# Tsunami Source Standardization for Hazards Mitigation in the United States

## Science Center Objects

The goal of this Powell Center Working Group is to produce a collection of vetted and standardized earthquake and landslide tsunami sources that can be used to produce the meaningful hazard assessment products required for effective tsunami hazard mitigation and risk reduction. The need for a set of realistic and consistent tsunami sources was identified as a high priority at a 2016 workshop b...

The goal of this Powell Center Working Group is to produce a collection of vetted and standardized earthquake and landslide tsunami sources that can be used to produce the meaningful hazard assessment products required for effective tsunami hazard mitigation and risk reduction.  The need for a set of realistic and consistent tsunami sources was identified as a high priority at a 2016 workshop between USGS scientists and the National Tsunami Hazards Mitigation Program (NTHMP).  The Powell Center Working Group will include scientists from the USGS, NOAA, the NTHMP, academia, and consulting companies.

Tsunamis are extreme events that have caused devastation worldwide over the past several decades.  The tsunami from the 2004 Indonesian earthquake caused over 230,000 casualties in 14 different countries.  The tsunami from the 2011 Tohoku-Oki earthquake took over 18,000 lives and is also considered the costliest natural disaster ($235 billion) by the World Bank. All U.S. coastal states and territories are vulnerable to tsunamis. For example, the area from northern California to British Columbia is under the threat of a massive (M9) local earthquake and tsunami from the Cascadia subduction zone, which has ruptured 19 times in the last 10,000 years with the most recent rupture in 1700. More recently, 165 people in Hawaii, Alaska and California lost their lives in the 1946 tsunami generated by an earthquake near the Aleutian Islands. An earthquake in 1918 off the coast of Puerto Rico caused a tsunami that took 40 lives there. In 1958, a magnitude 7.7 earthquake in southeast Alaska caused a rockfall in Lituya Bay that generated a wave with a maximum height of 1720 feet, the world’s largest recorded tsunami. The fourth largest recorded tsunami happened very recently, and without a large earthquake. In October, 2015, a mountainside collapsed into a fjord of Icy Bay, Alaska, creating a wave that sheared trees more than 500 feet up the hillside. Even without notable inundation of dry land in California, the 2010 Chilean and 2011 Tohoku tsunamis caused damages totaling nearly$100 million to dozens of harbors.

The process of analyzing these vetted sources will include: 1) determination of various tsunami hazard planning efforts (evacuation, mitigation, land-use, etc.) and U.S. regions in need of standardized sources; 2) evaluation of existing tsunami sources used in tsunami hazard products; and 3) characterization of the sources in both a deterministic and probabilistic sense which meets the needs of tsunami hazard planning efforts.

Principal Investigator(s):

Stephanie L Ross (Pacific Coastal and Marine Science Center)

Marie Eble (National Oceanic and Atmospheric Administration)

Dmitry J. Nicolsky (University of Alaska Fairbanks)

Rick Wilson (California Geological Survey)

Fellow:

Christos Kyriakopoulos (University of Memphis)