Oceanic lithosphere is the rigid outer shell of Earth underlying ocean basins, comprising oceanic crust and the uppermost mantle, mechanically coupled and behaving as a coherent tectonic plate segment. It forms at mid-ocean ridges through decompression melting of the mantle, producing basaltic crust overlying a lithospheric mantle that cools, thickens, and increases in density with age and distance from the ridge. Its thermal and mechanical structure controls plate flexure, isostasy, and patterns of seismicity, and it ultimately returns to the mantle at subduction zones, playing a central role in plate tectonics, mantle convection, and global geochemical cycling.
The first-known direct observations of a seafloor spreading event at a mid-ocean ridge in the Indian Ocean are presented in Nature. The observations offer insight into how new oceanic crust is created.
Earth Sciences
11 hours ago
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Most of the earthquakes we hear about are due to tectonic plates colliding or sliding past each other near plate boundaries. Yet researchers have detected some enigmatic earthquakes happening inside the more stable interiors ...
Over 40,000 seamounts—undersea mountains that don't breach the ocean's surface—are scattered across the ocean floor. Some form linear chains, while others occur as dispersed, isolated features that are not part of well-defined ...
Earth Sciences
Jun 15, 2026
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Thousands of small earthquakes, detected for the first time by a machine-learning process, reveal the distinct, razor-sharp edge of the Yakutat microplate as it subducts beneath the North American plate.
Earth Sciences
Jun 7, 2026
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Deep below the Tyrrhenian Sea offshore Italy, scientists drilled into what they thought would be dark mantle rock—and found pieces of granite that seemingly had no business being there. Those unexpected intrusions turned ...
Earth Sciences
Jun 4, 2026
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Earth was mostly devoid of oxygen for much of its 4.5 billion year lifetime. That is, until certain processes started to allow for the eventual buildup of oxygen up to the levels we have now (around 21% of the atmosphere). ...
A new look at the Juan de Fuca tectonic plate beneath the coast of northern Oregon suggests this subducting slab is shallower than previously thought, with impacts on potential peak ground shaking during a Cascadia megathrust ...
Earth Sciences
Apr 16, 2026
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Recent seismic imaging off Vancouver Island has revealed something extraordinary: a tear in the subducting oceanic plate beneath the Cascadia Subduction Zone. The finding briefly raised the public's hopes that Cascadia might ...
Earth Sciences
Apr 10, 2026
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The history of Earth is written on the great tablets of tectonic plates. The motions of plates shaped land masses, formed oceans, and created the varied climates and habitats that set the stage for evolution and the diversity ...
Earth Sciences
Mar 19, 2026
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The Cascadia Subduction Zone is unusually quiet for a megathrust fault. Spanning more than 600 miles from Canada to California, the fault marks the convergence of the Juan de Fuca and North American plates. While other subduction ...
Earth Sciences
Feb 27, 2026
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