The eruption began Sunday evening at 11:30 p.m. local time (9:30 a.m. Monday GMT), the American Institute of Geophysics (USGS) announced in a warning message.
“Currently, the lava flows are contained at the summit and do not threaten populations downstream,” he first clarified.
On Monday morning, in response to a photo posted on Twitter that appeared to show lava, the USGS said it "appears that lava may be escaping from the caldera."
"There is no indication of any progress of the eruption into a rift zone," which allows magma to travel more easily underground, the institute added on Monday.
“The first phases of a Mauna Loa eruption can evolve quickly and the location and progress of lava flows can change quickly,” warned the Institute in its first note on Sunday.
The Mauna Loa volcano erupting in Hawaii on November 28, 2022 Handout US Geological Survey / AFP
The winds could carry "volcanic gas and Pele's hair," volcanic glass fibers, the USGS said.
The US Weather Service (NWS) has warned that volcanic ash could accumulate around the volcano.
Mauna Loa, which rises to 4,169 meters, is located on the island of Hawaii, the largest of this Pacific archipelago.
The volcano has erupted 33 times since 1843. Its last was in 1984, and lasted 22 days.
© 2022 AFP