GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    PRIMARY ABDOMINAL (PERITONEAL) PREGNANCY (1973)
    Oxford, UK : Blackwell Publishing Ltd
    BJOG 80 (1973), S. 0 
    Details
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A case of primary abdominal pregnancy occurring in a 40-year-old Jamaican negress is recorded, the patient presenting with lower abdominal pain and eventually succumbing to massive intraperitoneal haemorrhage. Studdiford's criteria for primary abdominal pregnancy are enumerated and assessed. A brief review of the literature with a table of the more popularly quoted cases is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-0528.1973.tb02987.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A model of lower crustal electrical anisotropy for the Pontiac Subprovince of the Canadian Shield (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 111 (1992), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Magnetotelluric data from the Pontiac Subprovince of the Canadian Shield indicate that the crustal electrical conductivity structure of the region is very uniform. Because the data are distorted by near-surface electrical heterogeneities, the exact parameters of the resistivity structure may vary for different static shift corrections but the same sequence of layers is retained. An approximate one-dimensional model of the Pontiac, based on inversion of the effective impedance recorded at each site, consists of a thin conductive weathered layer, underlain by at least 12 km of resistive upper crust at 5000 Ωm or more. A mid-crustal layer of 200 Ωm extends to a depth of 25 km or more, below which there is evidence of an increase in the bulk resistivity in the lower crust and/or upper mantle. However, this last layer displays marked non-one-dimensional magnetotelluric responses which appear to be quite uniform along the profile. Similar responses have been seen in other parts of the Canadian Shield and the Baltic Shield. This feature in the MT data can be explained by azimuthal electrical anisotropy or by a two-dimensional conductive structure. The absence of any large vertical magnetic field responses suggests that anisotropy is the more likely cause. Modelling the anisotropy shows that a ratio of horizontal resistivities between 1:6 and 1:13 is representative of the lower crust and/or the upper mantle in the area. The higher conductivity is found for electric fields measured in the east-west direction subparallel to the tectonic fabric of the shield in this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1992.tb00560.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Archaean cratonic roots, mantle shear zones and deep electrical anisotropy (1995)
    [s.l.] : Nature Publishing Group
    Nature 375 (1995), S. 134-137 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Magnetotellurics, a deep-sounding electromagnetic technique based on measurements of natural electric and magnetic fields at the surface of the Earth, is well suited to probing the electrical response of the lithosphere. Because the upper crust of the Canadian shield is very resistive3 ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/375134a0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    facet.materialart.
    Unknown
    A 3‐D Model of Gas Generation, Migration, and Gas Hydrate Formation at a Young Convergent Margin (Hikurangi Margin, New Zealand) (2019)
    AGU (American Geophysical Union) | Wiley
    In:  Geochemistry, Geophysics, Geosystems, 20 (11). pp. 5126-5147.
    Details
    Publication Date: 2022-01-31
    Description: We present a three-dimensional gas hydrate systems model of the southern Hikurangi subduction margin in eastern New Zealand. The model integrates thermal and microbial gas generation, migration, and hydrate formation. Modeling these processes has improved the understanding of factors controlling hydrate distribution. Three spatial trends of concentrated hydrate occurrence are predicted. The first trend (I) is aligned with the principal deformation front in the overriding Australian plate. Concentrated hydrate deposits are predicted at or near the apexes of anticlines and to be mainly sourced from focused migration and recycling of microbial gas generated beneath the hydrate stability zone. A second predicted trend (II) is related to deformation in the subducting Pacific plate associated with former Mesozoic subduction beneath Gondwana and the modern Pacific-Australian plate boundary. This trend is enhanced by increased advection of thermogenic gas through permeable layers in the subducting plate and focused migration into the Neogene basin fill above Cretaceous-Paleogene structures. The third trend (III) follows the northern margin of the Hikurangi Channel and is related to the presence of buried strata of the Hikurangi Channel system. The predicted trends are consistent with pronounced seismic reflection anomalies related to free gas in the pore space and strength of the bottom-simulating reflection. However, only trend I is also associated with clear and widespread seismic indications of concentrated gas hydrate. Total predicted hydrate masses at the southern Hikurangi Margin are between 52,800 and 69,800 Mt. This equates to 3.4–4.5 Mt hydrate/km2, containing 6.33 × 108–8.38 × 108 m3/km2 of methane.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1029/2019GC008275
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 5
    facet.materialart.
    Unknown
    Seismic P Wave Velocity Model From 3-D Surface and Borehole Seismic Data at the Alpine Fault DFDP-2 Drill Site (Whataroa, New Zealand) (2021)
    Details
    Publication Date: 2021-09-24
    Description: The New Zealand Alpine Fault is a major plate boundary that is expected to be close to rupture, allowing a unique study of fault properties prior to a future earthquake. Here we present 3-D seismic data from the DFDP-2 drill site in Whataroa to constrain valley structures that were obscured in previous 2-D seismic data. The new data consist of a 3-D extended vertical seismic profiling (VSP) survey using three-component and fiber optic receivers in the DFDP-2B borehole and a variety of receivers deployed at the surface. The data set enables us to derive a detailed 3-D P wave velocity model by first-arrival traveltime tomography. We identify a 100–460 m thick sediment layer (mean velocity 2,200 ± 400 m/s) above the basement (mean velocity 4,200 ± 500 m/s). Particularly on the western valley side, a region of high velocities rises steeply to the surface and mimics the topography. We interpret this to be the infilled flank of the glacial valley that has been eroded into the basement. In general, the 3-D structures revealed by the velocity model on the hanging wall of the Alpine Fault correlate well with the surface topography and borehole findings. As a reliable velocity model is not only valuable in itself but also crucial for static corrections and migration algorithms, the Whataroa Valley P wave velocity model we have derived will be of great importance for ongoing seismic imaging. Our results highlight the importance of 3-D seismic data for investigating glacial valley structures in general and the Alpine Fault and adjacent structures in particular.
    Keywords: 622.15 ; vertical seismic profiling ; P wave velocity tomography ; distributed acoustic sensing ; Deep Fault Drilling Project ; subglacial valley
    Language: English
    Type: map
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    CITATION GEO-LEO
  • 6
    facet.materialart.
    Unknown
    3D Active Source Seismic Imaging of the Alpine Fault Zone and the Whataroa Glacial Valley in New Zealand (2021)
    In:  Journal of Geophysical Research: Solid Earth
    Details
    Publication Date: 2022-12-22
    Description: The Alpine Fault zone in New Zealand marks a major transpressional plate boundary that is late in its typical earthquake cycle. Understanding the subsurface structures is crucial to understand the tectonic processes taking place. A unique seismic survey including 2D lines, a 3D array, and borehole recordings, has been performed in the Whataroa Valley and provides new insights into the Alpine Fault zone down to ∼2 km depth at the location of the Deep Fault Drilling Project (DFDP)-2 drill site. Seismic images are obtained by focusing prestack depth migration approaches. Despite the challenging conditions for seismic imaging within a sediment filled glacial valley and steeply dipping valley flanks, several structures related to the valley itself as well as the tectonic fault system are imaged. A set of several reflectors dipping 40°–56° to the southeast are identified in a ∼600 m wide zone that is interpreted to be the minimum extent of the damage zone. Different approaches image one distinct reflector dipping at ∼40°, which is interpreted to be the main Alpine Fault reflector located only ∼100 m beneath the maximum drilled depth of the DFDP-2B borehole. At shallower depths (z 〈 0.5 km), additional reflectors are identified as fault segments with generally steeper dips up to 56°. Additionally, a glacially over-deepened trough with nearly horizontally layered sediments and a major fault (z 〈 0.5 km) are identified 0.5–1 km south of the DFDP-2B borehole. Thus, a complex structural environment is seismically imaged and shows the complexity of the Alpine Fault at Whataroa.
    Language: English
    Type: info:eu-repo/semantics/article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    GFZ OAI
  • 7
    facet.materialart.
    Unknown
    SeismicP Wave Velocity Model From 3‐D Surface and Borehole Seismic Data at the Alpine Fault DFDP‐2 Drill Site (Whataroa, New Zealand) (2020)
    In:  Journal of Geophysical Research: Solid Earth
    Details
    Publication Date: 2020-12-14
    Description: The New Zealand Alpine Fault is a major plate boundary that is expected to be close to rupture, allowing a unique study of fault properties prior to a future earthquake. Here we present 3‐D seismic data from the DFDP‐2 drill site in Whataroa to constrain valley structures that were obscured in previous 2‐D seismic data. The new data consist of a 3‐D extended vertical seismic profiling (VSP) survey using three‐component and fiber optic receivers in the DFDP‐2B borehole and a variety of receivers deployed at the surface. The data set enables us to derive a detailed 3‐D P wave velocity model by first‐arrival traveltime tomography. We identify a 100–460 m thick sediment layer (mean velocity 2,200 ± 400 m/s) above the basement (mean velocity 4,200 ± 500 m/s). Particularly on the western valley side, a region of high velocities rises steeply to the surface and mimics the topography. We interpret this to be the infilled flank of the glacial valley that has been eroded into the basement. In general, the 3‐D structures revealed by the velocity model on the hanging wall of the Alpine Fault correlate well with the surface topography and borehole findings. As a reliable velocity model is not only valuable in itself but also crucial for static corrections and migration algorithms, the Whataroa Valley P wave velocity model we have derived will be of great importance for ongoing seismic imaging. Our results highlight the importance of 3‐D seismic data for investigating glacial valley structures in general and the Alpine Fault and adjacent structures in particular.
    Language: English
    Type: info:eu-repo/semantics/article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    GFZ OAI
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...