Structure of the crust and uppermost mantle of Iceland from
... of 3260 kg m33 is used in the modelling. This value is derived from the estimated average mantle (harzburgite) composition below Iceland at 40 km depth and 1000^1100³C (Maclennan, personal communication, 1999). It is lower than the densities generally assigned to `typical' mantle since it includes t ...
... of 3260 kg m33 is used in the modelling. This value is derived from the estimated average mantle (harzburgite) composition below Iceland at 40 km depth and 1000^1100³C (Maclennan, personal communication, 1999). It is lower than the densities generally assigned to `typical' mantle since it includes t ...
Earthquakes and the Earth`s Interior
... stresses continue to be present more earthquakes are likely to occur on the fault. Thus faults move in spurts and this behavior is referred to as Stick Slip. If the displacement during an earthquake is large, a large earthquake will be generated. Smaller displacements generate smaller earthquakes. N ...
... stresses continue to be present more earthquakes are likely to occur on the fault. Thus faults move in spurts and this behavior is referred to as Stick Slip. If the displacement during an earthquake is large, a large earthquake will be generated. Smaller displacements generate smaller earthquakes. N ...
Caract´erisation du r´eflecteur sismique en contexte isotrope
... Of particular interest are the size of the IFZ and the size of the volume of the reflector involved in reflection time measurements because each one can be related to the horizontal and vertical resolutions of seismic methods [2]. Until now, only the IFZ and the penetration depth of the FV below the ...
... Of particular interest are the size of the IFZ and the size of the volume of the reflector involved in reflection time measurements because each one can be related to the horizontal and vertical resolutions of seismic methods [2]. Until now, only the IFZ and the penetration depth of the FV below the ...
Design of Lateral Load Resisting Frames Using Steel Joists and
... reserve capacity and will continue to resist load until enough members have failed that the structure becomes unstable and collapses. The excess strength is expressed as the difference between this collapse load and the load generating the first failure in an individual element (hinging, yielding, o ...
... reserve capacity and will continue to resist load until enough members have failed that the structure becomes unstable and collapses. The excess strength is expressed as the difference between this collapse load and the load generating the first failure in an individual element (hinging, yielding, o ...
Seismic structure of Cocos and Malpelo Volcanic Ridges and
... improve the signal-to-noise ratio. [10] The Pg phase is clearly observed in all the record sections. The pattern of this phase is similar in most of the instruments from the three lines, though some strong lateral variations related with prominent bathymetric features are also observed. At near offs ...
... improve the signal-to-noise ratio. [10] The Pg phase is clearly observed in all the record sections. The pattern of this phase is similar in most of the instruments from the three lines, though some strong lateral variations related with prominent bathymetric features are also observed. At near offs ...
- Wiley Online Library
... range and shot size, and so estimated errors were assigned to each pick, and used throughout the interpretation. Almost all the seismograms had a ‘ringy’ character. Fig. 7 shows an example of this, on a section recorded by the hydrophone of OBS R12 on line B, along the fracture zone. This phenomenon ...
... range and shot size, and so estimated errors were assigned to each pick, and used throughout the interpretation. Almost all the seismograms had a ‘ringy’ character. Fig. 7 shows an example of this, on a section recorded by the hydrophone of OBS R12 on line B, along the fracture zone. This phenomenon ...
Very low frequency earthquakes excited by the 2004 off the... earthquakes: A dynamic deformation process in the large accretionary prism
... are considered as regular micro-aftershocks, which are too small to be detected by JMA. On the other hand, we can see some wave trains only in the low-frequency component panel without corresponding high-frequency signals during the time period T2 and T3 in Fig. 2. These are the VLF ...
... are considered as regular micro-aftershocks, which are too small to be detected by JMA. On the other hand, we can see some wave trains only in the low-frequency component panel without corresponding high-frequency signals during the time period T2 and T3 in Fig. 2. These are the VLF ...
- Wiley Online Library
... recorded by the earliest oceanic crust. However, the late stages of continental extension and the eventual breakup of the continent, at the Iberia-Newfoundland margin, occurred during the Cretaceous constant polarity interval (121–83 Ma), resulting in a lack of strong magnetic reversals which would ...
... recorded by the earliest oceanic crust. However, the late stages of continental extension and the eventual breakup of the continent, at the Iberia-Newfoundland margin, occurred during the Cretaceous constant polarity interval (121–83 Ma), resulting in a lack of strong magnetic reversals which would ...
