United States and Territories National Tsunami Hazard Assessment: historical record and sources for waves–update U.S. States and Territories National Tsunami Hazard Assessment: Historical Record and Sources for Waves, Update

The national assessment in this report is essentially the same as that in 2008 except for two changes in hazard levels. The first is the increase to High hazard from Moderate for American Samoa, Guam, and the Northern Mariana Islands. This reflects both the devastating 2009 tsunami and better accounting for the tectonic setting within a major subduction zone. The location of all U.S. Pacific Islands in subduction zones warrants a High hazard assessment irrespective of the available (or known) runup data. In this report we examine the frequency and distribution of runup heights in each state. This resulted in the second change, raising the hazard level for the U.S. West Coast from High to High to Very High 2015 Library Public Domain 2288