[Lamplighter]

Fracking and the east coast earthquake ???

Can Humans Cause Earthquakes?
By Natalie Wolchover, Life's Little Mysteries Staff Writer
12 January 2011 11:50 AM ET

Life's little mysteries...

According to John Vidale, director of the Pacific Northwest Seismic Network,
there are actually many ways that human activity can trigger earthquakes.
"The main one is by filling large dams," he told Life's Little Mysteries.
"The weight of the water that builds up behind a dam exerts
a huge amount of stress on the land below."

Occasionally the land shifts under all that new weight.
In the 1930s, for example, the construction of Hoover Dam in Arizona
unleashed a burst of seismic activity in the vicinity that reached magnitude 5 on the Richter scale.
And in 1963, a severe earthquake — magnitude 7 — shook the reservoir behind Koyna Dam in India
shortly after its construction, killing 200 people in a nearby town.

Forcefully injecting fluid into the planet's crust also can induce earthquakes.
For a three-year period in the 1960s, the government injected wastewater byproducts
12,000 feet deep into rock fractures in the Rocky Mountains in Colorado, Vidale said.
"Then suddenly you got a whole slew of earthquakes near Denver, so they had to stop," he said.

Similarly, enhanced geothermal-energy projects have been known to make the ground shake.
This process involves pumping pressurized water a mile into the Earth,
then sucking up the heated liquid to make steam and drive turbines to generate electricity.
But as folks in Basel, Switzerland, found out in 2006,
sometimes the injection phase can trigger larger earthquakes,
especially if the pumping is centered over an already geologically active area.