Mauna Loa: The world's largest active volcano erupts in Hawaii for the first time in 40 years

The world's largest active volcano in Hawaii, Mauna Loa erupted for the first time in a 40-year period.

The majority of lava channels are still present in the top of the mountain, but the community is already on standby. Initially, people around the mountain were also warned of the power of ash rain.

The United States Geological Service (USGS) explains conditions can vary rapidly.

The status of this volcano is already enhanced from "vigilant" to "watch out" - the highest level.

There was no rescue order, and residents living in the vicinity of the mountain were not affected at this stage, officials on the spot said.

Mauna Loa, is within the territory of Hawaii Volcanoes National Park which includes half of the Great Island in that U.S. side of the country.

The volcano has an elevation of 13,679 feet (4,169 mtr.) at sea level, and has an area of more than 2,000 square miles (5,179 sq km).

The mountain erupted at 23:30 a.m. time on the spot at MMinggu (09:30 GMT Monday) at Moku'āweoweo, a caldera of volcanic peaks.

The caldera is a large arch created shortly after the emptying of the magma kitchen chamber in a volcanic explosive eruption.

The eruption was a series of initial warnings if an eruption was likely to occur after a series of earthquakes, accounting for several dozen earthquakes delivered on Sunday alone.

An ash rain warning - which could pollute water stocks, kill some plants and irritate the lungs - was applied last night to residents in the mountain's surrounding area, but the warning has been withdrawn.

"Based on the initial events, the initial stages of the Mauna Loa eruption can be really active, and the locations and channels of the lava can differ rapidly," the USGS said.

If the eruption switches beyond the caldera wall, the lava channel can "move rapidly down the slope," he continued.

Based on USGS records, Mauna Loa has exploded about 33 times since 1843. The most recent eruption occurred in 1984 in which lava channels poured out within 5 miles of Hilo, the island's most populous city.

But the community on the Big Island has more than 2x since 1980 to 200,000. Hawaii's civil defense body has warned its people it can deal with "lava calamities".

"These lava channels rarely pose a risk of death, but they can completely destroy infrastructure," said Dr Jessica Johnson, a British volcano geophysicist who had worked at the Hawaiian Volcano Observatory.

He warned that lava channels could be at risk in Hilo and Kona (other densely populated areas), and added that volcanic gas could cause respiratory problems for residents on the spot.

Mauna Loa is the largest active volcano in the world. There are other volcanoes getting bigger and bigger, but their status is not active again. The meaning has long been unexploded, or extinguished, and almost certainly not exploded in the period to come.

Mauna Loa is on a Big Island along with Mauna Kea - the highest mountain in the world, when measured from its base of nearly 20,000 feet at sea level.