The abundance of submarine volcanism in arcs

Abstract

Explosive submarine arc volcanoes can cause tsunamis, affect climate, and pose hazards to airplanes and ships. Although 70 % of the Earth is submarine, only 15 % of Holocene arc volcanoes in the Smithsonian Global Volcanism database are submarine. Merging locations of active submarine hydrothermal vents in arcs and the above database, we found 71 unlisted submarine arc volcanoes. Using Baker [2017, doi: 10.1016/j.oregeorev.2017.02.006], only 44 % of hydrothermal vents in arcs are known. Only 77 of the vent fields are on volcanoes in the Smithsonian database. Assuming that unknown submarine arc volcanoes are present in the same proportions as unknown vents, there are ~160 as-yet undiscovered Holocene age submarine arc volcanoes. Using geophysical data, we located 291 unsurveyed seamounts <30 km from arc axes, the distance within which active vents occur. We estimate 119±16 have active vents. Because more unknown seamounts exist, this means that >32 % of Holocene arc volcanoes are submarine.