The supervolcano forming under the Pacific that could wipe out life (but don't panic - we have 100 million years before it erupts)

Researchers say eruption could cause 'very massive destruction' on Earth

Warnings similar eruptions have lead to 'extinction events'

Researchers have warned of a catacysmic supervolcano forming under the Pacific they say could threaten life.

The University of Utah team say two or more continent-sized 'piles' of rock are colliding as they move at the bottom of Earth’s thick mantle 1,800 miles beneath the ocean.

They say the movement could be the beginning of a vast eruption that could threaten life on earth in 100-200 million years.

Volcanic lightning is seen over the Puyehue volcano, over 500 miles south of Santiago, Chile, on Sunday, June 5, 2011: Researchers now say undersea movement could lead to a 'supervolcano' eruption that could cause mass destruction on Earth in 100-200million years

WHAT COULD HAPPEN

The undersea movement is creating is creating a Florida-sized zone of partly molten rock, which researchers say could lead to one of two huge eruptions: A hotspot plume supervolcano eruptions like those during the past 2 million years at Wyoming’s Yellowstone caldera, which covered North America with volcanic ash. A gargantuan flood basalt eruption, similar to those which created Columbia River basalts 17 million to 15 million years ago, India’s Deccan Traps some 65 million years ago and the Pacific’s huge Ontong Java Plateau basalts, which buried an Alaska-sized area 125 million to 199 million years ago.

The discovery was made when seismologist Michael Thorne, the study’s principal author and an assistant professor of geology and geophysics at the University of Utah, analyzed seismic waves that bombarded Earth’s core.

'What we may be detecting is the start of one of these large eruptive events that – if it ever happens – could cause very massive destruction on Earth,' he said.

But disaster is 'not imminent,' he claims,



'This is the type of mechanism that may generate massive plume eruptions, but on the timescale of 100 million to 200 million years from now.



'So don’t cancel your cruises.'

The new study, set for publication this week in the journal Earth and Planetary Science Letters, found that two or more continent-sized 'piles' of rock are colliding as they move at the bottom of Earth’s thick mantle and atop the thicker core some 1,800 miles beneath the Pacific.



That is creating a Florida-sized zone of partly molten rock, which researchers say could lead to one of two huge eruptions.

The first would be a hotspot plume supervolcano eruptions like those during the past 2 million years at Wyoming’s Yellowstone caldera, which covered North America with volcanic ash.

The second possibility is a gargantuan flood basalt eruption, similar to those which created Columbia River basalts 17 million to 15 million years ago, India’s Deccan Traps some 65 million years ago and the Pacific’s huge Ontong Java Plateau basalts, which buried an Alaska-sized area 125 million to 199 million years ago.

'These very large, massive eruptions may be tied to some extinction events,' Thorne says.



The Ontong eruptions have been blamed for oxygen loss in the oceans and a mass die-off of sea life.



This map shows Earth¿s surface superimposed on a depiction of what a new University of Utah study indicates is happening 1,800 miles deep at the boundary between Earth¿s warm, rocky mantle and its liquid outer core. Using seismic waves to probe Earth¿s deep interior, seismologist Michael Thorne found evidence that two continent-sized piles of rock are colliding as they move, creating a Florida-sized blob of partly molten rock ¿ called a 'mega ultra low velocity zone' ¿ which is the beginning stage of massive volcanic eruptions that won¿t occur for another 100 million to 200 million years.

Since the early 1990s, scientists have known of the existence of two continent-sized 'thermochemical piles' sitting on top of Earth’s core and beneath most of Earth’s volcanic hotspots – one under much of the South Pacific and extending up to 20 degrees north latitude, and the other under volcanically active Africa.

Using the highest-resolution method yet to make seismic images of the core-mantle boundary, Thorne and colleagues found evidence the pile under the Pacific is the result of an ongoing collision between two or more piles.



Where they are merging is a spongy blob of partly molten rock the size of Florida, Wisconsin or Missouri beneath the volcanically active Samoan hotspot.

The study’s computer simulations 'show that when these piles merge together, they may trigger the earliest stages of a massive plume eruption,' Thorne says.

Black Sand Basin in Yellowstone National Park: Three eruptions at Yellowstone in the US over the past two million years covered much of North America with ash. Now researchers are warning of a new threat under the Pacific which could lead to a new 'supervolcano' eruption

Thorne conducted the new study with Allen McNamara and Edward Garnero of Arizona State University, and Gunnar Jahnke and Heiner Igel of the University of Munich.



'We did hundreds of simulations for lots of different variations of what the Earth might look like at the core-mantle boundary – the most simulations anybody has ever done to look at the core-mantle boundary structure,' Thorne said.



'My study might be the first to show actual seismic evidence that the piles are moving.

'They move around on the core somewhat like continental plates drift at Earth’s surface.'

HOW THEY DID IT

Seismic imaging uses earthquake waves to make images of Earth’s interior similar to the way X-rays make CT scan pictures of the inside of the human body. The new study assembled the largest set of data ever used to map the lower mantle in the Pacific region by using 4,221seismograms from hundreds of seismometers around the world that detected 51 deep earthquakes originating more than 60 miles under the surface. Thorne and colleagues looked for secondary earthquake shear waves known as S-waves that travel through much of the Earth, hitting the core, and then convert to primary compressional waves or P-waves as they travel across the top of the core.

Then they convert back to S-waves as they re-enter the mantle and then reach seismometers. Thorne says the short bursts of P-wave energy are very sensitive to detecting variations in the rock at the core-mantle boundary. Thorne performed 200 days of supercomputer simulations at the University of Utah’s Center for High Performance Computing.

He simulated hundreds of possible shapes of the continent-sized piles and state-sized blobs until he found the shapes that could best explain the seismic wave patterns that were observed.

Thorne says the merging piles are each about 1,800 miles diameter, forming a single pile some 3,600 miles wide from east to west and stretching across Earth’s core beneath an area from Australia almost to South America.



Two blobs of partly molten rock – called a 'mega ultra low velocity zone', on the piles’ edges merged to form a new blob that is perhaps 6 to 10 miles thick and covers an area about 500 miles long and 150 miles wide, about the area of Florida or 'eight to 10 times larger than any ULVZs we observed before,' Thorne claims.