Tag: inner core

A groundbreaking study has found "clear evidence" that the Earth's inner core has slowed its rotation relative to the planet's surface since 2010, potentially affecting the length of a day by a fraction of a second. The inner core, a solid sphere of iron and nickel, is encased within the liquid outer core and stabilized by gravity. Researchers typically study the core through seismograms, which record waves generated by earthquakes. "When I first saw the seismograms showing these changes, I was shocked," said John Widale, Earth sciences professor at the University of Southern California. "But after finding dozens more observations with the same pattern, the conclusion was inescapable. The inner core has slowed down for the first time in decades," added Widale, co-author of the study ...