Vesta is not an intact protoplanet
... the extremely limited presence of exposed olivine on its surface. Vesta has a mean density of 3456 kg/m3 and its surface composition is well matched by howardites. The Dawn gravity data suggest a nickel-iron core of radius 110 km and density 7500–7800 kg/m3 . The Rheasilvia impact basin, formed with ...
... the extremely limited presence of exposed olivine on its surface. Vesta has a mean density of 3456 kg/m3 and its surface composition is well matched by howardites. The Dawn gravity data suggest a nickel-iron core of radius 110 km and density 7500–7800 kg/m3 . The Rheasilvia impact basin, formed with ...
Constraints on asthenospheric flow from the depths of oceanic
... al. [2003] and Sleep [2006]). The slow motion of hot spot locations relative to each other has lead to the idea that the bulk of the mantle is very slow moving [e.g., Stock and Molnar, 1983; Molnar and Stock, 1987; Müller et al., 1993]. Giant quasispherical heads at the top of nascent plumes are of ...
... al. [2003] and Sleep [2006]). The slow motion of hot spot locations relative to each other has lead to the idea that the bulk of the mantle is very slow moving [e.g., Stock and Molnar, 1983; Molnar and Stock, 1987; Müller et al., 1993]. Giant quasispherical heads at the top of nascent plumes are of ...
Geologic Structures and Deformation
... • imaginary line constructed on the down slope surface of a sedimentary bed or fault--dip has 2 attributes: 1)bearing of dip is perpendicular to strike direction; 2)angle of dip measured from horizontal plane to top of bed or fault-dip cannot exceed 90 degrees • In a series of dipping sedimentary ro ...
... • imaginary line constructed on the down slope surface of a sedimentary bed or fault--dip has 2 attributes: 1)bearing of dip is perpendicular to strike direction; 2)angle of dip measured from horizontal plane to top of bed or fault-dip cannot exceed 90 degrees • In a series of dipping sedimentary ro ...
Thermal, Density, Seismological, and Rheological Structure of the
... This thesis presents a first-of-its-kind combined geophysical-petrological methodology to study the thermal, compositional, density, rheological, and seismological structure of different lithospheric domains. The methodology is incorporated in a finite-element code (LitMod) that solves simultaneousl ...
... This thesis presents a first-of-its-kind combined geophysical-petrological methodology to study the thermal, compositional, density, rheological, and seismological structure of different lithospheric domains. The methodology is incorporated in a finite-element code (LitMod) that solves simultaneousl ...
Mantle flow, melting, and dehydration of the Iceland mantle plume
... mark the upper extent of the partially molten mantle (I. Bjarnason, personal comm., 1998). A depth of ¾40 km is also consistent with a final melting depth of ¾45 km inferred from basalt chemistry [8]. The melt production rate per unit length of ridge axis is calculated by integrating melting rates i ...
... mark the upper extent of the partially molten mantle (I. Bjarnason, personal comm., 1998). A depth of ¾40 km is also consistent with a final melting depth of ¾45 km inferred from basalt chemistry [8]. The melt production rate per unit length of ridge axis is calculated by integrating melting rates i ...
The role of magmatically driven lithospheric thickening on arc front
... descends into the Earth’s deep interior. Arc volcanism forms one of the primary connections between longterm climate, landscape, and mantle dynamics. For example, convergent margin igneous activity is one of the main drivers of crustal differentiation and the formation of continents. Arc volcanoes c ...
... descends into the Earth’s deep interior. Arc volcanism forms one of the primary connections between longterm climate, landscape, and mantle dynamics. For example, convergent margin igneous activity is one of the main drivers of crustal differentiation and the formation of continents. Arc volcanoes c ...
Monitoring Geothermal Activity at Aso Volcano, Japan, After Small
... We interpret the gravity change data to construct the 3D model of density change distribution through 3D inverse modeling software. This GRAV3D inversion method was developed at the UBC Geophysical Inversion Facility (2005) and referred to the algorithm of Li and Oldenburg (1997, 1998). Usually this ...
... We interpret the gravity change data to construct the 3D model of density change distribution through 3D inverse modeling software. This GRAV3D inversion method was developed at the UBC Geophysical Inversion Facility (2005) and referred to the algorithm of Li and Oldenburg (1997, 1998). Usually this ...
Compressional to shear wave conversion in oceanic crust
... prevent the occurrence of strong doubly converted crustal S-waves. Basement P-wave velocities increase with age over the first 20-40 Myr after formation at a spreading centre (Houtz & Ewing 1976), so we might expect to see some age dependence of converted shear energy from the lower crust. Porositie ...
... prevent the occurrence of strong doubly converted crustal S-waves. Basement P-wave velocities increase with age over the first 20-40 Myr after formation at a spreading centre (Houtz & Ewing 1976), so we might expect to see some age dependence of converted shear energy from the lower crust. Porositie ...
