Faculty members combine seismology expertise with development of GPS software in the ‘race against time’ in detecting tsunamis RENO, Nev. – Scientists at the University of Nevada, Reno are at the forefront on a number of seismological fields, including helping the world better determine whether an earthquake is big enough to generate an ocean-wide tsunami.
Through work at the Nevada Seismological Laboratory on the Nevada campus, important data on seismological events throughout the world is compiled, including Monday’s fatal occurrence in the Solomon Islands, where at least 13 people were killed. Tsunamis triggered by an undersea earthquake crashed ashore and wiped away entire villages and set off alerts from Australia to Hawaii.
A research team led by Geoffrey Blewitt of the Nevada Bureau of Mines and Geology and Seismological Laboratory has demonstrated that a large quake’s true size can be determined within 15 minutes using Global Positioning System data. This swift exchange of information, which is much faster than is possible with current methods, can be critical in determining whether an earthquake might trigger a tsunami. Together with a seismometer and ocean buoy data, GPS has the potential to become an important tool in improving tsunami danger assessments, Blewitt said.
“We’ll always need seismology as the first level of alert for large earthquakes, and we’ll need ocean buoys to actually sense the tsunami waves,” Blewitt said. “The advantage of including GPS in warning systems is that it quickly tells how much the ocean floor moved, and that information can directly set tsunami models into motion.”
The new method, called GPS displacement, works by measuring the time radio signals from GPS satellites arrive at ground stations located within a few thousand kilometers of a quake. From these data, scientists can calculate how far the stations moved because of the quake. They can then derive an earthquake model and the quake’s true size, called its ‘moment magnitude.’ This magnitude is directly related to a quake’s potential for generating tsunamis.
University seismological experts such as John Anderson, director of the Nevada Seismological Laboratory, and Richard Schweikert, professor of geological sciences and engineering, have used analysis similar to that used in studying the propagation of tsunamis in oceans in determining the likelihood of a tsunami occurring at Lake Tahoe. They’ve used as many three hypothetical earthquake scenarios and simulated faulting beneath the lake that could generate a tsunami, and whether magnitude 7 earthquakes could pose hazards to Tahoe’s shoreline communities.
Large prehistoric earthquakes have occurred beneath Lake Tahoe. Considering the lake’s size and active tectonic history, the researchers’ objective has been to determine if magnitude 7 earthquakes can generate a tsunamis which would pose a hazard to Tahoe’s shoreline communities.
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Contact: John Trent, public relations director
University of Nevada, Reno
(NOTE: Contact John Anderson at (775) 784-4265; contact Geoff Blewitt at (775) 784-6691, ext. 28778; contact Rich Schweikert at (775) 784-6901.)
Nevada’s land-grant university founded in 1874, the University of Nevada, Reno has more than 16,000 students and four campuses with Cooperative Extension education programs in all Nevada counties. The University is listed as one of the country’s top 150 research institutions by the Carnegie Foundation, and is home to America’s sixth-largest study abroad program and the state’s medical school.