One is the occasional methane eruption from underwater methane clathrate deposits in these areas. In waters 300 to 2000 meters deep, methane clathrate (methane hydrate) can form at specific temperatures. Changes in pressure and temperature allow methane to escape from the hydrate pieces. If the changes occur suddenly, large amounts of methane can form in a concise time, and an eruption occurs. An eruption can be triggered by a sea quake (an earthquake in coastal regions) or tectonic shifts.
