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Thwaites Glacier geological map and associated geophysical information.
The geology underlying Thwaites Glacier plays a critical role in mediating ice flow in this region yet is extremely poorly known. Using new compilations of airborne radar, magnetic and gravity data, supported by published geological evidence, we have interpreted the subglacial geology of the Thwaites Glacier region. Here we provide the new data compilations, results of 3D inversions and vector components defining the lithological units on our new geological sketch map.
British Antarctic Survey (BAS) National Capability contribution to the International Thwaites Glacier Collaboration (ITGC) (TJ), NERC Grant NE/S006621/1 (Geophysical Habitats of Subglacial Thwaites (Ghost)) (BK), Antarctic Science Collaboration Initiative program (Australian Government) (ST), European Space Agency (ESA) 4D Antarctica project (FF).
Simple
- Date (Creation)
- 2023-03-17
- Date (Revision)
- 2023-03-17
- Date (Publication)
- 2023-03-17
- Date (released)
- 2023-03-17
- Edition
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1.0
- Unique resource identifier
- https://doi.org/10.5285/189823ed-6a14-4eba-87fb-38ba3e5e30fb
- Codespace
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doi
- Unique resource identifier
- GB/NERC/BAS/PDC/01720
- Codespace
- Unique resource identifier
- NE/S006621/1
- Codespace
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award
- Other citation details
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Please cite this item as: Jordan, T., Thompson, S., Kulessa, B., & Ferraccioli, F. (2023). Thwaites Glacier geological map and associated geophysical information. (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/189823ed-6a14-4eba-87fb-38ba3e5e30fb
- Credit
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No credit.
- Status
- Completed
- Point of contact
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Organisation name Individual name Electronic mail address Role British Antarctic Survey Jordan, Tom Author University of Tasmania Thompson, Sarah Author Swansea University Kulessa, Bernd Author British Antarctic Survey Ferraccioli, Fausto Author NERC EDS UK Polar Data Centre Point of contact
- Maintenance and update frequency
- As needed
- Maintenance note
- Completed
- Theme
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Thwaites glacier
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basal roughness
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bed elevation
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geological map
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gravity
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magnetic
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GEMET - INSPIRE themes, version 1.0
- Access constraints
- Other restrictions
- Other constraints
- no limitations to public access
- Access constraints
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- no limitations
- Use constraints
- License
- Other constraints
- Open Government Licence v3.0
- Use constraints
- Other restrictions
- Other constraints
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Jordan, T.A., Thompson, S., Kulessa, B., & Ferraccioli, F. (2023). Thwaites Glacier geological map and associated geophysical information. (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/189823ED-6A14-4EBA-87FB-38BA3E5E30FB
- Use constraints
- Other restrictions
- Other constraints
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None
- Unique resource identifier
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- Cross reference
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doi
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url
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doi
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- Spatial representation type
- Text, table
- Language
- English
- Character set
- UTF8
- Topic category
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- Geoscientific information
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- Supplemental Information
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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.
- Title
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European Petroleum Survey Group (EPSG) Geodetic Parameter Registry
- Date (Publication)
- 2008-11-12
- Cited responsible party
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Organisation name Individual name Electronic mail address Role European Petroleum Survey Group
Publisher
- Unique resource identifier
- urn:ogc:def:crs:EPSG::3031
- Version
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6.18.3
Distributor
- Distributor contact
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Organisation name Individual name Electronic mail address Role NERC EDS UK Polar Data Centre Distributor
- Distributor format
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Name Version text/plain
- Units of distribution
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bytes
- Transfer size
- 413138944
- OnLine resource
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Protocol Linkage Name WWW:LINK-1.0-http--link
https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=189823ed-6a14-4eba-87fb-38ba3e5e30fb Get Data
- Hierarchy level
- Dataset
- Statement
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Methodology:
This dataset includes three components: Input geophysical compilations, inversion results and interpreted geological boundaries. Details of the data compilation, inversion and basic geological interpretation are presented here. This dataset is the companion to the following paper Jordan et al., (in prep) Geological sketch map and implications for ice flow of Thwaites Glacier, West Antarctica, from integrated aerogeophysical observations, Science Advances., which contains full details of the geological interpretation and should be cited when this dataset is used.
