Baylor Seismometer Records Alabama Earthquake

by Judy Long

Baylor University's new seismometer, installed in March at the China Spring seismic site in a cooperative program with Geotech Instruments, recorded the 4.9 magnitude earthquake that shook northeast Alabama at 3:59 a.m. April 29.
The U.S. Geological Survey (USGS) reported that the Alabama quake caused limited damage--cracked foundations and fallen bricks reported at Fort Payne, Ala. and muddy water in pipes at Valley Head, Ala. The USGS also reported that although Alabama is not located near the edge of a tectonic plate, numerous small faults buried below the earth's surface crisscross the area, causing occasional small to moderate earthquakes.
"Our seismograph recorded it beautifully even though the quake registered only a 4.9 on the Richter scale," geology chair Tom Goforth said.
The three-component broadband instrument picks up movements in the earth's crust by sensing ground motion along three directions: vertical, east-west horizontal, and north-south horizontal, facilitating geological research. "This provides a complete three-dimensional description of the motion of the earth," he added.
Goforth uses the data from the seismic station in his investigation of the crust and upper mantle of Central Texas. "Determining the seismic response of the upper 1000 km of the earth is necessary to understand the geological evolution of the crust and for the determination of seismic source parameters," Goforth said.
The Baylor Sciences Building, currently under construction and slated to be completed by August 2004, will house a complementary seismometer. A foundation pier of the building has been sunk to the bedrock but decoupled from the structure. A seismometer will be attached to the pier, and the data will be routed upstairs to the Geophysics Lab.