a 22 page PDF of this title
... areas of Earth with different density and elastic properties from those seen at the surface. This reasoning showed that Earth is not homogeneous and that its properties vary ...
... areas of Earth with different density and elastic properties from those seen at the surface. This reasoning showed that Earth is not homogeneous and that its properties vary ...
Structure of The Earth - University of Agriculture Abeokuta
... denser materials exist within Earth's core. Further evidence for the high density core comes from the study of seismology. Seismic measurements show that the core is divided into two parts, a solid inner core with a radius of ~1,220 km and a liquid outer core extending beyond it to a radius of ~3,40 ...
... denser materials exist within Earth's core. Further evidence for the high density core comes from the study of seismology. Seismic measurements show that the core is divided into two parts, a solid inner core with a radius of ~1,220 km and a liquid outer core extending beyond it to a radius of ~3,40 ...
Mantle Melting Beneath Mid-Ocean Ridges The Harvard community
... say, elements that are incompatible with the crystals remaining in the solid mantle, called “magmaphile” elements) have concentrations that are inversely proportional to the extent of melting. The most abundant element with this behavior is sodium. High extents of melting lead to liquids with low so ...
... say, elements that are incompatible with the crystals remaining in the solid mantle, called “magmaphile” elements) have concentrations that are inversely proportional to the extent of melting. The most abundant element with this behavior is sodium. High extents of melting lead to liquids with low so ...
PDF (Chapter 9. The Source Region)
... ation, may be restricted to depths less than 100 km, where diapiric ascent is slowed by high viscosities, high-strength lithosphere or buoyancy considerations. Finally, the elastic properties of the transition zone (see Chapter 4) are compatible with an eclogite-rich composition. Basalts are chemica ...
... ation, may be restricted to depths less than 100 km, where diapiric ascent is slowed by high viscosities, high-strength lithosphere or buoyancy considerations. Finally, the elastic properties of the transition zone (see Chapter 4) are compatible with an eclogite-rich composition. Basalts are chemica ...
Magma Supply Vs Magma Plumbing
... What is an Earthquake • “An earthquake is a sudden and sometimes catastrophic movement of a part of the Earth's surface. Earthquakes result from the dynamic release of elastic strain energy that radiates seismic waves. Earthquakes typically result from the movement of faults, planar zones of deform ...
... What is an Earthquake • “An earthquake is a sudden and sometimes catastrophic movement of a part of the Earth's surface. Earthquakes result from the dynamic release of elastic strain energy that radiates seismic waves. Earthquakes typically result from the movement of faults, planar zones of deform ...
Thermodynamic Properties
... The acceptance of mantle convection in the late 1960s provided a natural explanation for the high thermal gradients near the Earth's surface; they are a consequence of thermal boundary layers associated with mantle convection. Beneath the boundary layers heat transport is primariiy by convection and ...
... The acceptance of mantle convection in the late 1960s provided a natural explanation for the high thermal gradients near the Earth's surface; they are a consequence of thermal boundary layers associated with mantle convection. Beneath the boundary layers heat transport is primariiy by convection and ...
The break-up of continents and the formation of new ocean basins
... melt volumes) over normal-temperature mantle for a model that takes account of heat loss by conduction. The shaded box marks the estimated melt thickness in the zone of exhumed mantle in the southern Iberia Abyssal Plain (IAP) and inferred rift duration from drilling and geophysical observations. (b ...
... melt volumes) over normal-temperature mantle for a model that takes account of heat loss by conduction. The shaded box marks the estimated melt thickness in the zone of exhumed mantle in the southern Iberia Abyssal Plain (IAP) and inferred rift duration from drilling and geophysical observations. (b ...
Influence of continental roots and asthenosphere on plate
... 5. Discussion and Conclusions [11] We have shown that the rheology of the lower lithosphere and asthenosphere exerts a primary control on the magnitude, but not the direction, of tractions that mantle flow exerts on the Earth’s plates. However, we find that the thickness of the lithospheric layer, a ...
... 5. Discussion and Conclusions [11] We have shown that the rheology of the lower lithosphere and asthenosphere exerts a primary control on the magnitude, but not the direction, of tractions that mantle flow exerts on the Earth’s plates. However, we find that the thickness of the lithospheric layer, a ...
Seismic evidence for subduction-transported water in the lower mantle
... from subduction zones down deep into the lower mantle, with no indication of a thermal or chemical boundary layer at the 660-km discontinuity [Antolik et al., 2004; Grand, 2002; Karason and van der Hilst, 2001; Masters et al., 2000; Megnin and Romanowicz, 2000; Ritsema and van Heijst, 2000]. Whether ...
... from subduction zones down deep into the lower mantle, with no indication of a thermal or chemical boundary layer at the 660-km discontinuity [Antolik et al., 2004; Grand, 2002; Karason and van der Hilst, 2001; Masters et al., 2000; Megnin and Romanowicz, 2000; Ritsema and van Heijst, 2000]. Whether ...
Chapter 4: Plate tectonics on the terrestrial planets
... composition and density of melt products and the thickness of the lithosphere. Our results show that the onset time of negative buoyancy for oceanic lithosphere is reasonable (less than a few hundred million years) for potential temperatures below ∼ 1500o C for the Earth and ∼ 1450o C for Venus. In ...
