What do you think exists around the Earth’s core, just below the solid mantle layer? I’ll give you some time to guess. Okay. Did you say: “Large structures (which are much more common and expansive than they were previously thought to be) made of a hot, dense material (the composition of which is still unknown, though it could be magma or molten iron leaking from the Earth’s core)”?
Correct!
A team of University of Maryland geophysicists recently found evidence of these hot, dense structures, and published their findings on Thursday in the journal Science. The molten “blobs,” as Science Alert dubbed them, lie at the boundary between the molten core and the mantle, about 1,800 miles below the Earth’s surface. (The mantle, which makes up most of the Earth’s interior, is mostly solid and exists between the core and the crust.) The geophysicists were able to locate them by analyzing thousands of pieces of earthquake data using an algorithm called the Sequencer.
The “blobs” are also known as “ultralow velocity zones” because their density slows down the velocity of an earthquake’s seismic waves.
The data showed the existence of a previously unknown ultralow velocity zone beneath the Marquesas Islands. It also found that the zone beneath the Hawaiian Islands is much bigger than it was previously thought to be.
“We found echoes on about 40 percent of all seismic wave paths,” the study’s co-author Vedran Lekic said. “That was surprising because we were expecting them to be rarer, and what that means is the anomalous structures at the core-mantle boundary are much more widespread than previously thought.”
Will even more blobs be found around the core of our Earth? Are we walking around on blobs all day, blobs that could be magma or molten iron, or something else entirely, and we don’t even know it? Hm. It seems possible, but unless Earth whispers her secrets to us personally, I guess we’ll have to wait for the geophysicists, and the Sequencer, to find out for sure.
