Published in the September 28 – October 11, 2016 issue of Morgan Hill Life
By Marty Cheek
It’s too bad Jim Berkland died July 22. That was just a couple of months shy of an announcement in mid-September that major earthquakes might be caused by the moon. Research published in Nature Geoscience magazine shows the pull of the moon’s gravity — the same force of physics that causes ocean tides — might also trigger Earth’s most fragile faults to go “Big One.”
I once had a nice phone chat with Berkland for a story I wrote about a decade ago when the book “The Man Who Predicts Earthquakes” came out. His way-out theory of trying to forecast quakes was based on not just tidal forces and the moon’s phases but also disoriented pets, irregularities in geyser activities in Napa and changes to the Earth’s magnetic field.
Berkland was a geologist who worked for Santa Clara County. He got his first big success when he was interviewed by a reporter for the Gilroy Dispatch and the article came out Oct. 13, 1989 predicting an earthquake with a magnitude between 3.5 and 6.0 hitting the Bay Area on a date somewhere between Oct. 14 and Oct. 21 of that year. The Loma Prieta earthquake struck Oct. 17 with a 6.9 magnitude. According to Berkland, officials with the county asked him not to make any more predictions because they feared people might panic.
Berkland published his earthquake predictions in newsletters and a website. He based his method on the idea that the Earth’s tectonic forces, powered by the magma far below, bring crustal rock to the brink of failure. Energy gets stored, increasing the stress load on the rock. All that energy can then be triggered by the tidal forces of the Sun and moon pulling on the rock, Berkland believed.
The highest point of lunar and solar tidal gravity forces happens at the points of orbit when there is a new moon or a full moon, creating Berkland’s “Seismic Window Theory.” His idea seemed like a good way to explain what might cause temblors. But there was never any real scientific evidence to show the earthquake-moon connection to be true. Berkland claimed a 75-percent accuracy rate, which was hard to verify. Many people took him for a crack-pot.
Well, it might turn out that Berkland has had the last laugh. He can thank researchers at the University of Tokyo. Japan is known for its catastrophic earthquakes, so an effective way to predict major quakes for the island nation might save thousands of lives if people can get enough warning time. The Japanese scientists calculated the levels of “tidal stress” before the major earthquakes that have occurred in past few decades. Much like Berkland’s predictions, they found that high levels of lunar tidal stress were often followed by major earthquakes.
I’m still intrigued by his notion that animals somehow can sense an impending seismic slip. If the number of “missing cat” ads in newspapers increased at a statistically relevant level, maybe that was a sign our feline friends were worried about impending doom and were taking cover far from home.
In the 1970s, my dad participated with the United States Geological Survey in a one-year study on animal behavior and earthquakes. He recorded any unusual activities among our dogs and livestock. These could include erratic barking or other strange behavior. Once a week he phoned an answering machine at the Menlo Park office and left a voice message reporting anything he thought might be odd. Nothing seemed to come out of the animals-behaving-oddly research.
I enjoyed that phone chat with Berkland so many years ago. When he described to me the mechanism of tidal forces on the planet and that stressor on rock, it seemed his idea might be plausible.
During the interview, I suggested his idea might be verified on a historical basis. When the moon was formed 4.5 billion years ago after a cataclysmic collision of two planetoids, Earth’s sister world was only about 12,000 to 15,000 miles away. It would have appeared as a monstrous eye in the sky. Maybe when it was so close, its gravity well would have caused greater tidal forces on our planet — and thus created massive earthquakes and volcanic activity (especially with Earth’s thinner crust). Well, my idea of greater earthquake activity long ago triggered a little quake of anger in the geologist. I quickly moved the conversation to another question.
The scientific evidence showing the tidal forces aspect of Berkland’s earthquake-moon prognostication system might be good news for South Valley. Continued research might one day enable a warning system to save lives in Japan, California and other earthquake-prone areas of the world.