Researchers thought that Earth's inner core was "solid," but new research suggests that it may be closer to a mush than a solid.
A new study published in the journal Physic of the Earth and Planetary Interiors on September 20 details that the planet's inner core can range from being hard to a semisoft liquid metal. According to Jessica Irving, a seismologist at the University of Bristol in England and not involved in the aforementioned study, "The more that we look at it, the more we realize it's not one boring blob of iron. We're finding a whole new hidden world."
As for the researchers behind the study, they were measuring the seismic waves that are created by large earthquakes. These quakes travel from one side of the globe to the other. Recording these massive vibrations in the form of straight-line compressional waves and undulating shear waves using special instruments, researchers are able to recreate a picture of what the inner planet looks like.
Rhett Butler, a geophysicist at the Hawai'i Institute of Geophysics and Planetology, found that the quakes that were being measured were creating mismatched numbers. The shear waves data should represent the vibration passing through a solid ball of metal, Earth's inner core, but instead were being deflected in certain areas.
Butler and his colleagues re-adjusted their model of Earth's inner core to account for the mismatched numbers and found that the observed waves worked if Earth's inner core had pockets of liquid and "mushy," semisolid iron near its surface.
Butler said, "We've seen evidence that not only is it not soft everywhere; it's really hard in some places. It's got hard surfaces right up against melted or mushy iron. So we're seeing a lot of detail within the inner core that we didn't see before."
To read more about this discovery, check out this link here.