The earthquake was initially reported as 8.0 Mw before it was downgraded to 7.9.[3] The rupture was on a normal fault, at ~107 km depth. Based on the geometry of the slab, and the relative movement of the tectonic plates, the slip vector is likely to have been oblique down-dip towards the ESE. The fault plane appears to be oblique, striking NW-SE and cutting steeply into the subducting slab.
Tsunami
A tsunami warning was issued,[4] but was soon downgraded to a tsunami advisory for much of the Aleutian Islands;[5] however, the hypocenter was too deep to generate a tsunami that would affect the Pacific basin.[6] A small non-destructive tsunami was generated, with heights of 17 cm on Amchitka.[7][8]