JOLT GIVES SHAKE-UP CALL TO SEISMOLOGISTS, RESIDENTS.Byline: David R. Baker Daily News Staff Writer It was a quick, sharp jolt, hardly enough to cause serious damage. But the temblor that shook the San Fernando Valley San Fernando Valley Valley, southern California, U.S. Northwest of central Los Angeles, the valley is bounded by the San Gabriel, Santa Susana, and Santa Monica mountains and the Simi Hills. on Sunday night Sunday Night, later named Michelob Presents Night Music, was an NBC late-night television show which aired for two seasons between 1988 and 1990 as a showcase for jazz and eclectic musical artists. , coming just six days before the Northridge Earthquake anniversary Jan. 17, served as a reminder of how much scientists know about quakes - and 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. . Although seismologists have learned a lot from the deadly Northridge temblor, actually predicting quakes remains just a dream. Even some aspects of smaller shakers, like Sunday night's, remain a mystery. Recent small quakes around the Los Angeles Basin The Los Angeles Basin is the coastal sediment-filled plain located between the peninsular and transverse ranges in southern California in the United States containing the central part of the city of Los Angeles as well as its southern and southeastern suburbs (both in Los Angeles , for example, could be connected or completely separate, said Tom Henyey, director of the Southern California Earthquake Center The Southern California Earthquake Center (SCEC), headquartered at the University of Southern California, was founded in 1991 with a mission to:
``We don't know if they're related to any overall movement going on in the crust or if they're totally random,'' he said. ``They could be either.'' Hitting at 10:36 p.m., Sunday's quake measured magnitude 3.2 - a far cry from Northridge's destructive 6.7 magnitude. It struck about two miles south-southwest of Panorama City, emanating from a point buried more than four miles below the Valley floor. ``It felt like a big explosion,'' said Norman Checkor, who has been living with his son in Studio City since a fire touched off by the Northridge Earthquake burned down his Sherman Oaks home. But Checkor said this recent quake wasn't strong enough to damage his son's house or even rearrange the furniture. Police and fire officials agreed that Sunday's shaker was fairly benign, adding they had received no reports of damage or injuries. Henyey said Sunday's jolt could be either a Northridge Quake aftershock af·ter·shock n. 1. A quake of lesser magnitude, usually one of a series, following a large earthquake in the same area. 2. or its own temblor. In either case, he said it did not necessarily point to bigger earthquakes ahead. In an earthquake-prone place like Southern California, such small shakers remain just a fact of life. ``These are tiny little events,'' he said. ``I don't think they portend por·tend tr.v. por·tend·ed, por·tend·ing, por·tends 1. To serve as an omen or a warning of; presage: black clouds that portend a storm. 2. anything significant.'' Seismologists with 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. in Pasadena and the U.S. Geological Survey said the quake did not appear to be another Northridge aftershock, even though it hit just five miles from Northridge's epicenter in Reseda. ``If you look at all the Northridge aftershocks, they seem to be in a cluster, and this is a little to the east,'' said Jim Mori with the USGS USGS United States Geological Survey (US Department of the Interior) . Exactly which fault was at fault for Sunday's quake was not clear. With smaller temblors, it is often difficult to peer through the Valley's thick blanket of sedimentary soil and find the specific fault responsible, Mori said. Such uncertainty remains in spite of recent advances in the scientific understanding of earthquakes. Analyzing data from the Northridge Earthquake, seismologists have learned how different kinds of rock focus waves of energy in an earthquake, much like a lens focuses light, Henyey said. That discovery helped explain why some areas outside the Valley - places including Santa Monica or Fillmore - were hard hit by the Northridge Quake, while other locations closer to the epicenter had minimal damage. Scientists have also found that the Los Angeles Basin's sedimentary soil shakes less in severe earthquakes than they had predicted. ``The patterns of ground motion are much more complex than we originally thought,'' Henyey said. |
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