Tomographic evidence for hydrated oceanic crust of the Pacific slab
... 457,038 (S wave) differential travel-time data at 145 stations. Grid intervals were set at 25 km in the along-arc direction, 10 km perpendicular to it, and 5 –10 km in the vertical direction (Figure 1). The 1D velocity structure of Hasegawa et al. [1978] was adopted as an initial P-wave velocity mod ...
... 457,038 (S wave) differential travel-time data at 145 stations. Grid intervals were set at 25 km in the along-arc direction, 10 km perpendicular to it, and 5 –10 km in the vertical direction (Figure 1). The 1D velocity structure of Hasegawa et al. [1978] was adopted as an initial P-wave velocity mod ...
Seismic wave attenuation and dispersion resulting from wave
... different regions of the rock — must also be significant. There are a number of scenarios where this is manifestly the case. Two most obvious scenarios that have received substantial attention in recent years are patchy saturated rocks and fractured reservoirs. If two immiscible pore fluids with sub ...
... different regions of the rock — must also be significant. There are a number of scenarios where this is manifestly the case. Two most obvious scenarios that have received substantial attention in recent years are patchy saturated rocks and fractured reservoirs. If two immiscible pore fluids with sub ...
Factors controlling elastic properties in carbonate sediments and rocks
... Cementation can transform carbonate sediment within months into a rock. These shallow subsurface cementation processes add stiffness to the young rocks, which results in a significant increase in velocity that is much greater than the velocity increase due to compaction. Figure 3 illustrates this ph ...
... Cementation can transform carbonate sediment within months into a rock. These shallow subsurface cementation processes add stiffness to the young rocks, which results in a significant increase in velocity that is much greater than the velocity increase due to compaction. Figure 3 illustrates this ph ...
B. Measurement of Seismic Wave
... orogenic belt, and the surface and subsurface geological conditions are very complicated [6-7]. The conventional seismic exploration techniques (such as dynamite source, vibrator, air gun and the sparker, etc) can not meet the requirements of the seismic exploration in these areas. The phased array ...
... orogenic belt, and the surface and subsurface geological conditions are very complicated [6-7]. The conventional seismic exploration techniques (such as dynamite source, vibrator, air gun and the sparker, etc) can not meet the requirements of the seismic exploration in these areas. The phased array ...
Printer-friendly Version - Solid Earth Discussions
... of a couple of per cent. Regional 1-D S wave velocity models obtained for the central part of the Baltic Shield from the SVEKALAPKO array (Kozlovskaya et al., 2008) show that velocities beneath craton are significantly bigger (about 4 % down to a depth of 250 km) compared to standard model iasp91 (K ...
... of a couple of per cent. Regional 1-D S wave velocity models obtained for the central part of the Baltic Shield from the SVEKALAPKO array (Kozlovskaya et al., 2008) show that velocities beneath craton are significantly bigger (about 4 % down to a depth of 250 km) compared to standard model iasp91 (K ...
Receiver Functions of Seismic Waves in Layered Anisotropic Media
... to the time derivative of that of the radial component, indicating that shear-wave splitting happens to the Ps phase during the propagation in the surface anisotropic layer (Silver and Chang, 1991). Similar splitting is also seen in waveforms of the later phases reverberated in the surface layer. Th ...
... to the time derivative of that of the radial component, indicating that shear-wave splitting happens to the Ps phase during the propagation in the surface anisotropic layer (Silver and Chang, 1991). Similar splitting is also seen in waveforms of the later phases reverberated in the surface layer. Th ...
MagmastoragebeneathAxialvolcano on the Juan de Fuca mid
... The compressional-velocity image of the volcano presented here is based on data collected during a 1999 active-source seismic experiment (Fig. 1). 5,025 shots from the airgun array (20 guns totalling 142 litres) of the RV Maurice Ewing were recorded on six ocean-bottom seismometers12 deployed on the ...
... The compressional-velocity image of the volcano presented here is based on data collected during a 1999 active-source seismic experiment (Fig. 1). 5,025 shots from the airgun array (20 guns totalling 142 litres) of the RV Maurice Ewing were recorded on six ocean-bottom seismometers12 deployed on the ...
Earthquake slip on oceanic transform faults
... precursory ramp in the highly ®ltered time-domain records has also been claimed as supporting evidence for precursory slip4, but the amplitude is so small that these observations are ambiguous. The depths of all 14 earthquakes obtained in the broadband body-wave modelling are shown in Fig. 5. The sy ...
... precursory ramp in the highly ®ltered time-domain records has also been claimed as supporting evidence for precursory slip4, but the amplitude is so small that these observations are ambiguous. The depths of all 14 earthquakes obtained in the broadband body-wave modelling are shown in Fig. 5. The sy ...
