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).