Articles tagged with Upper Mantle
Tulane researchers discovered that an area of the African tectonic plate, previously thought to be weak, is now resisting deformation due to dehydration 80 million years ago. This process strengthened the plate and made it more resistant to future breakup.
Research finds that pyrope garnet can retain up to 0.2 wt.% water, potentially dominating water transport via basaltic slabs into the lower mantle. The study also reveals strong pressure-temperature dependence of water solubility in pyrope garnet.
Researchers have discovered that the underside of the North American continent is experiencing 'cratonic thinning', a phenomenon where the continent is slowly losing its stability and rock layers. This process, driven by the subduction of the Farallon Plate, may eventually stop as the plate sinks deeper into the mantle.
New research from Macquarie University identifies the probable locations and mechanisms of accumulations of critical metals at the margins of old cores of continents. These areas have been found to contain more sulfur and copper than elsewhere on the continents, making them potential targets for future exploration activities.
Researchers at University of Maryland have discovered that the South Pole-Aitken basin, the moon's oldest and largest visible crater, is more circular than previously believed. The team used high-resolution data to analyze mountain formations around the basin, revealing a rounder shape indicating a more vertical impact angle.
Researchers found that global chemical heterogeneity of the convecting mantle emerged approximately 300 million years after modern plate tectonics began. This process involved the transport of subducted slabs back to the upper mantle via mantle upwellings.
Researchers discovered a mysterious subduction zone deep beneath the Pacific Ocean, reshaping our understanding of Earth's interior structure. The team found an unusually thick area in the mantle transition zone, suggesting the presence of colder material that slows down oceanic slabs as they sink through the mantle.
Researchers confirm multi-stage lithospheric dripping as cause of basin subsidence in Central Anatolian Plateau. Laboratory experiments and satellite data reveal intricate connection between plateau uplift and basin formation events.
A recent study from the University of Copenhagen found that the oldest Scandinavian bedrock originated in Greenland approximately 3.75 billion years ago. The discovery provides new insights into the formation of continents and the emergence of life on Earth, highlighting the importance of fixed continents for supporting life.
A groundbreaking scientific drilling project has unearthed the world's longest geological record of the Cretaceous period, spanning over 50 million years. The project, led by Professor Wang Chengshan, has provided crucial insights into paleoclimate research and will continue to aid in predicting future climate trends.
Researchers have discovered distinct characteristics of the lower mantle flow field beneath the Philippine Sea Plate. They found that ancient N-S fast velocity directions exist at depths of 700-900 km and are not related to slab subduction or a mantle plume.
Researchers discovered that a massive anomaly deep within the Earth's interior may be a remnant of the collision that formed the Moon 4.5 billion years ago. The early Earth exhibited mantle stratification, with different compositions and states in the upper and lower mantle.
Researchers believe convection in the mantle was stratified into two distinct layers, isolated from each other, until a phase transition at 660 km depth. This restriction to upper mantle recycling and mixing has implications for our understanding of Earth's primordial composition.
The study reveals that LLSVPs exhibit higher densities at the bottom of the lower mantle, while displaying lower densities above a depth of approximately 2700 kilometers. Elevated temperatures and enriched concentrations of iron and bridgmanite are also detected.
A study by Caltech scientists reveals that Earth primarily consisted of dry, rocky materials during its early stages, with a major addition of life-essential volatiles occurring only in the last 15% of its formation. This finding provides crucial insights into the planet's formation process and has important implications for theories o...
Researchers found that stable cratons have repeatedly deformed beneath their crust since formation, contradicting decades of plate tectonics theory. This deformation is caused by dense mantle keels peeling away from the lithosphere during supercontinent breakup.
A study from Smithsonian researchers deepens understanding of Earth's crust by testing and eliminating the garnet hypothesis about why continental crust is lower in iron and more oxidized. The findings suggest that intense heat and pressure cannot produce the necessary conditions for garnet formation, contradicting a popular explanation.
Scientists have discovered a layer of fluid rock at the bottom of the upper mantle, which may explain some observed phenomena in seismology. The discovery was made by analyzing data from GPS sensors on islands after a deep earthquake in the Pacific Ocean.
Researchers have discovered a new layer of partly molten rock under the Earth's crust that helps settle a long-standing debate about how tectonic plates move. The study reveals that the melt layer has no significant influence on plate tectonics, with convection of heat and rock being the prevailing force.
A new study by Brown researchers reveals that changes in tectonic plate thickness impact the location of the Denali Fault, a major strike-slip fault. The findings provide key insights into how geological faults behave as they deepen, shedding light on earthquake hazards.
