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... motion (Deschamps et al., 2008b). Previous studies utilized earthquake sources, which are naturally spatially and temporally limited. Areas with inhomogeneous distributions of earthquakes such as the European Alps are difficult to image with these methods. Noise-based tomography does not use earthqua ...
... motion (Deschamps et al., 2008b). Previous studies utilized earthquake sources, which are naturally spatially and temporally limited. Areas with inhomogeneous distributions of earthquakes such as the European Alps are difficult to image with these methods. Noise-based tomography does not use earthqua ...
Orienting Ocean-Bottom Seismometers from P
... analyses (PCA) of three different data covariance matrices (2 PCA in two dimensions ...
... analyses (PCA) of three different data covariance matrices (2 PCA in two dimensions ...
Making the Earth Shake - Paleontological Research Institution
... Shale natural gas extraction, uses water and chemicals under high pressure to break the rock and create pathways that connect the pores, which allows the gas to flow into wells for extraction. How Earthquakes Are Generated An earthquake is usually generated by a sudden movement in the Earth’s brittl ...
... Shale natural gas extraction, uses water and chemicals under high pressure to break the rock and create pathways that connect the pores, which allows the gas to flow into wells for extraction. How Earthquakes Are Generated An earthquake is usually generated by a sudden movement in the Earth’s brittl ...
Multi-mode conversion imaging of the subducted Gorda and Juan
... at these times on the RFs to the theoretical location of scatterers, either as forward (i.e. direct conversion) or backward scattering (i.e. multiples). Each individual mode is thus handled separately, and produces a separate image. Due to an increase of velocity with depth in the reference model, t ...
... at these times on the RFs to the theoretical location of scatterers, either as forward (i.e. direct conversion) or backward scattering (i.e. multiples). Each individual mode is thus handled separately, and produces a separate image. Due to an increase of velocity with depth in the reference model, t ...
earthquakes
... Richter Scale – based on largest amplitude of a seismic wave from seismograph during an earthquake An increase by 1 in magnitude equals 10x increase in amplitude Measure of the amount of energy released Energy released increases 32 x’s for each unit Charles Richter ...
... Richter Scale – based on largest amplitude of a seismic wave from seismograph during an earthquake An increase by 1 in magnitude equals 10x increase in amplitude Measure of the amount of energy released Energy released increases 32 x’s for each unit Charles Richter ...
2. Data processing and group velocity measurements
... preferential azimuths. In addition, in aseismic regions surface wave dispersion can be measured only from distant earthquakes. Second, it is difficult to obtain high-quality short-period (<20 s) dispersion measurements from teleseismic events due to intrinsic attenuation and scattering along ray pat ...
... preferential azimuths. In addition, in aseismic regions surface wave dispersion can be measured only from distant earthquakes. Second, it is difficult to obtain high-quality short-period (<20 s) dispersion measurements from teleseismic events due to intrinsic attenuation and scattering along ray pat ...
Aftershock observation of the 2011 off the Pacific coast of... by using ocean bottom seismometer network
... was used to construct an initial model for the 2-D ray tracing method (Zelt and Smith, 1992). This used a trial-anderror method to obtain a 2-D velocity model that can explain the observed travel times of first and later arrivals for all the OBSs on the profiles. Although the study area has large la ...
... was used to construct an initial model for the 2-D ray tracing method (Zelt and Smith, 1992). This used a trial-anderror method to obtain a 2-D velocity model that can explain the observed travel times of first and later arrivals for all the OBSs on the profiles. Although the study area has large la ...
The lithosphere–asthenosphere boundary in the North
... Tien Shan–Karakoram area, respectively. These findings lead us to suppose that the LAB may be a globally existing and observable discontinuity, comparable to the Moho. The S-receiver function technique therefore appears to be a very useful tool for mapping the global LAB. However, as mentioned above ...
... Tien Shan–Karakoram area, respectively. These findings lead us to suppose that the LAB may be a globally existing and observable discontinuity, comparable to the Moho. The S-receiver function technique therefore appears to be a very useful tool for mapping the global LAB. However, as mentioned above ...
Geology 3015 Lecture Notes Week 7b
... average speeds of P- and Swaves. Based on these average speeds, P-S wave travel times have been determined for distances between focus and seismograph. Time-distance graphs plot “P-S time interval” versus “travel distance” and are used to locate epicenters. ...
