SGER: Reconnaissance Survey of the July 17, 2006 Central Javan Earthquake and Tsunami

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This award funds a reconnaissance survey of the July 17, 2006 Central Javan earthquake and tsunami. The most recent estimate of the human toll from the tsunami is approaching 700. This is a nearly incomprehensible number, given that there was a warning issued by the Pacific Tsunami Warning Center and the warning was received in Jakarta. Also, a similar earthquake struck in 1994 in Southeast Java, with a death toll from the tsunami of about 200 (Synolakis et al, 1994). Initial media reports and some estimates from local scientists relate runup heights in excess of 5m.It is important to analyze this event through field observations, for the following reasons:1) Early reports from the field suggest that the impact zone seems to be highly localized, and some scientists have already speculated that the offshore earthquake may have triggered an offshore landslide. The distribution of inundation heights needs to be quantified a la Okal and Synolakis (2004) to help clarify whether a submarine landslide needs to be invoked and whether further offshore marine geology work is urgently needed.2) At least seven animations with runup projections have been posted on the InternationalTsunami Information Center list-server. Collecting high quality inundation measurements will build a high quality data set that will then allow the community to infer the predictive capability of different models and evaluate their potential uses for inundation mapping and operational forecasts. This is the first time ever that so many initial pre-survey predictions have been publicly posted and shared. Model validation is an important step to credible predictions of the impact of future tsunamis.The proposed work has significant broader impacts:1) The incommensurate death toll of the 2006 tsunami (compared to the size of the parentearthquake) needs to be understood, particularly in view of the fairly small initially reported inundation distances, and the lesser impact of the "similar" 1994 event which struck close by.2) The shortcoming of emergency management - if indeed they occurred as suggested by TIME (July 20, 2006) - need to be identified. As suggested, the central government had received the PTWC warning, but the warning was not disseminated to local authorities because the warning mentioned the earthquake only and had no tsunami information. More information is needed on the level of emergency preparedness, particularly in this area which is one of the top tourist destinations in Java. Such information will help identify possible deficiencies in emergency plans in the US and around the world.