HISTORICAL TSUNAMI AND PALEOTSUNAMI RECONNAISSANCE IN THE ISLANDS OF THE FOUR MOUNTAINS, ALEUTIAN ISLANDS, ALASKA

Tsunami studies in the Aleutian Islands are a key to producing accurate probabilistic hazard maps for communities around the Pacific Rim. The directionality of the subduction zone means all sizeable tsunamis produced in the Aleutians will likely cause measureable trans-Pacific runup, including many major cities along the west coast of North America. Logistical complications have limited the number of studies in the Aleutians to date, thus basic questions such as “how often do tsunamis happen” cannot be answered for the archipelago. Fieldwork we conducted as part of the Prehistoric Resilience in the Islands of the Four Mountains project (summer of 2014) is one of the western-most studies of historical tsunamis and paleotsunamis in the Aleutians. The data collected by our reconnaissance to these islands, along with radiocarbon dating and tephrochronology of the coastal stratigraphy, provides preliminary tsunami recurrence intervals and tsunami magnitude estimates for the area.