Seamount

A Seamount in simple terms is a mountain rising from the sea floor. Seamounts are usually found in chains. A classic example, one clearly demonstrating plate tectonics, is found in the Emperor Seamounts. Isolated seamounts and those without clear volcanic origins appear to be less common.

Seamounts often project into the zone more hospitable to sea life and thus provide submerged islands for marine species that would not be found in the surrounding ocean. In addition to simply providing a bottom in this zone the seamount may deflect currents and create upwelling bringing nutrients into the photosynthetic zone producing islands of food production in otherwise desert like open ocean. Seamounts may thus be vital stopping points for migratory animals. There is also evidence that some animals, particularly the large whales, may use seamounts as navigational aids.

The classic seamount is submerged. In fact, many oceanic islands are simply exposed seamounts. Mauna Loa is a classic example.

Links:

• Volcanic History of Seamounts in the Gulf of Alaska (http://oceanexplorer.noaa.gov/explorations/02alaska/background/geology/geology.html)

• Hydrographic structure and circulation at the Great Meteor Seamount (http://www.awi-bremerhaven.de/Modelling/BRIOS/seamount.html) showing an example of an isolated seamount and the formation of a submerged island of life.

• Seamount Oasis (http://www.uaf.edu/seagrant/NewsMedia/02ASJ/09.13.02seamount-oasis.html)

Mauna Loa (http://wwwhvo.wr.usgs.gov/maunaloa/) Earth's Largest Volcano from USGS