Input geophysical compilations:
This dataset includes compilations of aerogeophysical data collected across the Thwaites Glacier region of West Antarctica over the past several decades. Surveys used include: AGASEA and BBAS which collected radar, magnetic and gravity data (Diehl et al., 2008; Holt et al., 2006; Jordan et al., 2010; Vaughan et al., 2006). NASA Operation Ice Bridge (OIB) which collected radar and gravity data (Paden et al., 2010, updated 2021; Tinto et al., 2010, updated 2019). The International Thwaites Glacier Collaboration (ITGC) which collected radar, magnetic and gravity data (Jordan et al., 2020a; Jordan and Robinson, 2021a; Jordan and Robinson, 2021b, c; Jordan et al., 2020c). Additional magnetic data was taken from the ADMAP2 compilation (Golynsky et al., 2018).
The presented bed-elevation dataset was created from the radar-derived bed elevation picks from the surveys noted above interpolated onto a 2 km mesh raster, padded with gravity derived bathymetry beneath adjacent ice shelves (Jordan et al., 2020b) and BEDMAP2 in more distal areas (Fretwell et al., 2013). All topographic data were corrected to an ellipsoidal reference frame prior to integration.
The presented subglacial topographic roughness grid was created from the along track standard deviation of the picked radar bed elevation within a 1 km wide moving window, interpolated onto a 2 km mesh raster. Areas where the bed was poorly resolved, defined as having along-line data gaps more than 50 percent of the analysis window (500 m), were excluded from the gridded product.
The presented aeromagnetic compilations were created from line data available through the ADMAP2 project (Golynsky et al., 2018) and incorporating new ITGC data (Jordan et al., 2020a; Jordan and Robinson, 2021c). Data were upward/downward continued to 500 m above the ice/sea surface to place all observations on a common surface prior to reapplication of statistical levelling. After levelling and continuation crossover errors were 18.79 nT. An alternative continuation to 2500 m above the underlying rock was also carried out to give a view of the data with a consistent distance to the closest possible source. The two versions of the final continued line data were interpolated onto a 1 km mesh, and subject to a 3 pass Hanning filter.
The presented free air gravity anomalies are from the surveys noted above after detailed data editing and levelling. Note that strictly the presented gravity compilation reflects ''gravity disturbances'', rather than anomalies as they are referenced to the ellipsoid. The line data from ITGC, AGASEA and BBAS were statistically levelled and edited using the OIB dataset as a reference after high altitude (more than 1500 m above ice surface) OIB survey lines had been removed. The line free air data was continued to a uniform level of 2500 m. After levelling and continuation the free air gravity data had an internal crossover error of 2.94 mGal. The line data were interpolated onto a 2 km raster mesh using a minimum curvature method.
The presented Bouguer gravity anomaly includes correction for a full 3D model of the gravity effect of the topography, bathymetry and ice, based on the topographic compilation noted above and ice surface elevations taken from the BEDMAP2 (Fretwell et al., 2013). An o...(54)
Data quality:
See Lineage for data quality of data compilations.
Metadata
- File identifier
- 189823ed-6a14-4eba-87fb-38ba3e5e30fb XML
- Metadata language
- English
- Character set
- UTF8
- Hierarchy level
- Dataset
- Hierarchy level name
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dataset
- Date stamp
- 2023-03-17
- Metadata standard name
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ISO 19115 Geographic Information - Metadata
- Metadata standard version
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ISO 19115:2003(E)
- Metadata author
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Organisation name Individual name Electronic mail address Role NERC EDS UK Polar Data Centre Point of contact
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