New Study Reveals Earth’s Core Slowing Down
A recent scientific study has found that the Earth’s inner core has begun to slow its rotation relative to the planet’s surface. This discovery challenges previous assumptions about the core’s behavior and could have implications for understanding geomagnetic fields and day length variations.
Researchers analyzed seismic wave data from earthquakes over the past several decades. They observed subtle changes in wave travel times, indicating that the inner core’s rotation has decelerated since around 2009. The study suggests that the core is now rotating slightly slower than the Earth’s mantle and crust, a phenomenon not seen in recent history.
This slowdown is believed to be part of a longer-term oscillation, where the core speeds up and slows down over decades. While the effects on daily life are negligible, scientists emphasize that this finding helps refine models of Earth’s internal dynamics and magnetic field generation.
The team used data from global seismic networks to track the core’s motion. By comparing waveforms from repeating earthquakes, they could measure tiny shifts in timing, which reveal rotational changes. The results were published in the journal Nature Geoscience.
Future research will focus on monitoring these changes more closely and understanding the forces driving the core’s variable rotation, including gravitational interactions with the mantle and electromagnetic coupling.
Earth’s inner core
The Earth’s inner core is a solid, dense ball of iron and nickel located at the planet’s center, with a radius of about 1,220 kilometers. It formed over 4.5 billion years ago as the Earth cooled, with the inner core solidifying from the liquid outer core approximately 1–1.5 billion years ago. This region plays a crucial role in generating Earth’s magnetic field through the geodynamo process.
Earth’s mantle
The Earth’s mantle is a thick layer of solid, yet slowly flowing rock located between the planet’s crust and core, extending to a depth of about 2,900 kilometers. It has existed since Earth’s formation over 4.5 billion years ago, and its convective motion drives plate tectonics, volcanic activity, and the recycling of the planet’s surface. Because it is inaccessible to direct observation, scientists study its composition and history through seismic waves, volcanic rocks, and laboratory experiments.
Earth’s crust
The Earth’s crust is the outermost solid layer of our planet, ranging from about 5 to 70 kilometers in depth. Its formation began over 4.5 billion years ago as the planet cooled, with lighter materials rising to create continental and oceanic crust. This dynamic layer is divided into tectonic plates that have shifted throughout Earth’s history, shaping continents, mountains, and ocean basins.
Nature Geoscience
“Nature Geoscience” is a prestigious monthly peer-reviewed scientific journal published by the Nature Portfolio, first launched in January 2008. It focuses on publishing high-quality research across all disciplines of the Earth and planetary sciences, including geology, climate science, and environmental studies. The journal is known for its rigorous peer-review process and significant impact on advancing scientific understanding of Earth’s systems and processes.