A team of researchers led by Goethe University Frankfurt analyzed a diamond from Botswana, revealing significant amounts of water stored in the transition zone. The discovery has far-reaching consequences for the dynamic situation inside the Earth, potentially altering global material circulation.
A team of researchers has confirmed that regions in the central Andes Mountains were formed through a process called lithospheric dripping, where parts of the planet's outer shell sink into the mantle over millions of years. This discovery may have implications for other terrestrial planets with non-Earth-like plate tectonics.
A new study suggests that Earth's deep mantle was drier than initially thought, with a water concentration 4-250 times lower than the upper mantle. This finding challenges the assumption that the mantle was uniform from its formation and may have prevented mixing within the mantle.
Researchers successfully reproduced the formation of methane from diamonds under high-pressure conditions, shedding light on the deep Earth's carbon cycle. This finding suggests that hydrocarbons like methane can be created without biological activities, which has significant implications for our understanding of the planet's climate.
Scientists have discovered a 900-mile mantle pipeline stretching from the Gal ªgapos Hotspot to Central America, suggesting that hotspots are not fixed in place. This new finding transforms our understanding of geologic processes occurring beneath the Earth's surface.
Researchers at KAUST have updated the model for earthquake-prone regions like California, finding that the strength lies in the upper crust and the lower crust exhibits more ductility over time. This 'crème brûlée' model supports regional hazard assessments for populated territories.
Researchers found evidence that thinning of the lithosphere is generating heat needed to initiate process of stabilizing continental crust. This challenges previous understanding of mountain building and suggests a new mechanism for continent stability.
Researchers study crust and upper mantle velocity structure in SE Tibet to understand geodynamic processes. The study reveals three major geodynamic modes: rigid block extrusion, plastic deformation, and asthenospheric upwelling.
Researchers found that carbonate-rich molten rock can alter the physical properties of rocks, affecting seismic waves. The study provides new insights into the elasticity, density, and compressibility of these rocks, potentially revealing a substantial carbon reservoir in the Earth's deep upper mantle.
Researchers investigated the dynamics of the Earth's transition zone, a boundary layer between ~410 and ~660 km depth. They found that deformation mechanisms shift from dislocation creep to pure climb creep at geological stresses, influencing the Earth's geochemical evolution.
Researchers discovered new variants of feldspar stable under extreme pressure conditions, potentially altering seismologic signatures and plate dynamics. The high-pressure polymorphs were formed through severe geometrical distortions in the tetrahedral framework.
The NASA InSight lander has recorded over 450 marsquakes on Mars, providing insights into the planet's internal structure and tectonic activity. The data reveals a stronger attenuation in the upper mantle compared to the lower mantle, indicating a more fractured crust.
A recent study published in Science Advances analyzed a shocked meteorite sample, revealing the presence of bridgmanite and metallic iron nanoparticles. Bridgmanite is considered the dominant material in the Earth's lower mantle, making up about 38 volume percent of our planet.
A new theory by QUT geologist Professor Balz Kamber explains why diamonds formed as precious gemstones rather than graphite, contradicting a common belief. The study suggests the upper mantle was relatively cool, leading to diamond formation during the Archaean era.
A new study reveals that the Earth's lower mantle is more dynamic than previously thought, with increased flow in regions where ancient ocean floors plunge into the planet's core. This discovery has significant implications for understanding how quickly Earth is cooling and the dynamic evolution of our planet.
Researchers have detected deep low-frequency earthquakes at great depths, suggesting the movement of magmatic fluids beneath Laacher See Volcano. The earthquakes are characterized by unusually low frequencies and occur episodically in groups along a specific depth range.
A new model provides the clearest picture yet of the geology below the Tibetan Plateau, revealing tears in the Indian upper mantle layer. The research suggests that these tears are responsible for earthquakes in the region, shedding light on the complex geological processes at play.
Scientists have discovered regions with lower seismic wave velocities beneath both ends of the Cascadia fault zone, indicating rising pieces of the Earth's upper mantle. These anomalies could modulate plate coupling forces and influence the location, frequency, and strength of earthquake events.
Research at Finnish Museum of Natural History sheds light on great magma eruptions, revealing two contrasting sources: the upper mantle and a deep mantle plume. This study resolves long-standing controversies and presents an interesting new framework for future geological research.
Geologists at MIT found that ancient Earth's mantle was up to 200 degrees Celsius hotter, causing subducting plates to sink all the way to the bottom of the mantle. This led to a 'graveyard' of slabs atop the Earth's core, suggesting a significant change in how mantle convection and plate tectonic processes occurred.
