LOS ANGELES (AP) — Leon Knopoff, a University of California, Los Angeles, researcher who pioneered the use of mathematical modeling for earthquakes, helped develop a way to date ancient pottery and examined how music affects human perception, has died. He was 85.

The university says Knopoff died of respiratory failure on Jan. 20 at his home in Sherman Oaks.

Knopoff and his colleague, Robert Burridge, worked out a mathematical model that helps in earthquake forecasting. He also discovered that small earthquakes usually don’t predict major temblors on earthquake faults.

Knopoff also co-invented a method of dating ancient pottery using thermoluminescence — the light emitted by radiation trapped by the material.

He was on the UCLA faculty for more than 60 years authored more than 350 research papers and co-edited five books.

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