Il Nuovo Postiglione - Hawaii deploys National Guard in volcano eruption response

Twenty National Guard members were deployed "to assist Hawaii County with traffic control and other roles in the Mauna Loa eruption," the Pacific island state's emergency management agency announced in a tweet Monday.

Mauna Loa, on the US archipelago's largest island, erupted on November 27 and continues to spew rivers of molten rock on its northern slope.

While the flow has slowed significantly in recent days as it hit flatter ground -- now at an average rate of about 20 feet per hour (6 meters per hour), according to the US Geological Survey -- the volcano continues to pump out a steady supply of lava.

The eruption so far has not threatened any homes but flows have been creeping toward the Daniel K. Inouye Highway, known as Saddle Road.

Lava was 2.2 miles (3.5 kilometers) from the thoroughfare -- the closure of which would force residents to make long detours -- as of Monday afternoon, a USGS bulletin said.

Conditions have made it "difficult to estimate when or if the flow will impact Daniel K. Inouye Highway," the bulletin published Monday added.

The USGS added that sulfur dioxide emissions are down but are still high enough to have "moderate to severe impacts on regional air quality, depending on plume rise rate and wind direction."

The largest volcano on Earth by volume, Mauna Loa, whose name means "Long Mountain," accounts for half of the entire island of Hawaii, known as the Big Island, and is larger than the rest of the Hawaiian islands combined.

One of six active volcanoes on the archipelago, Mauna Loa has not erupted since 1984.

Kilauea, a volcano on the southeastern flank of Mauna Loa, erupted almost continuously between 1983 and 2019, and a minor eruption there has been ongoing for months.

M.Costa--INP