[3] The earthquake was associated with a 600 km long rupture along the plate boundary, based on the distribution of aftershocks.

Modelling of the tsunami supports the idea that the earthquake consisted of three sub-events, related to three structural 'blocks' within the overriding plate.

[5] The main shock was followed by an earthquake of magnitude 7.6 nearly two months later, that triggered a small tsunami.

It was also observed in Peru, Ecuador, Mexico, California, Japan and eastern Russia.

[2] Minor damage from the earthquake was recorded on both Attu and Shemya islands in the form of cracks in runways.