Officials at ONC have stressed that the effects will be mild and local, and that residents on land are extremely unlikely to feel the quake.

Nor is it likely to trigger tsunami activity, as a tsunami is set off by a different type of tectonic plate boundary movement: pushing together and slipping, rather than pulling apart.

'No one should be alarmed about this great swarm of earthquakes. They are far offshore and cause no danger. Rather, the data are exciting to the science community and certainly not menacing,' said Kate Moran, ONC President and CEO, in the statement from ONC.