January 1998 Press Releases

Press Release
Seismological Laboratory
University of Nevada, Reno

15 January 1998 10:00 AM PST
At 7:12 AM on Thursday, January 15, the Seismological Laboratory at UNR recorded a minor earthquake. The earthquake had a local Richter magnitude of 3.7 and was centered 8 mi N of Truckee, CA, near the west end of Stampede Reservoir, 39.444N, 120.168W, at a depth of approximately 12 km. At present, the Seismological Laboratory has received many felt reports from Tahoe, Truckee, Reno, Sparks and Carson City. No aftershocks have been recorded at this time.

This earthquake is located just north of the aftershock zone of the September 12, 1966 Truckee earthquake. That 1966 earth- quake had a magnitude of 6.0.

The data reported here are preliminary. For more information, contact the Seismological Laboratory at (702) 784-4975, or at the WWW site http://www.seismo.unr.edu . The free pamphlet Earthquakes in Nevada and How to Survive Them, is available on request.

Press Release
Seismological Laboratory
University of Nevada, Reno

7 January, 1998 11:00 AM PST
The seismographic network operated by the Seismological Laboratory recorded the explosion at the chemical plant east of Sparks this morning. We estimate that the time of the explosion was about 2 seconds after 7:54 AM. The explosion generated waves in the ground with amplitudes equivalent to those of an earthquake with magnitude under 2.0.

We received a number of reports from people who felt the explosion. Probably what most people felt is the air wave which the explosion generated. This air wave shook the ground also, and at our stations the signal from the air wave is larger than the waves that traveled through the earth. This is typical of explosions above the ground surface. The air wave travels relatively slowly, taking about 5 seconds to travel a mile. It was recorded at least as far away as our station south of Gardnerville, as well as all stations closer to the explosion. In the air wave, we see two distinct pulses separated by about three seconds.

The data reported here are preliminary. For more information, contact the Seismological Laboratory at (702) 784-4975, or at the WWW site http://www.seismo.unr.edu . The free pamphlet Earthquakes in Nevada and How to Survive Them, is available on request.