Immense Underwater Volcano Is The Biggest On Earth

Scientists report in the journal Nature Geoscience that they've uncovered the largest volcano on Earth in the Northwest Pacific Ocean, about 1,000 miles east of Japan. In fact it's one of the largest in the solar system, second only to Olympus Mons on Mars. Scientists have been studying the massive structure for decades, but now are confirming it's a single volcano about the size of New Mexico. It rises about four miles off the sea floor, but doesn't break through the ocean surface. Called Tamu Massif, it hasn't erupted in more than 130 million years, helping to keep its true nature secret.

Copyright © 2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

ROBERT SIEGEL, HOST:

In the northwestern Pacific Ocean, scientists have found what they believe to be the biggest volcano on Earth. In fact, to find a volcano of a similar size, you'd have to go to Mars. As NPR's Christopher Joyce reports, the volcano is, fortunately, dormant, but in its prime, it changed the face of the Earth.

CHRISTOPHER JOYCE, BYLINE: William Sager says he brings conversations to a halt when he tells people he's a geophysicist. But now, he says he's got a story that gets people's attention.

WILLIAM SAGER: Where we say, oh, look, there are volcanoes here as big as any that we've seen elsewhere in the solar system. So it's sort of like discovering a new whale or something.

JOYCE: The only bigger one known to science is on Mars, called Olympus Mons. He calls his volcano Tamu Massif. It's about the size of New Mexico. Its top rises 2 1/2 miles, but it doesn't break the surface of the ocean. It's so massive, it caved in the Earth's crust. Sager studies oceanic plateaus and seamounts, the mountain ranges of the oceans. There are thousands of them, but none like this one.

SAGER: You see these little pimples out there, and those are the normal seamounts, and this Tamu Massif just dwarfs them.

JOYCE: The volcano was formed 144 million years ago and is nestled in an underwater plateau. Geoscientist Jackie Caplan-Auerbach at Western Washington University says scientists knew there had been volcanic activity there.

JACKIE CAPLAN-AUERBACH: But we've always thought they were clusters, you know? You would have eruptions at a number of places, and they would all sort of overlap. But this is not. You basically had one place just cranking out enormous amounts of lava.

JOYCE: Sager's team has only surveyed a small part of Tamu Massif, however. It will take further examination to convince the scientific community that it's a single volcano and has earned the title world's biggest. The volcano arose in a section of the Earth's crust where three huge crustal plates come together. How it formed is unclear, possibly when a giant blob of material floated up from inside the Earth, got cooked into magma and burst through the crust. Sager at the University of Houston describes the Tamu Massif in the journal Nature Geoscience. As for the name Tamu, it's the initials of Texas A&M University, where he used to work. Christopher Joyce, NPR News.

Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.