Crustal motion in the Southern Andes (26°–36°S): Do the Andes
... by assuming the Nazca boundary is only 50% locked and that slip of 10–15mm/yr occurs on backarc reverse faults locked to 20km depth. Kendrick et al. [2001] produced an improved velocity field for the region, and Bevis et al. [2001] argued that this favored 100% locking of the Nazca plate boundary ...
... by assuming the Nazca boundary is only 50% locked and that slip of 10–15mm/yr occurs on backarc reverse faults locked to 20km depth. Kendrick et al. [2001] produced an improved velocity field for the region, and Bevis et al. [2001] argued that this favored 100% locking of the Nazca plate boundary ...
application of micro-seismic methods to geothermal exploration
... Malin, 1999). Spectral analysis of individual events shows that they are characterized by unique, low frequency source mechanisms. The events are often emergent, lack clear phases, and contain several ...
... Malin, 1999). Spectral analysis of individual events shows that they are characterized by unique, low frequency source mechanisms. The events are often emergent, lack clear phases, and contain several ...
Crustal structure beneath the Indochina peninsula
... [4] SKS splitting analysis [Bai et al., 2009] has indicated that the delay time between the fast and slow shear waves is larger beneath Indochina than beneath eastern Tibet where the crust and mantle have been deformed substantially. The fast polarization directions revealed a pronounced transition ...
... [4] SKS splitting analysis [Bai et al., 2009] has indicated that the delay time between the fast and slow shear waves is larger beneath Indochina than beneath eastern Tibet where the crust and mantle have been deformed substantially. The fast polarization directions revealed a pronounced transition ...
Upper mantle beneath Southeast Asia from S velocity tomography
... spectrum has to be discarded. Thus another advantage of a multimode technique is that it can utilize more measurements at shorter source-station distances, which allows to obtain information on averages over smaller volumes in the Earth and to include waves at higher frequencies, ultimately increasi ...
... spectrum has to be discarded. Thus another advantage of a multimode technique is that it can utilize more measurements at shorter source-station distances, which allows to obtain information on averages over smaller volumes in the Earth and to include waves at higher frequencies, ultimately increasi ...
Target-oriented full waveform inversion of seismic data
... The linear forward modeling algorithm used for this project calculates a seismic response in the (sx , τ ) domain, where sx is the horizontal slowness and τ is the two-way traveltime of a plane-wave through the medium. Slowness is defined as the inverse of p-wave velocity ( v1p ) and the horizontal s ...
... The linear forward modeling algorithm used for this project calculates a seismic response in the (sx , τ ) domain, where sx is the horizontal slowness and τ is the two-way traveltime of a plane-wave through the medium. Slowness is defined as the inverse of p-wave velocity ( v1p ) and the horizontal s ...
Seismic structure of the lithosphere and upper mantle
... subduction. In a broader perspective, the thermal contraction of lithosphere created at the ridge also defines the shape of the mid-oceanic ridge (Parsons and Sclater, 1977). The lithosphere is the rigid outer shell, made up of the crust and the uppermost part of the mantle that floats over a lowerv ...
... subduction. In a broader perspective, the thermal contraction of lithosphere created at the ridge also defines the shape of the mid-oceanic ridge (Parsons and Sclater, 1977). The lithosphere is the rigid outer shell, made up of the crust and the uppermost part of the mantle that floats over a lowerv ...
Seismic detection and characterization of the
... radial components of the seismograms to find the lag and amplitude of the first and largest spike (Gaussian) in the receiver function. Then the current estimate of the receiver function is convolved with the vertical component and subtracted from the radial component, and the procedure is repeated to ...
... radial components of the seismograms to find the lag and amplitude of the first and largest spike (Gaussian) in the receiver function. Then the current estimate of the receiver function is convolved with the vertical component and subtracted from the radial component, and the procedure is repeated to ...
gge_orals_nov8_2006 - Department of Earth and Planetary
... find a more accurate maximum of the correlogram, requires more computational burden than simply not down-sampling the signals from their original sample rate to achieve similar accuracy. With all possible (n2-n)/2 pairings correlated, the magnitude of the maximum correlation coefficient, its sign, a ...
... find a more accurate maximum of the correlogram, requires more computational burden than simply not down-sampling the signals from their original sample rate to achieve similar accuracy. With all possible (n2-n)/2 pairings correlated, the magnitude of the maximum correlation coefficient, its sign, a ...
Mantle flow beneath Arabia offset from the opening Red Sea
... below Arabia but rotated to a more north‐south trend consistent with that of the younger volcanics. Figure 4 shows such a scenario, in which present plate motions are used throughout because their detailed history is not well known. The deflection is favored by the fact that Arabia’s absolute motion ...
