Upper-plate structure and tsunamigenic faults near the Kodiak Islands, Alaska, USA

Abstract The Kodiak Islands lie near the southern terminus of 1964 Great Alaska earthquake rupture area and within subduction zone segment. Both local trans-Pacific tsunamis were generated during this devastating megathrust event, but tsunami source region causative faults are poorly understood. We provide an updated view hazard for through modeling geophysical data analysis. Using seismic bathymetric data, we characterize a regionally extensive seafloor lineament related to shelf fault zone, with focused uplift along 50-km-long portion newly named Ugak as most likely in 1964. present evidence Holocene motion Albatross Banks suggest that did not produce relate major structural boundaries active forearc splay faults, where tectonic is collocated gravity lineations. Differences interseismic locking, seismicity rates, potential field signatures argue different stress conditions at depth presumed segment boundaries. find have clear expression linked upper-plate structure faulting. tsunamigenic higher when compared nearby suggesting short wave travel paths little warning time communities.