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People, Land & Water The Advanced National Seismic System: A Sure Bet for a Shaky Nation By David Hebert Twenty-six U.S. f you were to learn that in 1886, urban areas, identi- ✩ Proposed ANSS urban networks. fied in the map at The earthquake a major U.S. city was ravaged by hazards map of the a magnitude-7.3 earthquake in right, are at risk of conterminous United significant seismic States shows the ar- which 60 people were killed and eas of highest seismic millions of dollars of damage activity: hazard in red and low- est seismic hazard in Idone, where would you guess it had hap- grey. The stars indicate pened — Los Angeles? San Francisco? Albuquerque, N.M. urban areas where dense urban monitor- Anchorage? Anchorage, Alaska ing networks are Highest hazard proposed. The regional Try Charleston, S.C. Boise, Idaho networks (not shown) In fact, damaging earthquakes have Boston, Mass. will be concentrated rocked several U.S. cities far from Alaska in the areas of highest Charleston, S.C. risk, and the national or California — Boston, Memphis and networks (not shown) Chattanooga- will have sites evenly Salt Lake City, to name a few. Chances Alaska, Hawaii and Puerto Rico Knoxville, Tenn. also have proposed sites. distributed throughout are, they will again, and those at risk need Lowest hazard the country. Eugene- All other sites to be determined to be ready. on a region-by-region basis. Springfield, Ore. That’s where the Advanced National Seismic System (ANSS) comes in. Evansville, Ind. Provo-Orem, Utah San Francisco-Oakland, Calif. The ANSS is a proposed nationwide Fresno, Calif. earthquake-monitoring system designed Las Vegas, Nev. Reno, Nev. San Juan, P.R. to provide accurate and timely data and Los Angeles, Calif. Sacramento, Calif. Santa Barbara, Calif. information products for seismic events, Memphis, Tenn. St. Louis, Mo. Seattle, Wash. including their effects on buildings New York, N.Y. Salinas, Calif. Stockton-Lodi, Calif. and structures. Portland, Ore. Salt Lake City, Utah “The ultimate goal of the ANSS is to San Diego, Calif. save lives, ensure public safety and re- duce economic losses,” said Bill Leith, a USGS scientist and coordinator of the mean that research and monitoring are Coast in South Carolina, New York and John Ebel, a professor of geophysics at ANSS. “Rapid, accurate information necessary everywhere. Massachusetts. Boston College and northeast coordina- about earthquake location and shak- “When people think of faults and The ANSS, when fully implemented, tor for ANSS implementation, estimates ing, now available in parts of California, earthquakes, they tend to think of the San will integrate all regional and national that damaging earthquakes (magnitude 5 Washington and Utah, is generated by Andreas Fault, but earthquakes in the networks with 7,000 new seismic instru- or greater) happen in New England every data from a dense network of seismic- eastern United States might be different,” ments, including 6,000 strong-motion 50 to 60 years. In 1940, there was a mag- monitoring instruments installed in high- said Eugene Schweig, a USGS geologist sensors in 26 at-risk urban areas. (See nitude-5.5 quake in New England, and risk urban areas. The information has in Memphis, Tenn. “Assuming buildings revolutionized the response time of emer- map for a list of these areas.) the clock is ticking. gency managers to an earthquake in these will shake the same in the East as they do Boston is one of those urban areas “I talk to people all the time who ask, areas, but its success depends on further in California is probably not valid.” — indeed, it has experienced damaging ‘Earthquakes don’t really happen here, deployment of instruments in other vul- ANSS network instruments are already earthquakes before. In 1755, an earth- do they?’ ” Ebel said. “And I answer, ‘Yes, nerable cities across the United States.” at work in many areas and are planned quake centered near Cape Ann, Mass., they do.’ ” Although the frequency of earthquakes for other earthquake-prone regions na- caused building damage and chimney Although the frequency of earth- on the West Coast is higher than other tionwide, including Northern and South- collapses in Boston. The buildup of the quakes is much greater in the West, the areas of the contiguous United States, ern California, the Pacific Northwest, city since then would likely make matters damaging effects of a quake in the East the geologic characteristics nationwide Alaska, Salt Lake City, the New Madrid much worse if such an earthquake were travel farther. Seismic Zone, and along the Atlantic to happen there today. “The 1994 magnitude-6.7 Northridge, USGS Earthquake Scientists — A Nationwide Notion of Pride By David Hebert Susan Hough to keep these instruments running for leaps in understanding have invariably the next few months, recording many come after large earthquakes not only USGS scientists from across the Title: Geophysicist/Seismologist thousands of aftershocks. strike but are recorded by increas- ingly sophisticated