Triggering earthquakes!

From an article on earthquakes following the tsunami in Asia a discussion of ways to trigger earthquakes!

Can earthquakes be tamed?
Human activity can cause quakes, but preventing them is harder
Cars are piled on top of each other in Phuket, Thailand in the tsunami’s aftermath
Barry West / EPA via Sipa Press
Can devastation such as that seen is this picture from Phuket, Thailand, be prevented?

Analysis
By James Oberg
NBC News space analyst
Special to MSNBC
Updated: 7:37 p.m. ET Dec. 27, 2004
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Accidental discoveries
People have triggered natural earthquakes through a number of activities on the Earth’s surface, most notably in the construction of large water reservoirs. As the weight of water accumulates in such reservoirs, lower rock layers yield to the stress and shift.

A different kind of large pit was behind what is probably the best-known epsiode of human-induced earthquakes. In 1961, the Army drilled a 12,000-foot disposal well at its Rocky Mountain Arsenal in Colorado, northeast of Denver. Beginning in March 1962, waste fluids from arsenal operations were dumped down the well.

Then a funny thing happened: An unusual series of earthquakes broke out in the area. By the end of 1962, there had been almost 200 earthquakes. At first they were small, but in December they damaged several buildings in nearby towns. Over the ensuing five years the quakes increased in frequency and force, and in April 1967 one measured magnitude 5.0.

A connection was soon established between the waste dumping and the earthquakes, and dumping stopped. The quakes continued, however. So the following year, the Army started to withdraw fluid from the well in an effort to reduce the quakes. Sure enough, as the fluid concentration in the deep rocks dropped, the quakes slowed down.

What was happening was that the fluids seemed to lubricate the rock layers that already were under tension. In that sense, the Army didn’t create the earthquakes, it just hurried them along by making it easier for the rocks to slip. Instead of one big quake at some point decades in the future, Colorado experienced a series of smaller quakes.

Could this principle be applied to other more famous fault lines? In theory, deep wells could insert fluids into one segment of a fault line, while other wells at the segment’s ends would suck out fluids thus releasing the tension harmlessly. The process could continue segment by segment as the fault line was tamed, forestalling a massive earthquake sometime in the future.

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