4 documents found in 138ms
# 1
Anderson, James M. • Xu, Ming H.
Abstract: Plots of closure delay, closure phase, and closure amplitude are provided for the geodetic very long baseline interferometry (VLBI) observations of the Continuous VLBI Campaign 2014 (CONT14) experiment of the International VLBI Service for Geodesy and Astrometry (IVS, https://ivscc.gsfc.nasa.gov/ , see https://ivscc.gsfc.nasa.gov/program/cont14/ for a description of CONT14, and see https://ivscc.gsfc.nasa.gov/about/org/components/dc-list.html for a list of IVS data centers from which the CONT14 data can be downloaded) as calculated by Anderson and Xu for their article titled _Source Structure and Measurement Noise Are as Important as All Other Residual Sources in Geodetic VLBI Combined_, submitted to the Journal of Geophysical Research - Solid Earth in 2018. Closure quantities are insensitive to station-based calibration terms, such as station clock errors, atmospheric delay errors, phase offsets, station position errors, amplitude calibration errors, and so on, and as a result are sensitive only to source structure (the two-dimensional brightness distribution of source emission on the sky, which is typically time and frequency dependent), measurement noise, and closure errors such as bandpass mismatch and polarization leakage. We used closure quantities derived from the CONT14 data to investigate the amount of source structure present in the celestial sources observed in the CONT14 experiment. Details: Three data files are included:(1) closure_delay_Anderson_Xu_JGR_2018.tar.gz(2) closure_phase_Anderson_Xu_JGR_2018.tar.gz(3) closure_amplitude_Anderson_Xu_JGR_2018.tar.gz The file with the name starting with "closure_delay" contains closure delay plots, the file with the name starting with "closure_phase" contains closure phase plots, and so on. These three files are collections of files made by the UNIX tar program that have been compressed with the gzip program.
# 2
Williams, Jack • Toy, Virginia • Massiot, Cecile • McNamara, David
Abstract: The orientations and densities of fractures in the foliated hanging-wall of the Alpine Fault provide insights into the role of a mechanical anisotropy in upper crustal deformation, and the extent to which existing models of fault zone structure can be applied to active plate-boundary faults. Three datasets were used to quantify fracture damage at different distances from the Alpine Fault principal slip zones (PSZs): (1) X-ray computed tomography (CT) images of drill-core collected within 25 m of the PSZs during the first phase of the Deep Fault Drilling Project that were reoriented with respect to borehole televiewer (BHTV) images, (2) field measurements from creek sections at <500 m from the PSZs, and (3) CT images of oriented drill-core collected during the Amethyst Hydro Project at distances of ~500-1400 m from the PSZs. Results show that within 160 m of the PSZs in foliated cataclasites and ultramylonites, gouge-filled fractures exhibit a wide range of orientations. At these distances, fractures are interpreted to form at high confining pressures and/or in rocks that have a weak mechanical anisotropy. Conversley, at distances greater than 160 m from the PSZs, fractures are typically open and subparallel to the mylonitic foliation or schistosity, implying that fracturing occurred at low confining pressures and/or in rocks that are mechanically anisotropic. Fracture density is similar across the ~500 m width of the hanging-wall datasets, indicating that the Alpine Fault does not have a typical “damage zone” defined by decreasing fracture density with distance. Instead, we conclude that the ~160 m-wide zone of intensive gouge-filled fractures provides the best estimate for the width of brittle fault-related damage. This estimate is similar to the 60-200 m wide Alpine Fault low-velocity zone detected through fault zone guided waves, indicating that a majority of its brittle damage occurs within its hanging-wall. The data provided here include CT scan 'core logs' for drill-core from both boreholes of the first phase of the Deep Fault Drilling Project (DFDP-1A and DFDP-1B) and from the Amethyst Hydro Project (AHP), the code to generate 'unrolled' CT images (which is to be run on imageJ), and an overview image of the integration of unrolled DFDP-1B CT images and BHTV images (DFDP-1B_BHTV-CT-Intergration.pdf). The header for the scan log images indicate 'core run-core section-upper depth-lower depth' for DFDP and 'borehole-core run-core section-upper depth-lower depth' for AHP boreholes. CT scan core logs cover the depth range 67.5-91.1 m in DFDP-1A drill-core and all of DFDP-1B drill-core. A classification of fracture type is given in Williams et al (2016). For DFDP-1 CT scan logs, title of each page labelled by: core run - core section - depth range. For AHP CT scan log, header of each page gives: borehole - core run - core section - depth. These are supplementary material to Williams et al. (submitted), in which a methodology for matching unrolled CT and BHTV images is given in Appendix A.
# 3
Heidbach, Oliver • Custodio, Susana • Kingdon, Andrew • Mariucci, Maria Theresa • Montone, Paola • (et. al.)
Abstract: The Stress Map of the Mediterranean and Central Europe 2016 displays 5011 A-C quality stress data records of the upper 40 km of the Earth’s crust from the WSM database release 2016 (Heidbach et al, 2016, http://doi.org/10.5880/WSM.2016.001). Focal mechanism solutions determined as being potentially unreliable (labelled as Possible Plate Boundary Events in the database) are not displayed. Further detailed information on the WSM quality ranking scheme, guidelines for the various stress indicators, and software for stress map generation and the stress pattern analysis is available at www.world-stress-map.org.
The World Stress Map (WSM) is a global compilation of information on the crustal present-day stress field. It is a collaborative project between academia and industry that aims to characterize the stress pattern and to understand the stress sources. It commenced in 1986 as a project of the International Lithosphere Program under the leadership of Mary-Lou Zoback. From 1995-2008 it was a project of the Heidelberg Academy of Sciences and Humanities headed first by Karl Fuchs and then by Friedemann Wenzel. Since 2009 the WSM is maintained at the GFZ German Research Centre for Geosciences and since 2012 the WSM is a member of the ICSU World Data System. All stress information is analysed and compiled in a standardized format and quality-ranked for reliability and comparability on a global scale.
# 4
Heidbach, Oliver • Rajabi, Mojtaba • Reiter, Karsten • Ziegler, Moritz
Abstract: The World Stress Map (WSM) is a global compilation of information on the crustal present-day stress field. It is a collaborative project between academia and industry that aims to characterize the stress pattern and to understand the stress sources. It commenced in 1986 as a project of the International Lithosphere Program under the leadership of Mary-Lou Zoback. From 1995-2008 it was a project of the Heidelberg Academy of Sciences and Humanities headed first by Karl Fuchs and then by Friedemann Wenzel. Since 2009 the WSM is maintained at the GFZ German Research Centre for Geosciences and since 2012 the WSM is a member of the ICSU World Data System. All stress information is analysed and compiled in a standardized format and quality-ranked for reliability and comparability on a global scale. The stress map displays A-C quality stress data records of the upper 40 km of the Earth’s crust from the WSM database release 2016 (doi:10.5880/WSM.2016.001). Focal mechanism solutions determined as being potentially unreliable (labelled as Possible Plate Boundary Events in the database) are not displayed. Further detailed information on the WSM quality ranking scheme, guidelines for the various stress indicators, and software for stress map generation and the stress pattern analysis is available at http://www.world-stress-map.org.
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