Geotherms One layer model
... There is a limit to the lithospheric thickness available for cooling ...
... There is a limit to the lithospheric thickness available for cooling ...
Kerguelen plateau : a volcanic passive margin fragment ?
... dominates crustal thickening. Seismic velocities in oceanic layer 2 vary widely in oceanic crust and thus cannot indicate crustal type. The average seismic velocity in layer 3 increases as crustal thickness increases (Mutter and Mutter, 1993), which agrees with the observation that oceanic plateaus ...
... dominates crustal thickening. Seismic velocities in oceanic layer 2 vary widely in oceanic crust and thus cannot indicate crustal type. The average seismic velocity in layer 3 increases as crustal thickness increases (Mutter and Mutter, 1993), which agrees with the observation that oceanic plateaus ...
EENS 2120 Petrology Prof. Stephen A. Nelson Igneous Rocks of the
... Partial melting of peridotite, containing Ol + Cpx + Opx at any of these pressures would first produce liquids with a composition at the intersection of the boundary curves. Note that the composition of the first liquid produced shifts away from the SiO2 corner of the diagram with increasing pressur ...
... Partial melting of peridotite, containing Ol + Cpx + Opx at any of these pressures would first produce liquids with a composition at the intersection of the boundary curves. Note that the composition of the first liquid produced shifts away from the SiO2 corner of the diagram with increasing pressur ...
Terrestrial planets fractionated synchronously
... thin unbroken lithosphere that was transformed by plume-generated vertical tectonism a half-billion years ago. Venusian topography then generated has since been precisely maintained dynamically by rising plumes and sinking antiplumes with constant configurations and velocities and no new effects. Ma ...
... thin unbroken lithosphere that was transformed by plume-generated vertical tectonism a half-billion years ago. Venusian topography then generated has since been precisely maintained dynamically by rising plumes and sinking antiplumes with constant configurations and velocities and no new effects. Ma ...
Lithospheric Layering in the North American Craton
... Huaiyu Yuan (Berkeley Seismological Laboratory), Barbara Romanowicz (Berkeley Seismological Laboratory) Recent receiver function studies detect structural boundaries under continental cratons at depths too shallow to be consistent with the lithosphere-asthenosphere boundary (LAB) as inferred from se ...
... Huaiyu Yuan (Berkeley Seismological Laboratory), Barbara Romanowicz (Berkeley Seismological Laboratory) Recent receiver function studies detect structural boundaries under continental cratons at depths too shallow to be consistent with the lithosphere-asthenosphere boundary (LAB) as inferred from se ...
The north Pyrenean Front and related foreland basin along the Bay
... The Parentis Basin, striking E-W, appears as bounded southwards by a major north-dipping planar fault with a normal displacement of near 15 km. It is filled up by a thick (up to 10 km) sequence of Jurassicupper Cretaceous carbonates affected by salt domes and diapirs of Triassic evaporites and mudst ...
... The Parentis Basin, striking E-W, appears as bounded southwards by a major north-dipping planar fault with a normal displacement of near 15 km. It is filled up by a thick (up to 10 km) sequence of Jurassicupper Cretaceous carbonates affected by salt domes and diapirs of Triassic evaporites and mudst ...
reprint
... oriented mantle material (characterized by a fast polarization direction φ and a delay time δt) that arise due to lattice-preferred orientation in olivine (Silver & Chan 1991). Russo & Silver’s (1994) used the pattern of shear-wave splitting observations and geoid features around South America to in ...
... oriented mantle material (characterized by a fast polarization direction φ and a delay time δt) that arise due to lattice-preferred orientation in olivine (Silver & Chan 1991). Russo & Silver’s (1994) used the pattern of shear-wave splitting observations and geoid features around South America to in ...
Experiments With Portable Ocean Bottom - OBSIP
... The study of almost all subduction-related processes requires the use of ocean bottom seismometers. Approximately 50% of all volcanic arcs are oceanic (Figure 1). In addition, the trenches and major portions of the subduction zones associated with terrestrial arcs are also offshore. While significan ...
... The study of almost all subduction-related processes requires the use of ocean bottom seismometers. Approximately 50% of all volcanic arcs are oceanic (Figure 1). In addition, the trenches and major portions of the subduction zones associated with terrestrial arcs are also offshore. While significan ...
univERsity oF copEnhAGEn
... Seismic and seismological evidence for the existence of the LVZ in the Earth’s mantle below a depth of ca. 100 km has been found in many regional studies, for example, in North America and Europe (Burdick, 1981; Zielhuis and Nolet, 1994), the Siberian Craton (Nielsen et al., 1999), and Tibet (Romano ...
... Seismic and seismological evidence for the existence of the LVZ in the Earth’s mantle below a depth of ca. 100 km has been found in many regional studies, for example, in North America and Europe (Burdick, 1981; Zielhuis and Nolet, 1994), the Siberian Craton (Nielsen et al., 1999), and Tibet (Romano ...
Deformation of the Continental Crust
... Mountains are one part of the continuum of plate tectonics—the most ...
... Mountains are one part of the continuum of plate tectonics—the most ...
Divergent Plate Boundaries - North Coast Distance Education
... MAJOR CONCEPTS 1. Divergent plate boundaries are zones where lithospheric plates move apart ...
