The hundred or so geologists and seismologists who turned up for the informal monthly meeting of California's Pick and Hammer Club expected an evening of socializing and routine gossip about faults, core samples and volcanoes. Instead, they heard scientific history in the making. As part of his work for the U.S. Geological Survey's Earthquake Research Center, Seismologist Malcolm Johnston had just finished analyzing data from seven monitoring stations set up along the San Andreas Fault in the quake-prone Hollister area. His figures, Johnston told his colleagues, showed that the strength of the local magnetic field had suddenly risen between two of the stations, then gradually subsided over a period of one week. Furthermore, the surface of the earth in the same area had undergone slight but noticeable changes in tilt. Those changes, he said, were just "the sort one would expect to see before a quake." John Healy, another USGS scientist, was even more emphatic. Johnston's data, he said, left little doubt that Hollister could expect a moderate earthquake of up to magnitude 5 on the Richter scale.* When? "Maybe tomorrow," said Healy.
The next afternoon, Nov. 28, 1974, while residents of Hollister were sitting down to their Thanksgiving Day dinners, the earth began to sway and rumble beneath them. The brief 1-to 2-sec. quake measured 5.2 magnitude and did little damage. But its impact still reverberates through the world of seismology. The accurate forecast of the Hollister temblor was a dramatic demonstration that scientists are on the verge of being able to predict the time, place and even the size of earthquakes.
Recently, in fact, U.S. and Russian seismologists have quietly—and correctly—forecast several other earthquakes. In China, where the understanding of earthquakes has become an important national goal, ten quakes are said to have been accurately predicted in the past few years. Before two large recent quakes, the government confidently issued public warnings and evacuated vulnerable areas. Buoyed by their rapid progress in forecasting, scientists are already talking about an even more exciting possibility: actually taming the more destructive convulsions of the earth. "We can't start next year," says Geologist Healy, "but it's not a Buck Rogers idea. Every step we've taken encourages us to go on."
The control of quakes would be an enormous victory over nature at its crudest. Along with war and pestilence, earthquakes rank as one of the world's great killers. Striking without warning, opening great fissures in mankind's ultimate sanctuary of terra firma, quakes have inspired terror and awe since man first walked the earth. During recorded history, earthquakes—and the floods, fires and landslides they have triggered —are estimated to have taken as many as 74 million lives (see box next page).