Skip to main content
U.S. flag

An official website of the United States government

Population vulnerability to tsunami hazards informed by previous and projected disasters: A case study of American Samoa

October 1, 2018

Population vulnerability from tsunamis is a function of the number and location of individuals in hazard zones and their ability to reach safety before wave arrival. Previous tsunami disasters can provide insight on likely evacuation behavior, but post-disaster assessments have not been used extensively in evacuation modeling. We demonstrate the utility of post-disaster assessments in pedestrian evacuation modeling for tsunami hazards and use the US territory of American Samoa as our case study. We model pedestrian travel times out of tsunami inundation zones recreated for the 2009 Mw 8.1 Samoa earthquake, as well as for a probable maximum tsunami zone for future threats. Modeling assumptions are guided by fatality trends and observations of 2009 evacuation behavior, including insights on departure delays, environmental cues, transportation mode, and demographic characteristics. Differences in actual fatalities from the 2009 disaster and modeled population vulnerability suggest that a single set of estimated travel times to safety does not fully characterize evacuation potential of a dispersed, at-risk population. Efforts to prepare coastal communities in American Samoa for future tsunamis may be challenging given substantial differences in wave characteristics and evacuation potential of the probable maximum hazard compared to the 2009 event.

Publication Year 2019
Title Population vulnerability to tsunami hazards informed by previous and projected disasters: A case study of American Samoa
DOI 10.1007/s11069-018-3493-7
Authors Nathan J. Wood, Jeanne M. Jones, Yoshiki Yamazaki, Kwok-Fai Cheung, Jacinta Brown, Jamie Jones, Nina Abdollahian
Publication Type Article
Publication Subtype Journal Article
Series Title Natural Hazards
Index ID 70204107
Record Source USGS Publications Warehouse
USGS Organization Western Geographic Science Center