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Mantle Convection

All articles tagged with #mantle convection

Antarctic Gravity Dip Unmasks 70 Million Years of Deep-Earth Dynamics
science1 month ago

Antarctic Gravity Dip Unmasks 70 Million Years of Deep-Earth Dynamics

Researchers reconstructed the Antarctic geoid low over ~70 million years, showing a persistent gravity valley shaped by deep mantle flow and evolving upper-mantle buoyancy. A major change in amplitude and position occurred between 50 and 30 million years ago, linked to long‑term subduction and upwelling, with a possible connection to true polar wander and Antarctica’s ice-sheet history. The study cautions that while deep-Earth dynamics can reshape the gravity field, translating this into climate or ice-sheet impacts requires further work.

via Indian Defence Review|
#antarctica#geoid#gravity
Antarctica’s Subtle Gravity Dip Unveils a 70-Million-Year Deep-Earth Tale
science1 month ago

Antarctica’s Subtle Gravity Dip Unveils a 70-Million-Year Deep-Earth Tale

A new study using seismic data and mantle-flow modeling shows Antarctica hides a large, persistent gravity low called the Antarctic Geoid Low. Reconstructing roughly 70 million years of mantle motion, researchers find this gravity feature is not a transient anomaly but a long-lived imprint of deep-Earth dynamics that intensified around 34 million years ago as Antarctica became permanently ice-covered. While it’s not a literal hole, the gravity dip reveals how mass is distributed deep inside Earth and could subtly influence regional sea levels, underscoring how slow, deep-earth processes reshape the planet’s gravity field over geological time.

via Space|
#antarctic-geoid-low#deep-earth#gravity
Antarctic gravity low strengthens as mantle dynamics reshape the geoid
science1 month ago

Antarctic gravity low strengthens as mantle dynamics reshape the geoid

Scientists mapped Earth’s interior with earthquakes to build a 3D mantle model and a map of the Antarctic Geoid Low, finding the depression has persisted for about 70 million years but has intensified over the last 40–50 million years as subducted slabs sank and buoyant mantle material rose. The results, which also align with true polar wander, suggest deep Earth processes can subtly shift sea level and influence the growth of Antarctica’s ice sheet; the work was published in Scientific Reports.

via ScienceAlert|
#antarctic-geoid-low#gravity-field#ice-sheets
Scientists Uncover 75-Year-Old Mystery of Indian Ocean's 'Gravity Hole'
science8 months ago

Scientists Uncover 75-Year-Old Mystery of Indian Ocean's 'Gravity Hole'

Scientists have solved the 75-year-old mystery of the Indian Ocean Geoid Low, a massive gravity anomaly, by demonstrating that mantle convection and hot, low-density material rising from the African superplume cause the gravity low, with simulations tracing its formation back 140 million years. This discovery enhances understanding of Earth's deep interior and its dynamic processes.

via The Brighter Side of News|
#earth-interior#geoid-low#geophysical-modeling
Hidden Deep Earth Blobs Could Trigger Future Extinctions and Volcanic Eruptions
science8 months ago

Hidden Deep Earth Blobs Could Trigger Future Extinctions and Volcanic Eruptions

A new study suggests that large basal structures in Earth's mantle, called BLOBS, are likely to move slowly over time, which could influence the location of massive volcanic eruptions and potentially impact future mass extinctions. Researchers reconstructed Earth's mantle dynamics over billions of years, finding that BLOBS drift at about one centimeter per year, affecting mantle plumes and volcanic activity.

via Yahoo|
#blobs#geology#mantle-convection
Swift and Surprising: The Speed of Early Plate Tectonics
earth-science2 years ago

Swift and Surprising: The Speed of Early Plate Tectonics

A new study led by Dr. Jennifer Kasbohm of Yale reveals that the Pilbara Craton, an early continent, moved at a rapid pace of up to 64 centimeters (25 inches) per year around 2.7 billion years ago. By analyzing ancient magnetic fields and dating rocks from Western Australia, the researchers aimed to understand the nature of plate tectonics during the Archean eon. The findings suggest that early plate tectonics may have been faster due to the hotter mantle and its impact on mantle convection. The study, which took a decade to complete, provides valuable insights into the movement of ancient continents and the evolution of Earth's tectonic processes.

via Ars Technica|
#archean-eon#basalt-lava#earth-science
Earth's Plate Tectonics: A Recent Fundamental Shift
earth-science2 years ago

Earth's Plate Tectonics: A Recent Fundamental Shift

A recent study from the University of Copenhagen suggests that Earth's plate tectonics may be a more recent phenomenon, with the mantle previously stratified into upper and lower regions that were isolated from each other. The researchers developed a new method to measure the isotopic composition of titanium in rocks, which allowed them to trace the recycling of surface material in Earth's mantle over billions of years. The findings indicate that the lower mantle could contain undisturbed primordial material, potentially providing insights into Earth's original composition and the source of volatiles essential for life.

via SciTechDaily|
#earth-science#earths-history#mantle-convection
Earth's Plate Tectonics: Recent Shifts and Ancient Origins
earth-science2 years ago

Earth's Plate Tectonics: Recent Shifts and Ancient Origins

A new study suggests that Earth's plate tectonics may be a more recent feature of its geologic history. Researchers from the University of Copenhagen found evidence that convection in the mantle was stratified into upper and lower mantle regions that were isolated from each other for most of Earth's history. This is in contrast to the current understanding of plate tectonics, where subducting plates sink to the lower mantle. By analyzing the isotopic composition of titanium in rocks, the scientists were able to trace the recycling and mixing of tectonic plates in Earth's mantle. The study also suggests the existence of a primordial mantle reservoir in the deep Earth, which could provide insights into Earth's original composition and the development of life.

via Phys.org|
#earth-science#earths-history#isotopic-composition
Unraveling the Mystery of the Giant Gravity Hole in the Indian Ocean
science2 years ago

Unraveling the Mystery of the Giant Gravity Hole in the Indian Ocean

Researchers from the Indian Institute of Science believe they have discovered the cause of a gravity anomaly in the Indian Ocean. By modeling tectonic plate and global mantle convection over millions of years, they suggest that ancient tectonic plates sinking beneath the ocean have created a plume of hot mantle, which is less dense than the sunken crust. This plume, along with the mantle structure, is responsible for the lower gravity observed in the area.

via IFLScience|
#geoid-low#gravity-anomaly#indian-ocean