Two enormous continent-sized mountains 100 times taller than Everest are hidden thousands of kilometres beneath the Earth’s surface, according to new research that has left experts stunned.
The gigantic rocky islands, dwarfing any other mountain on Earth, lie just above the planet’s core.
One sits under Africa, the other beneath the Pacific Ocean.
These vast chunks of rock are a staggering 1,000km tall, easily eclipsing the 8.8km height of Mount Everest in Nepal.
Scientists from Utrecht University have revealed these gigantic peaks sit among a “graveyard” with other bits of rock that have sunk thousands of kilometres below the Earth’s surface.
Their study, published in the journal Nature, shares how they were pushed down by the “subduction” of tectonic plates.
The huge mountains are thought to be at least a billion years old, but they could date back as far as four billion years to the birth of our planet.
The discovery has stunned researchers as no one can pinpoint exactly what they are, or how they formed.
Lead researcher Dr Arwen Deuss said: “Nobody knows what they are, and whether they are only a temporary phenomenon, or if they have been sitting there for millions or perhaps even billions of years.”
The titanic mountainous slabs are also hotter than other bits of surrounding rock, the researchers revealed.
“The islands are hot and because of their large viscosity they don’t move very easily, so they have been staying where they are at the base of the mantle for at least a billion years, but perhaps much longer. They form huge mountains, with a height of almost 1,000km,” Dr Deuss explained.
These strange regions within the Earth’s mantle were originally discovered several years ago when geologists found seismic waves triggered by earthquakes slowed as they sent shockwaves in a process dubbed the Large Low Seismic Velocity Provinces (LLSVPs).
Dr Deuss added : “I think that they may well be a remnant from the time when our planet was originally formed.”
They could even be a phenomenon scientists have long speculated about involving legendary reservoirs in the planet’s mantle that have remained “untouched since the Earth originated”.
Another mountain, Mauna Kea in Hawaii, also dwarfs Everest by a staggering 10,205m in height. That’s nearly 20 football pitches taller than the Himalayan giant.
The long-dormant volcano in Hawaii is submerged under the Pacific Ocean, with scientists believing the base goes down nearly 6,000m beneath the water, with only 4,205 metres visible above sea level.
Despite being inactive for about 4,500 years, scientists believe the volcano is still very much alive and will erupt one day. A spokesman for the Smithsonian Institution said: “Mauna Kea’s peaceful appearance is misleading. The volcano is not dead.”
