BEDMAP1 - Ice thickness, bed and surface elevation for Antarctica - standardised data points
GB/NERC/BAS/PDC/01619
Abstract:
We present here the Bedmap1 ice thickness, bed and surface elevation standardised CSV data points that were used to create the Bedmap1 gridding products. The data consists of 2 million data points acquired in Antarctica from 1960s to 2000.
The associated Bedmap datasets are listed here: https://www.bas.ac.uk/project/bedmap/#data
This work is supported by the SCAR Bedmap project and the British Antarctic Survey's core programme: National Capability - Polar Expertise Supporting UK Research
Citation:
Lythe, M., Vaughan, D., BEDMAP 1, c., Fremand, A., & Bodart, J. (2022). BEDMAP1 - Ice thickness, bed and surface elevation for Antarctica - standardised data points (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/f64815ec-4077-4432-9f55-0ce230f46029
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| Use: | This data is covered by a Creative Commons License (https://creativecommons.org/licenses/by/4.0/) Further by downloading this data the user acknowledges that they agree with the NERC data policy (http://www.nerc.ac.uk/research/sites/data/policy.asp), and the following conditions: 1. To cite the data and the Bedmap1 publication in any publication as follows: REFERENCE: Lythe, M. B. and Vaughan, D. G.: BEDMAP: A new ice thickness and subglacial topographic model of Antarctica, Journal of Geophysical Research: Solid Earth, 106, 11335-11351, https://doi.org/10.1029/2000JB900449, 2001. DATA: Lythe, M., Vaughan, D., BEDMAP 1, consortia, Fremand, A., & Bodart, J. (2022). BEDMAP1 - Ice thickness, bed and surface elevation for Antarctica - standardised data points (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/F64815EC-4077-4432-9F55-0CE230F46029 2. The user recognizes the limitations of data. Use of the data is at the users' own risk, and there is no warranty as to the quality or accuracy of any data, or the fitness of the data for your intended use. The data are not necessarily fully quality assured and cannot be expected to be free from measurement uncertainty, systematic biases, or errors of interpretation or analysis, and may include inaccuracies in error margins quoted with the data. |
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Basic Information
| Creation Date: | 2022-02-28 |
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| Dataset Progress: | Planned |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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Additional Information
| Reference: | REFERENCE MATERIALS Fretwell, P., Pritchard, H. D., Vaughan, D. G., Bamber, J. L., Barrand, N. E., Bell, R., Bianchi, C., Bingham, R. G., Blankenship, D. D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A. J., Corr, H. F. J., Damaske, D., Damm, V., Ferraccioli, F., Forsberg, R., Fujita, S., Gim, Y., Gogineni, P., Griggs, J. A., Hindmarsh, R. C. A., Holmlund, P., Holt, J. W., Jacobel, R. W., Jenkins, A., Jokat, W., Jordan, T., King, E. C., Kohler, J., Krabill, W., Riger-Kusk, M., Langley, K. A., Leitchenkov, G., Leuschen, C., Luyendyk, B. P., Matsuoka, K., Mouginot, J., Nitsche, F. O., Nogi, Y., Nost, O. A., Popov, S. V., Rignot, E., Rippin, D. M., Rivera, A., Roberts, J., Ross, N., Siegert, M. J., Smith, A. M., Steinhage, D., Studinger, M., Sun, B., Tinto, B. K., Welch, B. C., Wilson, D., Young, D. A., Xiangbin, C., and Zirizzotti, A.: Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, The Cryosphere, 7, 375-393, https://doi.org/10.5194/tc-7-375-2013, 2013. Lythe, M. B. and Vaughan, D. G.: BEDMAP-bed topography of the Antarctic, British Antarctic Survey, Natural Environment Research Council, 2000. Lythe, M. B. and Vaughan, D. G.: BEDMAP: A new ice thickness and subglacial topographic model of Antarctica, Journal of Geophysical Research: Solid Earth, 106, 11335-11351, https://doi.org/10.1029/2000JB900449, 2001. DATA: BEDMAP1 Lythe, M., Vaughan, D., BEDMAP 1, consortia, Fremand, A., & Bodart, J. (2022). BEDMAP1 - Ice thickness, bed and surface elevation for Antarctica - standardised data points (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/F64815EC-4077-4432-9F55-0CE230F46029 Lythe, M., Vaughan, D., BEDMAP 1, consortia, Fremand, A., & Bodart, J. (2022). BEDMAP1 - Ice thickness, bed and surface elevation for Antarctica - standardised shapefiles and geopackages (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/925AC4EC-2A9D-461A-BFAA-6314EB0888C8 BEDMAP2 Fretwell, P., Fremand, A., Bodart, J., Pritchard, H., Vaughan, D., Bamber, J., Barrand, N., Bell, R. E., Bianchi, C., Bingham, R., Blankenship, D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A., Corr, H., Damaske, D., Damn, V., ... Zirizzotti, A. (2022). BEDMAP2 - Ice thickness, bed and surface elevation for Antarctica - standardised data points (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/2FD95199-365E-4DA1-AE26-3B6D48B3E6AC Fretwell, P., Pritchard, H., Vaughan, D., Bamber, J., Barrand, N., Bell, R. E., Bianchi, C., Bingham, R., Blankenship, D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A., Corr, H., Damaske, D., Damn, V., Ferraccioli, F., Forsberg, R., ... Bodart, J. (2022). BEDMAP2 - Ice thickness, bed and surface elevation