DEEP QUAKE FAULTS HOLD HIDDEN DANGER.Byline: Lisa Mascaro Staff Writer Fault lines found far below the earth's surface Noun 1. Earth's surface - the outermost level of the land or sea; "earthquakes originate far below the surface"; "three quarters of the Earth's surface is covered by water" surface in Los Angeles Los Angeles (lôs ăn`jələs, lŏs, ăn`jəlēz'), city (1990 pop. 3,485,398), seat of Los Angeles co., S Calif.; inc. 1850. and elsewhere can cause catastrophic temblors stronger than previously believed, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. a report released Tuesday. Scientists believe a blind thrust fault, among those that until now were thought to cause no more than a 7.3-magnitude quake, brought one 2.5 times as strong in India last month, causing massive damage. ``It's like this hidden threat you don't know Don't know (DK, DKed) "Don't know the trade." A Street expression used whenever one party lacks knowledge of a trade or receives conflicting instructions from the other party. where it is,'' said Jonathan P. Stewart, assistant professor of civil engineering at the University of California, Los Angeles UCLA comprises the College of Letters and Science (the primary undergraduate college), seven professional schools, and five professional Health Science schools. Since 2001, UCLA has enrolled over 33,000 total students, and that number is steadily rising. . Stewart returned from a trip earlier this month with the Earthquake Engineering Research Institute to the quake-battered region where the 7.7- magnitude temblor killed 20,000 and left villages destroyed. The professor said preliminary indications are that the quake was caused by a blind thrust fault - one that doesn't rupture the surface. Southern California sits on blind thrust faults, experts say. ``What was so alarming was that it was so large and it didn't break the surface,'' Stewart said. ``It's potentially of great concern.'' Seismologist seis·mol·o·gy n. The geophysical science of earthquakes and the mechanical properties of the earth. seis Susan Hough at the U.S. Geological Survey on the campus of the California Institute of Technology California Institute of Technology, at Pasadena, Calif.; originally for men, became coeducational in 1970; founded 1891 as Throop Polytechnic Institute; called Throop College of Technology, 1913–20. said the research is another indicator that you don't need a fault like San Andreas running through the city to have a 7.5-magnitude quake, as some have previously believed. ``It's one more bit of evidence and one more nail in the coffin,'' said Hough n. 1. Same as Hock, a joint. v. t. 1. Same as Hock, to hamstring. [ imp. & p. p. os> r>; p. pr. & vb. n. os> n. 1. An adz; a hoe. v. t. 1. To cut with a hoe. . ``I think most scientists were coming around to agree that a 7.5 is plausible for L.A.'' Hough, who is working on related research, said recent studies show that the fault that produced the 5.9-magnitude Whittier Narrows Quake on Oct. 1, 1987, is the same kind of blind thrust fault. ``There's actually been quite a bit of work done to look for these guys and image them,'' Hough said about the faults. ``It's like pushing a bulldozer underground and trying to interpret that mess,'' she said. ``It's hard to know what could be lurking out there.'' She added, ``There was a time maybe 20 years ago when they weren't appreciated. ... There's an awareness now these are out there.'' Stewart said researchers will need to do more work, looking into the aftershocks and depth of the quake, to learn more about the fault and its lessons for the region. ``It may potentially hold very important lessons on the thrust faulting in Los Angeles,'' he said. |
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