Mauna Loa volcano: No evac orders, but residents on alert

Mauna Loa erupting tonight. #MaunaLoaErupts pic.twitter.com/OOVAna68dI

— Laney K (@laneybalaoro) November 29, 2022

Mauna Loa volcano is erupting

Mauna Loa volcano – the world’s largest active volcano – began erupting on Sunday (November 27, 2022) for the first time since 1984. AP reported early on November 29 that, for now, lava is not threatening any homes or communities. Despite some social media assertions to the contrary, no evacuation orders have been issued. Some residents are evacuating voluntarily. AP said this morning:

Lava could eventually reach neighborhoods as it flows downhill, though it could take a week or more for molten rock to reach populated areas.

It must be a spectacular sight, though, with reports of lava shooting 100 to 200 feet (30 to 60 meters) into the air. Also, we’re seeing many photos like the one above, showing reddened skies above the volcano.

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This preliminary map of the eruptive activity at Mauna Loa shows the location of three fissures erupting on the Northeast Rift Zone. We will be providing a more detailed map once our field crews have reported flow locations. #MaunaLoa #MaunaLoaErupts pic.twitter.com/GPP3OEV3iw

— USGS Volcanoes? (@USGSVolcanoes) November 28, 2022

Report from the Hawaiian Valcano Observatory

The Hawaiian Volcano Observatory (HVO) issued its most recent report on Tuesday, November 29 at 2:55 UTC. It wrote:

The eruption of Mauna Loa continues on the Northeast Rift Zone. Three fissures erupted and as of 1:30 p.m., only the lowest of the three fissures was active. Estimates of the tallest fountain heights are between 100–200 feet (30 – 60 meters), but most are a few yards (meters) tall. The fissures sent lava flows to the northeast and parallel to the rift zone.

Lava flows from the two higher fissures moved downslope but stalled about 11 miles (18 km) from Saddle Road.

Fissure 3 is currently feeding lava flows moving east parallel to the Northeast Rift Zone. These remain at above 10,000 feet elevation and over 10 miles (16 km) away from Saddle Road. We do not expect upper fissures to reactivate. However, additional fissures could open along the Northeast Rift Zone below the current location, and lava flows can continue to travel downslope.

There is no active lava within Moku’aweoweo caldera, and there is no lava erupting from the Southwest Rift Zone. We do not expect any eruptive activity outside the Northeast Rift Zone. No property is at risk currently. There is a visible gas plume from the erupting fissure fountains and lava flows, with the plume primarily being blown to the northwest.

The HVO had said yesterday that – if the eruption remains in Moku’aweoweo – lava flows will most likely be confined within the caldera walls. However, if the eruptive vents migrate outside its walls, lava flows has the potential to move rapidly downslope.

To recap, 3 fissures erupted but as of 1:30 PM, only the lowest of the three fissures was active. Estimates of the tallest fountain heights are between 100–200 ft (30–60 m), but most are a few yards (meters) tall. pic.twitter.com/hdchghwB1N

— USGS Volcanoes? (@USGSVolcanoes) November 29, 2022

Residents should remain alert

Residents at risk from Mauna Loa lava flows should review preparedness and refer to Hawai‘i County Civil Defense information for further guidance.

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.

Mauna Loa volcano is the largest active volcano on Earth, it just started erupting. Here's the caldera filling up with lava in the last 2 hours (last frame from 14min ago). Take care my friends on Big Island!
Images used to make this gif from: https://t.co/dIK3AnLiYX https://t.co/uUVkIIBrlC pic.twitter.com/ZfvVi5O7Oi

— Dr James O'Donoghue (@physicsJ) November 28, 2022

Summit, cabins and high-elevation areas closed

The surrounding Hawai‘i Volcanoes National Park had previously closed Mauna Loa’s summit, cabins and high-elevation areas due to increased seismic activity, as the USGS continued to closely monitor Mauna Loa for changes.

Around 11:30 p.m. HST last night, @NOAA's #GOESWest ?? captured the eruption of Hawaii's #MaunaLoa volcano, inside @Volcanoes_NPS.

This imagery shows the heat signature and the sulfur dioxide released from the #volcano's summit caldera, Moku‘?weoweo. pic.twitter.com/gHEG63rbLb

— NOAA Satellites (@NOAASatellites) November 28, 2022

Bottom line: Mauna Loa volcano in Hawaii is erupting for the 1st time in 38 years. As of Tuesday morning, November 29, 2022, the Hawaiian Volcano Observatory is reporting “no property is at risk” at this time.

Read more from AP: How dangerous is Mauna Loa’s eruption in Hawaii?