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Geophysics

All articles tagged with #geophysics

Hidden mantle blobs could rewrite Earth's tectonic story
science8 days ago

Hidden mantle blobs could rewrite Earth's tectonic story

Seismologists using high-resolution full-waveform inversion on earthquake data detected large, anomalous pockets in the lower mantle beneath the Pacific, visible as regions where seismic waves move unusually fast or slow. These “sunken worlds” may be remnants of ancient plates or other mantle materials, challenging traditional ideas about subduction and plate evolution. A ETH Zurich–Caltech team notes the exact composition is unclear and more data and methods (including EM signals and mineral physics) are needed, but the findings could require updates to models of mantle convection and heat transfer. The study appears in Scientific Reports.

Antarctica’s Gravity Hole Grows Stronger, Hinting at Deep Mantle Shifts
earth-science11 days ago

Antarctica’s Gravity Hole Grows Stronger, Hinting at Deep Mantle Shifts

Scientists used earthquakes and geophysical data to reconstruct Earth’s interior and map a gravity hole beneath Antarctica that began weakening but has grown stronger over roughly 50–30 million years, driven by competing mantle flows (cold, sinking material beneath and hotter, rising material above). This amplified mass deficit alters the geoid and regional sea-level dynamics, offering clues about ice-sheet stability and climate-related sea-level changes, though the exact future impact remains uncertain.

Scientists Discover Unprecedented Massive Structure Beneath Bermuda
science2 months ago

Scientists Discover Unprecedented Massive Structure Beneath Bermuda

Bermuda's unique geological structure is explained by a 20-kilometer-thick, less dense mantle layer beneath it, which acts like a mantle plume, despite Bermuda lacking recent volcanic activity or typical plume features. This discovery challenges existing models of mantle plumes and suggests Bermuda is supported by an unusual mantle layer, possibly due to its geological history or composition.

Scientists Detect Massive Internal Shift Within the Earth
science4 months ago

Scientists Detect Massive Internal Shift Within the Earth

Scientists analyzing data from NASA's GRACE satellites discovered evidence of a massive shift deep within the Earth's interior near the core-mantle boundary, possibly caused by changes in mantle minerals like perovskite, which may have influenced Earth's magnetic field and caused a geomagnetic jerk around 2007. They plan to use data from the follow-up GRACE-FO mission to further investigate these deep Earth processes.