KEY POINTS

  • Scientists have identified the largest shield volcano in the world. 
  • Puhahonu is twice as big as the Mauna Loa volcano in Hawaii
  • The volcano has an extremely hot mantle

Scientists have confirmed that one of Hawaii’s five volcanoes is the largest shield volcano in the world. According to a new study, it is about twice the size of Hawaii’s Mauna Loa, which was the previous titleholder.

Shield volcanoes are characterized by their dome shapes. Like a shield on the ground, it has a low profile and is composed almost entirely of fluid lava flows.

Previously, Mauna Loa was regarded as the largest shield volcano on Earth. It covers a massive area of 2,035 square miles and is known as one of the five volcanoes that form the island of Hawaii.

Recently, a team of scientists revisited another volcano on the island known as Pūhāhonu. Like Mauna Loa, Pūhāhonu is also one of the five volcanoes that formed the region.

In 1974, Pūhāhonu was regarded as the largest volcano in Hawaii. However, it lost the title to Mauna Loa after its portions hidden below sea level were discovered.

In a new study, which was published in the journal Science Direct, scientists used computer models and new mapping systems to analyze Pūhāhonu’s total size. Through their analysis, the scientists learned that Pūhāhonu is about twice as big as Mauna Loa. Although the latter is still taller, the former covers a wide area in Hawaii.

“Until our study, everyone believed that Mauna Loa was the world's largest volcano—it remains the tallest volcano,” Michael Garcia, of the University of Hawaii’s Department of Earth Sciences told Newsweek.

“We were surprised to find the Pūhāhonu was twice the size of Mauna Loa,” he continued. “Marine eruption has removed much of the volcano, so it is no longer as tall or taller than Mauna Loa.”

Aside from being the biggest shield volcano, the scientists also noted that Pūhāhonu is the hottest. They discovered that it has an extremely hot mantle. They recorded a temperature of 1,700 degrees Celsius from the volcano’s rocks and minerals.

According to the scientists, the volcano’s extremely hot temperature was most likely triggered by the large volume of magma needed to create Pūhāhonu’s massive size.

“The gargantuan size of Pūhāhonu reflects its high melting temperature, the highest reported for any Cenozoic basalt,” Garcia stated.

Mount Merapi is Indonesia's most active volcano
Mount Merapi is Indonesia's most active volcano BNPB / Handout