... average speeds of P- and Swaves. Based on these average speeds, P-S wave travel times have been determined for distances between focus and seismograph. Time-distance graphs plot “P-S time interval” versus “travel distance” and are used to locate epicenters. ...
Pore pressure and water saturation variations
... Measuring of the AVO gradient term often requires data recorded at mid-to-far offsets, which is not in agreement with the assumption that the incident angle should be small. Meadows (2001) suggested that changes in gradient should be calculated as a function of impedances and density instead of bein ...
... Measuring of the AVO gradient term often requires data recorded at mid-to-far offsets, which is not in agreement with the assumption that the incident angle should be small. Meadows (2001) suggested that changes in gradient should be calculated as a function of impedances and density instead of bein ...
For several decades single-component seismic reflection methods
... stacked images. In the case of land seismic surveys acquired with surface sources, the main contributions to the static are the time delays associated with the weathering layer in the vicinity of the source and receiver. In PS reflection, a P-wave source is used. Hence the source static can be deriv ...
... stacked images. In the case of land seismic surveys acquired with surface sources, the main contributions to the static are the time delays associated with the weathering layer in the vicinity of the source and receiver. In PS reflection, a P-wave source is used. Hence the source static can be deriv ...
Analysis of seismic anisotropy parameters for sedimentary strata
... relationships among the Thomsen parameters. The study showed little indication of the correlations between the anisotropy parameters except for the possible range and sign of the parameters. The simulation results were not very helpful for understanding the seismic anisotropic properties of sediment ...
... relationships among the Thomsen parameters. The study showed little indication of the correlations between the anisotropy parameters except for the possible range and sign of the parameters. The simulation results were not very helpful for understanding the seismic anisotropic properties of sediment ...
Order of magnitude increase in subducted HO due to
... suggest that the velocity structures in the lower subducting lithosphere are serpentinized peridotite along dipping faults of various length scales. Low-velocity fault zones of 1–2 km width are detectable, as they act as a seismic waveguide. Smaller-scale fault zones are not detectable in this way, ...
... suggest that the velocity structures in the lower subducting lithosphere are serpentinized peridotite along dipping faults of various length scales. Low-velocity fault zones of 1–2 km width are detectable, as they act as a seismic waveguide. Smaller-scale fault zones are not detectable in this way, ...
Earth Science 8.2 Measuring Earthquakes
... Surface waves move up and down as well as side-to-side. Surface waves are usually much larger than body waves, so surface waves are usually the most destructive seismic waves. ...
... Surface waves move up and down as well as side-to-side. Surface waves are usually much larger than body waves, so surface waves are usually the most destructive seismic waves. ...
What is a wave?
... Reflection & refraction of waves ! P & S waves are reflected, refracted (bent), and converted at sharp changes (discontinuities) in seismic velocity (as occur between rock layers) refracted S refracted P (most energy) One incident P or S wave results in up to four waves ...
... Reflection & refraction of waves ! P & S waves are reflected, refracted (bent), and converted at sharp changes (discontinuities) in seismic velocity (as occur between rock layers) refracted S refracted P (most energy) One incident P or S wave results in up to four waves ...
Structure of the Earth`s Crust in Fennoscandia as Revealed from
... profile). At the same time the thickness of the sedimentary layer decreases from about 8 km to 1 or 2 km. The typical Palaeozoic crystalline crust of the North German Caleonides is divided into two layers: in the upper one the P-wave velocity varies from 6.0 to 6.3 km/s, and in the lower one from 6. ...
... profile). At the same time the thickness of the sedimentary layer decreases from about 8 km to 1 or 2 km. The typical Palaeozoic crystalline crust of the North German Caleonides is divided into two layers: in the upper one the P-wave velocity varies from 6.0 to 6.3 km/s, and in the lower one from 6. ...
Seismic retrofit - TU Delft Repositories
... done, weighing the criteria and making a choice for the final seismic strategy. A starter is made in the final chapters of this paper, by stating examples of implications which the stated criteria can have on the chosen engineering solutions and introducing a case study, on which the research shall ...
... done, weighing the criteria and making a choice for the final seismic strategy. A starter is made in the final chapters of this paper, by stating examples of implications which the stated criteria can have on the chosen engineering solutions and introducing a case study, on which the research shall ...
Numerical modeling of shear-wave splitting and azimuthal
... to anisotropic layer are also apparent on both vertical and radial component data. The time-shift on radial data is up to 5ms and the amplitude change is up to 46%. The modeled data correlate nicely with the well data. Considering the correlation results of well and surface seismic data in the previ ...
