ALBERT

Description: Padang in West-Sumatra is one of the priority regions of the German-Indonesian Tsunami Early Warning System project (GITEWS). From 2006 onwards, Alfred Wegener Institute (AWI) as the lead organization within GITEWS for simulation products, has contributed simulation results and inundation map information to the community of Padang. In this memorandum, we intend to communicate latest results of our simulations.

Description: The magnitude 7.6 earthquake (USGS) on September 30, 2009 at 10:16 UTC close to the city of Padang in West Sumatra generated a minor tsunami. Earthquakes in this region however have the potential to generate destructive waves as it was shown in historical and recent events. Taking into account the large number of casualties due to this earthquake it is important to prepare for possible future events which might be accompanied by a tsunami. Due to the geographical setting of Padang a tsunami might have disastrous impact. An effective early warning system is crucial.The tsunami modeling group of Alfred Wegener Institute is part of the GITEWS project (German Indonesian Tsunami Early Warning System) and is responsible for creating a database of pre-calculated tsunami scenarios of various magnitudes and epicenter locations covering the Sunda Trench. These scenarios are calculated with the newly developed model TsunAWI. It is based on the nonlinear shallow water equations and employs the finite element method in unstructured meshes.In case of a tsunamigenic earthquake, sensor data (comprising seismometers, GPS instruments, tide gauges, buoys and ocean bottom pressure sensors) will be evaluated. The most probable scenario will be selected and used to forecast arrival times and estimated wave height along the coast. The unstructured discretisation employed in TsunAWI allows for a high resolution around the city of Padang. In this presentation we show preliminary examples of the results of the GITEWS simulation system. We evaluate our pre-computed scenarios and analyze their deficiencies. Additional simulations based on diverse source models are performed to analyze the predictability of near-field tsunamis within short time. We compare simulation results to tide gauge data from Padang harbor and find good agreement.