Word: seismicity
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Rock Festival. This time the EVA (ExtraVehicular Activity) will include some fireworks-real ones. Earlier lunar seismic experiments have been largely passive; that is, the seismometers have usually depended on the occurrence of moonquakes or other natural rumblings to make readings. Now, with the help of a new gadget called a "thumper," which resembles a heavily weighted walking stick, Mitchell will create some miniature moonquakes of his own. As he walks past three widely spaced seismic listening devices called geophones, he will place the thumper on the surface and detonate one of 21 explosive charges in its base plate...
...Caudillo, 78, methodically pumped his right hand up and down for emphasis as he spoke in his lisping, high-pitched voice of trade-union reforms, of Spain's Common Market hopes, of Richard Nixon's visit in October. But of the political crisis that continued to send seismic waves throughout the country Franco said practically nothing. There was an odd, stilted sentence-"A spattering of the currents of upheaval agitating the world has reached us"-and little more...
Granite Slabs. Wilson traces the path of the rise (see map) by such subtle evidence as heat flow in rocks, remains of ancient magnetic fields and the variations in the velocity of seismic waves under different parts of the West. He also points to much more conspicuous signs of its presence: the hot springs in California and Yellowstone National Park, the remnants of old volcanoes-Arizona's Kitt Peak, for example, and Crater Lake in Oregon-the upward tilt of the American plains as they stretch westward toward the Rockies and the shape of the mountains themselves. Unlike...
...Geological Survey's lab at Menlo Park, a fired-up corps of young scientists is "bugging" central California's creaking faults with ultrasensitive new instruments. The lab has already set up more than 100 seismic stations, one-eighth of the world's total, to detect ever smaller earth tremors...
...ideal solution: earthquake prevention. Some scientists have proposed using H-bombs to jar loose locked sections of faults, thus relieving accumulating strain that would otherwise build up to dangerous levels. More realistic is the possibility of using pressurized water or liquid waste to release this pent-up seismic energy. At two carefully studied sites in Colorado, liquid injections have been found to "lubricate" locked fault systems. This allows the plates to resume sliding past each other, setting off small but relatively harmless energy-dissipating tremors...