Researchers have warned of a catacysmic supervolcano forming under the Pacific they say could threaten life.
1800 miles below the surface of Samoa, the University of Utah team says two or more continent-sized 'piles' of rock are colliding as they move at the bottom of Earth’s thick mantle.
They say the movement could be the beginning of a vast eruption that could threaten life on earth in 100-200 million years.
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.
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.
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.