An
oceanic plateau (also
submarine plateau) is a large, relatively flat submarine region that rises well above the level of the ambient seabed. While many oceanic plateaus are composed of
continental crust, and often form a step interrupting the
continental slope, some plateaus are undersea remnants of
large igneous provinces. These were formed by the equivalent of continental
flood basalts such as the
Deccan Traps in India and the
Snake River Plain in the
Pacific Northwest of the
United States. There are over 180 oceanic plateaus covering an area of 18,486,600 km2, or about 5% of the oceans. The South Pacific region around Australia and New Zealand contains the greatest number of oceanic plateaus (see map).