Resolving the lithosphereasthenosphere boundary with seismic
... lithosphere–asthenosphere boundary (LAB). We investigate the sensitivity of Rayleigh waves to LAB properties and find that if the LAB is associated with a 2–3 per cent shear speed reduction at a depth less than 100 km, then 10–20 km variations in its depth translate into phase-velocity changes of up ...
... lithosphere–asthenosphere boundary (LAB). We investigate the sensitivity of Rayleigh waves to LAB properties and find that if the LAB is associated with a 2–3 per cent shear speed reduction at a depth less than 100 km, then 10–20 km variations in its depth translate into phase-velocity changes of up ...
Seismic characteristics and distribution of volcanic
... westward at least to the regional escarpments, but sills have also been interpreted west of the Faroe– Shetland Escarpment on a few high-quality profiles across the Møre margin (Planke & Alvestad 1999). The eastern extent of the sill complex is fairly well defined, except in the very northern and so ...
... westward at least to the regional escarpments, but sills have also been interpreted west of the Faroe– Shetland Escarpment on a few high-quality profiles across the Møre margin (Planke & Alvestad 1999). The eastern extent of the sill complex is fairly well defined, except in the very northern and so ...
geology guidance for teaching
... e.g. Component 1 Q 8 requires learners to justify the observations they would make in a field investigation to establish past geological processes in an area shown in a photograph. This asks learners to develop and justify practical procedures and is assigned to AO3 element 1f. ...
... e.g. Component 1 Q 8 requires learners to justify the observations they would make in a field investigation to establish past geological processes in an area shown in a photograph. This asks learners to develop and justify practical procedures and is assigned to AO3 element 1f. ...
Shallow-crustal magma chamber beneath the axial high of the
... Fuca Ridge extends from ;5 to ;80 km north from the summit caldera of Axial volcano, the most recent of the Cobb-Eickelberg chain of volcanoes (Fig. 1). The Coaxial segment occupies an en echelon position with respect to the north rift of Axial volcano. Magmatism and resulting crustal accretion of t ...
... Fuca Ridge extends from ;5 to ;80 km north from the summit caldera of Axial volcano, the most recent of the Cobb-Eickelberg chain of volcanoes (Fig. 1). The Coaxial segment occupies an en echelon position with respect to the north rift of Axial volcano. Magmatism and resulting crustal accretion of t ...
Draft 2.5 - posted 15 June 2014 /2500k
... adjustments (this mechanism is hereinafter called ellipsoidal demand), which generates crustal strain fluctuations that may trigger quakes and eruptions, event locations are not indicated. For ellipsoidal demand to be proven useful for forecasting events, a significant history of its time derivative ...
... adjustments (this mechanism is hereinafter called ellipsoidal demand), which generates crustal strain fluctuations that may trigger quakes and eruptions, event locations are not indicated. For ellipsoidal demand to be proven useful for forecasting events, a significant history of its time derivative ...
Joint location of microseismic events in the
... event locations as well as the correlations among these locations. Such correlations are in part due to uncertainty in the velocity model. In most situations, event location is not the final goal, but a step toward a more complete description of geophysical features such as fractures, faults, pressu ...
... event locations as well as the correlations among these locations. Such correlations are in part due to uncertainty in the velocity model. In most situations, event location is not the final goal, but a step toward a more complete description of geophysical features such as fractures, faults, pressu ...
Rio Grande rift: Problems and Perspectives
... Beneath the axis of the Rio Grande rift, existing seismic-refraction data (mainly from the DICE THROW profile) indicate that the Moho is a sharp transition at the resolution of 1.0-1.5 km provided by the dominant 1-10-Hz frequencies characteristic of regional earthquake and explosion sources. On the ...
... Beneath the axis of the Rio Grande rift, existing seismic-refraction data (mainly from the DICE THROW profile) indicate that the Moho is a sharp transition at the resolution of 1.0-1.5 km provided by the dominant 1-10-Hz frequencies characteristic of regional earthquake and explosion sources. On the ...
STUDyIng EArTh`S LAyErS
... If the Earth is like a giant, hard-boiled egg, then the core of the Earth is like the yolk. As the planet cooled, the heavy iron contained in the mix of melted rock started to separate out to collect as a core at the center of the planet. According to some earth scientists, core formation happened v ...
... If the Earth is like a giant, hard-boiled egg, then the core of the Earth is like the yolk. As the planet cooled, the heavy iron contained in the mix of melted rock started to separate out to collect as a core at the center of the planet. According to some earth scientists, core formation happened v ...
The Dynamic Earth - Betavak-NLT
... explained to other, similar cases. You will have to use what you have learned in your other courses as well as what you have just learned from this course. You should be able to apply your new knowledge to these cases. 4****: Four asterisks denote optional exercises which are more challenging. Every ...
