P-wave velocity changes in freezing hard low
... (2004) definition, and the applicability of electrical and seismic methods to these is yet unclear. While the relationship between electrical resistivity and frozen low-porosity bedrock has been investigated by Krautblatter et al. (2010), this article will focus on the applicability of p-wave refrac ...
... (2004) definition, and the applicability of electrical and seismic methods to these is yet unclear. While the relationship between electrical resistivity and frozen low-porosity bedrock has been investigated by Krautblatter et al. (2010), this article will focus on the applicability of p-wave refrac ...
Imaging the lithosphere‐asthenosphere boundary
... asthenosphere boundary (LAB). Examples of corresponding operators that are convolved with the reference waveform in the forward model are shown for (c) an oceanic Moho and (d) the lithosphere‐asthenosphere boundary. from the best fitting attenuated waveform, the inversion results for depth using two ...
... asthenosphere boundary (LAB). Examples of corresponding operators that are convolved with the reference waveform in the forward model are shown for (c) an oceanic Moho and (d) the lithosphere‐asthenosphere boundary. from the best fitting attenuated waveform, the inversion results for depth using two ...
seismic activity, Yangtze River – Yellow Sea seismic belt, trend
... such as maximum prediction, regression analysis, periodogram analysis, statistical prediction of stationary independent processes, wavelet analysis, entropy spectrum analysis, and so on. In applying those methods, there are two things need to be noticed: (1) the prediction results obtained from diff ...
... such as maximum prediction, regression analysis, periodogram analysis, statistical prediction of stationary independent processes, wavelet analysis, entropy spectrum analysis, and so on. In applying those methods, there are two things need to be noticed: (1) the prediction results obtained from diff ...
Earth And Planetary Science Letters
... function of basalt fraction. The velocity varies non-linearly with basalt fraction, so that the compositional derivative dVS / df, where f is basalt fraction, is a strong function of bulk composition. These variations can readily be understood on the basis of the phase equilibria: as basalt fraction ...
... function of basalt fraction. The velocity varies non-linearly with basalt fraction, so that the compositional derivative dVS / df, where f is basalt fraction, is a strong function of bulk composition. These variations can readily be understood on the basis of the phase equilibria: as basalt fraction ...
Pore pressure and water saturation variations
... simulated effective stress changes on the order of 1.5 MPa. In the Meadows (2001) method, we obtained better results for the changes in net stress (-4.3 [MPa]). With the second Meadows (2001) modification, we calculated 35 % changes in water saturation which is more or less in agreement with the ori ...
... simulated effective stress changes on the order of 1.5 MPa. In the Meadows (2001) method, we obtained better results for the changes in net stress (-4.3 [MPa]). With the second Meadows (2001) modification, we calculated 35 % changes in water saturation which is more or less in agreement with the ori ...
Porosity prediction using attributes from 3C–3D seismic data
... The neural network consists of a set of neurons that are arranged into two or more layers. The neurons are connected in the following fashion: inputs to neurons in each layer come from outputs of previous layer, and outputs from these neurons are passed to neurons in the next layer. Each connection ...
... The neural network consists of a set of neurons that are arranged into two or more layers. The neurons are connected in the following fashion: inputs to neurons in each layer come from outputs of previous layer, and outputs from these neurons are passed to neurons in the next layer. Each connection ...
Extinct spreading center in the Labrador Sea
... were deployedbetweenOBS positions(Figure 2) andrecorded times for user selected refracted, head wave or reflected phases on analogFM tape. Two of these,S/B 11 and 12, were usedin axedetermined by raytracingthroughan irregularnetworkof the subsequent analysisbecauseof a failure of one OBS. blockswhic ...
... were deployedbetweenOBS positions(Figure 2) andrecorded times for user selected refracted, head wave or reflected phases on analogFM tape. Two of these,S/B 11 and 12, were usedin axedetermined by raytracingthroughan irregularnetworkof the subsequent analysisbecauseof a failure of one OBS. blockswhic ...
Directional Variations in Travel-Time Residuals of Teleseismic P
... slowest P-wave travel-time direction is ⳮ5.0⬚ Ⳳ 4.8⬚ (almost directly north) and the magnitude of variation is 1.71 Ⳳ 0.13 sec. This result is consistent with an upwelling lower mantle plume. For the two-lobe model, the slowest P-wave traveltime directions (anisotropy term) are 89.7⬚ and 269.7⬚ Ⳳ 4. ...
... slowest P-wave travel-time direction is ⳮ5.0⬚ Ⳳ 4.8⬚ (almost directly north) and the magnitude of variation is 1.71 Ⳳ 0.13 sec. This result is consistent with an upwelling lower mantle plume. For the two-lobe model, the slowest P-wave traveltime directions (anisotropy term) are 89.7⬚ and 269.7⬚ Ⳳ 4. ...
