When children learn about the layers of our planet, the components are often simplified into three easily understandable parts: crust, mantle, and core. However, a new study published in Science this week has complicated that notion by suggesting that mountains perhaps bigger than Everest also lie deep inside Earth.
Princeton geophysicists Jessica Irving and Wenbo Wu worked alongside Sidao Ni from the Institute of Geodesy and Geophysics in China to analyze the seismic data of Bolivia’s massive 1994 earthquake to look at what lies beneath, Science Daily reported.
What they found were mountains situated on a layer 410 miles below the Earth’s surface.
The team’s preliminary name for this section between layers, which seems to have housed these mountain ridges and other topography all along, is “the 660-km boundary.”
For Irving, only earthquakes and their seismic shifts have provided scientists like her with the kind of data they need to encounter findings like these.
“You want a big, deep earthquake to get the whole planet to shake,” she said.
While the seismic data of smaller quakes can certainly be studied just as well, big ones produce 30 times more energy with every single step up on the Richter scale — allowing Bolivia’s disaster in 1994 to provide prime data for the Princeton team to wade through.
The most useful information Irving gets comes from earthquakes with a magnitude of 7.0 or higher, as those produce shockwaves that shoot across all directions and are capable of traveling through the earth’s core to the other side of the planet — and back.
The seismic data of larger, deeper quakes, “instead of frittering away their energy in the crust, can get the whole mantle going,” explained Irving.
With an 8.2 magnitude, Bolivia’s quake in 1994 was the second-biggest deep earthquake ever recorded, allowing the researchers to get as clear a look beneath the Earth as possible.