... below Arabia but rotated to a more north‐south trend consistent with that of the younger volcanics. Figure 4 shows such a scenario, in which present plate motions are used throughout because their detailed history is not well known. The deflection is favored by the fact that Arabia’s absolute motion ...
NUMERICAL RESEARCH ON THE EQUIVALENT
... frequency interval Δω .So it is impossible for DFT method to get the spectrum at any frequencies. While in this paper, based on the notations of the vibratory motion: trigonometric form in time domain and complex exponential form in frequency domain, the equivalent transformation condition of vibrat ...
... frequency interval Δω .So it is impossible for DFT method to get the spectrum at any frequencies. While in this paper, based on the notations of the vibratory motion: trigonometric form in time domain and complex exponential form in frequency domain, the equivalent transformation condition of vibrat ...
Lithospheric Layering in the North American Craton
... have made common conversion point (CCP) stacked Ps and Sp receiver function image volumes to determine, in more detail and higher resolution than previously obtained, the crustal thickness and the depth to the Moho and lithosphere-asthenosphere boundary (LAB) throughout the Western U.S. Individual r ...
... have made common conversion point (CCP) stacked Ps and Sp receiver function image volumes to determine, in more detail and higher resolution than previously obtained, the crustal thickness and the depth to the Moho and lithosphere-asthenosphere boundary (LAB) throughout the Western U.S. Individual r ...
Seismic structure of Iceland from Rayleigh wave inversions and
... The lowest phase velocities at 50 s form a narrow band in central Iceland and follow the trend of the rift zones. Relatively low velocities at longer periods concentrate in the western volcanic zone in southwestern Iceland and at the Tjornes fracture zone to the north of Iceland. Fast velocity anoma ...
... The lowest phase velocities at 50 s form a narrow band in central Iceland and follow the trend of the rift zones. Relatively low velocities at longer periods concentrate in the western volcanic zone in southwestern Iceland and at the Tjornes fracture zone to the north of Iceland. Fast velocity anoma ...
Descriptive Essay: The Night Market
... (ii)a word which is added to the end of the verb (iii)the name of a place or thing A conjunction is a word (i)shown by the sign (ii)a word which join two groups of words (iii)a word which means ‘belonging to’ A clause is a group of words (i)which can be used either as a whole sentence or as a part o ...
... (ii)a word which is added to the end of the verb (iii)the name of a place or thing A conjunction is a word (i)shown by the sign (ii)a word which join two groups of words (iii)a word which means ‘belonging to’ A clause is a group of words (i)which can be used either as a whole sentence or as a part o ...
Geophysical imaging reveals topographic stress control of bedrock
... (22), support the interpretation that faster velocities correspond to less abundant open fractures. The variations in seismic velocity are highly similar in shape to the variations in modeled F and slc, particularly in the zones of low velocity (n P < 4 km/s; Fig. 3, G to I), which generally corresp ...
... (22), support the interpretation that faster velocities correspond to less abundant open fractures. The variations in seismic velocity are highly similar in shape to the variations in modeled F and slc, particularly in the zones of low velocity (n P < 4 km/s; Fig. 3, G to I), which generally corresp ...
Abstract of the Dissertation-JNL
... For the survey presented in Chapter 4, 48 active channels recorded input from an array of 6 geophones planted for each channel in an alignment that reduces the effect of seismic waves traveling along the surface of the ground. The seismic signal was created using a 16-lb (7-kg) sledgehammer on a ste ...
... For the survey presented in Chapter 4, 48 active channels recorded input from an array of 6 geophones planted for each channel in an alignment that reduces the effect of seismic waves traveling along the surface of the ground. The seismic signal was created using a 16-lb (7-kg) sledgehammer on a ste ...
m/s - James M. Hill High School
... 3. How does friction depend on surface area between the two objects rubbing together? Think of a case where surface area could play a significant role in the force of friction. 4. Summarize the three situations when basic surface friction theory will not be applied. 5. Why will two identical pieces ...
... 3. How does friction depend on surface area between the two objects rubbing together? Think of a case where surface area could play a significant role in the force of friction. 4. Summarize the three situations when basic surface friction theory will not be applied. 5. Why will two identical pieces ...
LIGO and Shot Noise
... A very important observation was made when the system had been followed for some years. This followed theoretical predictions made shortly after the original discovery of the pulsar. It was found that the orbit period is declining: the two astronomical bodies are rotating faster and faster about eac ...
... A very important observation was made when the system had been followed for some years. This followed theoretical predictions made shortly after the original discovery of the pulsar. It was found that the orbit period is declining: the two astronomical bodies are rotating faster and faster about eac ...
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.