The Biggest Volcano In The United States Just Erupted

The largest US volcano, Mauna Loa in Hawaii, is currently experience eruption activity

By Jennifer Hollohan | Updated

Mauna Loa us volcano largest
Mauna Loa in Hawaii

After a year of seemingly endless bad news, we almost made it to the end without something else cropping up. Almost. Unfortunately, the news that a large US volcano is erupting dashes any hopes of a quiet rest of 2022.

Mauna Loa is located in Hawaii and is the world’s largest volcano. The massive US volcano last erupted 40 years ago. And according to the BBC, “The latest eruption began on Sunday night at Moku’āweoweo, the volcano’s summit caldera.”

Currently, the activity is restricted to the summit caldera, a hollow spot carved out by a previous eruption. The likely cause of Mauna Loa’s awakening is a series of earthquakes in recent days. There were a dozen tremors reported Sunday before the volcano’s activity started.

It is an extremely dynamic situation. The US volcano’s activity is under close surveillance by the US Geological Service (USGS). And the agency rapidly upgraded the public notice from “advisory” status to “warning” on Monday. A USGS “warning” status is the highest volcanic classification the agency uses. Emergency personnel are currently on standby. Additionally, it issued a warning about ashfall.

According to local officials, “Lava flows are contained within the summit area and are not threatening downslope communities.” However, that situation could change rapidly. If the US volcano’s lava crests over the caldera’s walls, it would move downslope quickly.

Given Mauna Loa’s eruption history, USGS officials are wary. They said, “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.” The last time the massive US volcano erupted was in 1984.

That eruption lasted two months – March and April. And the lava got within 5 miles of Hilo, a town on Hawaii (or the Big Island). Based on census data from 2020, over 45,000 people call the city home. 

The island of Hawaii is one of the eight major islands in the archipelago. And it has a population of over 200,000. So, news of the potential danger from the US volcano understandably has tens of thousands of people on edge. However, Mauna Loa is not the only active volcano on the Big Island. The island of Hawaii has five volcanoes, four of which are active. The other three are Hualālai, Kīlauea, and Mauna Kea. 

Data from the USGS shows that “The Island of Hawai’i, with four active volcanoes, is liveliest. Between 1912 and 2012, there were nearly 50 Kīlauea eruptions, 12 Mauna Loa eruptions, and one Hualālai intrusion of magma. Mauna Kea most recently erupted only about 4,000 years ago.”

And the entire Hawaiian archipelago has a shocking 15 volcanoes. Six of those (including the four on Hawaii) are active. So, unfortunately, news of an eruption is all too common. 

The USGS and local officials urge caution and preparedness. They will monitor the situation and issue updated alert statuses as needed. Additionally, local emergency crews will remain on standby until the monster US volcano decides to calm down.