... composition and density of melt products and the thickness of the lithosphere. Our results show that the onset time of negative buoyancy for oceanic lithosphere is reasonable (less than a few hundred million years) for potential temperatures below ∼ 1500o C for the Earth and ∼ 1450o C for Venus. In ...
Diamonds in Ophiolites
... The chromite grains and perhaps some small chromitites carrying diamonds appear to have formed at or near the top of the mantle transition zone. The presence of many silicate minerals, such as zircon, corundum, kyanite, and rutile in ophiolitic chromitites and peridotites (Robinson et al. 2011; Yam ...
... The chromite grains and perhaps some small chromitites carrying diamonds appear to have formed at or near the top of the mantle transition zone. The presence of many silicate minerals, such as zircon, corundum, kyanite, and rutile in ophiolitic chromitites and peridotites (Robinson et al. 2011; Yam ...
Notes: Seafloor Spreading In the early 1900`s, the
... A magnetometer is a device that can ____________________ small changes in ______________________________. It is towed behind a ____________ and records the ____________________ fields produced by the ocean ____________. Mid-Ocean Ridges and Trenches Of all of the features discovered, _________ ...
... A magnetometer is a device that can ____________________ small changes in ______________________________. It is towed behind a ____________ and records the ____________________ fields produced by the ocean ____________. Mid-Ocean Ridges and Trenches Of all of the features discovered, _________ ...
The Yellowstone magmatic system from the
... often interpreted as a magma reservoir. Several of these studies also image the top of a second The interaction of the North American Plate moving LVB at greater crustal depths (18, 19); however, they usually southwestward across a mantle plume creates the 16.5 lose resolution with depth quickly due ...
... often interpreted as a magma reservoir. Several of these studies also image the top of a second The interaction of the North American Plate moving LVB at greater crustal depths (18, 19); however, they usually southwestward across a mantle plume creates the 16.5 lose resolution with depth quickly due ...
The viability and style of the modern plate
... subduction below an 5-cm/yr overriding plate is followed by a sudden drop in vconv and vrms , as a result of the removed overriding plate motion. Subduction then slowly develops until the slab reaches 400 km depth, and the subduction is reinforced by the extra phase buoyancy of the exothermic olivin ...
... subduction below an 5-cm/yr overriding plate is followed by a sudden drop in vconv and vrms , as a result of the removed overriding plate motion. Subduction then slowly develops until the slab reaches 400 km depth, and the subduction is reinforced by the extra phase buoyancy of the exothermic olivin ...
PLATE TECTONICS - Oakton Community College
... • plumes of magma that rise from deep within the mantle erupt (Fig. 2.24) p 62 T 54 • Plates moving across hot spots cause chains of volcanic islands Hawaiian Islands (Fig. ...
... • plumes of magma that rise from deep within the mantle erupt (Fig. 2.24) p 62 T 54 • Plates moving across hot spots cause chains of volcanic islands Hawaiian Islands (Fig. ...
Far-reaching transient motions after Mojave
... evolve much differently from those resulting from Newtonian rheology, they produce similar surface deformation patterns (when the depth of flow is similar), and these patterns do not vary much with time. [11] We can also rule out significant contributions of localized afterslip below the seismogenic ...
... evolve much differently from those resulting from Newtonian rheology, they produce similar surface deformation patterns (when the depth of flow is similar), and these patterns do not vary much with time. [11] We can also rule out significant contributions of localized afterslip below the seismogenic ...
The lithosphere under stress
... when the mantle rises and decompresses beneath thinning lithosphere. Again it is oceanic spreading centres that provide the best constraints on the asthenospheric temperature from this process, because the complete separation of the lithospheric plates at such locations means that it is possible to ...
... when the mantle rises and decompresses beneath thinning lithosphere. Again it is oceanic spreading centres that provide the best constraints on the asthenospheric temperature from this process, because the complete separation of the lithospheric plates at such locations means that it is possible to ...
The lithosphere–asthenosphere boundary in the North
... High-viscosity lithospheric plates moving over a lower-viscosity asthenosphere is a basic element of plate tectonics. Lithosphere and asthenosphere are originally mechanical definitions with regards to their reaction to forces acting over thousands or millions of years [1]. However, additional usage ...
... High-viscosity lithospheric plates moving over a lower-viscosity asthenosphere is a basic element of plate tectonics. Lithosphere and asthenosphere are originally mechanical definitions with regards to their reaction to forces acting over thousands or millions of years [1]. However, additional usage ...
The Oceanic Lithosphere
... crust has a compositional connotation, and in oceanic basins it is assimilated to a layered succession of gabbro, diabase and basalt, resulting from the mantle melting, which is emplaced above the Moho (mantle-crust transition). Discussion and description of the oceanic lithospheric structure also r ...
... crust has a compositional connotation, and in oceanic basins it is assimilated to a layered succession of gabbro, diabase and basalt, resulting from the mantle melting, which is emplaced above the Moho (mantle-crust transition). Discussion and description of the oceanic lithospheric structure also r ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.