mantle
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Earth
Scientists reveal the evolutionary history of regions of the deep mantle continent size
Visualization of the seismic model S40RTS (Ritsema et al., 2011) showing African LLVPs (big red regions) created using Gplates software (Ritsema et al., 2011). Credit: Jeroen Ritsema et al. New research reveals that two continent-sized regions of the Earth’s deep mantle have distinctive history and resulting chemical composition, in contrast to the general assumption that they are the same. The…
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Earth
Geodynamic mantle flow model explains deformation of continental crustal blocks in northern China
Crustal structure and reconstruction of deforming plates in Northeast Asia and the Western Pacific. Credit: Nature Geoscience (2024). DOI: 10.1038/s41561-024-01513-2 Cratons are fascinating but mysterious geological formations. Cratons, known as relatively stable parts of Earth’s continental crust, have remained largely unchanged for billions of years. Although cratons have survived many geological events, some are undergoing decratonization, a process characterized by…
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Earth
Tracking missing mantle plume in ancient Samoa: researchers shed light on 30 million year gap
Bathymetric map of the Pacific region focusing on the trajectory of Samoa’s Hotspot 100 Mil, from Samoa’s hotspot active volcanoes (Vailuluu Seamount) to the Dutton Ridge (near the Mariana Trench). Credit: AGU Advances (2024). DOI: 10.1029/2023AV001079 As magma plumes rise through the Earth’s lithosphere, volcanoes, islands, seamounts, and other features form on the Earth’s surface. As tectonic plates move over…
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Earth
Easter Island’s volcanic history suggests that Earth’s mantle behaves very differently than previously assumed
The structure of the mantle plume beneath Easter Island. Credit: Douwe van Hinsbergen Geography textbooks describe the Earth’s mantle, which lies beneath the plates, as a well-mixed, viscous rock that moves with the plates like a conveyor belt. But this idea was first broached about 100 years ago, and it’s surprisingly difficult to prove. A mysterious discovery on Easter Island,…
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Earth
Research into the Afar mantle plume provides new insights into deep Earth processes
Schematic of mantle He concentrations and 3He/4He (Ra), showing how the Afar plume 3He/4He signature is generated. Credit: Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01675-2. https://www.nature.com/articles/s43247-024-01675-2 Advanced analysis of tiny bubbles of ancient gas trapped in volcanic rocks, combined with new geophysical modelling, has shed new light on a long-held hypothesis about the deep Earth. An international team of scientists…
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Earth
Study identifies superionic iron hydride as key to ultra-low velocity zone at the boundary between Earth’s core and mantle
Mean square displacements (MSD) of Fe and H atoms in fcc-FeH at different temperatures and volumes from NVT-FPMD simulations. The core-mantle boundary (CMB) is a key boundary within the Earth, marking the boundary between the outer core and the lower mantle. Over the past two decades, seismological studies have identified anomalously low-velocity regions above the CMB, such as the Large-Scale…
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