Mauna Loa lava flow

The Mauna Loa Volcanic Eruption in Context

Cover image: A lava flow from the 2022 eruption of Mauna Loa. Credit:

Mauna Loa Volcanic Eruption

For the first time since 1984, the largest active volcano on earth has erupted. That volcano is Mauna Loa, a 13,679-foot-tall behemeth, which covers more than 2,000 square miles on the Island of Hawaii in the Pacific Ocean. The eruption, which primarily consists of gas plumes and lava flows, was preceded by a period of unrest and seismic activity stretching back to mid-September of 2022.

While the lava flows do not directly threaten any homes, there is concern that they might reach the busy Daniel K. Inouye Highway, which runs from east to west across the Big Island. The smaller, nearby Kilauea volcano has been erupting continuously for 39 years and has destroyed hundreds of homes.

Below is a nighttime photo of the Mauna Loa eruption.

The Mount St. Helens Eruption

While the current Mauna Loa eruption is geologically significant and visually striking, it pales in comparison to the eruption that devastated parts of southwestern Washington, U.S.A. on May 18, 1980. That, of course, was the massive explosive eruption that blew the top off Mount St. Helens. Prior to that eruption, there were two months of tremors and the formation of a mile-wide, magma-filled bulge on the side of the volcano. The blast caused one of the biggest landslides in world history and was followed by devastating pyroclastic flows and floods. The Mount St. Helens eruption killed 57 people, laid waste to 210 square miles of wilderness, and flattened some 10 million trees.

The 1980 Mount St. Helens eruption. Credit:

The Most Dangerous Active Volcanoes in the World

Though Mauna Loa is not threatening human life at the moment, future eruptions might be more dangerous. There are numerous other volcanoes around the world that pose a threat to civilization. Here are just a few:

  • Yellowstone Caldera, U.S.A.: It is the largest super volcano in the world and it is right here in Wyoming. A magnitude-8 eruption rocked the region 640,000 years ago.
  • Mount Vesuvius, Italy: Millions of Naples residents live in the shadow of this famous volcano, which buried Pompeii in 79 AD.
  • Sakurajima, Japan: An extremely active site, this volcano is a threat to the residents of Kogoshima.
Naples, Italy with Mount Vesuvius in the background.

The Biggest Volcanic Eruptions of All Time

Although Mauna Loa is getting press, this is not because it will have a significant impact on the regional or world ecosystems. Other eruptions, however, have had impacts that radiated around the globe. Here are three major events from the past several hundred years.

  • Laki, Iceland (1783): Atmospheric haze from this eruption stretched all the way to Syria. The fallout and subsequent famine killed a quarter of all Icelanders.
  • Mount Pinatubo, Philippines (1991): The explosive eruption of this 4,800-foot volcano sent ash 28 miles up into the atmosphere. It was the largest eruption in the 20th Century.
  • Krakatoa, Indonesia (1883): The eruption on the small, uninhabited island of Krakatoa was epic in scale. The blast was heard thousands of miles away and generated a massive tsunami that killed 34,000 people. Atmospheric disturbances and pollution were detected around the world.
The eruption of Mount Pinatubo, Philippines. Credit:

Receive exclusive content and special updates by joining the ELEVATION mailing list below.

Success! You're on the list.

Leave a Reply