In a paper just published in Nature, A team led by Paul Segall and Peter Cervelli describe a silent earthquake which has caused one slope of the Kilauea Volcano to slide almost 3 and a half inches into the Pacific Ocean. That volcano has been erupting continuously since 1983 in an event called Pu`u `O`o. Volcanoes collapsing into the ocean have caused massive tsunamis in the past.