Date: August 27, 2004

CONTACT: Jamie Thompson, Public Affairs Officer, (775) 623-1500

STANFORD UNIVERSITY TO STUDY EARTH'S CRUST BENEATH NORTHERN NEVADA

The Bureau of Land Management (BLM) Winnemucca Field Office has issued a permit to Stanford University to measure the thickness and composition of the Earth's crust under northern Nevada between the Oregon state line and central Nevada. Stanford scientists and graduate students will use over 1,000 portable seismographs and geophones to record seismic waves created by six precisely timed and located downhole explosions.

The simultaneous explosions will occur at night to reduce interference from background noise. Before the detonation, shotpoint areas will be cleared for safety, and visual and audio alarms will be used to signal the impending shot. Noise from each shot will be a muffled thud sometimes accompanied by a sharp crack similar to a rifle shot that might be heard up to a mile away. Ground rolls from the detonations will not be felt beyond a few hundred feet. Measurements of the time it takes for the waves from each location to reach the recording instruments will be used to create an accurate picture of the different rock types and structures present deep in the Earth's crust.

Six boreholes will be drilled along a roughly east-west line in remote areas north of the Black Rock Desert in northwestern Nevada and into northeast California. “An environmental analysis completed for the project has determined that there will be minimal surface disturbance from the drilling and plugging of the holes," said Lynn Harrison, Planning and Environmental Coordinator at BLM’s Winnemucca Field Office. “The recording devices will be located along existing roads.”

The recording devices will be retrieved following the detonations and the recorded data transferred to a central computer. All data gathered as a result of the project will be archived and publicly released through an Earthscope Data Center. Earthscope is a National Science Foundation program that is also providing the latest technology and equipment for the project.

Stanford will also use the project, scheduled to take place before September 15th, to train a group of its undergraduate students in geologic and geophysical techniques required to study the continents. The goal of the project is to increase public appreciation of local geology and expand knowledge of the Earth’s crust to help scientists better understand the earthquake hazard in the region.

- BLM -