Earthquake Rocks Nevada
Seismic Activity in Northeast Nevada Jolts Residents
The February 21, 2008, Wells earthquake reminded Nevada residents that the ground beneath them is among the most seismically active in the U.S.
California isn’t the only state susceptible to earthquake hazards, as was proven early morning, February 21, 2008, when a 6.0 magnitude earthquake struck the region of Wells, Nevada, located in the northeast corner of the state.
Faults situated in this area are characterized by their location and type – normal faults snuggled up against the feet of various mountain ranges. Seismological data shows that this earthquake was caused by a normal fault that cuts through the desert from north to south and has a dip of about 30-60 degrees. Imagine taking a large knife that is oriented north-south and cutting downward through the top of a layered cake at about a 30-60 degree angle. Then take the portion of the cake that is on top of the knife and slide it downwards away from the other portion of the cake – that is how this kind of fault works.
Earthquakes in the desert are quite common, and there are hundreds of known active faults scattered across the desert from Southern California, straight up north through the entire state of Nevada. The most famous of these faults is the San Andreas Fault, which cuts through just about the entire coast of California – about 800 miles. Other faults, like those located in Nevada, are much shorter – some only a few miles long.
It is not yet known which particular fault caused the February 21st earthquake to occur, only that it is located in an area northeast of Wells, Nevada, the rural city that felt the most shaking. Many buildings in Wells suffered major earthquake damage, although only minor injuries have been reported. The U.S. Geological Survey (USGS) reports that there is a large, 39-mile-long fault located in this region, known as the Independence Valley Fault Zone; but that this fault was probably not the source of the earthquake as its location is too far southeast of the epicenter of the Well’s earthquake.
Reports to the USGS website’s “Did You Feel It?” link show that people in many counties from neighboring states felt the earthquake. Although it would have felt very strong and jolting to the residents of Wells, by the time the seismic waves made their way to neighboring states, it would have felt more like a gentle rolling motion, causing very little damage, if any at all.
Since the main February 21st event, there have been about 30 more related aftershocks recorded ranging in magnitude from 4.6 to 2.3. The last one being a magnitude 3.2 quake at about 7:30 a.m. February 22nd.
Source: US Geological Survey (www.usgs.gov)
