Authorities say flows of lava are not yet threatening local communities, but that it is impossible to predict how long the volcano's first eruption in four decades would last.
Mauna Loa, the world's largest active volcano, erupted for the first time in nearly four decades the US Geological Survey (USGS) said. The volcano's eruption began late Sunday night at the summit on Hawaii's Big Island. The eruption moved from the summit to the northeast rift zone on Monday, where fissures are feeding several lava flows the USGC said. The agency however added that they weren't threatening communities down the mountain. The USGS has warned residents at risk from lava flows to review their eruption preparations. "Based on past events, the early stages of a Mauna Loa eruption can be very dynamic and the location and advance of lava flows can change rapidly," the USGS warned. Mauna Loa, which takes up more than half of the Big Island in Hawaii, last erupted in 1984, sending a flow of lava within 5 miles (8.05 km) of the city of Hilo. It is one of five volcanoes that together make up the Big Island of Hawaii, and has erupted 33 times since 1843, according to USGS. During a 1950 eruption, the mountain's lava traveled 15 miles (24 kilometers) to the ocean in less than three hours.