UConn Physics Colloquium
Tsunamis: Generation, Propagation, and Forecasting
University of Connecticut
Propagation of tsunami waves is well predicted from the theory of gravity waves in water. The principal sources of excitation of tsunamis are large (magnitude exceeding 7), shallow focus (less than 20 km) earthquakes having a significant component of vertical displacement beneath oceans along continental margins and island-arcs. Phase and group velocities of tsunamis are proportional to the square root of depth. Given detailed bathymetry together with accurate earthquake locations and faulting mechanisms in near real time makes it possible to forecast tsunami arrival times and heights with high precision within several hours of their arrival. Currently operating tsunami warning systems are based on rough initial estimates of earthquake location and estimated faulting mechanisms. These systems have made tsunami forecasting routine along the Pacific rim for the past several decades, supplemented by water-height measurements from buoys and tide gauges to reduce the false alarm rate. The obstacles to mitigating tsunami disasters are not in scientific understanding, but rather in communication of the forecast and planning evacuation of shorelines.
Friday, January 21, 2005
Gant Science Complex
(We will meet for refreshments prior to the talk at 3:30 p.m., in the Gant Science Complex, Physics Library, Room P-103.)