... MAJOR CONCEPTS 1. Divergent plate boundaries are zones where lithospheric plates move apart ...
Evolution of Seafloor Spreading Rate Based on 40Ar
... Turekian,1964;Hamduoand Ozima, 1978],the coefficient of degassingrate was given as an adjustableparameter for the degassinghistory and called "degassingconstant". However, in this study, we define the coefficientof degassingrate as ...
... Turekian,1964;Hamduoand Ozima, 1978],the coefficient of degassingrate was given as an adjustableparameter for the degassinghistory and called "degassingconstant". However, in this study, we define the coefficientof degassingrate as ...
Focus and Epicenter
... epicenter, the one with the shallower focus causes more damage. Seismic waves from a deep-focus earthquake lose more of their energy as they travel farther up to Earth’s surface. The depths of earthquakes along tectonic plate boundaries are related to the directions in which the plates move. For exa ...
... epicenter, the one with the shallower focus causes more damage. Seismic waves from a deep-focus earthquake lose more of their energy as they travel farther up to Earth’s surface. The depths of earthquakes along tectonic plate boundaries are related to the directions in which the plates move. For exa ...
Planet Earth - Wayne State University Physics and Astronomy
... the rock deep below the surface and others to raise to large heights (sometimes many kilometers!) This is how mountain ranges are formed on Earth The Alps result from the interaction of the African Plate with the European plate ...
... the rock deep below the surface and others to raise to large heights (sometimes many kilometers!) This is how mountain ranges are formed on Earth The Alps result from the interaction of the African Plate with the European plate ...
Ultraslow, slow, or fast spreading ridges
... spreading regimes. Both observations overall indicate that the mantle convection pattern is increasingly chaotic underneath slow and ultraslow spreading ridges. We suggest that this is due to far-field tectonics at the other ends of lithospheric plates: not only it modulates the spreading rates but i ...
... spreading regimes. Both observations overall indicate that the mantle convection pattern is increasingly chaotic underneath slow and ultraslow spreading ridges. We suggest that this is due to far-field tectonics at the other ends of lithospheric plates: not only it modulates the spreading rates but i ...
Shorelines - Bakersfield College
... slope descends abruptly into a deep-ocean trench Located primarily around the Pacific Ocean Accumulations of deformed sediment and scraps of ocean crust form accretionary wedges ...
... slope descends abruptly into a deep-ocean trench Located primarily around the Pacific Ocean Accumulations of deformed sediment and scraps of ocean crust form accretionary wedges ...
D o e I
... being carried out by Jeff McGuire and Mark Behn underscores how important technology development is to conducting world-class experiments on fundamental earth and ocean science problems. Their experiment is unique. It will provide not only crucial tests of hypotheses about how ocean island flanks de ...
... being carried out by Jeff McGuire and Mark Behn underscores how important technology development is to conducting world-class experiments on fundamental earth and ocean science problems. Their experiment is unique. It will provide not only crucial tests of hypotheses about how ocean island flanks de ...
Continuing evolution of the Pacific–Juan de Fuca–North America
... segment just south of the Pioneer fracture zone ca. 29–27 Ma (Fig. 4c– d); (2) subduction of the ridge segment between the Mendocino and Pioneer fracture zones ca. 26–25 Ma (Fig. 4e–f); (3) capture of the Monterey ridge system and subduction of the northern Cocos ridge segments ca. 20–16 Ma (Fig. 4g ...
... segment just south of the Pioneer fracture zone ca. 29–27 Ma (Fig. 4c– d); (2) subduction of the ridge segment between the Mendocino and Pioneer fracture zones ca. 26–25 Ma (Fig. 4e–f); (3) capture of the Monterey ridge system and subduction of the northern Cocos ridge segments ca. 20–16 Ma (Fig. 4g ...
The World in Wax - Bodenschatz group
... Oldenburg and Brune hadn’t previously noticed. Bodenschatz knows that his experiment can’t be translated to the lithosphere one to one. Due to the enormous mass, the forces in the Earth’s crust are naturally much stronger than in the wax. The densities of wax and magma are, however, quite similar. A ...
... Oldenburg and Brune hadn’t previously noticed. Bodenschatz knows that his experiment can’t be translated to the lithosphere one to one. Due to the enormous mass, the forces in the Earth’s crust are naturally much stronger than in the wax. The densities of wax and magma are, however, quite similar. A ...
Plate tectonics
Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός ""pertaining to building"") is a scientific theory that describes the large-scale motion of Earth's lithosphere. This theoretical model builds on the concept of continental drift which was developed during the first few decades of the 20th century. The geoscientific community accepted the theory after the concepts of seafloor spreading were later developed in the late 1950s and early 1960s.The lithosphere, which is the rigid outermost shell of a planet (on Earth, the crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight major plates (depending on how they are defined) and many minor plates. Where plates meet, their relative motion determines the type of boundary; convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates typically varies from zero to 100 mm annually.Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the globe remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle. Earlier theories (that still have some supporters) propose gradual shrinking (contraction) or gradual expansion of the globe.Tectonic plates are able to move because the Earth's lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by the rotation of the globe and the tidal forces of the Sun and Moon. The relative importance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.