Articles tagged with Asthenosphere
A study by Okayama University reveals that garnet governs the formation of Earth's 660-km seismic boundary, shaping the mineral transitions that control heat and material circulation. This finding provides a unified explanation for complex seismic observations and supports a homogeneous, pyrolite-like mantle composition.
Researchers discover that asthenosphere composition controls magma flux and spreading mode at slow- to ultraslow-spreading ridges. The study found higher volumes of ancient refractory mantle domains in the asthenosphere during asymmetric spreading, supporting the hypothesis that the asthenosphere modulates magma flux.
Researchers investigate the effect of oxygen content on mantle rock melting and early Earth magma ocean formation. The study reveals that oxygen fugacity significantly influences melting temperatures, suggesting current models need revision.
A team of researchers from Japan found that water enhances energy dispersion and reduces elastic moduli in rocks, leading to increased seismic wave attenuation. The study suggests the oceanic asthenosphere must contain water, explaining sharp velocity drops and near-constant attenuation observed at the LAB.
Researchers have found evidence of 20 million years of 'hot spot' magmatism under the Cocos plate, with a long-lived melt channel that originated from a mantle plume. The study suggests that this channel is regionally extensive and may be a widespread source for intraplate magmatism.
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.
Scientists from the University of Arizona have discovered a giant active mantle plume pushing the surface of Mars upward, causing earthquakes and volcanic eruptions. The finding suggests that Mars' deceptively quiet surface may hide a more tumultuous interior than previously thought.
A joint research team has discovered ancient continental rocks at the Southwest Indian Ridge, dating back 2.7 billion years. The rocks' composition suggests they were recycled from the neighboring African continent through the asthenosphere, challenging current understanding of oceanic crust formation.
A team of researchers from the University of Houston found that the asthenosphere, a hot and softer layer beneath tectonic plates, is flowing vigorously, driving plate motions. This 'river of rocks' has been actively flowing for eight million years, shaping the Earth's surface and influencing earthquakes.
Scientists have discovered that a tiny amount of molten rock, less than 0.7% by volume, is present in the asthenosphere under all oceanic plates, reducing the viscosity and 'decoupling' them from the underlying mantle. This research improves our understanding of plate tectonics and how it drives plate movement.
New research by Rice University geophysicists reveals that the asthenosphere's convective cycling and pressure-driven flow can move faster than the tectonic plates on top of it. This challenges a long-held theory that the lithosphere moves independently of the asthenosphere.
A new study has found that smaller-scale processes in the Earth's mantle have a more significant impact on plate tectonics than previously thought. The research used high-resolution imaging to map the flow of the mantle beneath the ocean's tectonic plates, revealing that convection channels play a crucial role in driving plate movement.
Research by Franz Neubauer and Fariba Kargaranbafghi reveals lithospheric thinning associated with the formation of a metamorphic core complex in the Central Iranian plateau. The study suggests that this process was linked to extension, upwelling of hot asthenosphere, and subsequent uplift of the plateau.
A University of Oregon study discovers the source of Galapagos eruptions to be a plume 150 kilometers southeast of Fernandina Island, contradicting previous modeling. This finding sheds light on volcanic activity in the islands and raises questions about plate tectonics and Earth's internal convection.
Scientists have discovered a new understanding of the Earth's mantle beneath the Pacific Ocean, revealing that the Gutenberg discontinuity is closely related to the lithosphere-asthenosphere boundary. The study suggests that partially molten rock plays a key role in forming the Gutenberg discontinuity.
A NASA-sponsored researcher found that a melt-rich layer under the Pacific Ocean basin is not the only mechanism allowing continents to gradually shift their position. This discovery sheds new light on plate tectonics, providing insight into the movement of Earth's crustal plates over millions of years.
A team of scientists led by Rice University geologist Alan Levander has figured out why the Colorado Plateau is rising even as parts of its lower crust appear to be falling. The region's uplift is caused by magmatic material from the depths slowly rising to invade the lithosphere, causing layers to peel away and sink.
Researchers used GPS satellite systems to measure tide-induced displacements and estimate density and elastic moduli, revealing an abnormal low-density asthenosphere under the western United States and eastern Pacific Ocean. The study provides new directions for understanding Earth's chemical and mechanical dynamics.
Researchers use seismic technique to detect boundary between old and new lithosphere beneath the North American continent. The study reveals a layer cake of ancient rock on top of newer material, challenging traditional theories on continental formation.
The article discusses four main questions: Subducted oceanic asthenosphere flow beneath the Juan de Fuca slab, Arkosic rocks from the San Andreas Fault Observatory at Depth (SAFOD) borehole, long-term strain records of the Parkfield Earthquake Prediction Experiment, and mechanisms responsible for map-view curvature over a range of scal...
A graduate student's seismic study has found a sharp dividing line between the lithosphere and asthenosphere, contradicting the idea that the transition is gradual. The research suggests water or partly molten rock must be present in the asthenosphere to cause such an abrupt change.
A team of UC Berkeley scientists resolves a long-standing puzzle in earth science by clarifying the depth of the continental lithosphere. By re-examining earthquake-generated seismic waves, they determine that the boundary between the lithosphere and asthenosphere lies at 200-250 kilometers.