The headline in the Gilroy Dispatch on Oct. 13, 1989, was alarming enough: “Is World Series Quake Coming?”
Amazingly, it was. The magnitude-6.9 Loma Prieta earthquake struck four days later, killing 63 people, causing billions of dollars in damage and interrupting Game 3 of the World Series at Candlestick Park.
It also made a name for Jim Berkland, a county geologist who had given the newspaper that incredible prediction. Berkland, an employee for Santa Clara County who grew up in Glen Ellen, claimed to have developed new methods for doing what many scientists say is impossible: predicting earthquakes before they strike.
These days, the 83-year-old Berkland is back in Glen Ellen, living on the family property where he grew up. There he tends the grounds, cares for his wife, Jan, watches the birds from his front porch and continues his prognostications, issuing a monthly newsletter in which he scores his own previous predictions while making new ones.
“I’m certainly expecting at least a 3.5 to a 5.5,” he said earlier this week, referring to the magnitude of quake he predicts will occur sometime soon within 140 miles of Mount Diablo. The exact time frame – or “seismic window,” to use a phrase he coined years ago – for Berkland’s current prediction is between Jan. 29 and Feb. 5, and is based on “extreme tidal forces.”
Lunar phases are at the heart of Berkland’s predictions, and he believes the moon’s gravitational tug is key to understanding when and where a quake will strike. The theory led him to predict Loma Prieta, and it has guided the hundreds of other predictions he has made over the years (for which he claims to have a 75 percent accuracy rate).
Before that realization, “I believed what everybody else believed, that earthquakes were random events,” Berkland said. But in 1974, the geologist noticed a connection between tides and a series of quakes occurring in the region.
“All of them came just after the newer full moon in the time of perigee, and the tides were high,” he explained. Could the moon’s gravitational forces be putting a strain on tectonic plates, leading to earthquakes?
He decided to test his theory by predicting when the next quake would hit, and, “Two days later we got a 4.4 quake down by Gilroy.”
Encouraged, Berkland began predicting quakes as a kind of hobby, and in 1979 he hit upon a second possible insight, thanks to a nudge from a fellow scientist.
That year, in early August, “We had the strongest quake in Santa Clara County since 1911,” he said. Berkland had predicted the Coyote Lake quake (centered near Gilroy), and soon after, a physicist from Xerox called him up at home with an observation.
“He had been watching the lost-and-found column in the Mercury News and noticed there was this huge number of missing cats” at the time around the quake, Berkland recalled. Indeed, “Our cat Rocky had disappeared six days before that quake.”
Berkland, who is highly attuned to animals – he watches the wildlife around Glen Ellen closely, speaks frequently of former pets, and even once had a bobcat named Cee-cee – thought about this, and decided it was possible that cats, dogs and other animals respond to localized changes in the Earth’s magnetic field prior to earthquakes.