Continental hyperextension, mantle exhumation and thin oceanic
... recorded by the earliest oceanic crust. However, the late stages of continental extension and the eventual breakup of the continent, at the Iberia-Newfoundland margin, occurred during the Cretaceous constant polarity interval (121–83 Ma), resulting in a lack of strong magnetic reversals which would ...
... recorded by the earliest oceanic crust. However, the late stages of continental extension and the eventual breakup of the continent, at the Iberia-Newfoundland margin, occurred during the Cretaceous constant polarity interval (121–83 Ma), resulting in a lack of strong magnetic reversals which would ...
Mantle hydration and Cl-rich fluids in the subduction forearc
... license, and indicate if changes were made. ...
... license, and indicate if changes were made. ...
Factors influencing magmatism during continental break
... middle of the plateau, and the latter a coralline cay on the outer shelf. In order to ensure a common ...
... middle of the plateau, and the latter a coralline cay on the outer shelf. In order to ensure a common ...
Reflection and transmission coefficients of a thin bed
... and Meixner (1969) present the time delayed transmission/reflection method and deduce thin-bed reflection coefficients by multiplying the reflecting and transmitting coefficients of the top and bottom interfaces. Widess (1973) studies the normal pulse reflections from the top and bottom of a thin be ...
... and Meixner (1969) present the time delayed transmission/reflection method and deduce thin-bed reflection coefficients by multiplying the reflecting and transmitting coefficients of the top and bottom interfaces. Widess (1973) studies the normal pulse reflections from the top and bottom of a thin be ...
Structure and evolution of the "Olistostrome" - E
... Reflection profiles characterize the structure and the upper Mesozoic to Cenozoic deposits of the Gulf of Ciidiz region. Two long ENE-WSW multichannel seismic lines (ca. 400-500 km long) are analyzed to study the evolution of the area from the continental shelf to the Horseshoe and Seine abyssal pla ...
... Reflection profiles characterize the structure and the upper Mesozoic to Cenozoic deposits of the Gulf of Ciidiz region. Two long ENE-WSW multichannel seismic lines (ca. 400-500 km long) are analyzed to study the evolution of the area from the continental shelf to the Horseshoe and Seine abyssal pla ...
Originally published as: Ivanova, A., Kashubin, A
... saline aquifer, at approximately 620 m depth, as of the summer 2011. We present here results from the 1st repeat 3D seismic survey that was performed at the site in the autumn 2009, after about 22000 tons of CO2 had been injected. We show here that rather complex time-lapse signatures of this CO2 ca ...
... saline aquifer, at approximately 620 m depth, as of the summer 2011. We present here results from the 1st repeat 3D seismic survey that was performed at the site in the autumn 2009, after about 22000 tons of CO2 had been injected. We show here that rather complex time-lapse signatures of this CO2 ca ...
Compressional to shear wave conversion in oceanic crust
... 1978; Spudich 1979; White & Matthews 1980; Stephen et al. 1980). A number of theoretical approaches are available to calculate the seismic velocities of a cracked solid (Anderson, Minister & Cole 1974), although the large number of variables such as the crack orientations and size distribution, thei ...
... 1978; Spudich 1979; White & Matthews 1980; Stephen et al. 1980). A number of theoretical approaches are available to calculate the seismic velocities of a cracked solid (Anderson, Minister & Cole 1974), although the large number of variables such as the crack orientations and size distribution, thei ...
shear-wave splitting, new geophysics, and earthquake stress
... Transversely-polarised seismic shear waves propagating through in situ rocks with some form of elastic anisotropy, such as aligned microcracks, split into two orthogonal polarisations which propagate with different velocities, and hence lead to shear-wave splitting. The polarisations are strictly or ...
... Transversely-polarised seismic shear waves propagating through in situ rocks with some form of elastic anisotropy, such as aligned microcracks, split into two orthogonal polarisations which propagate with different velocities, and hence lead to shear-wave splitting. The polarisations are strictly or ...
5. Structure of the Outer Izu-Bonin Forearc from Seismic
... is little sediment in the Izu-Bonin Trench, so the Izu-Bonin arc has only a small accretionary wedge (Horine et al., 1988). Accretion and erosion are mechanical interactions. Chemical interactions, such as those produced by dewatering of the subducting slab, are also possible. As the oceanic crust d ...
... is little sediment in the Izu-Bonin Trench, so the Izu-Bonin arc has only a small accretionary wedge (Horine et al., 1988). Accretion and erosion are mechanical interactions. Chemical interactions, such as those produced by dewatering of the subducting slab, are also possible. As the oceanic crust d ...
