Seismologists Confirm 1,300-km Innermost Iron Core Using Earthquake Echoes
Updated
Updated · spacedaily.com · Jul 14
Seismologists Confirm 1,300-km Innermost Iron Core Using Earthquake Echoes
3 articles · Updated · spacedaily.com · Jul 14
Summary
A 1,300-kilometre iron sphere at Earth’s center has been confirmed as a distinct innermost core inside the larger solid inner core, sharpening the planet’s structure from four classic layers to effectively five.
Roughly 200 large earthquakes supplied the evidence: Phạm and Tkalčić stacked reverberating P-wave echoes that rang through Earth for days and found the deepest 650 kilometres of the core transmitted waves differently.
Those signals showed a shift in crystal alignment—north-south in the outer shell of the inner core, but tilted closer to east-west in the innermost region—indicating a separate zone rather than one uniform iron ball.
The result strengthens a long-debated idea first proposed in 2002 and supports theories that the center either preserves an older growth phase of the core or contains a different iron crystal structure under extreme pressure.
Because the inner core grows about 1 millimetre a year and helps power Earth’s magnetic field, mapping this hidden boundary offers a clearer view of how the deep planet evolved and how rocky worlds can be probed by seismic waves.
Earth's core has five layers and Mars's is solid. What do these discoveries reveal about the hidden interiors of other rocky planets?
Earth’s inner core is changing rotation. Could this newly discovered fifth layer be the reason why?
A tilted 'fossil' was found deep inside Earth's core. How does this relic from our planet's birth explain its evolution?
Earth's Inner Core Revealed: New Discoveries Reshape Our Understanding of Planetary Structure and Dynamics
Overview
Recent scientific breakthroughs have transformed our understanding of Earth's deep interior. These discoveries challenge old beliefs and reveal that the planet's core is far more dynamic and complex than once thought. Scientists have found that the inner core is not a uniform solid but shows signs of dynamic deformation and structural changes. This new evidence is reshaping the models geoscientists use to describe Earth's core, highlighting the important role of light elements under extreme pressure. Together, these findings offer a fresh perspective on the planet beneath our feet and open new directions for research.