b809a040-8305-4bc5-baff-76aa2b823734 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2020-11-13 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Microseismic icequake catalogue, Rutford Ice Stream (West Antarctica), November 2018 to February 2019 2020-11-13 creation 2020-11-13 revision 2020-11-13 publication 2020-11-13 released 1.0 https://doi.org/10.5285/b809a040-8305-4bc5-baff-76aa2b823734 doi GB/NERC/BAS/PDC/01432 https://data.bas.ac.uk/ NE/G014159/1 award NE/G013187/1 award Please cite this item as: Kufner, S., Brisbourne, A., Smith, A., Hudson, T., Murray, T., Schlegel, R., Kendall, J., Anandakrishnan, S., & Lee, I. (2020). Microseismic icequake catalogue, Rutford Ice Stream (West Antarctica), November 2018 to February 2019 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/b809a040-8305-4bc5-baff-76aa2b823734 This dataset contains ASCII files with hypocenter information, event times and magnitudes for 227029 micro-earthquakes with a magnitude range from -2.0 to -0.3 recorded from a 35-station seismic network located ~40 km upstream of the grounding line of Rutford Ice Stream, West Antarctica. For 87910 of these events, earthquake focal mechanisms (strike/dip/rake) are available. The seismic network, which recordings are the base for the event catalogue, broadly formed a rectangle with 1 km station spacing. Details on the station locations, instrument types and operation periods are included in these data files. The event catalogue encloses the geographic region between 084.142 to 083.760 degrees West and 78.204 to 78.113 degrees South. Events are located between 1.553 and 2.416 km depth. Recording took place between 20th November 2018 and 16th February 2019. The spatio-temporal arrangement of these micro-earthquakes can be used to characterize frictional properties at the ice-bed interface of Rutford Ice Stream. 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. No credit. completed Kufner, Sofia-Katerina British Antarctic Survey Researcher author Brisbourne, Alex British Antarctic Survey Researcher author Smith, Andrew British Antarctic Survey Researcher author Hudson, Thomas University of Oxford Researcher author Murray, Tavi Swansea University Researcher author Schlegel, Rebecca Swansea University Researcher author Kendall, John University of Oxford Researcher author Anandakrishnan, Sridhar Pennsylvania State University Researcher author Lee, Ian Pennsylvania State University Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glacier Motion/Ice Sheet Motion EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets EARTH SCIENCE > Solid Earth > Seismology theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher BEAMISH West Antarctica glacier bed ice stream icequake microseismicity theme Rutford Ice Stream Antarctica place Elevation Geology theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions This data is supplied under Open Government Licence v3.0 otherRestrictions No restrictions apply. url url largerWorkCitation doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference url url crossReference doi doi crossReference url url crossReference url url dependency url url dependency url url dependency textTable eng utf8 geoscientificInformation -84.142 -83.76 -78.204 -78.113 2018-11-20 2019-02-16 0.304 0.359 urn:ogc:def:crs:EPSG::5714 MSL height Not specific to any location or epoch. Hydrography. It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor text/plain bytes 58720256 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=b809a040-8305-4bc5-baff-76aa2b823734 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: Event locations were gained from the continuous passive seismic records using the QuakeMigrate (Hudson et al., 2019; J. D. Smith et al., 2020) and Nonlinloc (Lomax et al., 2000) software. A two-layer velocity model (firn layer above an ice layer) according to E. C. Smith et al. (2015) was used in the Nonlinloc location step. Based on Nonlinloc locations, we accept only events with a total root-mean-square (RMS) value of 0.02 s, a maximum azimuthal gap of 280 degrees, maximum 10% of picks with a P/S residual larger than 0.02 s/0.2 s and at least 3 P picks and 2 S picks for the final event catalogue. We account for the movement of the seismic stations relative to the bed due to ice flow by shifting each event in the final catalogue downstream. Rutford Ice Stream moved ~94 m downstream during the 90 day survey period, whereas our stations are specified at fixed locations during event location, clearly evidencing the necessity for such a shift. We perform this shift by calculating the stations' locations at the time of each individual event relative to the start of the deployment, using their GPS locations, and apply this lateral shift to that event hypocenter. This is repeated for all events in the catalogue to compensate for ice flow. Magnitudes were calculated from the far-field displacement of the P-wave (Mw; Shearer (2009); implementation of Hudson (2019)) for a 1-day data subset. A local magnitude scale (ML) was then derived based on these Mw values. The local magnitude scale follows the equation: ML = log10(A) + m x depi - t where A is the maximum amplitude of either of the two horizontal components (in instrument counts corrected for the instrument type). The distance term m accounts for the decay of amplitudes with increasing epicentral distance, depi is the epicentral distance and t is a scaling parameter that bridges the offset between Mw and ML. Focal mechanisms were calculated from first motion polarities and P to S- amplitude ratios using the HASH software (Hardebeck & Shearer, 2002, 2003). The final set of good solutions is derived based on quality criteria, which are the stability of solution upon variations of input, the azimuthal gap of the final set of stations (should be smaller than 180 degrees) used and the final number of input picks (should be larger than seven). Detailed information on catalogue creation will be contained in Kufner et al. (in prep.). 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: Event detection from continuous data: QuakeMigrate (https://github.com/QuakeMigrate/QuakeMigrate); October 2019-Version Event relocation: Nonlinloc (http://alomax.free.fr/nlloc/); Version 4, including updates until 2017 First motion focal mechanisms: HASH (https://www.usgs.gov/software/hash-12); Version 1.2, January 2008 Data quality: See Lineage for quality restrictions applied to the event hypocenters and focal mechanisms. Location errors are given directly in the data file. asNeeded completed