Hawaii’s Mauna Loa, the world’s largest active volcano, has begun to erupt, causing ash and volcanic debris to fall nearby, authorities said Monday.
The eruption began late Sunday evening in the volcano’s summit caldera on the Big Island, the US Geological Survey said. Early Monday, he said the lava flows were contained in the summit area and did not threaten nearby communities.
“However, the lava flows in the summit area are visible from Kona. There is currently no indication of a migration of the eruption into a fault zone,” the Hawaii Volcano Observatory said in a statement. A fault zone is where the mountain separates , the rock is cracked and relatively weak and it is easier for magma to emerge.
The USGS has warned residents threatened by Mauna Loa lava flows to review their eruption preparations. Scientists were on high alert due to a recent spike in earthquakes at the top of the volcano, which last erupted in 1984.
Parts of the Big Island were under an ashfall advisory issued by the Honolulu National Weather Service, which said up to 0.6 centimeters of ash could accumulate in some areas.
Mauna Loa is one of five volcanoes that together form the Big Island of Hawaii, which is the southernmost island in the Hawaiian archipelago.
Mauna Loa, rising 4,169 meters above sea level, is the much larger neighbor of the Kilauea volcano, which erupted in a residential area and destroyed 700 homes in 2018. Some of its slopes are much steeper than Kilauea’s, so when it erupts, its lava can flow much faster.
During an eruption in 1950, lava from the mountain traveled 15 miles (24 kilometers) to the ocean in less than three hours.