... explained to other, similar cases. You will have to use what you have learned in your other courses as well as what you have just learned from this course. You should be able to apply your new knowledge to these cases. 4****: Four asterisks denote optional exercises which are more challenging. Every ...
Thinning of continental backarc lithosphere by flow
... Lower lithosphere instability is enhanced by higher subduction rates, weaker intrinsic rheology, higher compositional density, and hotter initial thermal structure. The numerical model results are in good agreement with a buoyancy stability analysis, which includes the vertical gradients in temperat ...
... Lower lithosphere instability is enhanced by higher subduction rates, weaker intrinsic rheology, higher compositional density, and hotter initial thermal structure. The numerical model results are in good agreement with a buoyancy stability analysis, which includes the vertical gradients in temperat ...
On Earth`s Mantle Constitution and Structure from Joint Analysis of
... and bulk composition. For this purpose we use the thermodynamic formulation of Stixrude and Lithgow-Bertelloni (2005) with parameters as in Stixrude and Lithgow-Bertelloni (2011). Although Gibbs energy minimization has long been advocated for geophysical problems (e.g., Sobolev and Babeyko 1994; Bin ...
... and bulk composition. For this purpose we use the thermodynamic formulation of Stixrude and Lithgow-Bertelloni (2005) with parameters as in Stixrude and Lithgow-Bertelloni (2011). Although Gibbs energy minimization has long been advocated for geophysical problems (e.g., Sobolev and Babeyko 1994; Bin ...
Chapter 12
... mountains and crumple and fold rocks. As rocks respond to these forces, they undergo deformation, which results in changes in shape and/or volume of the rocks. The resulting features are termed geologic structures. This deformation can produce dramatic and beautiful scenery, as evidenced in Figure 1 ...
... mountains and crumple and fold rocks. As rocks respond to these forces, they undergo deformation, which results in changes in shape and/or volume of the rocks. The resulting features are termed geologic structures. This deformation can produce dramatic and beautiful scenery, as evidenced in Figure 1 ...
Chapter 11 SEDIMENTARY BASINS
... 5.1 Much effort has gone into developing ways of figuring out paths of dispersal of sedimentary material in basins. One of the standard ways is to measure paleocurrent directions recorded locally in the rocks. (A paleocurrent is just what the term implies: a current, of water or wind, that existed a ...
... 5.1 Much effort has gone into developing ways of figuring out paths of dispersal of sedimentary material in basins. One of the standard ways is to measure paleocurrent directions recorded locally in the rocks. (A paleocurrent is just what the term implies: a current, of water or wind, that existed a ...
TECTONIC ANALYSIS OF NORTHWESTERN SOUTH AMERICA
... includes a complex and dangerous mosaic of tectonic plates that have produced devastating earthquakes, tsunamis, volcanic eruptions and landslides in the last decades. The region’s economic development has also seriously suffered because the region is poorly explored for natural resources. To more e ...
... includes a complex and dangerous mosaic of tectonic plates that have produced devastating earthquakes, tsunamis, volcanic eruptions and landslides in the last decades. The region’s economic development has also seriously suffered because the region is poorly explored for natural resources. To more e ...
Geodynamic Significance of the Kontum Massif in
... nonfoliated granites. Mesozoic sediments are present as well. All of these rocks have been extensively faulted by structures generally striking N to NNW, whereas Neogene-Quaternary basalts and sediments in the region are not deformed by brittle deformation. The Kannack metamorphic complex includes s ...
... nonfoliated granites. Mesozoic sediments are present as well. All of these rocks have been extensively faulted by structures generally striking N to NNW, whereas Neogene-Quaternary basalts and sediments in the region are not deformed by brittle deformation. The Kannack metamorphic complex includes s ...
Ringwood Phase transformations and their bearing on the
... petrological differentia~on of pyrolite at mid-ocean spreading centres to form new oceanic lithosphere. The MORB basaltic crust is underlain by a layer of harzburgite. During subduction, these lithologies each respond to sequential phase transformations in a different manner, so that at any given de ...
... petrological differentia~on of pyrolite at mid-ocean spreading centres to form new oceanic lithosphere. The MORB basaltic crust is underlain by a layer of harzburgite. During subduction, these lithologies each respond to sequential phase transformations in a different manner, so that at any given de ...
Earthscope
Earthscope is an earth science program using geological and geophysical techniques to explore the structure and evolution of the North American continent and to understand the processes controlling earthquakes and volcanoes. The project has three components: USARRAY, the Plate Boundary Observatory, and the San Andreas Fault Observatory at Depth.The project is funded by the National Science Foundation (NSF), and the data produced is publicly accessible in real-time. Organizations associated with the project include UNAVCO, the Incorporated Research Institutions for Seismology (IRIS), Stanford University, the United States Geological Survey (USGS) and National Aeronautics and Space Administration (NASA). Several international organizations also contribute to the initiative.