Crustal structure beneath the Strait of Juan de Fuca and southern
... acceptable starting model that roughly matches the observed and calculated travel times. The travel times were then inverted using the raytrace-based inversion scheme of Zelt and Smith [1992]. This inversion is performed in a layerstripping fashion, where the parameters of successively deeper layers ...
... acceptable starting model that roughly matches the observed and calculated travel times. The travel times were then inverted using the raytrace-based inversion scheme of Zelt and Smith [1992]. This inversion is performed in a layerstripping fashion, where the parameters of successively deeper layers ...
Structure of the crust beneath the southeastern Tibetan Plateau from
... and layers as thin as 2 km may influence the inverse modeling. Furthermore, we fix the Poisson’s ratios and Moho depths at the values derived from the slant-stacking method. We invert only for the S-wave velocity; the P-wave velocity is derived from these results in conjunction with the VP /VS ratio ...
... and layers as thin as 2 km may influence the inverse modeling. Furthermore, we fix the Poisson’s ratios and Moho depths at the values derived from the slant-stacking method. We invert only for the S-wave velocity; the P-wave velocity is derived from these results in conjunction with the VP /VS ratio ...
S-Velocity Structure of the Upper Mantle
... structure beneath Anatolia, we used teleseismic P-wave tomography and data from several temporary and permanent seismic networks deployed in the region. A major part of the data comes from the North Anatolian Fault passive seismic experiment (NAF) that consists of 39 broadband seismic stations opera ...
... structure beneath Anatolia, we used teleseismic P-wave tomography and data from several temporary and permanent seismic networks deployed in the region. A major part of the data comes from the North Anatolian Fault passive seismic experiment (NAF) that consists of 39 broadband seismic stations opera ...
Continental crust under compression: A seismic refraction study of
... [11] Marine seismic data were acquired using an array of 20 air guns on board the R/V Maurice Ewing with a total capacity of 139 liter. The air guns were fired every 50 m on the offshore portions of the seismic transects (Figure 1). The two-way travel time to the acoustic basement is constrained usi ...
... [11] Marine seismic data were acquired using an array of 20 air guns on board the R/V Maurice Ewing with a total capacity of 139 liter. The air guns were fired every 50 m on the offshore portions of the seismic transects (Figure 1). The two-way travel time to the acoustic basement is constrained usi ...
Green`s function representations for seismic interferometry
... of an arbitrary horizontally layered lossless earth yields its reflection response. This result has been generalized for three-dimensional inhomogeneous media by the authors 共Wapenaar et al., 2002, 2004b兲. It appeared that the reflection response between a source and receiver at two positions at the ...
... of an arbitrary horizontally layered lossless earth yields its reflection response. This result has been generalized for three-dimensional inhomogeneous media by the authors 共Wapenaar et al., 2002, 2004b兲. It appeared that the reflection response between a source and receiver at two positions at the ...
Geophysical and petrological modelling of the
... melts and calcalkaline to ultrapotassic mafic magmas. – Mafic rocks: extrusive and hypabyssal subvolcanic bodies with calcalkaline, potassic and ultrapotassic (lamproitic) composition. Also present as mafic enclaves in several acid intrusive and extrusive rocks. ...
... melts and calcalkaline to ultrapotassic mafic magmas. – Mafic rocks: extrusive and hypabyssal subvolcanic bodies with calcalkaline, potassic and ultrapotassic (lamproitic) composition. Also present as mafic enclaves in several acid intrusive and extrusive rocks. ...
Three-dimensional seismic anisotropy in the crust and uppermost
... In total, we used data from 115 seismic stations in the Taiwan area, which are shown in Figure 2. Anisotropic tomography inversion requires denser coverage and higher data quality than regular isotropic inversion. Therefore, we only used relatively strong events with more than 30 recorded P and S ph ...
... In total, we used data from 115 seismic stations in the Taiwan area, which are shown in Figure 2. Anisotropic tomography inversion requires denser coverage and higher data quality than regular isotropic inversion. Therefore, we only used relatively strong events with more than 30 recorded P and S ph ...
Seismic Hazard Forecasting
... California between 1994 and 2024 An alternative model (assuming different cascade behavior and increased maximum magnitudes) matches the observed distribution somewhat better, and predicts an 80-89% probability of an m ≥ 7 earthquake in Southern California between 1994 and 2024 Uncertainty is probab ...
... California between 1994 and 2024 An alternative model (assuming different cascade behavior and increased maximum magnitudes) matches the observed distribution somewhat better, and predicts an 80-89% probability of an m ≥ 7 earthquake in Southern California between 1994 and 2024 Uncertainty is probab ...
Morphology of the distorted subducted Pacific slab beneath the
... images making smaller scale structures more difficult to resolve and made assumptions to simplify the modeling process. As technology and data quality has improved more recent studies have been able to define the geometry of the Japan–Kurile arc–arc junction in more detail using enhanced methodology ...
