Kilauea has oozed lava and ash onto Hawaii’s Big Island for a week—and the volcano might be ready for its most violent eruption yet.
The volcano’s “lava lake” is starting to drop, according to the U.S. Geological Survey’s Hawaiian Volcano Observatory. When the lava lake starts to drop, it gets closer to groundwater under the volcano. If water seeps into the lava lake, it becomes steam. If falling rock plugs the lava conduit from above while steam pressure builds from below, it triggers an explosive eruption.
Steam-driven volcanic eruptions can hurl massive boulders (some weighing up to several tons) as far as half a mile from the volcano’s cone. Smaller rocks could go several miles. Ash and toxic gas like sulfur dioxide could erupt as well. The eruption could come with “very little warning,” the HVO notes.
“At this time, we cannot say with certainty that explosive activity will occur, how large the explosions could be, or how long such explosive activity could continue,” the HVO said Wednesday.
Because of the threat a “possible explosive steam event,” Hawaii Volcanoes National Park is set to close Friday until further notice, the National Park Service announced Thursday.
“Due to the possibility of a steam-induced explosion at the summit of Kīlauea due to the receding lava lake, an ensuing ash fall event, plus southerly wind patterns forecasted for Friday, the majority of the park will be closed Friday until further notice,” the announcement read. “We will reopen when it is safe to do so.”
For the past week, most of Kilauea’s eruptions have come through the ground in the area around the volcano. Fissure eruptions spewed lava into the Leilani Estates subdivision earlier in the week, forcing the evacuation of 1,700 people and destroying 26 homes. A magnitude-6.9 earthquake last week added to the carnage.
But while Kilauea seemed to rest on Tuesday, it has since reawakened with a vengeance. Another 66 feet of lava flowed through the subdivision on Wednesday, the USGS said. In the afternoon, a new steaming-hot lava flow had emerged near the Big Island’s Highway 130.