Mauna Loa: World's largest active volcano erupts in Hawaii

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, a message reinforced by the Big Island mayor.

"At this time, it's not a time to be alarmed,'' mayor Mitch Roth said.

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.

Are residents near the volcano in danger? 

The agency said it was impossible to predict how long the eruption would last and whether it could cause lava to flow to populated areas of the island.

"But I can tell you, we're in constant communication right now with Hawaii Civil Defense, and they're providing updates to community members,'' Miel Corbett, a USGS spokesperson said.

The National Weather Service in Honolulu issued an ashfall advisory warning, saying up to a quarter-inch (0.6 centimeters) of ash could accumulate in some areas.

Mauna Loa: The biggest volcano on Hawaii's Big Island

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.

lo/rt (AP, AFP, Reuters)