All articles tagged with #plate tectonics
A Science Advances study argues Gondwana was a true supercontinent, spanning up to ~80% of Earth's landmass and wrapped by a ~35,000 km Ring of Fire. Its formation around 750–550 million years ago released vast volcanic gases, shifting Earth’s climate from icehouse to greenhouse and helping catalyze the Cambrian explosion of life.
New isotopic mapping of rocks shows Gondwana formed a massive supercontinent that covered about 80% of Earth's land between 550 and 500 million years ago, a configuration linked to the Cambrian explosion and the rise of complex life, highlighting how deep-Earth processes helped drive major biodiversity upheavals.
Scientists say the Pacific Ocean is slowly shrinking as surrounding subduction zones consume ocean floor, with the water mass remaining constant. Computer models project the basin could close in about 200–300 million years, potentially forging a new supercontinent called Amasia as the Americas collide with Asia; other simulations suggest different futures. The process is geological and extremely gradual, not driven by climate change.
Geologists once thought the ocean floor formed from steady upwelling magma that cools into basalt, but a 2009 high-resolution sonar survey revealed low-angle detachment faults that pull mantle rock up to the seafloor, creating oceanic core complexes. With more than 170 identified along slow-spreading ridges, these structures show mantle rock, not just crust, is exposed to seawater, triggering serpentinization and powering hydrothermal vents. The findings reframe crust formation, illuminate global geochemical cycles, and offer models for extraterrestrial oceans.
Seismic data from NASA’s InSight lander indicate a deep, interconnected magma system beneath Mars, formed by molten rock pooling and extending hundreds to thousands of miles. This challenges the idea of isolated magma chambers and implies a chemically active crust capable of recycling elements, potentially supporting atmosphere and ocean formation and offering a habitable window for rocky planets even without plate tectonics.
The mid-ocean ridge is the Earth’s longest mountain range, a 65,000‑km system of underwater volcanoes that encircles the globe and lies mostly beneath the sea. It forms where tectonic plates pull apart and new ocean crust is created. Mapped in the 1950s by Marie Tharp and colleagues, with major atlases published in 1957 and 1977, the ridge reshapes our view of the planet. Despite decades of sonar and satellite work, only about 28–29% of the seafloor has high‑resolution mapping as of 2026, and explorers have seen a vanishingly small fraction of the deep ocean floor, underscoring how much of Earth remains unseen.
Everest’s summit rocks are Ordovician limestone from the Qomolangma Formation that formed in an ancient sea and host fossils of trilobites, ostracods and crinoids, anchoring the summit to a marine environment long before the Himalayan uplift. The fossils survive in rocks that were squeezed and lifted during the India–Asia collision, reinforcing a long-running geological narrative rather than a single new discovery.
A 2024 French study near the Amsterdam–Saint Paul Plateau shows mid-ocean ridge spreading can occur in intense bursts: dyke intrusions, sudden subsidence of a magma reservoir, and meters of horizontal extension happened within days, with some events lacking seismic signals. About 150 million cubic meters of new material were produced, and the total extension equates to roughly 38 years of normal spreading, suggesting ocean-floor creation may be episodic rather than steady.
Researchers analyzing 3.1‑billion‑year‑old pillow lavas from Western Australia’s Pilbara Craton show the mantle contained as much water as today’s arc volcanic settings, indicating an early deep water cycle. They propose 'dripduction'—a process where soft, water‑rich crust sagged and sank into the mantle, delivering water and triggering volcanism long before plate tectonics governed subduction. This finding demonstrates Earth was recycling surface water well before modern plate tectonics began.
A new study argues that intense asteroid impacts during the Hadean heated and thinned Earth’s crust far more than internal heat sources, keeping the crust molten and preventing plate tectonics. As the impact flux waned around 3.9–3.5 billion years ago, internal heat then dominated, allowing the crust to thicken and enabling the rise of continental tectonics. This outer-heating scenario helps explain the scarcity of preserved Hadean crust and zircons, with lunar crater data helping calibrate the impact history and models predicting eventual crust recycling and the emergence of continents in the Archean.
A machine-learning study analyzes 2018–2021 seismic data to map a 250-km, razor-sharp edge of the Yakutat microplate beneath Alaska, extending under the North American plate and along the Denali fault. This hidden edge illuminates how the subducted slab shapes stress and earthquake nucleation in the region, including the 2002 magnitude-7.9 Denali quake, and suggests a broader, dynamically interacting plate boundary that influences regional volcanic activity.
Plate tectonics–driven simulations of the Alps, Pyrenees and Baetic mountains suggest deep mantle rocks rose and interacted with water to release hydrogen, which then accumulated in porous rock layers—making the Alps and Pyrenees plausible natural hydrogen reservoirs. The Baetic range, by contrast, uplifted and eroded too rapidly for large hydrogen volumes to form or be retained. If validated, this approach could guide searches for other natural hydrogen sources to support a hydrogen-powered economy.
Researchers mapped a continent-scale bedrock system under East Antarctica—the East Antarctic Fan-Shaped Basin Province—comprising 30 pull-apart basins formed by distributed rotational extension. Using airborne gravity, magnetic surveys and seismic imaging, they suggest thinner, younger crust under much of the East Antarctic Ice Sheet, which could alter ice-flow patterns and heat transfer, with implications for ice-sheet stability and sea-level rise. The study, published in Nature Geoscience, challenges the idea of a single, stable crust beneath East Antarctica and underscores how hidden geology can influence the fate of Earth's freshwater ice.
The Pacific Ocean is so vast it can swallow all Earth’s land (land area ~149 million sq km) with water to spare, with ocean-area estimates around 155–165 million sq km. A leftover water-free area of roughly 16 million sq km remains—larger than Russia. The ocean covers about two-thirds of the planet’s surface and, despite its enormity, is relatively shallow; through subduction the Pacific is slowly shrinking while the Atlantic widens, reminding us that Earth’s blue appearance is a dynamic, not fixed, fact. A common analogy even suggests Earth’s water would form a tiny sphere inside a ping-pong ball, underscoring how little of the planet is actually water relative to its size.
A new study ties Earth’s oxygen buildup to the subduction of carbon and sulfur: when subduction runs cooler, more C and S are carried into the mantle, later returning to the surface via volcanism and scavenging oxygen; warmer subduction releases more of these elements toward the surface, boosting atmospheric O2. The timing matches major oxygenation events (Great Oxygenation ~2.4–2.0 Ga and later boosts) and tracks with the cooling Earth and supercontinent cycles (Columbia, Gondwana, Pangaea). The findings suggest oxygen levels result from a complex interplay of biology, deep Earth chemistry, and plate tectonics.