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The Chinese, too, were making rapid progress in their earthquake-forecast studies. When a delegation of U.S. scientists headed by M.I.T. Geologist Frank Press toured Chinese earthquake-research centers in October 1974, they were astonished to learn that the country had some 10,000 trained earthquake specialists (more than ten times the American total). They were operating 17 major observation centers, which in turn receive data from 250 seismic stations and 5,000 observation points (some of which are simply wells where the radon content of water is measured). In addition, thousands of dedicated amateurs, mainly high school students, regularly collect earthquake data.
The Chinese have good reason to be vigilant. Many of their people live in vulnerable adobe-type, tile-roofed homes that collapse easily during tremors. And the country shudders through a great number of earthquakes, apparently because of the northward push of the Indian plate against the Eurasian plate. Says Press: "It is probably the one country that could suffer a million dead in a single earthquake."
Chinese scientists read every scientific paper published by foreign earthquake researchers. They also pay close attention to exotic prequake signals—including oddities of animal behavior—so far largely overlooked by other nations. Before a quake in the summer of 1969, the Chinese observed that in the Tientsin zoo, the swans abruptly left the water, a Manchurian tiger stopped pacing in his cage, a Tibetan yak collapsed, and a panda held its head in its paws and moaned. On his return from the China tour, USGS's Barry Raleigh learned that horses had behaved skittishly in the Hollister area before the Thanksgiving Day quake. "We were very skeptical when we arrived in China regarding animal behavior," he says. "But there may be something in it."
Though the U.S. does not have the national commitment of the Chinese, there is no lack of urgency among American scientists. California has not had a great earthquake since the San Francisco disaster in 1906, and seismologists are warily eying at least two stretches of the San Andreas Fault that seem to be "locked." One segment, near Los Angeles, has apparently not budged, while other parts of the Pacific and North American plates have slid some 30 ft. past each other. Near San Francisco, there is another locked section. Sooner or later, such segments will have to catch up with the inexorable-movement of the opposing plates. If they do so in one sudden jolt, the resulting earthquakes, probably in the 7-to 8-pt. Richter range and packing the energy of multimegaton hydrogen bombs, will cause widespread destruction in the surrounding areas.
If one of those quakes occurs in the San Francisco area, the results will be far more calamitous than in 1906 (see box page 40). A comparable earthquake near Los Angeles could kill as many as 20,000 and injure nearly 600,000.