Tsunami forecast analysis for the May 2006 Tonga tsunami
Tang, L., V.V. Titov, Y. Wei, H.O. Mofjeld, M. Spillane, D. Arcas, E.N. Bernard, C. Chamberlin, E. Gica, and J. Newman
J. Geophys. Res., 113, C12015, doi: 10.1029/2008JC004922 (2008)
|This study applies tsunami forecast models developed for NOAA's Tsunami Warning and Forecast System to investigate the May 2006 Tonga Tsunami. Inversion of the Deep-ocean Assessment and Reporting of Tsunamis (DART) measurements estimates a tsunami magnitude equivalent to an earthquake moment magnitude of 8.0. The DART-constrained modeling forecasts show good agreement with observations at eight coastal tide stations in Hawaii, U.S. West Coast, and Alaska, including first arrival times, wave periods, wave amplitudes, and decay during the day following the earthquake. The forecast system correctly reproduces the reflected waves from North America and the scattered waves by the bottom topography in the South Pacific, which arrived in the Hawaiian Islands 16 and 18.5 h after the earthquake, respectively. Wavelet analysis of the tsunami waves suggests that harbor and local shelf resonances may be predominantly responsible for the late occurrence of the maximum wave observed in some coastal areas. These results suggest expanding the operational use of the real-time forecast models and demonstrate the applicability of the forecast results for “all-clear” evaluations, search and rescue operations, as well as event and postevent planning. This research highlights the value of high-resolution inundation models in real-time forecasts during a long-duration hazard for coastal communities. It also provides a rigorous and successful test of the performance and accuracy of the forecast models when run in real-time mode.