Obituary

06 March 2002 |

Thomas McEvilly
Seismologist Thomas McEvilly, a professor emeritus of earth and planetary science and a renowned expert on California earthquake faults, died Feb. 22 after an eight-month fight with cancer. He was 67.

McEvilly, who for 11 years directed the Earth Science Division at Lawrence Berkeley National Laboratory, is best known for his 15-year project with U.S. Geological Survey scientists to monitor movement of the San Andreas fault at Parkfield, Calif.

The seismologist believed that if he found changes in the fault preceding an earthquake, he would be able to predict large temblors. Parkfield is hit by magnitude 6 earthquakes on a regular basis every 20 to 25 years.

As one of the principle investigators for the “Parkfield Prediction” experiment, McEvilly and colleagues in 1986 began installing bore-hole seismometers, strain gauges and creep meters to monitor fault movement.

McEvilly’s most important contribution was installation of state-of-the-art deep bore-hole sensors and recording systems for the High Resolution Seismic Network.

“Tom was very technologically innovative, going straight into earthquake faults with the latest instruments to examine how they work,” said William Dietrich, professor and chair of Berkeley’s Department of Earth and Planetary Science.

McEvilly learned a vast amount about day-to-day movement of the fault from the deep bore-hole recordings, which allowed scientists to detect very small “microquakes.” Repeated clusters of microquakes, reported by McEvilly and Robert Nadeau, an assistant research geophysicist at the Berkeley Seismological Laboratory, were found to be useful in predicting the rate at which the fault is slipping deep underground.

“Tom got a lot of data that really helped characterize the physics of earthquake faults on the San Andreas system,” Nadeau said. “He was working with the USGS and the National Science Foundation to improve instruments on the fault, so he could get data that would let him correlate surface observations with the physical properties of the fault at depth.”

McEvilly also helped set up a high-frequency bore-hole seismic network along the Hayward Fault near San Francisco, which is judged the most dangerous fault in the state. Monitoring of the fault helped determine that the northern Hayward Fault slips deep underground to relieve strain and is thus much less likely to generate severe quakes.

The Department of Earth and Planetary Science has plans to create a McEvilly graduate student seismology fellowship in his honor. Those wishing to make a donation in McEvilly’s honor are invited to send contributions to the department, 307 McCone Hall, University of California, Berkeley, CA 94720-4767. Checks should be made out to “The Regents of the University of California.”