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For more information on these science news and feature story tips, please contact the public information officer at the end of each item at (703) 292-8070. Editor: Cheryl Dybas Contents of this News Tip:
UNEXPECTED EARTHQUAKE THREAT TO L.A.Prehistoric earthquake evidence recently unearthed near Pasadena, California, is likely to shake up emergency preparedness and building code officials throughout southern California, according to Charles Rubin, a geologist at Central Washington University whose research is funded by the National Science Foundation (NSF) through its Southern California Earthquake Center. According to Rubin and his colleagues, the Sierra Madre fault, which runs along the southern flank of the San Gabriel Mountains -- and passes less than a dozen miles from downtown Los Angeles -- has produced earthquakes ranging in magnitude from 7.2 to 7.6 on the Richter scale at least twice in the past 15,000 years. In comparison, a 7.2-magnitude quake would release six times as much energy as the 1994 Northridge, California, quake, which registered 6.7 in magnitude. By excavating a trench across the Sierra Madre fault to look at buried evidence (strata of soil, gravel, and sand) at a site near Pasadena, Rubin estimates that at least two prehistoric earthquakes have shifted one edge of the fault upward more than 30 feet. "Most seismic hazard and risk assessments of the L.A. region don't even consider such large vertical ground displacements and strong ground-motions, which result from earthquakes of 7.0 and larger," cautions Rubin. "Until our recent excavation work, no one had any clue that an earthquake of magnitude 7.5 had ever occurred here. Earthquakes in this region have been larger than previously documented--and they could well happen again." [Cheryl Dybas] NSF LOOKS AT DEBT INCURRED BY NEW PH.D.sIndebtedness among undergraduate students and failure to pay off student loans are issues often in the news, but few studies have looked at debt among those with advanced degrees, especially Ph.D.s. In the first picture of the debt burden painted for new Ph.D.s., a study published in a new NSF Issue Brief shows that, starting with 1993 doctoral recipients in science and engineering (S&E;), almost half have no debt at the time their degrees are conferred. About six percent of this same group had a debt of $30,000 or more. Meanwhile, foreign Ph.D. recipients are doing much better than U.S. citizens in the S&E; fields when it comes to being debt-free. Over 60% of foreign Ph.D.-holders in each graduation year starting in 1993 report being debt free, while less than 40% of U.S. citizens in the S&E; fields reported no debt. "Computer scientists, engineers and mathematics majors appear to have the least debt," says Alan Rapoport, who compiled the issue brief for NSF's Division of Science Resources Studies. "About half the engineers and mathematicians, and about 55 percent of the computer scientists reported no debt at the time of graduation." [Bill Noxon] The entire issue brief is at: http://www.nsf.gov/sbe/srs/stats.htm ACADEMIA HIRING MORE S&E; POSTDOCSThe academic community's trend toward hiring more Ph.D.-holding scientists and engineers (S&E;) into postdoctorate positions has continued, and even accelerated, over the first half of the 1990s, according to a new National Science Foundation (NSF) Issue Brief. The shift away from employing full-time S&E; senior faculty toward more hiring of Ph.D.-holders outside the traditional faculty ranks is not a new trend. But it has been accentuated by a steeply rising number of new Ph.D.s entering S&E; fields since the late 1980s, according to NSF's Division of Science Resources Studies, which prepared the brief. "Robust growth has taken place outside the faculty ranks, as a growing proportion of these new Ph.D.s have received postdoctorate opportunities," says Rolf Leming, who authored the issue brief. "The duration of postdoc appointments has also increased in many fields." The issue brief notes that from 1991 to 1995, the number of full professors in S&E; has declined by six percent, but the number of full-time junior faculty members has risen by 10% overall. It's too early to tell whether the patterns of the early 90s represent a temporary adjustment or a more enduring trend, the brief concludes. [Bill Noxon] The entire issue brief is at: http://www.nsf.gov/sbe/srs/issuebrf/ib98312.htm
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