Attention has turned to the Alaskan-Aleutian subduction zone, a region where one of the earth's tectonic plate, carrying the Pacific Ocean, drops beneath the North American plate.
A particular section of the fault near the Semidi Islands has not ruptured since at least 1788, and measurements on this area - which lies four to five kilometres under water - reveal the pressure is accumulating rapidly.
If the Pacific Ocean plate slips, as happened in the geographically-similar Tohoku subduction zone off the coast of Japan, a tsunami could occur - and the deaths could happen as far away as Hawaii and California. Read More