for Antarctica - standardised shapefiles and geopackages (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/0F90D926-99CE-43C9-B536-0C7791D1728B Fretwell, P., Pritchard, H., Vaughan, D., Bamber, J., Barrand, N., Bell, R. E., Bianchi, C., Bingham, R., Blankenship, D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A., Corr, H., Damaske, D., Damn, V., Ferraccioli, F., Forsberg, R., ... Zirizzotti, A. (2022). BEDMAP2 - Ice thickness, bed and surface elevation for Antarctica - gridding products (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/FA5D606C-DC95-47EE-9016-7A82E446F2F2 BEDMAP3 Fremand, A., Fretwell, P., Bodart, J., Pritchard, H., Aitken, A., Bamber, J., Bell, R. E., Bianchi, C., Bingham, R., Blankenship, D., Casassa, G., Catania, G., Christianson, K., Conway, H., Corr, H., Cui, X., Damaske, D., Damn, V., Drews, R., .... Zirizzotti, A. (2022). BEDMAP3 - Ice thickness, bed and surface elevation for Antarctica - standardised data points (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/91523FF9-D621-46B3-87F7-FFB6EFCD1847 Fretwell, P., Pritchard, H., Fremand, A., Bodart, J., Aitken, A., Bamber, J., Bell, R. E., Bianchi, C., Bingham, R., Blankenship, D., Casassa, G., Catania, G., Christianson, K., Conway, H., Corr, H., Cui, X., Damaske, D., Damn, V., Drews, R., ... Zirizzotti, A. (2022). BEDMAP3 - Ice thickness, bed and surface elevation for Antarctica - standardised shapefiles and geopackages (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/A72A50C6-A829-4E12-9F9A-5A683A1ACC4A |
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| Quality: | All non-value data were converted to -9999, including any negative ice thickness values and any points with clear outliers. We checked the minimum and maximum values of each field to ensure the data are in a reasonable range and calculated mean and standard deviation on each dataset to identify potential issues. For example, if longitude/latitude values did not fall within the expected -180 to 180 or -50 to -90 degrees range respectively, the entire row was removed. When no ice thickness values were provided but surface and bed elevation values existed, we simply calculated ice thickness by subtracting the surface value from the bed value. At times, bed elevation was higher than surface elevation, likely due to issues with the semi-automatic picker used to extract the surface and bed reflector or a lack of distinctive reflectors in areas of shallow ice. To prevent this affecting the gridded product, we converted these values to -9999 for both the surface and the bed. Finally, we also conducted routine checks on the ice thickness data by comparing the given ice thickness value with the inferred ice thickness calculated from subtracting surface with bed. If these did not match, we placed -9999 on the ice thickness values. | |
| Lineage/Methodology: | The primary source data consist of survey point measurements of ice thickness, bed elevation and surface elevation, which principally comes from airborne radar surveys and seismic soundings, and to a smaller extent from ground-based radar surveys. All the data have been standardised to a specific CSV format. The format consists of (i) an extended header section where (a) each line is introduced by a comment ("#") character, (b) each line contains a single header item, (c) the colon character (":") is used as the key/value separator, (d) units are in parentheses, (e) attributes preferably use a common vocabulary such as the CF convention and includes attributes from the ACDD; (ii) a header row composed of the column name following the CF convention and units in parentheses; and finally (iii) the data using comma as the separator. The extended header consists of general information regarding each campaign such as the year, the name of the main investigator, funding and processing details. The variable names are as follows: trajectory_id Line or Flight ID trace_number Trace number from the specific line given in Line_ID longitude Longitude (WGS84 EPSG: 4326) in decimal degrees latitude Latitude (WGS84 EPSG: 4326) in decimal degrees date Date following ISO 8601 format: YYYY: year, MM: month, DD: day time_UTC UTC time following ISO 8601 format: HH: hours, MM: minutes, SS: seconds surface_altitude Surface elevation or altitude (referenced to WGS84) in meters land_ice_thickness Ice thickness in meters bedrock_altitude Bed elevation or altitude (referenced to WGS84) in meters two_way_travel_time Two-way travel time in seconds aircraft_altitude Aircraft elevation or altitude when applicable (referenced to WGS84) in meters along_track_distance Distance in the along-track direction in meters |
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Extent
| Temporal Coverage: | |
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| Start Date | 1966-01-01 |
| End Date | 2000-12-31 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -90 |
| Northernmost | -60 |
| Longitude | |
| Westernmost | -180 |
| Easternmost | 180 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | N/A |
Storage
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 170 MB |
| Distribution Format | ASCII |
| Fees | N/A |
| Data Storage: | This dataset consist of 1 CSV file ~170 MB. |