Scientists confirm existence of largest single volcano on Earth (Update)

Sep 05, 2013
MCS reflection Line A–B, across the axis of Tamu Massif. Credit: Nature

A University of Houston (UH) professor led a team of scientists to uncover the largest single volcano yet documented on Earth. Covering an area roughly equivalent to the British Isles or the state of New Mexico, this volcano, dubbed the Tamu Massif, is nearly as big as the giant volcanoes of Mars, placing it among the largest in the Solar System.

William Sager, a professor in the Department of Earth and Atmospheric Sciences at UH, first began studying the volcano about 20 years ago at Texas A&M's College of Geosciences. Sager and his team's findings appear in the Sept. 8 issue of Nature Geoscience, the monthly multi-disciplinary journal reflecting disciplines within the geosciences.

Located about 1,000 miles east of Japan, Tamu Massif is the largest feature of Shatsky Rise, an underwater mountain range formed 130 to 145 million years ago by the eruption of several underwater volcanoes. Until now, it was unclear whether Tamu Massif was a single volcano, or a composite of many eruption points. By integrating several sources of evidence, including core samples and data collected on board the JOIDES Resolution research ship, the authors have confirmed that the mass of basalt that constitutes Tamu Massif did indeed erupt from a single source near the center.

"Tamu Massif is the biggest single shield volcano ever discovered on Earth," Sager said. "There may be larger volcanoes, because there are bigger igneous features out there such as the Ontong Java Plateau, but we don't know if these features are one volcano or complexes of volcanoes."

IODP technician Margaret Hastedt labels pieces of core collected during IODP Expedition 324 (Shatsky Rise Formation) on board the JOIDES Resolution. Credit: Image courtesy Integrated Ocean Drilling Program/U.S. Implementing Organization [IODP-USIO]

Tamu Massif stands out among underwater volcanoes not just for its size, but also its shape. It is low and broad, meaning that the erupted lava flows must have traveled long distances compared to most other volcanoes on Earth. The seafloor is dotted with thousands of underwater volcanoes, or seamounts, most of which are small and steep compared to the low, broad expanse of Tamu Massif.

"It's not high, but very wide, so the flank slopes are very gradual," Sager said. "In fact, if you were standing on its flank, you would have trouble telling which way is downhill. We know that it is a single immense volcano constructed from massive lava flows that emanated from the center of the volcano to form a broad, shield-like shape. Before now, we didn't know this because oceanic plateaus are huge features hidden beneath the sea. They have found a good place to hide."

Tamu Massif covers an area of about 120,000 square miles. By comparison, Hawaii's Mauna Loa – the largest active volcano on Earth – is approximately 2,000 square miles, or roughly 2 percent the size of Tamu Massif. To find a worthy comparison, one must look skyward to the planet Mars, home to Olympus Mons. That giant volcano, which is visible on a clear night with a good backyard telescope, is only about 25 percent larger by volume than Tamu Massif.

The study relies on two distinct, yet complementary, sources of evidence – core samples collected on Integrated Ocean Drilling Program (IODP) Expedition 324 (Shatsky Rise Formation) in 2009, and seismic reflection data gathered on two separate expeditions of the R/V Marcus G. Langseth in 2010 and 2012. The core samples, drilled from several locations on Tamu Massif, showed that thick lava flows (up to 75 feet thick), characterize this volcano. Seismic data from the R/V Langseth cruises revealed the structure of the volcano, confirming that the lava flows emanated from its summit and flowed hundreds of miles downhill into the adjacent basins.

This 3D image of the seafloor shows the size and shape of Tamu Massif, a huge feature in the northern Pacific Ocean, recently confirmed to be the largest single volcano on Earth. Credit: Image courtesy Will Sager

According to Sager, Tamu Massif is believed to be about 145 million years old, and it became inactive within a few million years after it was formed. Its top lies about 6,500 feet below the ocean surface, while much of its base is believed to be in waters that are almost four miles deep.

"It's shape is different from any other sub-marine volcano found on Earth, and it's very possible it can give us some clues about how massive volcanoes can form," Sager said. "An immense amount of magma came from the center, and this magma had to have come from the Earth's mantle. So this is important information for geologists trying to understand how the Earth's interior works."

