Stratigraphic and microfossil evidence for a 4,500-year history of Cascadia subduction zone earthquakes and tsunamis at Yaquina

New research on the central Oregon coast reveals that 11 subduction zone earthquakes and associated tsunamis have affected the Newport, Oregon, USA, area in the past 4,500 years.

This research adds to a growing body of knowledge that implicates great subduction zone earthquakes recurring on average every 420-580 years.

Each earthquake is accompanied by abrupt land-level lowering of the coastal region of at least half a meter and by incursion of tsunami waves to the Yaquina Bay region.

Stratigraphic and microfossil evidence for a 4,500-year history of Cascadia subduction zone earthquakes and tsunamis at Yaquina River estuary, Oregon, USA N.A. Graehl et al. (Kelsey, corresponding author), Dept. of Geology, Humboldt State University, Arcata, California 95524, USA. Published online 7 Aug. 2014; http://dx.doi.org/10.1130/B31074.1.