Monday, 15 January 2007
Assimilation of real-time tsunami event data into forecasting models
212B (Henry B. Gonzalez Convention Center)
The NOAA National Center for Tsunami Research is developing a tsunami forecasting system for National Weather Service Tsunami Warning Centers. This system will incorporate real-time tsunami event data with numerical models to provide estimates of tsunami propagation and inundation amplitudes and arrival times for at-risk U.S. coastal communities. The first version of the system was implemented at each Tsunami Warning Center in Spring 2006, and provides tools that assimilate basic seismic data to estimate the source and calculate tsunami propagation within the Pacific Basin. Estimates of arrival time and maximum wave amplitudes are provided in a user-friendly interface for further analysis by warning center operators. The next version of the system scheduled for Spring 2007 will perform real-time data assimilation of deep-ocean pressure recorders that can detect a tsunami signal within a 30-millimeter threshold.
An analysis of available forecasting tools was performed for three tsunamigenic events in the Pacific Basin, including the recent mild tsunami due to a moment magnitude 7.9 earthquake off the coast of Nuku'alofa, Tonga. A comparison of tsunami wave arrival times and amplitudes between current numerical algorithms and observed values at available water-level gauges was performed. This analysis is the first step toward developing confidence limits for current algorithms used in the tsunami forecasting system and recommendations for future improvement.