March 2011 Archives

Earthquakes and Climate Change

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In September of 2009, just after back to back earthquakes in Samoa and Indonesia, I wrote an article entitled "Climate Change, A whole lot of shaking going on" where scientists have theorized that Earthquakes are increasing due to an unlikely cause - Climate Change. The theory is that while Earthquakes on different Tectonic plates do not cause others to occur, for instance the Samoan and Indonesian quakes happened within one day of each other, they can be correlated to other quakes and seismic activity - specifically to 'glacial quakes' caused by fast melting and moving multi-ton glaciers on Greenland. It's been nearly 2 years since then, let's reconsider this theory, and remember, 2 years is not even a blink of an eye in Geologic time. Consider since September of 2009 the following events: Haiti suffers the worst Earthquake in 200 years January 12th of 2010. Next,While not covered widely by the news, an unexplained Earthquake swarm begins and continues in Yellowstone Park just 7 days later. A month and a half later Chile is hit by an 8.8 quake that displaced 1.5 million residents. Earthquake swarms have also been recorded in the Mt. Saint Helens region - setting off renewed fears of an eruption. Increasing earthquake swarms in California are puzzling scientists but seem explainable due to its tectonic location, however, tectonic location can not explain the Earthquake swarms occurring now in Arkansas. February 2011 - Christchurch, New Zealand has its worst quake in 80 years. Finally, April of 2010 Iceland's long dormant Eyjafjallajökull Volcano erupted closing British Airports for months. It appears that the same area began experiencing an Earthquake swarm on March 10th, 2011 - the day before Japan was hit by the 8.8 Earthquake - the worst in Japan's recorded history. While the number of quakes has remained constant, the number of high intensity quakes has increased. Already, in the decade of the 2000 to 2010 we have had more 8.5 Earthquakes than the 1970's, 80's and 90's combined - 4 total, with none in the 3 previous decades. Without dismissing other theories for these quakes - ranging from gas drilling to the prophecy of the Mayan calendar - consider the Climate Change theory again. From the original article: ...the Earth's tectonic plates have sensitive fault lines, which when triggered to move, cause earthquakes and volcanoes. As a sphere, the Earth 'reflects' vibration internally, so that an earthquake in the South Pacific is picked up by seismologists across the world -- say in Alaska. The Indonesian quake resonated so strongly that it set off quakes in Alaska. (Samoa also had a 7.9 earthquake in March.) Now, add in this to the equation. In Greenland, and to a lesser extent, Antarctica, ice sheets and glaciers are melting and more importantly, sliding in rapid bursts. This is caused by moulins, which are holes that melting water form from the top of a glacier to the bottom. The water then lubricates and melts the underside of the glacier, causing them to detach from the bedrock -- and creating a 'slip-n-slide' for glaciers that weigh in the megatons -- some the size of Manhattan.
Robert Corell, chairman of the Arctic Climate Impact Assessment, said in Ilulissat [Greenland] yesterday: "We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at 2 meters an hour on a front 5km [3 miles] long and 1,500 meters deep. That means that this one glacier puts enough fresh water into the sea in one year to provide drinking water for a city the size of London for a year." The glacier is now moving at 15km a year into the sea although in surges it moves even faster. He measured one surge at 5km in 90 minutes - an extraordinary event.
The result, each 'slide' of these multi-ton glaciers sets off an 'ice quake' that register an average of 3 to 5 on the Richter scale. This might sound minor, but these are occurring multiple times a year. This means that the Earth is being jolted repeatedly by these ice quakes, destabilizing faults lines which has many, many consequences.
The latest scientific discipline to enter the fray over global warming is geology. And the forecasts from some quarters are dramatic - not only will the earth shake, it will spit fire. A number of geologists say glacial melting due to climate change will unleash pent-up pressures in the Earth's crust, causing extreme geological events such as earthquakes, tsunamis and volcanic eruptions. A cubic metre of ice weighs nearly a tonne and some glaciers are more than a kilometre thick. When the weight is removed through melting, the suppressed strains and stresses of the underlying rock come to life. University of Alberta geologist Patrick Wu compares the effect to that of a thumb pressed on a soccer ball - when the pressure of the thumb is removed, the ball springs back to its original shape. Because the earth is so viscous the rebound happens slowly, and the quakes that occasionally shake Eastern Canada are attributed to ongoing rebound from the last ice age more than 10,000 years ago. Melting of the ice that covers Antarctica or Greenland would have a similar impact, but the process would be accelerated due to the human-induced greenhouse effect. "What happens is the weight of this thick ice puts a lot of stress on the earth," says Wu. "The weight sort of suppresses the earthquakes but when you melt the ice the earthquakes get triggered." The Earth's crust is more sensitive than some might think. There are well-documented cases of dams causing earthquakes when the weight of the water behind a dam fills a reservoir. Alan Glazner, a volcano specialist at the University of North Carolina, said he was initially incredulous when he found a link between climate and volcanic activity off the coast of California. "But then I went to the library and did some research and found that in many places around the world especially around the Mediterranean they see similar sorts of correlations." "When you melt glacial ice, several hundred metres to a kilometre thick . . . you've decreased the load on the crust and so you've decreased the pressure holding the volcanic conduits closed. "They're cracks, that's how magmas gets to the surface . . . and where they hit the surface, that's where you get a volcano."
(written over 2 years before the historical eruption in Iceland) And it is not likely to slow down, but may instead speed up:
...quakes ranged from six to 15 per year from 1993 to 2002, then jumped to 20 in 2003, 23 in 2004, and 32 in the first 10 months of 2005 - matching an increase in Greenland temperatures.
That is tripling of earthquakes in a 15 year period and more importantly an exponential change in the activity. This trend is causing changes exponentially. For instance, since the Arctic has opened an ice free passage, the Arctic is no longer a stationary sea -- currents from the Pacific and the Atlantic are encroaching into the Arctic circle and creating an additional heating feedback loop -- which is as equally dangerous as a heating feedback loop as the loss of reflective ice. This video reports the feedback loop that Greenpeace scientists are seeing in Greenland - as reported by Al Jazeera - and curiously missed by the US media.
"Greenland's ice sheet has more than doubled its contribution to sea level increases in the past 7 years due to rapid and unpredicted loss of ice....There are large volumes of warm subtropical waters flowing through these fjords very quickly (causing melting)...One glacier is traveling 38 meters every day."
This report indicates that glaciers have tripled in their speed of movement towards the ocean since 2004. There are many consequences to this activity. First, Glaciers entering the ocean immediately cause sea level rise - threatening life for millions of people and animals of low lying islands.. Second, each time a glacier moves, another quake occurs - sending a jolt throughout the Earth - destabilizing numerous fault lines. While the debate about the danger of Climate Change has been discussed in gradual changes throughout the next century, it seems that Climate Change is much more direct and destructive resulting in exponentially stronger Earthquakes, Volcanoes, and Tsunamis. It's time for our politicians to stop make concessions to Fossil Fuel industries in the name of 'Energy concerns' and start making decisions based on limiting just how dangerous Climate Change is going to be.


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