On Hawaii’s Big Island, Mauna Loa is the world’s most active volcano. It’s erupting for the first time since 1984.
On Monday, November 28, the United States Geological Survey (USGS) issued a Volcano Alert Level set at “Warning,” and an Aviation Color Code “Red.” However, things could change rapidly; sign up for email updates here.
Covering more than half of the island, Mauna Loa has erupted 33 times since 1843. However, since the last eruption in 1984, the volcano has had the most extended quiet period in its history.
Experts say the eruption appears to be contained chiefly in the summit caldera, Moku’āweoweo. The last eruption also started with the summit caldera, but fissures opened quickly in the Southwest Rift Zone. As a result, lava flowed toward Hilo (but didn’t reach the city’s outskirts before the eruption ended).
Where Is Mauna Loa?
Mauna Loa’s summit crater is approximately 21 miles west of Kilauea. Kilauea is a smaller volcano that erupted in 2018, covering the Leilani Estates neighborhood with lava and destroying more than 700 homes.
Can I Still Travel To The Big Island?
Flights between Hilo and Honolulu have been affected. The two major airlines on the islands, Southwest and Hawaiian, are giving travel waivers to people holding tickets for those flights.
Per the Hawaii Department of Transportation, “Passengers with flights to Hilo International Airport (ITO) or the Ellison Onizuka Kona International Airport at Keahole (KOA) should check with their airline prior to heading to the airport due to the volcanic activity at Mauna Loa.”
Early on Tuesday, November 29, the USGS stated, “There is no active lava within Moku’āweoweo 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.”
Residents concerned about Mauna Loa lava flows should check emergency preparedness plans on the Hawaii County Civil Defense website.
There Were Signs Of Unrest
USGS has been monitoring Mauna Loa’s unrest; last month, they reported elevated seismic activity and a heightened possibility for earthquakes. Since June 2022, seismic events have increased from 5–10 a day to 10–20 a day in July and August. Earthquakes peaked at more than 100 a day on September 23 and 29.
In October, Hawaii Volcanoes National Park closed the Mauna Loa summit to backcountry hikers. However, the U.S. National Park Service said the park’s main section has remained open.
As in earlier eruptions, Mauna Loa activity can be unpredictable: where it erupts and in which direction the lava flows can change quickly. If the eruption stays in Moku’āweoweo, the caldera walls will likely contain the lava. However, lava will move swiftly downslope if vents open outside the caldera.
At this point, the activity does not threaten communities in the area and there are no evacuation orders. However, in a precautionary move, two shelters have opened. Authorities warn that people with respiratory issues should stay indoors and everyone should wear a mask over their mouth and nose when they go outside.
Want to learn more about volcanos in Hawaii and elsewhere? See these TravelAwaits articles: