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Gordon S Lister - One of the best experts on this subject based on the ideXlab platform.

  • imaging changes in morphology geometry and physical properties of the subducting pacific plate along the izu bonin mariana arc
    Earth and Planetary Science Letters, 2004
    Co-Authors: Meghan S Miller, Brian L.n. Kennett, Gordon S Lister
    Abstract:

    Abstract Recent studies on slab structure in the northwest Pacific have imaged variable geometries of the subducted oceanic lithosphere along the plate margin. Tomographic images show portions of the subducted Pacific plate penetrate vertically into the lower mantle below the Mariana arc, whereas below the Izu–Bonin arc, the slab appears to be lain down horizontally on top of the 670-km discontinuity. Using new technology to grid and visualize regional Seismic tomography data even more detail about the structure of the subducting plates can be extracted from the three-dimensional images. We investigate the morphology and geometry of the subducting Pacific plate as it changes between horizontal to nearly vertical using P-wave tomographic images. The most profound result from these new models is the presence of a distinct change of Seismic Property in the downgoing Pacific slab beneath the Izu–Bonin arc at a depth of 350–400 km. The position of this anomaly corresponds to a region north and west of the Ogasawara Plateau. We propose the change in morphology and physical Property of the slab is related to the distortion of the Pacific plate geometry as its shape converts from near horizontal to vertical, together with the subduction of the Ogasawara Plateau.

  • Imaging changes in morphology, geometry, and physical properties of the subducting Pacific plate along the Izu–Bonin–Mariana arc
    Earth and Planetary Science Letters, 2004
    Co-Authors: Meghan S Miller, Brian Kennett, Gordon S Lister
    Abstract:

    Abstract Recent studies on slab structure in the northwest Pacific have imaged variable geometries of the subducted oceanic lithosphere along the plate margin. Tomographic images show portions of the subducted Pacific plate penetrate vertically into the lower mantle below the Mariana arc, whereas below the Izu–Bonin arc, the slab appears to be lain down horizontally on top of the 670-km discontinuity. Using new technology to grid and visualize regional Seismic tomography data even more detail about the structure of the subducting plates can be extracted from the three-dimensional images. We investigate the morphology and geometry of the subducting Pacific plate as it changes between horizontal to nearly vertical using P-wave tomographic images. The most profound result from these new models is the presence of a distinct change of Seismic Property in the downgoing Pacific slab beneath the Izu–Bonin arc at a depth of 350–400 km. The position of this anomaly corresponds to a region north and west of the Ogasawara Plateau. We propose the change in morphology and physical Property of the slab is related to the distortion of the Pacific plate geometry as its shape converts from near horizontal to vertical, together with the subduction of the Ogasawara Plateau.

Meghan S Miller - One of the best experts on this subject based on the ideXlab platform.

  • imaging changes in morphology geometry and physical properties of the subducting pacific plate along the izu bonin mariana arc
    Earth and Planetary Science Letters, 2004
    Co-Authors: Meghan S Miller, Brian L.n. Kennett, Gordon S Lister
    Abstract:

    Abstract Recent studies on slab structure in the northwest Pacific have imaged variable geometries of the subducted oceanic lithosphere along the plate margin. Tomographic images show portions of the subducted Pacific plate penetrate vertically into the lower mantle below the Mariana arc, whereas below the Izu–Bonin arc, the slab appears to be lain down horizontally on top of the 670-km discontinuity. Using new technology to grid and visualize regional Seismic tomography data even more detail about the structure of the subducting plates can be extracted from the three-dimensional images. We investigate the morphology and geometry of the subducting Pacific plate as it changes between horizontal to nearly vertical using P-wave tomographic images. The most profound result from these new models is the presence of a distinct change of Seismic Property in the downgoing Pacific slab beneath the Izu–Bonin arc at a depth of 350–400 km. The position of this anomaly corresponds to a region north and west of the Ogasawara Plateau. We propose the change in morphology and physical Property of the slab is related to the distortion of the Pacific plate geometry as its shape converts from near horizontal to vertical, together with the subduction of the Ogasawara Plateau.

  • Imaging changes in morphology, geometry, and physical properties of the subducting Pacific plate along the Izu–Bonin–Mariana arc
    Earth and Planetary Science Letters, 2004
    Co-Authors: Meghan S Miller, Brian Kennett, Gordon S Lister
    Abstract:

    Abstract Recent studies on slab structure in the northwest Pacific have imaged variable geometries of the subducted oceanic lithosphere along the plate margin. Tomographic images show portions of the subducted Pacific plate penetrate vertically into the lower mantle below the Mariana arc, whereas below the Izu–Bonin arc, the slab appears to be lain down horizontally on top of the 670-km discontinuity. Using new technology to grid and visualize regional Seismic tomography data even more detail about the structure of the subducting plates can be extracted from the three-dimensional images. We investigate the morphology and geometry of the subducting Pacific plate as it changes between horizontal to nearly vertical using P-wave tomographic images. The most profound result from these new models is the presence of a distinct change of Seismic Property in the downgoing Pacific slab beneath the Izu–Bonin arc at a depth of 350–400 km. The position of this anomaly corresponds to a region north and west of the Ogasawara Plateau. We propose the change in morphology and physical Property of the slab is related to the distortion of the Pacific plate geometry as its shape converts from near horizontal to vertical, together with the subduction of the Ogasawara Plateau.

Deren Yuan - One of the best experts on this subject based on the ideXlab platform.

  • Use of Portable Seismic Property Analyzer to Assess Colorado's Hanging Lake Tunnel Liner
    Transportation Research Record, 2014
    Co-Authors: Hoda Azari, Soheil Nazarian, Deren Yuan
    Abstract:

    A survey of the condition of the tunnel liner in Hanging Lake Tunnel, near Glenwood Springs, Colorado, was performed with a handheld device, the portable Seismic Property analyzer (PSPA), within the framework of SHRP 2 Project R06G. The PSPA simultaneously applies two stress wave-based nondestructive testing (NDT) methods: the ultrasonic surface wave (USW) and the impact-echo (IE). The USW method can provide the average modulus as an indication of the quality of the concrete. The IE method can provide the thickness of the concrete liner or the depth of any reflector within the liner. The objective of this study was to evaluate the applicability of the PSPA to tunnel work and the performance of the IE and USW methods in estimating the thickness and evaluating the quality of the tunnel liner. For this purpose, several sections of the plenum of Hanging Lake Tunnel were tested. The selection of the testing areas was based on a visual inspection, infrared thermography, and the surface dielectric constant measu...

Mondol, Nazmul Haque - One of the best experts on this subject based on the ideXlab platform.

  • Compaction, rock physics and rock properties of sandstones of the Stø Formation: Case study of five wells from the south-western Barents Sea, Norway
    'Elsevier BV', 2020
    Co-Authors: Ogebule, Oluwakemi Yetunde, Jahren Jens, Mondol, Nazmul Haque
    Abstract:

    Five wells containing Lower-Middle Jurassic sandstones of Stø Formation from the Hammerfest Basin (7120/9–1, 7121/7–1), the Ringvassøy-Loppa Fault Complex (7119/12–1, 7119/12–4) and the Troms-Finnmark Fault Complex (7019/1-1) in the Barents Sea area are considered in this study. The Stø Formation sandstones contain dominantly very fine-to medium-grained quartz arenites with occasional coarse-grained sandstone layers. Feldspathic and quartz wackes are also present. The effect of compaction and exhumation on reservoir properties (porosity and permeability) and Seismic Property (P-wave velocity) of these sandstones have been investigated. Source of quartz cement has also been investigated. Forty polished thin sections embedded in blue epoxy were studied using optical microscopy, scanning electron microscopy and cathodoluminiscence. Bulk mineralogy was also analysed using X-ray diffraction. The studied sandstones have experienced Cenozoic exhumation ranging between 820 and 1050 m. P-wave velocity is higher; porosities and permeabilities are lower in the western wells (7019/1-1, 7119/12–1 and 7119/12–4) compared to the eastern wells (7120/9–1 and 7121/7–1). Rock physics models and diagnostics show that the western wells are diagenetically more mature, stiffer, more compacted and more cemented than the eastern wells. These trends are attributed largely to difference in burial history from the east to the west and less to textural variations. Quartz cement is the most important authigenic mineral in these sandstones. Quartz cement in the western well (7119/12–1) is predominantly derived from clay-induced dissolution at macrostylolites whereas the eastern wells (7120/9–1 and 7121/7–1) are mostly sourced from clay-induced dissolution at grain contacts or microstylolites. While cementational porosity loss dominates in the western wells, compactional porosity loss dominates in the eastern wells. Compaction can reduce porosities down to 26% and this might be the reason for better porosity preservation and reservoir quality in the eastern wells than in the western wells.publishedVersio

  • Compaction, rock physics and rock properties of sandstones of the Stø Formation: Case study of five wells from the south-western Barents Sea, Norway
    2020
    Co-Authors: Ogebule, Oluwakemi Yetunde, Jahren Jens, Mondol, Nazmul Haque
    Abstract:

    Five wells containing Lower-Middle Jurassic sandstones of Stø Formation from the Hammerfest Basin (7120/9–1, 7121/7–1), the Ringvassøy-Loppa Fault Complex (7119/12–1, 7119/12–4) and the Troms-Finnmark Fault Complex (7019/1-1) in the Barents Sea area are considered in this study. The Stø Formation sandstones contain dominantly very fine-to medium-grained quartz arenites with occasional coarse-grained sandstone layers. Feldspathic and quartz wackes are also present. The effect of compaction and exhumation on reservoir properties (porosity and permeability) and Seismic Property (P-wave velocity) of these sandstones have been investigated. Source of quartz cement has also been investigated. Forty polished thin sections embedded in blue epoxy were studied using optical microscopy, scanning electron microscopy and cathodoluminiscence. Bulk mineralogy was also analysed using X-ray diffraction. The studied sandstones have experienced Cenozoic exhumation ranging between 820 and 1050 m. P-wave velocity is higher; porosities and permeabilities are lower in the western wells (7019/1-1, 7119/12–1 and 7119/12–4) compared to the eastern wells (7120/9–1 and 7121/7–1). Rock physics models and diagnostics show that the western wells are diagenetically more mature, stiffer, more compacted and more cemented than the eastern wells. These trends are attributed largely to difference in burial history from the east to the west and less to textural variations. Quartz cement is the most important authigenic mineral in these sandstones. Quartz cement in the western well (7119/12–1) is predominantly derived from clay-induced dissolution at macrostylolites whereas the eastern wells (7120/9–1 and 7121/7–1) are mostly sourced from clay-induced dissolution at grain contacts or microstylolites. While cementational porosity loss dominates in the western wells, compactional porosity loss dominates in the eastern wells. Compaction can reduce porosities down to 26% and this might be the reason for better porosity preservation and reservoir quality in the eastern wells than in the western wells

Hoda Azari - One of the best experts on this subject based on the ideXlab platform.

  • Use of Portable Seismic Property Analyzer to Assess Colorado's Hanging Lake Tunnel Liner
    Transportation Research Record, 2014
    Co-Authors: Hoda Azari, Soheil Nazarian, Deren Yuan
    Abstract:

    A survey of the condition of the tunnel liner in Hanging Lake Tunnel, near Glenwood Springs, Colorado, was performed with a handheld device, the portable Seismic Property analyzer (PSPA), within the framework of SHRP 2 Project R06G. The PSPA simultaneously applies two stress wave-based nondestructive testing (NDT) methods: the ultrasonic surface wave (USW) and the impact-echo (IE). The USW method can provide the average modulus as an indication of the quality of the concrete. The IE method can provide the thickness of the concrete liner or the depth of any reflector within the liner. The objective of this study was to evaluate the applicability of the PSPA to tunnel work and the performance of the IE and USW methods in estimating the thickness and evaluating the quality of the tunnel liner. For this purpose, several sections of the plenum of Hanging Lake Tunnel were tested. The selection of the testing areas was based on a visual inspection, infrared thermography, and the surface dielectric constant measu...