Volcanoes on the sea floor can grow and collapse in rapid pulses, reports a study published online this week in Nature Geoscience. Due to their inaccessible nature, little is known about the evolution of submarine volcanoes. This study provides insights into the frequency and rate at which such volcanoes can erupt and grow.

Anthony Watts and colleagues surveyed the topography of the active Monowai volcano, a submarine volcano on the southwest Pacific Ocean floor near Tonga, in May and June 2011. Over a two-week period, repeated mapping of the seafloor topography showed that parts of the volcano had collapsed by almost 19 m. Elsewhere, newly erupted lava flows helped to build up the volcano, increasing its height in some places by almost 72 m. The short-term collapse and growth rates measured at Monowai and reported in this study are incredibly high compared with known long-term growth rates for submarine volcanoes, implying that the sea floor can be dynamic.