Abstract:
Five seismic reflection profiles (Lake A to E) were acquired across Subglacial Lake Ellsworth (SLE), Antarctica, during the 2007-08 austral summer. SLE is a freshwater lake that lies under ice that is ~3.2 km thick. SLE is approximately 15 km long and 3 km wide. The data were acquired to determine the overlying ice thickness, the water depth in the lake, and the lake-bed material. The seismic lines were aligned perpendicular to the lake's long axis and spaced roughly 1.4 km apart, over what appears to be the deeper part of the lake. Seismic shot-point locations were determined using RTK GPS methods. Seismic sources were Pentolite explosives in 30 m deep holes made with a hot-water drill and backfilled with snow. The fieldwork was a collaboration between the British Antarctic Survey (BAS), Northumbria University and the University of Edinburgh.
Funding was provided by NERC AFI awards NE/D009200/1, NE/D008638/1 and NE/D008751/1. Equipment support by NERC Geophysical Equipment Facility loan numbers 838 and 870.
Keywords:
West Antarctic Ice Sheet, bathymetry, seismology, subglacial lake
Smith, A., Brisbourne, A., Woodward, J., Ross, N., & Siegert, M. (2025). Subglacial Lake Ellsworth seismic reflection profiles, raw seismic and GPS survey data, 2007/2008 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/f7eda2dc-245e-4704-aef8-4a267190c22a
| Access Constraints: | No restrictions apply. |
|---|---|
| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2025-10-10 |
|---|---|
| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
|
| Parameters: |
|
| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Andrew M Smith |
| Role(s) | Technical Contact, Investigator |
| Organisation | British Antarctic Survey |
| Name | Alex M Brisbourne |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | John Woodward |
| Role(s) | Investigator |
| Organisation | Northumbria University |
| Name | Neil Ross |
| Role(s) | Investigator |
| Organisation | Newcastle University |
| Name | Martin J Siegert |
| Role(s) | Investigator |
| Organisation | University of Exeter |
| Parent Dataset: | N/A |
| Reference: | A.M. Smith, J. Woodward, N. Ross, M.J. Bentley, D.A. Hodgson, M.J. Siegert, E.C. King (2018), Evidence for the long-term sedimentary environment in an Antarctic subglacial lake, Earth Planet. Sci. Lett., 504, 139-151, https://doi.org/10.1016/j.epsl.2018.10.011. Woodward, J., A. M. Smith, N. Ross, M. Thoma, H. F. J. Corr, E. C. King, M. A. King, K. Grosfeld, M. Tranter, and M. J. Siegert (2010), Location for direct access to subglacial Lake Ellsworth: An assessment of geophysical data and modeling, Geophys. Res. Lett., 37, L11501, https://doi.org/10.1029/2010GL042884. |
|
|---|---|---|
| Quality: | SEG-Y data include relative geometry in the headers with a shot point interval of 240 m and a receiver interval of 10 m. Only shot locations were surveyed to provide accurate location and elevation. Receiver locations must be determined by interpolation and extrapolation using the shot point profiles. | |
| Lineage/Methodology: | Shot-point location was determined using RTK GPS methods. Receivers used were Leica 530. One receiver operated as a base station, located in the middle of each survey area. The other receiver was operated as a real-time rover. Seismic source for each shot was 450 g of Pentolite explosive buried at 30 m depth in holes made by a hot-water drill. Data acquisition used a spread of 48 geophones (40 Hz natural frequency) spaced at 10 m intervals with an offset from shot to first geophone of 30 m. Shot-spacing and move-up per shot was 240 m, giving single fold coverage. Line length varied between 33 and 12 shots. The data provided comprise sorted raw shot gathers. Raw field data for each line were sorted into sequential traces and written to a single SEG-Y file. The metadata provided contain the GPS-derived position of each shot point (latitude (decimal degrees), longitude (decimal degrees), elevation (m relative to WGS-84 ellipsoid). Seismic data were processed with Halliburton-Landmark ProMAX software under academic license to BAS. Horizontal and vertical position of each shot point is given. These were determined using dual-frequency GPS surveying with a precision of approximately 10 cm. Vertical precision is given by the sample interval of 0.2 ms. Note this is given in time, not depth; no depth conversion has been applied. |
|
| Temporal Coverage: | |
|---|---|
| Start Date | 2007-12-02 |
| End Date | 2008-01-31 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -79.1 |
| Northernmost | -78.9 |
| Longitude | |
| Westernmost | -91 |
| Easternmost | -90 |
| Altitude | |
| Min Altitude | 1900 m |
| Max Altitude | 1920 m |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Subglacial Lake Ellsworth |
| Sensor(s): |
|
|---|---|
| Data Collection: | Seismic data were acquired using OYO 40 Hz single geophones and Geometrics GEODE 48-channel seismic data logger recording in SEG-2 format. Data were logged at 4 kHz; record length was 4 s. Data processing (sorting and writing to SEG-Y format) done using ProMax seismic processing software. |
| Distribution: | |
|---|---|
| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 309 MB |
| Distribution Format | N/A |
| Fees | N/A |
| Data Storage: | Five seismic data files - LakeX_raw_relative_geom.segy. Format is SEG-Y 4-byte IBM floating point (industry-standard seismic data format). Only relative locations in metres are included in the segy headers, as exported from Promax. These must be mapped to the GPS measured shot point locations. One metadata file listing shot point locations - GPS_locations_of_shotpoints.csv Format is CSV. Note - In case they are of use to extend the surface elevation profile, two additional GPS points are included, extending the Lake C profile, although no shot was fired at these sites (7920 and 8160). |