum of geological and geomorphological hazards in a warmer world, while observations suggest that the ongoing rise in global average temperatures may already be eliciting a hazardous response from the geosphere.
My bolding
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A link between past climate change and enhanced levels of potentially hazardous geological and geomorphological activity is well established.......Rapid planetary warming promoted a major reorganization of the global water budget as continental ice sheets melted to replenish depleted ocean volumes, resulting in a cumulative sea-level rise of ca 130 m.
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The effects of anthropogenic climate change will be greater and more rapidly apparent at high latitudes. The potential for triggering geological and geomorphological hazards is also elevated, most notably as ice mass is lost from the great ice sheets, smaller ice caps and individual glaciers and ice fields. In Greenland and Antarctica, isostatic rebound as ice mass is reduced may result in increased seismicit
Stands to reason
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Maslin et al 2010 note that isostatic rebound of Greenland and Antarctica may also involve adjacent continental slope, thereby reducing pressure on any gas hydrates contained in slope sediments, raising the chances of hydrate breakdown
Ooops, that does not sound good.
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Projected temperature rises for high latitudes will affect smaller ice caps, ice fields and glaciers more rapidly than the major ice sheets. Of these, the Vatnajökull ice cap (area ca 8000 km2) (figure 4) in Iceland presents the greatest threat in relation to the resultant triggering of a potentially hazardous geospheric response
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An increase in climate-change-driven, non-volcanic, mass movements at high latitudes may already be apparent. Huggel (2009) and Huggel et al. (2008, 2010) speculate that rising temperatures may be behind a recent series of major (volumes in excess of 106 m3) rock and ice avalanches in Alaska.
You won't see Fox reporting that connection
Quote:
Evidence from the study of periods of exceptional climate change, together with contemporary observations, supports a robust link between changing climatic conditions and a broad portfolio of potentially hazardous geological and geomorphological processes. Modelling studies and the projection of current trends argue for elevated levels of a range of geological and geomorphological hazards in a warmer world, while viable physical mechanisms capable of eliciting a geospheric reaction in response to small changes in environmental conditions are well established. Questions remain, however, most particularly in relation to the time scales over which a geospheric response may be detectable
Robust link, means they are pretty sure now. We can already detect the geomorphical response but there are still uncertainties.

OK so you already knew some of this but we like the peer reviewed stuff. If you look at McGuires paper there are many links on it. It is not just Hall's hypothesis now.
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Unread 02-26-2012
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Default Re: Rapid Deglaciation as an initiator of volcanic activity

http://www.guardian.co.uk/environmen...ge-shake-earth

http://www.guardian.co.uk/environmen...ge-shake-earth
Sunday 26 February 2012 Bill McGuire
Quote:
The idea that a changing climate can persuade the ground to shake, volcanoes to rumble and tsunamis to crash on to unsuspecting coastlines seems, at first, to be bordering on the insane. How can what happens in the thin envelope of gas that shrouds and protects our world possibly influence the potentially Earth-shattering processes that operate deep beneath the surface? The fact that it does reflects a failure of our imagination and a limited understanding of the manner in which the different physical components of our planet – the atmosphere, the oceans, and the solid Earth, or geosphere – intertwine and interact.
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The world we inhabit has an outer rind that is extraordinarily sensitive to change. While the Earth's crust may seem safe and secure, the geological calamities that happen with alarming regularity confirm that this is not the case. Here in the UK, we only have to go back a couple years to April 2010, when the word on everyone's lips was Eyjafjallajökull – the ice-covered Icelandic volcano that brought UK and European air traffic to a grinding halt. Less than a year ago, our planet's ability to shock and awe headed the news once again as the east coast of Japan was bludgeoned by a cataclysmic combination of megaquake and tsunami, resulting – at a quarter of a trillion dollars or so – in the biggest natural-catastrophe bill ever.
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Between about 20,000 and 5,000 years ago, our planet underwent an astonishing climatic transformation. Over the course of this period, it flipped from the frigid wasteland of deepest and darkest ice age to the – broadly speaking – balmy, temperate world upon which our civilisation has developed and thrived. During this extraordinarily dynamic episode, as the immense ice sheets melted and colossal volumes of water were decanted back into the oceans, the pressures acting on the solid Earth also underwent massive change. In response, the crust bounced and bent, rocking our planet with a resurgence in volcanic activity, a proliferation of seismic shocks and burgeoning giant landslides.
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Trapped within the thick layers of peat that pass for soil on Shetland – the UK's northernmost outpost – are intrusions of sand that testify to the inland penetration of three tsunamis during the last 10,000 years.
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The signs are that this is already happening. In the detached US state of Alaska, where climate change has propelled temperatures upwards by more than 3C in the last half century, the glaciers are melting at a staggering rate, some losing up to 1km in thickness in the last 100 years. The reduction in weight on the crust beneath is allowing faults contained therein to slide more easily, promoting increased earthquake activity in recent decades. The permafrost that helps hold the state's mountain peaks together is also thawing rapidly, leading to a rise in the number of giant rock and ice avalanches.
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The bottom line is that through our climate-changing activities we are loading the dice in favour of escalating geological havoc at a time when we can most do without it. Unless there is a dramatic and completely unexpected turnaround in the way in which the human race manages itself and the planet, then long-term prospects for our civilisation look increasingly grim.
Do not expect to read anything similar in the Murdoch press
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Unread 05-26-2013
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Default Re: Rapid Deglaciation as an initiator of volcanic activity

http://www.sciencedaily.com/releases...0524180252.htm
Two Volcanoes Erupting in Alaska: Scientists Are Monitoring and Providing Alerts On Pavlof and Cleveland Volcanoes
May 24, 2013 — Science Daily

Quote:
Two of Alaska's most active volcanoes -- Pavlof and Cleveland -- are currently erupting. At the time of this post, their activity continues at low levels, but energetic explosions could occur without warning.
Is this related to climate change? I do not know. But as Alaska's permafrost and glacies melt and loose mass you would expect an increase in Volcanic Activity.

On the otherhand
Quote:
Alaska's volcanoes make up about 31% of all active volcanoes in the United States. There are 52 that have been active within the last 10,000 years and can be expected to erupt again.
This probably relates to end of the last ice age.

It is probably too soon to even estimate increased probabilities, let alone allocate proportional responsibility.
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