What is Causing the Oregon Bulge?
Posted on September 8, 2005The U.S. Geological Survey is still uncertain what is causing the lake-sized bulge in Oregon that has been expanding since 1997. The Associated Press says the USG suspects a pool of magma is behind the bulge. It could possibly be a new volcano.
They say it probably began growing in 1997 and has been rising ever since at a rate of about 1.4 inches a year. It was first observed from space using a relatively new imaging technology known as radar interferometry that can measure changes in the Earth's surface.Deschutes National Forest geologist Larry Chitwood told the AP that the good news is that if it is a volcano it should not affect any major population areas. That's welcomed news considering we have had one disaster this year already. For more information, Slashdot has a discussion of the Oregon bulge.
The likely cause of the bulge is a pool of magma that, according to Deschutes National Forest geologist Larry Chitwood, is equal in size to a lake 1 mile across and 65 feet deep.
The magma lake is rising 10 feet each year, under tremendous pressure, and it deforms the Earth's surface as it expands, causing the bulge.
Other causes could be anything from the birth of a new volcano - a fourth Sister in the making - to a routine and anticlimactic pooling of liquid rock, researchers say.