Re-thinking the Distant Tsunami Hazard to Alaska

The science of tsunami has created as many questions as it has answers for vulnerable areas like those in Alaska's coastal communities. How a tsunami might inundate is determined by a variety of event-unique factors that are difficult to accurately prepare for; near shore dynamics and local bathymetry guarantee a distinctive experience at every locality. The island of St. Paul, located in the middle of the Bering Sea, measured a significant tsunami during the Japanese event in 2011. Believing that the Aleutian Chain would minimize tsunami energy into the Bering Sea, this was an eye-opening observation. Real science gives us real answers. The only way to accurately understand the effect of a tsunami is to have a tsunami; a completely unpredictable event without a season. Over the last few years, there have been several large events. Assessing impacts from the Chilean tsunami of 2010 and the Japanese tsunami of 2011, as well as other events such as Samoa and Haiti, has offered a fine-tuning to tsunami understanding and modeling. Using observed amplitudes, tsunami history, oral stories, and improved static modeling techniques, the ability to access threat by community is becoming possible. Communities previously ranked on broad generalizations are now assessed more specifically with data and modeling, providing new insights to their threat ranking. The critical though complex task of preparedness for Alaska, the state with the most coast-line and the least road system, is expensive and difficult. Translating the potential effects to emergency managers is a vague undertaking depending on the possible scenarios considered. Our understanding, with fine tuning, is proving to be essential in our approach. The reanalysis of the distance tsunami threat determined by updated tsunami science gives local officials the opportunity to improve community preparedness and allow communities to allocate scarce resources wisely.; Japanese Tsunami measured at Saint Paul Island showing significant sea level fluctuation.