The teleseismic signature of fossil subduction - Lamont
... Fort Simpson and Hottah terranes, and extending eastward beneath the Great Bear magmatic arc where it reaches a depth of 100 km (see Figure 1b for geographic location). Geological and geophysical evidence indicates that this feature is a remnant of Proterozoic subduction. Although several other sim ...
... Fort Simpson and Hottah terranes, and extending eastward beneath the Great Bear magmatic arc where it reaches a depth of 100 km (see Figure 1b for geographic location). Geological and geophysical evidence indicates that this feature is a remnant of Proterozoic subduction. Although several other sim ...
Asymmetry of high-velocity lower crust on the South
... lines 2 and 3 cross the broad Argentine continental shelf at or south of the Colorado transform fault, an area whose basement geology is buried by younger rocks. On the conjugate margin of South Africa, the coastal zone is underlain by the Neoproterozoic Kaoko, Damara and Gariep belts (from north to ...
... lines 2 and 3 cross the broad Argentine continental shelf at or south of the Colorado transform fault, an area whose basement geology is buried by younger rocks. On the conjugate margin of South Africa, the coastal zone is underlain by the Neoproterozoic Kaoko, Damara and Gariep belts (from north to ...
Seismic velocities, density, porosity, and permeability measured at a
... Hsu (2007) measured the values of vp and vs under an atmosphere pressure on the discrete rock samples from which the value of vp/vs are calculated. For some samples (e.g. R287sec1 and R351sec2 in Table 1), he measured the values of vp and vs in two segments with different thicknesses. Hence, we calc ...
... Hsu (2007) measured the values of vp and vs under an atmosphere pressure on the discrete rock samples from which the value of vp/vs are calculated. For some samples (e.g. R287sec1 and R351sec2 in Table 1), he measured the values of vp and vs in two segments with different thicknesses. Hence, we calc ...
Title: Energy Partitioning of Seismic Waves in Fractured Rocks
... stability of a rock mass and the flow of fluids through a rock mass. A goal of site characterization for waste isolation or mineral exploration is to detect and characterize the hydraulic and mechanical properties of fractures using seismic techniques. ...
... stability of a rock mass and the flow of fluids through a rock mass. A goal of site characterization for waste isolation or mineral exploration is to detect and characterize the hydraulic and mechanical properties of fractures using seismic techniques. ...
Nakajima_etal_GRL200.. - Research School of Earth Sciences
... detected a low-velocity layer immediately above the Pacific slab at depths deeper than 70 – 80 km and interpreted it as a hydrous layer composed of serpentine or chlorite, through which most of the water expelled from the slab is brought to greater depths. We obtain a similar low-velocity layer at t ...
... detected a low-velocity layer immediately above the Pacific slab at depths deeper than 70 – 80 km and interpreted it as a hydrous layer composed of serpentine or chlorite, through which most of the water expelled from the slab is brought to greater depths. We obtain a similar low-velocity layer at t ...
Chapter 1: Seismic Wave Attenuation
... earthquake. There are two main types of seismic waves, the surface waves and the body waves. Body waves are waves that penetrate deeply thorough the interior of the Earth. These waves represent short pulses of propagating energy. They follow refracted raypaths determined by the elastic moduli and de ...
... earthquake. There are two main types of seismic waves, the surface waves and the body waves. Body waves are waves that penetrate deeply thorough the interior of the Earth. These waves represent short pulses of propagating energy. They follow refracted raypaths determined by the elastic moduli and de ...
Receiver Functions of Seismic Waves in Layered Anisotropic Media
... are represented in Figure 1b. The transverse component disappears, and the radial component agrees exactly with that calculated by the Thomson–Haskell layer matrix method (Haskell, 1962). In the anisotropic case (Fig. 1a), the first arrival phase is a direct P wave, the second phase is identified as ...
... are represented in Figure 1b. The transverse component disappears, and the radial component agrees exactly with that calculated by the Thomson–Haskell layer matrix method (Haskell, 1962). In the anisotropic case (Fig. 1a), the first arrival phase is a direct P wave, the second phase is identified as ...
Geological and geophysical evidence for large
... with the seismic activity, are the most significant elements demonstrating recent and present-day crustal deformation. Based on the main geological structures and Cenozoic subsidence data, the Lower Rhine Graben can be divided into several tectonic units (Fig. 1b): (1) the Krefeld block, which borde ...
... with the seismic activity, are the most significant elements demonstrating recent and present-day crustal deformation. Based on the main geological structures and Cenozoic subsidence data, the Lower Rhine Graben can be divided into several tectonic units (Fig. 1b): (1) the Krefeld block, which borde ...
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.