Water And Oceanography

Underwater Volcanoes

Jennifer Boyd's image for:
"Underwater Volcanoes"
Image by: 

Many people have heard of undersea volcanoes but are clueless as to the different types and what each one may do or cause, the seamount is a mountain that rises from the ocean floor but often does not break the surface of the water. A seamount is usually formed by an extinct volcano that may rise unexpectedly and quickly from the sea floor. In 1964 a definitionwas given to what would be classified as a seamount: “an isolated elevation rising of 3,281 ft or more from the surrounding seafloor, and with a limited summit area.” Today though scientists have seen fit to be more lenient on what they classify as a seamount and have called rises with less than 328 feet a seamount.

Since most seamounts are originally volcanic in nature there is an abundance near ridges and plumes throughout the ocean floors. It is believed that nearly half of the estimated 100,000 seamounts are located within the Pacific Ocean while the rest are scattered throughout the Atlantic and Indian oceans. With the definition of the seamount becoming more lacks there are more small plateaus and mountain like structures that may qualify as a seamount boosting that 100,000 to as many as two million.

Due to the immense amount of believed seamounts they are one of the most common oceanic ecosystems to be found in the World’s oceans. A seamount is a virtual resort for sea creatures or could even be classified as a restaurant of sorts as the seamounts attract plankton, the plankton attract fish and the fish in turn attract larger varieties of fish that wish to feed upon those plankton eating fish. Sharks and large scavengers may be seen flocking to these undersea “restaurants” as the pickings offered are usually plentiful, it is also possible to occasionally see whales near seamounts as they migrate do the whales use the seamounts as a guiding system during migration or just know that a good meal can be had there.

Extensive damage can be caused to these seamount communities, intentionally or not as they are often a natural fishery offering up the fisherman some fine pickings. It is unknown what the long term effects of overfishing could cause on the oceanic ecosystem within the seamount area due to the lack of research being done on seamounts. One of the most often studied seamounts is Davidson Seamountlocated about 80 miles to the south of Monterey, California discovered in 1933 where six different expeditions have been done and over 60,000 different species have been observed and samples have been taken from such places as the deep sea coral garden where it was discovered that some species are over 100 years old. Thankfully in November of 2008 the Davidson Seamount was declared part of the Monterey Bay National Marine Sanctuary thus saving at least this seamount from untold destruction.

More about this author: Jennifer Boyd

From Around the Web

  • InfoBoxCallToAction ActionArrowhttp://www.eoearth.org/article/Seamount
  • InfoBoxCallToAction ActionArrowhttp://www.tos.org/oceanography/archive/23-1_staudigel6.pdf
  • InfoBoxCallToAction ActionArrowhttp://cmsdata.iucn.org/downloads/alexrogers_cbdcop7_seamounts_complete1_1.pdf
  • InfoBoxCallToAction ActionArrowhttp://montereybay.noaa.gov/research/dsmz/welcome.html