Virginia Tech geoscientist Ying Zhou found alterations in the Earth’s outer core. Zhou’s finding was aided by two 20-year-old earthquakes.
First, the scientist compared the seismic measurements and found discrepancies. These differences meant metal flow in the planet’s outer core changed significantly.
In May 1997, a large earthquake hit the South Pacific’s Kermadec Islands. Another earthquake hit the same region in September 2018. Since the earthquake struck the same area 20 years ago, it sent out the identical seismic waves. Zhou recognized it wasn’t anticipated.
According to Independent Turkish, seismic waves known as SKS waves travelled around a second quicker during the 2018 earthquake. Zhou said lighter elements were oscillating in the outer core, but he had no confirmation.
Due to Earth’s high pressure and temperature, a liquid outer core may surround the iron-containing solid inner core. Iron and nickel constantly circulate in this outer core. This convection creates the planet’s magnetic field. The magnetic field protects Earth’s surface from solar radiation and prevents the atmosphere from evaporating. Zhou says outer core convection isn’t constant.
“The north geomagnetic pole is shifting around 50 km each year from Canada to Siberia,” stated Zhou. Magnetic fields aren’t constant. Changes. We suspect outer core convection varies over time, but there’s no proof. Nope.
Zhou reported fresh evidence for this transition in Nature. The scientist compared the two earthquakes and found that the SKS waves travelled quicker in the second. This wave’s progression modified. So he’s faster now. It suggests 20-year-old stuff is gone. Zhou remarked, “New material is lighter.” Lighter elements rise and alter density. In the study, the scientist suggested that hydrogen, carbon, and oxygen had been expelled from the outer core since 1997.
This decreases the outer core’s density by 2-3%, according to the paper. Convection flow exceeds 40 km/h. Globally, 152 stations detect seismic waves in real time. Zhou: “We saw the outer core.”