What If The World’s Largest Active Volcano in Hawaii Erupted Right Now?

What If The World's Largest Active Volcano in Hawaii Erupted Right Now

Mauna Loa is the largest active volcano in the world, and it is located on the Big Island of Hawaii. It is so massive that its summit is about 13,678 feet (4,170 meters) above sea level. But its base is actually below sea level, making it the largest volcano by volume in the world! So, what would happen if Mauna Loa erupted right now? Let’s dive in to learn more about its catastrophic impacts.

Mauna Loa covers around half of the island of Hawaii. It had a few minor scale eruptions 34 times since 1843, and its last eruption was in 2022. When measured from the bottom of the sea, it stands up to 30,000 feet — more than 1,000 feet taller than the height of Mount Everest!

Typically, Mauna Loa eruptions start off with the heaviest volume first. We don’t want to try and second-guess the volcano. We have to let it actually show us what it’s going to do and then we inform people of what is happening ASAP,says the scientist-in-charge at the Hawaiian Volcano Observatory, Ken Hon.

Ways It Can Erupt

Mauna Loa can erupt in a variety of ways. The most common type of eruption is a Hawaiian eruption, which is characterized by the emission of lava flows. These lava flows can be very slow-moving, but they can also be very destructive!

Mauna Loa can also erupt in a strombolian eruption, which is characterized by the emission of ash, cinders, and bombs. These eruptions are typically more explosive than Hawaiian eruptions, but they do not produce as much lava.

In rare cases, Mauna Loa could erupt in a Plinian eruption, which is the most explosive type of volcanic eruption! Plinian eruptions are characterized by the emission of large amounts of ash, gas, and steam. These eruptions can be devastating, and they can have a global impact!

The location of the eruption would also play a role in its impact. If the eruption occurred on the summit of Mauna Loa, the lava flows would most likely flow down the flanks of the volcano and into the ocean! However, if the eruption occurred on the side of the volcano, the lava flows could potentially threaten populated areas.

Image source: PBS

Devastating Impact To The U.S.A

If Mauna Loa were to erupt right now, the consequences would be profound. First and foremost, it would pose a significant threat to the people living on the Island. The immediate danger would be from lava flows, which can move at approximate speeds of up to 35 miles per hour.

A massive eruption can result in damage to the entire island. The east and west sides of Hawaii will probably be destroyed completely. The consequences will be catastrophic for other islands in the Hawaiian archipelago as well. It doesn’t stop there. The coasts of California, Oregon, and Washington in the USA will also face the devastating impacts of an eruption! If proper warning is not given, there will be a loss of thousands of lives, if not millions.

Ash Plumes into the Atmosphere!

A massive eruption would send a plume of ash and gas into the atmosphere that could travel thousands of miles! This ash could fall on the island of Hawaii and other areas. It can even cause respiratory problems and other health problems. The ash could also contaminate water supplies and damage crops.

Another immediate concern would be air quality. The volcanic eruption would release vast amounts of sulfur dioxide (SO2) and other harmful gases into the atmosphere. This could lead to poor air quality. People with respiratory issues would be particularly vulnerable.

Image source: Telegraph co.uk

Volcanic Ash Reaching The Stratosphere!

The eruption of Mauna Loa would also have global implications. The release of volcanic gases, particularly sulfur dioxide, can reach the stratosphere and impact the Earth’s climate. These gases can lead to the formation of sulfate aerosols, which can reflect sunlight and cool the planet. The resulting “volcanic winter” effect could lower global temperatures, affecting agriculture and ecosystems worldwide.

If Mauna Loa erupted in the most destructive way right now, the effects would be felt even throughout the United States. The ash clouds would blanket the Hawaiian Islands, and even parts of the U.S.A. as well!

Ash clouds can stretch for hundreds of miles from the eruption source. Pyroclastic flows and debris will build up to thousands and thousands of feet. Output of lava will reach miles from the mountain summit or the top.

Image source: Associated press

Lahars and Tsunamis

One of the lesser-known dangers associated with Mauna Loa’s eruptions is the potential for lahars. Lahars are fast-moving volcanic mudflows that can occur during or after eruptions. These can be triggered by heavy rainfall or the melting of snow and ice on the volcano’s summit.

Lahars can be incredibly destructive! They sweep away everything in their path and impact communities downstream. The lava flows could inundate low-lying areas, such as the Hilo as well.

Additionally, Mauna Loa’s eruptions can trigger underwater landslides! This has the potential to lead to Catastrophic tsunamis. These tsunamis could affect not only Hawaii but also the West Coast of the United States! The waves could be hundreds of feet high and could cause widespread damage to coastal communities.

The tsunamis generated by the eruption could wipe out areas such as Honolulu, California, and Oregon. Warning systems would need to be activated to mitigate the impact on coastal communities.

The aftermath of a Mauna Loa eruption would be felt for years if not decades. Lava flows could reshape the landscape, covering large areas with new land. The volcanic soil would eventually become fertile ground for new plant growth, but it would take time for the ecosystem to recover fully.

Image source: Gifcen

There is still no warning of an eruption that scale. However, the Hawaiian Volcano Observatory and USGS are actively keeping an eye on the volcanic activity of Mauna Loa. So, the public will hopefully be warned before millions of lives are lost.


Mauna Loa is a powerful volcano that has the potential to cause significant damage. However, by being informed and prepared, we can reduce the risks posed by a Mauna Loa eruption.

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