... to anisotropic layer are also apparent on both vertical and radial component data. The time-shift on radial data is up to 5ms and the amplitude change is up to 46%. The modeled data correlate nicely with the well data. Considering the correlation results of well and surface seismic data in the previ ...
The influence of crenulation cleavage development on the bulk
... that is lower than a certain, set CI value (0.03) with the orientation and CI of neighboring points with the highest CI (“neighbor CI correlation”), and replace single points with a low CI and significantly different orientation than at least 3 neighboring points with the orientation of those neighb ...
... that is lower than a certain, set CI value (0.03) with the orientation and CI of neighboring points with the highest CI (“neighbor CI correlation”), and replace single points with a low CI and significantly different orientation than at least 3 neighboring points with the orientation of those neighb ...
Józef Kabiesz, Beata Sikora, Marek Sikora and Łukasz Wróbel
... The aim of this paper is to make an attempt at improving accuracy of seismic hazard prediction. Two hazard assessment methods, commonly applied in Polish hard coal mines, act as our reference point. These methods are so-called seismic method and seismoacoustic method which are described later in thi ...
... The aim of this paper is to make an attempt at improving accuracy of seismic hazard prediction. Two hazard assessment methods, commonly applied in Polish hard coal mines, act as our reference point. These methods are so-called seismic method and seismoacoustic method which are described later in thi ...
readingetal_geology_.. - Research School of Earth Sciences
... 10°–110°. The observed receiver functions (for RF method, see Shibutani et al., 1996; Reading et al., 2003a) are stacked for each station to further improve the signal-to-noise ratio. The bestfitting one-dimensional (1-D) shear wave-speed profile is modeled from each stacked waveform by searching th ...
... 10°–110°. The observed receiver functions (for RF method, see Shibutani et al., 1996; Reading et al., 2003a) are stacked for each station to further improve the signal-to-noise ratio. The bestfitting one-dimensional (1-D) shear wave-speed profile is modeled from each stacked waveform by searching th ...
Seismic Seismic waves
... Because P waves are the fastest seismic waves, they will usually be the first ones that your seismograph records. The next set of seismic waves on your seismogram will be the S waves. These are usually bigger than the P waves. The surface waves (Love and Rayleigh waves) are the other, often larg ...
... Because P waves are the fastest seismic waves, they will usually be the first ones that your seismograph records. The next set of seismic waves on your seismogram will be the S waves. These are usually bigger than the P waves. The surface waves (Love and Rayleigh waves) are the other, often larg ...
A crustal model of the ultrahigh-pressure Dabie Shan orogenic belt
... Methods of interpretation of seismic refraction data and model uncertainties are discussed by Mooney [1989], who estimates that seismic velocities are accurate to better than 3% and boundary depths (e.g., Moho) are accurate to better than 10% of the calculated depth. The phases Pg and Pn are recogni ...
... Methods of interpretation of seismic refraction data and model uncertainties are discussed by Mooney [1989], who estimates that seismic velocities are accurate to better than 3% and boundary depths (e.g., Moho) are accurate to better than 10% of the calculated depth. The phases Pg and Pn are recogni ...
Supporting Online Material for
... robust null observations have P660P/PP amplitudes of less than 1%. These ranges are shown in Figs. 5 and S7 using errors bars for the corresponding amplitude range at the average epicentral distance range. We computed reflection amplitudes of P660P (and S660S) as a percentage of the transmitted PP ( ...
... robust null observations have P660P/PP amplitudes of less than 1%. These ranges are shown in Figs. 5 and S7 using errors bars for the corresponding amplitude range at the average epicentral distance range. We computed reflection amplitudes of P660P (and S660S) as a percentage of the transmitted PP ( ...
PDF
... order to assess the seismic performance of multistory RC buildings designed based on modern codes. For this reason, a parametric study was performed considering two groups of buildings. In the first example, weak ground story and short column construction features were examined, while in the second ...
... order to assess the seismic performance of multistory RC buildings designed based on modern codes. For this reason, a parametric study was performed considering two groups of buildings. In the first example, weak ground story and short column construction features were examined, while in the second ...
Reflection seismology
Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite/Tovex, a specialized air gun or a seismic vibrator, commonly known by the trademark name Vibroseis. Reflection seismology is similar to sonar and echolocation. This article is about surface seismic surveys; for vertical seismic profiles, see VSP.