... images making smaller scale structures more difficult to resolve and made assumptions to simplify the modeling process. As technology and data quality has improved more recent studies have been able to define the geometry of the Japan–Kurile arc–arc junction in more detail using enhanced methodology ...
Mica, deformation fabrics and the seismic properties of the
... are often considered to develop first and to be cross-cut subsequently at high angles by C-planes, simultaneous formation of S–C planes is also possible (e.g. Berthé et al., 1979; Lister and Snoke 1984). The initial high angle between the two sets of planes can decrease with increasing shear strain l ...
... are often considered to develop first and to be cross-cut subsequently at high angles by C-planes, simultaneous formation of S–C planes is also possible (e.g. Berthé et al., 1979; Lister and Snoke 1984). The initial high angle between the two sets of planes can decrease with increasing shear strain l ...
Dynamic Behavior of Tropical Soils from Medllin
... dunite located in high slope areas, where it is seen incomplete weathering profile and they register higher values of velocity. The characteristic shear wave velocity in the residual soil - rock transition, in the subsoil of Medellin varies from 400 m/s to 600 m/s. ...
... dunite located in high slope areas, where it is seen incomplete weathering profile and they register higher values of velocity. The characteristic shear wave velocity in the residual soil - rock transition, in the subsoil of Medellin varies from 400 m/s to 600 m/s. ...
Erratum - Forward
... Fabry–Perot interferometer. The sample was probed using a solid state laser with a wavelength 532.15 nm and power of about 150 mW. For a symmetric scattering geometry, acoustic velocities are related to the measured Brillouin frequency shift ΔνB by: υ¼ ...
... Fabry–Perot interferometer. The sample was probed using a solid state laser with a wavelength 532.15 nm and power of about 150 mW. For a symmetric scattering geometry, acoustic velocities are related to the measured Brillouin frequency shift ΔνB by: υ¼ ...
Teleseismic imaging of subaxial flow at midocean ridges: traveltime
... This numerical approach does not incorporate possible effects of recrystallization (see Section 4), and, as is the case for nearly all polycrystal models, the lower-bound approach tends to overemphasize the role of texturing in polycrystal deformation. The predicted orientation distributions are qua ...
... This numerical approach does not incorporate possible effects of recrystallization (see Section 4), and, as is the case for nearly all polycrystal models, the lower-bound approach tends to overemphasize the role of texturing in polycrystal deformation. The predicted orientation distributions are qua ...
[0.1?0.5] Hz: some consequences for vibrating structures - HAL
... Lauro et al., 2005). One of these components was seen in the frequency band [0.1−0.5] Hz. It displays the same field properties of the high frequency band (>0.5 Hz), i.e. a radially polarised wavefield and an apparent velocity of ∼1 km/s. We remind the reader that this frequency band is affected by ...
... Lauro et al., 2005). One of these components was seen in the frequency band [0.1−0.5] Hz. It displays the same field properties of the high frequency band (>0.5 Hz), i.e. a radially polarised wavefield and an apparent velocity of ∼1 km/s. We remind the reader that this frequency band is affected by ...
Poisson`s ratio in the lower mantle beneath Alaska: Evidence for
... cannot be resolved, so that the interpretation in terms of the origin of the wave speed perturbations remains nonunique. Second, inferring variations in bulk sound speed or determining wave speed ratios should only be done in regions were the constraints on P wave speed are as good as that of S. In ...
... cannot be resolved, so that the interpretation in terms of the origin of the wave speed perturbations remains nonunique. Second, inferring variations in bulk sound speed or determining wave speed ratios should only be done in regions were the constraints on P wave speed are as good as that of S. In ...
FINAL EXAM -- REVIEW PROBLEMS
... W rite a complete solution in the form x = A sin Tt + B cos Tt with all numerical parameters evaluated. W rite a complete solution for the system in the form x = D sin ( Tt + N) with all parameters evaluated. ...
... W rite a complete solution in the form x = A sin Tt + B cos Tt with all numerical parameters evaluated. W rite a complete solution for the system in the form x = D sin ( Tt + N) with all parameters evaluated. ...
Oilfield Review Spring 2009
... Marine CSEM: Evolution of a Technology Interest in marine controlled-source electromagnetics (mCSEM) emerged during the cold war era. A postulated high-resistivity layer within the oceanic lithosphere was proposed as a means for secure communication in the event of nuclear war. In a more practical ...
... Marine CSEM: Evolution of a Technology Interest in marine controlled-source electromagnetics (mCSEM) emerged during the cold war era. A postulated high-resistivity layer within the oceanic lithosphere was proposed as a means for secure communication in the event of nuclear war. In a more practical ...
Surface wave inversion
Inversion is the set of methods used to infer properties through physical measurements. Surface wave inversion is the method by which elastic properties, density, and thickness of layers in the subsurface are attained through analysis of surface wavedispersion. The entire inversion process requires the gathering of seismic data, the creation of dispersion curves, and finally the inference of subsurface properties.