instrumentation. country have been part of many in- Location: Pasadena, Calif. On the morning of June 28, 1992, the magnitude-7.3 Landers earthquake struck Earthquakes do not, however, record credible and memorable earthquake Length of service with the USGS: 14 just to the north of where the Joshua themselves. Long- and short-term moni- years experiences. With that in mind, sev- Tree event had occurred. The portable toring requires ingenuity and commit- eral of them were asked, “What has In April of 1992, less than two months seismometers — instruments developed ment. The USGS has taken a leadership role with such efforts in the United States been your proudest, most exciting after joining the USGS office in Pasadena, by the USGS in Menlo Park — operated Calif., I led the deployment of portable faithfully, recording invaluable close-in for nearly half a century. Looking back at or most noteworthy moment in seismometers after the magnitude-6.1 seismograms of the largest earthquake in my own career, I am proud of any number USGS earthquake science?” “Joshua Tree” earthquake struck the California in 40 years. of accomplishments, but none more than Southern California desert near Palm the chance to contribute in a modest way Now, as in 1906, seismology remains a The answers are as different as the Springs. My colleagues and I were able to this tradition of excellence. scientists themselves. data-driven science: Our most important 22 PEOPLE, LAND & WATER ★ April 2006 Calif., earthquake was not felt in San the need for a consolidated, coopera- earthquake research and monitoring and felt the earthquake. [See page 33.] Francisco, less than 400 miles away,” tive approach to information gathering it has expertise in house.” • ShakeMap – A rapidly generated Ebel said. “If that same earthquake hap- and mitigation. The USGS is the only agency in the computer map that shows the location, pened in Boston, it would be felt in “The ANSS is working toward develop- United States responsible for the routine severity and extent of strong ground shak- Minneapolis-St. Paul, more than 1,000 ment and implementation of integrated monitoring and notification of earth- ing within minutes after an earthquake. miles away. There is potential for several software and human resources to more ef- quakes. The USGS fulfills this role by Fast information on strong shaking in ur- metropolitan areas to be damaged by a fectively use these with existing hardware operating the U.S. National Seismo- ban areas helps get emergency response single, large earthquake in the East.” resources to provide timely and valuable graph Network, the National Earthquake to the right places. In 1811 and 1812, a series of earth- information to the public,” Withers said. Information Center, the National Strong • Hazard Maps – Hazard maps identify quakes, ranging in estimated magnitude Timely and valuable information is Motion Program and by supporting 14 re- the areas of the country that are mostly from 7.5 to 8.0, started near New Madrid, a key ingredient to effective mitigation. gional networks in areas of moderate to likely to experience strong shaking in the Mo., and shook cities from St. Louis to A possibility USGS scientists have been high seismic activity. All of these efforts future. ZIP code or latitude-longitude are being integrated into the ANSS. Cincinnati. Although the probability for keenly aware of throughout the develop- lookup is available. [See pages 26, 30, 31.] “The ANSS contributes to the infra- another 1811/1812-type sequence in the ment of ANSS is that an early warning • Earthquake Notification – Automat- structure that enables monitoring to be ed notifications of earthquakes are avail- next 50 years is 7 to 10 percent, the prob- of even a few seconds would give school- much more cooperative and integrated, able through e-mail, pager or cell phone. ability for a magnitude-6 or greater during children enough time to get under their allowing information to the public that This provides rapid information and up- that same period is 25 to 40 percent. desks and would allow managers time to combines data from all regional partners,” dates to first responders and resources for “Based on paleoseismic work, we know stop trains and subways, shut off pipelines Withers said. media and local government. that 1811- and 1812-like events have hap- and suspend medical procedures. The goal of USGS earthquake moni- • Earthquake Catalog and Data – pened two or three times in the past,” These sorts of warnings can only be Users can search an online catalog and said Mitch Withers, seismic networks download information and technical director at the Center for Earthquake data. Research and Information at the Univer- • Real-time Waveforms – Real-time sity of Memphis. “So we know it’s not a The ultimate goal of the waveform displays from 60 stations, show- fluke and that they tend to come in se- “ ing the movement of seismic waves, are quences, where there are several events ANSS is to save lives, ensure available online 24 hours a day.
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