Strike-slip 23 January 2018 M_W 7.9 Gulf of Alaska rare intraplate earthquake: Complex rupture of a fracture zone system.

ABSTRACT: Large intraplate earthquakes in oceanic lithosphere are rare and usually related to regions of diffuse deformation within the oceanic plate. The 23 January 2018 M_W 7.9 strike-slip Gulf of Alaska earthquake ruptured an oceanic fracture zone system offshore Kodiak Island. Bathymetric compilations show a muted topographic expression of the fracture zone due to the thick sediment that covers oceanic basement but the fracture zone system can be identified by offset N-S magnetic anomalies and E-W linear zones in the vertical gravity gradient. Back-projection from global seismic stations reveals that the initial rupture at first propagated from the epicenter to the north, likely rupturing along a weak zone parallel to the ocean crustal fabric. The rupture then changed direction to east

SUBMITTER: Krabbenhoeft A 

PROVIDER: S-EPMC6135818 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature