Earth and the Other Terrestrial Worlds
... erosion or tectonics since the time of the heavy bombardment. b) parts of the surface are ancient, while others have been resurfaced within the last 100 million years. c) the entire planet was resurfaced about 750 million years ago. d) there has been ongoing regional resurfacing leading to a dist ...
... erosion or tectonics since the time of the heavy bombardment. b) parts of the surface are ancient, while others have been resurfaced within the last 100 million years. c) the entire planet was resurfaced about 750 million years ago. d) there has been ongoing regional resurfacing leading to a dist ...
Helium - Adrian Jones - Deep Carbon Observatory
... is a so-called primordial isotope. It was made in the Big Bang and incorporated into Earth during its initial accretion and in the subsequent long-term acquisition of “late veneer” material. 3He is not produced in any large quantities by radiogenic decay, and is thus not being added to Earth’s inven ...
... is a so-called primordial isotope. It was made in the Big Bang and incorporated into Earth during its initial accretion and in the subsequent long-term acquisition of “late veneer” material. 3He is not produced in any large quantities by radiogenic decay, and is thus not being added to Earth’s inven ...
(2016). A joint local and teleseismic tomography study of
... region surrounding the NMSZ. Interpretations of potential field data and active source reconnaissance seismic refraction and reflection experiments suggest significant crustal heterogeneity beneath the embayment related to a long and complex geological history of rifting, uplift, and subsidence [Mooney ...
... region surrounding the NMSZ. Interpretations of potential field data and active source reconnaissance seismic refraction and reflection experiments suggest significant crustal heterogeneity beneath the embayment related to a long and complex geological history of rifting, uplift, and subsidence [Mooney ...
The 2011 off the Pacific coast of Tohoku Earthquake related... a strong velocity gradient with the Pacific plate
... based on the velocity structure and earthquake hypocentral distribution. The upper boundary of the low-V oceanic crust corresponds to the plate boundary where thrust earthquakes are expected to occur. Where we don’t observe lowV oceanic crust, we determine the upper boundary of the upper layer of th ...
... based on the velocity structure and earthquake hypocentral distribution. The upper boundary of the low-V oceanic crust corresponds to the plate boundary where thrust earthquakes are expected to occur. Where we don’t observe lowV oceanic crust, we determine the upper boundary of the upper layer of th ...
1 The role of the mantle wedge in subduction zone dynamics and
... Heatflow, topography, gravity and geoid The heat flow variations across subduction zones provide important constraints on the thermal structure. In general the heatflow in the fore arc is low due to the subduction of cold lithosphere, moderately high in the back arc and high in the volcanic arc (e.g ...
... Heatflow, topography, gravity and geoid The heat flow variations across subduction zones provide important constraints on the thermal structure. In general the heatflow in the fore arc is low due to the subduction of cold lithosphere, moderately high in the back arc and high in the volcanic arc (e.g ...
Propagation of the Hawaiian-Emperor volcano chain by Pacific plate
... global oceanic lithosphere older than ~70 Ma, cooling of a 95-km thick plate with basal temperature 1450˚C is more consistent with heat flow and seafloor depth data than a half-space model (Stein and Stein, 1992). Our result is an approximation to the solution of a more realistic cooling problem whe ...
... global oceanic lithosphere older than ~70 Ma, cooling of a 95-km thick plate with basal temperature 1450˚C is more consistent with heat flow and seafloor depth data than a half-space model (Stein and Stein, 1992). Our result is an approximation to the solution of a more realistic cooling problem whe ...
Science Article PDF - Geological Society of America
... are exemplified by three simple but very different one-dimensional velocity models that explain the main amplitude relations among the seismic phases and give average crustal and mantle structure within each province (Figs. 2, 31). These are related through the two-dimensional interpretation (Fig. 2 ...
... are exemplified by three simple but very different one-dimensional velocity models that explain the main amplitude relations among the seismic phases and give average crustal and mantle structure within each province (Figs. 2, 31). These are related through the two-dimensional interpretation (Fig. 2 ...
PNAS-2014-Anderson-1..
... detail, they also violate the first and second laws of thermodynamics because they require noncooling boundaries and external sources of energy, material, and information (e.g., Maxwell demons); that is, the model planets are not closed, isolated, selforganizing systems living off of their own resou ...
... detail, they also violate the first and second laws of thermodynamics because they require noncooling boundaries and external sources of energy, material, and information (e.g., Maxwell demons); that is, the model planets are not closed, isolated, selforganizing systems living off of their own resou ...
Centre for Earth Evolution and Dynamics (CEED)
... for studying models of Earth evolution and dynamics (Chertova et al., Duretz et al., Ghazian & Buiter, Hillebrand et al., Rolf et al., Schmalholz et al., Shephard et al., Thieulot et al.). Insights into the age and origin of heterogeneities at the core-mantle boundary (Tuzo and Jason) are obtained b ...
... for studying models of Earth evolution and dynamics (Chertova et al., Duretz et al., Ghazian & Buiter, Hillebrand et al., Rolf et al., Schmalholz et al., Shephard et al., Thieulot et al.). Insights into the age and origin of heterogeneities at the core-mantle boundary (Tuzo and Jason) are obtained b ...
2015 PA SE Reg
... d. 2 miles west of the Mid-Atlantic Ridge e. Along the coast of Western Africa 6. When a mantle plume rises from the outer core boundary to the Earth’s surface, it results in a: a. Hot spot b. Volcanic island arc c. Subduction zone d. Suture zone e. Spreading center 7. The inside of the Earth is not ...
... d. 2 miles west of the Mid-Atlantic Ridge e. Along the coast of Western Africa 6. When a mantle plume rises from the outer core boundary to the Earth’s surface, it results in a: a. Hot spot b. Volcanic island arc c. Subduction zone d. Suture zone e. Spreading center 7. The inside of the Earth is not ...
Formation of the Crust and Continents
... Earth’s “Birth” • For about the first 4 billion years of Earth’s 4.6-billion-year existence, most of the life-forms that inhabited Earth were unicellular organisms. • In 1996, the announcement that a meteorite from Mars might contain microscopic fossils of bacteria rekindled scientific interest in t ...
... Earth’s “Birth” • For about the first 4 billion years of Earth’s 4.6-billion-year existence, most of the life-forms that inhabited Earth were unicellular organisms. • In 1996, the announcement that a meteorite from Mars might contain microscopic fossils of bacteria rekindled scientific interest in t ...
letters to nature - University of Oregon
... The extent to which crustal processes along mid-ocean ridges are controlled by either the pattern of mantle upwelling or the mode of magma injection into the crust is not known. Models of mantle upwelling vary from two-dimensional, passive flow1 to threedimensional, diapiric flow2–4. Similarly, bene ...
... The extent to which crustal processes along mid-ocean ridges are controlled by either the pattern of mantle upwelling or the mode of magma injection into the crust is not known. Models of mantle upwelling vary from two-dimensional, passive flow1 to threedimensional, diapiric flow2–4. Similarly, bene ...
KEY - Mrs. Wendorf
... b) Hopefully for part a, you answered that the time would be greater. It will be greater because the pillow causes a gradual slowing of the plate instead of a sudden slowing as it hits the floor. Go on to part c. c) The time of impact when the plate hits the pillow is 0.0085 s. Now calculate the for ...
... b) Hopefully for part a, you answered that the time would be greater. It will be greater because the pillow causes a gradual slowing of the plate instead of a sudden slowing as it hits the floor. Go on to part c. c) The time of impact when the plate hits the pillow is 0.0085 s. Now calculate the for ...
Evolution of mantle plumes and uplift of continents during the
... variation in the mantle encompasses more than 20 orders of magnitude. Without regard for melting processes, this range amounts to 5–8 orders. The exponent n in a dislocation creep model is usually taken equal to 3. The ideas of mantle convection and oceanic lithospheric plates spreading away from mi ...
