Keilis-Borok died on Oct. 19 at his home in Culver City after a long illness, according to the University of California, Los Angeles, where he had taught since 1998.
The Russian scientist gained prominence after a strong earthquake in Japan and another in Central California occurred in 2003 within a time period that was forecast by his international team of seismic experts.
"Earthquake prediction is called the Holy Grail of earthquake science and has been considered impossible by many scientists. It's not impossible," Keilis-Borok said in a statement released by UCLA in January 2004.
He then made a bold claim: A quake of magnitude-6.4 or larger would rock a 12,000-sqaure-mile region east of Los Angeles before Sept. 5, 2004—a large swath that includes the Mojave Desert, the Coachella Valley, the Imperial Valley and eastern San Diego County.
He gave it a 50-50 chance, basing his prediction on a pattern of earthquakes recorded in the region over the past decades including the magnitude-7.3 Landers earthquake in 1992 and the 7.1 Hector Mine quake in 1999.
But the quake never struck and critics said he had been lucky in his previous predictions. Despite the failed attempt, Keilis-Borok still had a few supporters.
Earthquake prediction today remains elusive. Most scientists are generally pessimistic about ever having that ability and have instead focused on emergency preparedness and advocating for an early warning system designed to give people a few seconds of notice after a quake occurs but before damaging waves spread widely.
Born in Moscow on July 31, 1921, Kellis-Borok earned his doctorate from the Academy of Sciences in Moscow. He worked at UCLA from 1998 to 2010, when he retired. He was known as "Volodya" by close friends.
Kellis-Borok is survived by a daughter, Irina Kashin, a granddaughter and two great-grandchildren, the Los Angeles Times reported Thursday.