Abstract:
This dataset contains an ASCII file with shear wave splitting results for 202,651 station-event pairs from glacial micro-seismicity, recorded from a 35-station seismic network located ~40 km upstream of the grounding line of Rutford Ice Stream, West Antarctica. Microseismicity is located at the base of the ice stream at ~2.2 km depth (relative to the ice surface). Seismic waveform data, which was used to calculate shear wave splitting parameters is provided in miniseed format. Event hypocenter information, event times and coordinates of receiving stations are listed in the ASCII file. Shear wave splitting was calculated using the software MFAST. Shear wave splitting parameters can be used to determine seismic anisotropy along the ray path, which helps to characterise ice fabric.
This work was funded within the BEAMISH project by NERC AFI award numbers NE/G014159/1 and NE/G013187/1. Seismic instruments were provided by NERC SEIS-UK (Loan 1017) and the Incorporated Research Institutions for Seismology (IRIS) through the PASSCAL Instrument Center at New Mexico Tech.
Keywords:
BEAMISH, Rutford Ice Stream, West Antarctica, ice fabric, icequake, microseismicity, seismic anisotropy, shear wave splitting
Kufner, S., Brisbourne, A., Smith, A., Wookey, J., Martin, C., Hudson, T., & Kendall, J. (2022). Shear wave splitting catalogue, Rutford Ice Stream (West Antarctica), November 2018 to February 2019 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/6fcc17ad-425b-4367-bd23-c4133a38e359
| Access Constraints: | The data are embargoed until 2023-03-01. |
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| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2022-06-13 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Sofia-Katerina Kufner |
| Role(s) | Investigator, Technical Contact |
| Organisation | British Antarctic Survey |
| Name | Alex M Brisbourne |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Andrew M Smith |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | James Wookey |
| Role(s) | Investigator |
| Organisation | University of Bristol |
| Name | Carlos Martin |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Thomas S Hudson |
| Role(s) | Investigator |
| Organisation | University of Oxford |
| Name | John M Kendall |
| Role(s) | Investigator |
| Organisation | University of Oxford |
| Parent Dataset: | N/A |
| Reference: | Kufner, S.-K., Wookey, J., Brisbourne, A. M., Martin, C., Hudson, T. S., Kendall, J.-M., & Smith, A. M. (2023). Strongly depth-dependent ice fabric in a fast-flowing Antarctic ice stream revealed with icequake observations. Journal of Geophysical Research: Earth Surface, 128, e2022JF006853. https://doi.org/10.1029/2022JF006853 Kufner, S. K., Brisbourne, A. M., Smith, A. M., Hudson, T. S., Murray, T., Schlegel, R., Kendall, J. M., Anandakrishnan, S., & Lee, I. (2021). Not all Icequakes are Created Equal: Basal Icequakes Suggest Diverse Bed Deformation Mechanisms at Rutford Ice Stream, West Antarctica. Journal of Geophysical Research: Earth Surface, 126(3). https://doi.org/10.1029/2020JF006001 Savage, M. K., Wessel, A., Teanby, N. A., & Hurst, A. W. (2010). Automatic measurement of shear wave splitting and applications to time varying anisotropy at Mount Ruapehu volcano, New Zealand. Journal of Geophysical Research: Solid Earth, 115(12). https://doi.org/10.1029/2010JB007722 Silver, P. G., & Chan, W. W. (1991). Shear wave splitting and subcontinental mantle deformation. Journal of Geophysical Research, 96(B10). https://doi.org/10.1029/91jb00899 Teanby, N. A., Kendall, J. M., & van der Baan, M. (2004). Automation of shear-wave splitting measurements using cluster analysis. Bulletin of the Seismological Society of America, 94(2). https://doi.org/10.1785/0120030123 |
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| Quality: | Errors on the splitting parameters are given in the ASCII data file. | |
| Lineage: | Icequake used for shear wave splitting analysis are chosen based on the event catalogue of Kufner et al. (2021). To calculate SWS parameters from the waveform data of these events, horizontal seismograms are filtered between 8 and 125 Hz, using a two-pole Butterworth filter, and downsampled from 1000 to 500 Hz. The MFAST (M. K. Savage et al., 2010) software is used for shear wave splitting analysis. MFAST implements a minimum eigenvalue analysis algorithm (Silver & Chan, 1991) to calculate shear wave splitting in multiple time windows around the S-onset. A cluster analysis method is then implemented on the splitting results from individual measurement windows to find the most stable set of splitting parameters (see Teanby et al. (2004) for more details). In MFAST, the start and end point of the measurement windows are variable, dependent on an event's dominant frequency. Detailed information on the methodology and interpretation of the results will be presented in Kufner et al. (in prep.). |
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| Temporal Coverage: | |
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| Start Date | 2018-11-20 |
| End Date | 2019-02-16 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -78.195 |
| Northernmost | -78.122 |
| Longitude | |
| Westernmost | -84.172 |
| Easternmost | -83.785 |
| Altitude | |
| Min Altitude | 0.304 km a.s.l |
| Max Altitude | 0.359 km a.s.l |
| Depth | |
| Min Depth | 1.609 km b.s.l |
| Max Depth | 2.200 km b.s.l |
| Location: | |
| Location | Antarctica |
| Detailed Location | Rutford Ice Stream |
| Sensor(s): |
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| Data Collection: | Instrumentation: Each station of the seismic network consisted of a Reftek RT-130 data logger with a 4.5 Hz 3-component geophone (either GS11-3D or L28-3D), which was buried to ~1 m depth. The sampling frequency was set to 1000 Hz. Energy supply was ensured through a solar panel and batteries. Timing was obtained from an attached GPS antenna. Software: Shear wave splitting: MFAST (https://mfast-package.geo.vuw.ac.nz/); Version 2.2. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 12 GB |
| Distribution Format | N/A |
| Fees | N/A |
| Data Storage: | This dataset contains: One ASCII data file: RutfordIceStream_ShearWaveSplittingResults_2018-19.txt; ~21 MB. One ASCII README file, which describes the content of the datafiles and folders: README.txt; ~1 kB. One nested folder structure, with waveform data in miniseed format: raw_event_data; ~12 GB. |