Researchers at University of Leicester discovered that the Earth's mantle is divided into two large domains that convect independently, with limited mixing between them. Upper mantle material flows to lower parts of the mantle when it reaches a subduction zone, maintaining separate domains.
Researchers used deep geophysical exploration and seismic tomography to study the deep tectonic environment of strong earthquakes in North China. Key findings include a complex tectonic setting with a listric normal fault and high-angle deep fault, and a low-velocity anomaly in the middle-lower crust
Researchers at Tohoku University used seismic tomography to image the three-dimensional structure of the Earth's interior, shedding new light on the deep Bonin deep earthquake. The study found that the Pacific slab is split and penetrated the lower mantle, with multiple factors contributing to its occurrence.
The study establishes a phase diagram of dry olivine up to 6.4 GPa, linking temperature and melting behavior. This relationship enables the comparison of the strength of the upper mantle with different thermal states and olivine composition.
Researchers used data from the Earth's gravity field, topography, seismology, and crustal structure to create a 3D model of the North American craton. The study found that the lower part of the craton's root has shifted by approximately 850 kilometers towards the west-southwest due to mantle flow.
Researchers have discovered that carbonates in the deep mantle can contain significant amounts of iron, contrary to previous thought. The study found that these minerals undergo a spin transition under pressure, redistributing iron between them.
Scientists have detected previously unknown channels of slow-moving seismic waves in Earth's upper mantle, helping explain the formation of hotspot volcanoes like Hawaii and Tahiti. The discovery provides an important piece of the puzzle in understanding these volcanoes' complex interactions with plumes and the shallow upper mantle.
Researchers investigate calving barchan dunes, stress fields on the West Salton detachment fault, and chemical interaction between peridotite and intruding melts. These studies provide insights into geological processes, such as landscape evolution and global climate models.
Researchers used the Secondary Ion Mass Spectrometer to examine the role of water in single olivine crystals at the near-atomic scale. The study found that water has a much lower effect on the mechanical weakening of olivine, challenging earlier concepts about its lubricating properties.
Researchers at Case Western Reserve University have discovered that parts of the moon's interior contain as much water as the Earth's upper mantle. The presence of this water challenges the current theory of the moon's formation and strengthens the idea that the moon and Earth share a common origin.
A team of scientists from Brown University has detected an Earth-equivalent amount of water within the moon, rivaling the amount found in the Earth's upper mantle. The discovery was made through measurements of lunar melt inclusions and suggests that the Moon's formation theory may need to be reevaluated.
Two studies published in Lithosphere suggest the existence of a pre-3.3 billion year old continent in the East Indian Shield, implying a possible original supercontinent. Additionally, measurements of SKS splitting in South America indicate that asthenospheric flow plays a significant role in shaping the upper mantle's anisotropy.
Researchers have developed a dynamic model to explain Mount Etna's existence, suggesting it resulted from decompression melting of upper mantle material. The theory provides an alternative explanation for the volcano's geological environment and surrounding volcanism.
Researchers have discovered an active strike-slip fault on the island of Trinidad, highlighting a major seismic hazard. The study also found that the lower crust is significantly weaker than the mantle at the Moho, and K/U ratio in the mantle records a snapshot of early Earth weathering.
Researchers investigate seismic activity in the Midwest US, shedding light on causes of intraplate earthquakes. The study reveals insights into stress within fault zones and the impact of glacial rebound on earthquake frequency. Key findings also highlight correlations between mantle density structures and topographic uplift.
Researchers suggest a 400km-deep density trap formed due to unique geophysical conditions 3.5 billion years ago, trapping gases like helium and argon inside the planet.
Researchers have imaged Yellowstone's plumbing using seismic waves, revealing a plume of hot rock rising from the northwest at a depth of at least 410 miles. The new findings suggest a larger magma chamber than previously thought, potentially leading to an even more catastrophic eruption.
Researchers from Oregon State University create the most complete seismic image of the Earth's crust and upper mantle beneath the Himalayas. The study reveals unusual geologic features that help explain how the region has evolved and advances research on various fronts, including strain accumulation prior to large earthquakes.
Researchers at Rice University and Harvard University developed a new model to explain how noble gases are lost from the Earth's interior during mantle convection. The model suggests that both the upper and lower mantle are involved in convection, but they affect each other differently.
Researchers found a large cylindrical blob of cold material, known as a lithospheric drip, beneath the Great Basin in central Nevada. The finding provides new insights into fine-scale mantle convection processes and their connections to volcanism and mountain-building.