On July 18, 2012, passengers on an airline flight over the Southwest Pacific Ocean glimpsed something unusual -- a raft of floating rock known as pumice that indicated an underwater volcanic eruption had occurred on the seafloor northeast of New Zealand. The raft eventually grew to more than 150 square miles (roughly the size of Philadelphia), a sign that the eruption was unusually large. An international research team led by the University of Tasmania and the Woods Hole Oceanographic Institution used the autonomous underwater vehicle Sentry and the remotely operated vehicle Jason to explore, map, and collect erupted materials from the Havre volcano during a 2015 expedition. They found that the eruption was surprising in many ways. More than 70 percent of all volcanic activity on Earth occurs on the seafloor, but details of these events are largely hidden from view by seawater. Based on the size of the 2012 pumice raft, the eruption of the Havre Volcano was estimated to be the largest documented underwater silicic eruption -- a particular type of eruption that produces viscous, gas-filled lava that often occurs explosively.
Visit Website | Image credit: Rebecca Carey/University of Tasmania/Adam Soule/Woods Hole Oceanographic Institution