Natural Wonder

Mauna Loa Volcano Erupting For First Time In 40 Years: What To Know

The Mauna Loa volcano on the island of Hawaii is actively erupting — here’s everything you should know.

Photo taken in Hilo, United States
Martin Klima / EyeEm/EyeEm/Getty Images

The world’s largest volcano is erupting for the first time in nearly 40 years. The Mauna Loa volcano on the island of Hawaii first appeared to have its lava confined to the volcano’s caldera, but reports say it’s now flowing downslope. The intense feat of nature is astounding, as are the unique qualities of this volcano. There is a livestream of the Mauna Loa eruption now for those of us far away — but, of course, there are dangers to know about for Hawaiians too.

What is the Mauna Loa volcano?

The Mauna Loa volcano is known as the world’s largest volcano, towering 13,677 feet above sea level, according to Britannica, and it makes up half of the Big Island of Hawaii’s area. The volcano’s dome is 75 miles long and 64 miles wide, with the summit caldera taking up approximately 6 square miles and going 600 feet deep.

According to NBC, the volcano, which means “Long Mountain,” covers half of the island. It has erupted 33 times since the United States Geological Survey (USGS) began keeping records in 1843. Mauna Loa is one of six volcanos in Hawaii, and it’s one of the most active in the world.

The USGS warned Hawaii residents early in September that an eruption was likely to occur since there was an increase in earthquakes, NBC reports. The Hawaiian Volcano Observatory told the publication that Mauna Loa has been in a state of “heightened unrest” since mid-September, when the number of summit earthquakes “jumped from 10 to 20 per day to 40 to 50 per day.”

Aerial photos taken at 7:15 AM local time (HST) from Civil Air Patrol flight. Northeast rift zone eruption of Mauna Loa.

Public Domain / United States Geological Survey

Why is it significant the volcano is erupting right now?

“Mauna Loa began to erupt at 11:30 PM HST on Sunday night,” the USGS tweeted. “The eruption is currently confined to the summit, and there is no indication that magma is moving into either rift zone at this time.”

The last time Mauna Loa erupted was in 1984, making this one of the longest periods of rest for the volcano, according to the USGS. “Over the past 3,000 years, Mauna Loa has erupted approximately once every 6 years,” the agency explains. That’s why an eruption now, 38 years later, is significant.

“The significance of Mauna Loa erupting comes from a variety of historical reasons,” tweeted Dr. Robin George Andrews, who holds a Ph.D. in volcanology. “But the fact that it is a hazardous mountain that hasn’t erupted since 1984 – the longest eruptive pause in its recorded history – is why we should all keep an eye on it.”

Mauna Loa eruption as viewed from Waikoloa at about 1:25am local time (HST). The eruption is occurring from the summit of the volcano, though lava has overflowed the caldera.

Public Domain / United States Geological Survey

Is the community near the volcano in danger?

According to the latest reports from the USGS, the eruption of Mauna Loa isn’t likely to threaten the local community's safety. However, the agency has issued a red warning for volcano activity.

“The eruption of Mauna Loa has migrated from the Summit to the Northeast Rift Zone,” the notice states, reiterating that the danger is not likely to move from there. But the community is ready just in case. People are urged to keep an eye on updates from USGS on its website.

There is a risk, however, of ash deposit from the volcano, which can potentially bring respiratory concerns.

“People with respiratory illnesses should remain indoors to avoid inhaling the ash particles, and anyone outside should cover their mouth and nose with a mask or cloth,” the Honolulu Tourism Authority warned. “Possible harm to crops and animals. Minor equipment and infrastructure damage. Reduced visibility. Widespread clean-up may be necessary.”

Aerial photos taken at 7:15 AM local time (HST) from Civil Air Patrol flight. Northeast rift zone eruption of Mauna Loa.

Public Domain / United States Geological Survey

You can watch the Mauna Loa volcano eruption on a livestream.

For families with kids interested in geological events like a volcano eruption, it can safely be watched from the comfort of your home. The USGS has a livestream video of Muana Loa from several angles, zones, and a thermal view.

Visit the USGS website for a full list of webcam images for the Mauna Loa volcano, though you should note that they may not be totally up-to-date and the webcams won’t be repaired immediately if one goes down — for what are fairly obvious reasons.