Explore further: Remote Alaska volcano emits lava flow, ash plume

More information: dx.doi.org/10.1038/ngeo1934

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User comments : 13

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wealthychef
2.1 / 5 (7) Sep 05, 2013
Cool, but a graphic showing its size relative to some known thing on the Earth's surface would have been helpful.
scottfos
2.7 / 5 (7) Sep 05, 2013
dude..."Covering an area roughly equivalent to the British Isles or the state of New Mexico"
johncmartin007
1.4 / 5 (9) Sep 05, 2013
I'm interested in knowing what happened to our ancestors, whatever we were at the time around 150 mya, and how did we survive this? Maybe we were amphibious at the time and survived? Just wondering...
shavera
1 / 5 (1) Sep 05, 2013
johncmartin007: it hasn't breached the surface of the ocean. It's kind of like how Mauna Kea is taller than Everest (more than twice as tall) if you count the distance from its base (ocean floor) to tip.
Gmr
1.8 / 5 (5) Sep 05, 2013
...and since it is a "shield" volcano, it's not the explosive type as per Mt. St. Helens... it was more an oozing lava flow that just didn't stop, all the while underwater.
Kiwini
1.6 / 5 (14) Sep 05, 2013
Cool, but a graphic showing its size relative to some known thing on the Earth's surface would have been helpful.


Here you go... http://www.thereg...volcano/
Captain Stumpy
1.7 / 5 (11) Sep 05, 2013
@Kiwini
Here you go... http://www.thereg...volcano/

nice graphic! at bottom of article for those who don't want to read all the way through.... shows Hawaii as well as Japan and further west!
I guess Toot just downvotes you without bothering to read... because that pic REALLY puts things to scale!
GSwift7
3 / 5 (6) Sep 06, 2013
and since it is a "shield" volcano, it's not the explosive type as per Mt. St. Helens... it was more an oozing lava flow that just didn't stop, all the while underwater


Exactly what I was going to say.

I would add that maybe what he was really thinking about are the large calderas, like Yellowstone. This one didn't have a caldera as big as the yellowstone caldera. It's just the mountain around the caldera that is big. Really big explosive calderas don't leave big mountains around them; they destroy them. :)

To be sure, when Yellowstone went up, life DID struggle to survive, in the ocean or on land. Yellowstone probably even blasted rocks out of Earth's gravity.

Speaking of which, there's an underground H-bomb test that was more powerful than expected. The film from the test site shows a man-hole cover blasted out. They never found it, and suspect it actually reached escape velocity. Imagine finding a man-hole cover floating around in space? Wild.
yyz
5 / 5 (2) Sep 06, 2013
@GSwift,

Dr. Robert Brownlee's version of the 'manhole-in-space' story: http://www.radioc...nlee.htm
ScooterG
1.5 / 5 (15) Sep 07, 2013
What is the heat exchange rate on this bad boy? Could it be contributing to the dreaded rising ocean temperatures??

We either need a computer model that shows no effect on ocean temps, or we need to plug the dam thing - we gotta' keep that fear-induced-AGW-money rolling in!
Gmr
2 / 5 (6) Sep 07, 2013
[A latecomer arrives to a picked-over carcass. It is not prey it is used to, but it tries to make a go of it. Clearly out of its normal environment, it roars its challenge to nobody, a token gesture to perhaps encourage itself.

Starvation can't be far behind. But such is the dread beauty of nature.]
Neinsense99
1 / 5 (4) Sep 10, 2013
What is the heat exchange rate on this bad boy? Could it be contributing to the dreaded rising ocean temperatures??

We either need a computer model that shows no effect on ocean temps, or we need to plug the dam thing - we gotta' keep that fear-induced-AGW-money rolling in!

From the article above, that ScooterG selectively misread: "According to Sager, Tamu Massif is believed to be about 145 million years old, and it became inactive within a few million years after it was formed." Somebody isn't clear on the concept of 'extinct' with regard to an extinct volcano.
GSwift7
2.3 / 5 (3) Sep 10, 2013
What is the heat exchange rate on this bad boy? Could it be contributing to the dreaded rising ocean temperatures??


good grief. go back to trolling the climate articles.

This is a long extinct volcano. The article would have been more accurate if it described Tamu as a volacanically formed mountain.

The signifigance of such a large mountain being formed by a single volcano is what that tells us about the conditions needed for that to happen.

The amount of lava needed to form such a big mountain means that the volcano had to be active for a very long time, which indicates some kind of persistent feature under the volcano.

It's not common to see a volcano stay in one place for that long, since the plates move around over the underground features that cause them.

This might be a good place to look for parts of the Earth's crust that are older than the rest, which would be a really cool thing to find.