... variation in the mantle encompasses more than 20 orders of magnitude. Without regard for melting processes, this range amounts to 5–8 orders. The exponent n in a dislocation creep model is usually taken equal to 3. The ideas of mantle convection and oceanic lithospheric plates spreading away from mi ...
Asthenospheric flow and origin of volcanism in the Baikal Rift area
... The origin of low-volume, hotspot-like volcanism often observed in continental rift areas is debated, as is the nature of the flow in the mantle beneath. In this paper we assemble seismic constraints on the mantle flow below the Baikal Rift Zone. We combine new evidence from upper-mantle tomography ...
... The origin of low-volume, hotspot-like volcanism often observed in continental rift areas is debated, as is the nature of the flow in the mantle beneath. In this paper we assemble seismic constraints on the mantle flow below the Baikal Rift Zone. We combine new evidence from upper-mantle tomography ...
Differentiation of the Earth, Core formation
... equilibrate with molten iron, remain in the silicate mantle. Major problem: ultramafic phases have Fe, but Fe should have segregated to core while still hot: no Fe expected in lower mantle, but seismology: Fe/(Mg+Fe) ~0.1 ...
... equilibrate with molten iron, remain in the silicate mantle. Major problem: ultramafic phases have Fe, but Fe should have segregated to core while still hot: no Fe expected in lower mantle, but seismology: Fe/(Mg+Fe) ~0.1 ...
FREE Sample Here
... 50) What is the relationship of the dense oceanic crust that is produced at a divergent plate boundary to the convergence or collision of an oceanic plate and a continental plate, such as the western margin of South America in the diagram below? ...
... 50) What is the relationship of the dense oceanic crust that is produced at a divergent plate boundary to the convergence or collision of an oceanic plate and a continental plate, such as the western margin of South America in the diagram below? ...
Anisotropy of the flexural response of the lithosphere in the
... maximum coherence in the different wavelength regimes. White circles indicate the center of regions where Te could be estimated. The region where Te could not be estimated is left white. Black and purple bars indicate the fast seismic axis and the high electrical conductivity direction. The dashed l ...
... maximum coherence in the different wavelength regimes. White circles indicate the center of regions where Te could be estimated. The region where Te could not be estimated is left white. Black and purple bars indicate the fast seismic axis and the high electrical conductivity direction. The dashed l ...
Chapter 7. Convection and Complexity
... the fluid-like behavior of the mantle but also provides the data for estimating its viscosity. In contrast to everyday experience mantle convection has some unusual characteristics. The container has spherical geometry. The ' fluid' has stress-, pressure- and temperature-dependent properties. It is ...
... the fluid-like behavior of the mantle but also provides the data for estimating its viscosity. In contrast to everyday experience mantle convection has some unusual characteristics. The container has spherical geometry. The ' fluid' has stress-, pressure- and temperature-dependent properties. It is ...
Evolution and diversity of subduction zones controlled by slab width
... W. P. Schellart1, J. Freeman1, D. R. Stegman2, L. Moresi2 & D. May2 ...
... W. P. Schellart1, J. Freeman1, D. R. Stegman2, L. Moresi2 & D. May2 ...
pdf-file - Art Periods
... and 40°S, where the largest coseismic displacement of the 1960 Valdivia earthquake occurred. A lowvelocity anomaly and high Vp/Vs values occur under the coastal region, indicating mantle serpentinisation and/or underthrusting of forearc material. Further east, a high-velocity anomaly is observed, in ...
... and 40°S, where the largest coseismic displacement of the 1960 Valdivia earthquake occurred. A lowvelocity anomaly and high Vp/Vs values occur under the coastal region, indicating mantle serpentinisation and/or underthrusting of forearc material. Further east, a high-velocity anomaly is observed, in ...
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.