Submarine Volcanism Group
The seamounts (submerged mountains) off California and some chains near mid-ocean spreading ridges are not of the usual hot spot or subduction arc origin. Near-ridge seamounts erupted near the axes of mid-ocean ridges onto recently formed oceanic crust. The seamounts off California erupted on top of abandoned ridges.
Volcanic eruptions and flank collapses are significant geologic hazards. While volcanic events and deposits in the ocean are largely concealed from view and more difficult to sample than volcanoes on land, submarine volcanoes are an integral part of the way the Earth works. The submarine volcanism group studies processes that form and modify volcanoes in the sea.