All articles tagged with #tectonic plates
Researchers have identified active fractures in the Juan de Fuca and Explorer plates beneath the Pacific Northwest, indicating the Cascadia subduction zone is dismantling in stages rather than failing all at once. This gradual breakup, captured via seismic imaging, offers insights into how tectonic systems die and may influence future earthquake behavior, though it does not alter immediate regional hazard levels.
Researchers using an underwater geodetic observatory documented a rare, coupled tectonic–magmatic event at a mid-ocean ridge: a massive magma sheet intruded beneath the seafloor, tearing crust apart at about 5 cm per minute, followed by surface collapse and seismic activity, offering new insight into how the ocean floor renews itself.
Scientists say the 2011 magnitude-9.0 Tohoku earthquake sent waves deep into Earth that bounced off the outer core and returned to the crust, causing nearly uniform eastward movement of mainland Japan across about 1,800 miles—roughly 5–6 millimeters—an unprecedented broad displacement with energy comparable to a magnitude-7.5 event, with potential implications for future seismic hazard understanding.
Scientists say Sub-Saharan Africa may be starting to split into a new tectonic boundary along the Kafue Rift. A Frontiers in Earth Science study reports mantle-derived helium-3 signals in hot springs and geothermal wells in Zambia, alongside other geophysical clues, suggesting active rifting in the area—though the evidence is preliminary (only six sites studied, with two others lacking the signal). If confirmed, this would provide a rare glimpse into how a plate boundary begins, a process that could take millions of years; in the near term Zambia could also gain from geothermal energy development and helium extraction.
Geologists studying the Kafue Rift in Zambia found mantle-derived helium signatures in hot springs, suggesting an active fault boundary and early signs that sub-Saharan Africa may be splitting; while this raises the possibility of geothermal energy opportunities, the researchers caution that data from other segments are needed to confirm a new plate boundary.
Geologists find the Turkana Rift in East Africa is thinner than expected and has entered the necking phase, signaling that Africa will keep splitting and eventually form a new ocean over millions of years, a process linked to unusually rich fossil preservation in the region.
Scientists using the CASIE21 seismic program off Vancouver Island captured the Juan de Fuca plate tearing into fragments as it sinks beneath North America—a gradual, piecewise breakup with major tears (including a ~5 km drop and a ~75 km fault) that helps explain ancient plate remnants and will refine Cascadia earthquake hazard models. Despite these changes, the region remains capable of large earthquakes and tsunamis, though models will improve by incorporating the new details.
University of Melbourne researchers show the Twelve Apostles formed when millions of years of tectonic uplift lifted limestone, followed by about 20,000 years of erosion; dating now places the rocks at 8.6–14 million years old, with tilted layers and fault lines revealing ancient earthquakes, and only seven stacks remaining after collapses in 2005 and 2009. The study uses photography, mapping, and microfossil analysis to trace 15 million years of Earth history and climate records.
A new study using computer models shows that Earth's plate tectonics—especially mid-ocean ridges and continental rifts—play a larger role in shaping global climate than previously thought by guiding the deep carbon cycle: carbon stored in seafloor sediments is buried and later released via subduction, driving greenhouse and icehouse periods over the last 540 million years and challenging the view that volcanic arcs are the primary CO2 source, with implications for future climate models.
New computer-model research shows Earth’s plate movements—especially mid-ocean ridges and continental rifts—have been a major driver of long-term carbon cycling. Carbon stored in seafloor rocks is released or sequestered as plates move and subduct, helping to trigger greenhouse or icehouse climates over the last 540 million years. Historically, volcanic arcs were thought to dominate carbon release, but the study finds that divergent plate boundaries played a larger role, with arc emissions rising mainly in the last ~120 million years due to the evolution of planktic calcifiers.
Scientists using a dense seismometer network tracked ultra-small, low-frequency earthquakes offshore to map a five-piece fault system where the San Andreas fault meets the Cascadia subduction zone, including a deep Pioneer fragment from the Farallon plate, which helps explain the unusually shallow 1992 quake and challenges prior boundary models; the work, published in Science, improves understanding of seismic hazards in this complex region.
Scientists using a dense array of seismometers tracked tiny, often imperceptible earthquakes to map five moving tectonic pieces beneath Northern California, including hidden fragments of the North American and Pioneer/Farallon blocks. The study refines the subduction-zone model around the Mendocino Triple Junction, explains a shallower-than-expected 1992 earthquake, and has implications for seismic hazard assessment along the Cascadia and San Andreas regions.
Zealandia, Earth's long-lost eighth continent, has been officially recognized after decades of scientific debate, covering nearly 1.9 million square miles mostly submerged beneath the southwest Pacific Ocean, with significant implications for geology, resource claims, and our understanding of plate tectonics.
Africa is slowly splitting into two due to the East African Rift System, which could eventually lead to the formation of a new ocean and the separation of East Africa from the rest of the continent over the next 5 to 10 million years, highlighting Earth's ongoing geological evolution.
Scientists have identified the Northern Appalachian Anomaly, a massive molten rock formation beneath New England, which originated from the Labrador Sea 80 million years ago and continues to drift slowly, influencing Earth's geological structure and supporting theories of mantle wave activity that shape continental features over millions of years.