Studying a planet’s interior is difficult no matter how you approach it. We’ve been able to determine that the Earth, like many celestial bodies, is divided up into layers as differences in pressure and temperature cause elements to stratify as you get closer to the core. We were reasonably sure that, below Earth’s crust, molten rock called magma made up the outer and inner mantle and that the center of our planet was solid. Now, as new studies are published, geologists are starting to question the age-old understanding that what lies below is liquid.
It’s What’s Inside That Counts
The surface we stand on is remarkably small compared to the rest of the planet. Sure, the crust covers the whole thing, but it makes up barely 1% of the Earth’s total mass. It’s between three and 40 miles thick, and it’s utterly insignificant when compared to the planet’s mantle. Divided into an upper and a lower section, the mantle makes up 84% of the Earth’s mass. Without it, our world would be a very different place. The Earth’s crust is broken up into a series of chunks called tectonic plates which drift on top of the mantle, converging and diverging along fault lines, continually changing the appearance of the planet’s surface.
Many of the minerals and elements essential to life on this planet’s surface are stored deep in the mantle. Just as subducting plates dive into the mantle and break down into component elements, new liquid rock bursts forth to the surface, replenishing the lost ground. Due to increasing pressure and temperature as you approach the center of the planet’s mass, Earth’s mantle mixes and stirs over time, leading to the transfer of elements from deep in the inner mantle up to the surface. What scientists have recently discovered through seismic measurements is that it’s not liquid all the way down. Vibrations don’t pass uniformly through the mantle, suggesting that the rock slurry at the heart of our planet isn’t all created equal. What’s more bizarre is that there appear to be massive lumps of solid rock hiding deep beneath the surface, along with some other spectacular surprises.
Journey To The Center Of The Earth
Recently, analysis of seismic activity passing through the Earth’s mantle has unveiled a bizarre discovery. Deep in the upper mantle, scientists have discovered two “mountain ranges” with peaks rivaling Mount Everest. These enigmatic clusters of dense rock are believed to be unincorporated chunks of subducted crust that have sunk like the Titanic to the bottom of the sea, breaking apart on the way down. The transition zone between the upper and lower mantle hosts these bizarre floating mountains. Scientists are still trying to determine what causes the formation of the layers within the planet. Due to their uneven nature, geologists believe that pressure and temperature aren’t working alone when forming these layers. The region in which the mountain range sits has a roughly 25-mile window of variation.
Subterranean mountains aren’t the only wonder hiding out beneath the Earth’s crust. A few years ago, geologists discovered massive reserves of water contained within a mineral called ringwoodite. Rarely escaping the furnace that is the Earth’s mantle, the suspended deposits of ringwoodite are believed to contain a small ocean worth of water. These high-pressure minerals also hang out in the mantle’s transition zone some 450 miles below the Earth’s surface. Ringwoodite isn’t the only jewel hiding in the dark. As seismic studies paint a better picture of the Earth’s insides, scientists have begun to modify the classic molten-orange view of what’s inside our planet. New research shows that, beneath the crust, the mantle is likely a dazzling ombre of green olivine giving way to deep-red garnet, and on to vivid blue ringwoodite and earthy bridgmanite.