Raw bathymetry data collected from a hull-mounted Kongsberg EM712 multibeam echosounder during RRS Sir David Attenborough SD041 cruise, 2024
GB/NERC/BAS/PDC/02223
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Summary
Abstract:
Presented here is the raw multibeam bathymetry data acquired from 2024-07-28 to 2024-08-13 as part of RRS Sir David Attenborough SD041 research cruise also referred to as KANG-GLAC. Bathymetry data were collected using a hull-mounted Kongsberg EM712 multibeam echo-sounder. Data is provided in raw Kongsberg format (.kmall and kmwcd for water column data). Data are unprocessed and therefore may contain incorrect depth measurements without further processing.
KANG-GLAC is a NERC funded project to investigate how the accelerating decay of the Greenland Ice Sheet will progress with climate change, and to better understand the knock-on effects this will have on ocean circulation and marine productivity. "This work was funded by Natural Environment Research Council (NERC) grant NE/V006509/1.
Keywords:
Greenland, RRS Sir David Attenborough, bathymetry, multibeam
Citation
O'Cofaigh, C., Hogan, K., Howe, J., Roberts, D., Donate, V., Fremand, A., Hunt, M., Jenkins, H., Larter, R., Metcalfe, J., & Strandlod, F. (2026). Raw bathymetry data collected from a hull-mounted Kongsberg EM712 multibeam echosounder during RRS Sir David Attenborough SD041 cruise, 2024 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/9929e59b-eff5-4add-ab51-9ca6138e677d
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REFERENCE MATERIALS
RELATED DATA SET METADATA
- https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/02222
- https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/02224
- https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/02225
- https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/02226
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Constraints
| Access Constraints: | None |
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| Use Constraints: | This data is covered by a UK Open Government Licence (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) 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 2. The user recognises the limitations of the data and will not use this data for navigation purposes. 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. NOT TO BE USED FOR NAVIGATION |
Basic Information
| Creation Date: | 2026-06-12 |
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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 | Prof Colm O'Cofaigh |
| Role(s) | Investigator |
| Organisation | Durham University |
| Name | Dr Kelly Hogan |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Prof John Howe |
| Role(s) | Investigator |
| Organisation | Scottish Association for Marine Science |
| Name | Prof Dave Roberts |
| Role(s) | Investigator |
| Organisation | Durham University |
| Name | Vicent Donate |
| Role(s) | Investigator |
| Organisation | Stockholm University |
| Name | Ms Alice C Fremand |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Dr Matthew Hunt |
| Role(s) | Investigator |
| Organisation | Durham University |
| Name | Holly Jenkins |
| Role(s) | Investigator |
| Organisation | Durham University |
| Name | Dr Robert Larter |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Joseph Metcalfe |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Ms Freja Strandlod |
| Role(s) | Investigator |
| Organisation | Geological Survey of Denmark and Greenland |
| Parent Dataset: | N/A |
Additional Information
| Reference: | Cruise report: https://www.bodc.ac.uk/resources/inventories/cruise_inventory/report/18764/ | |
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| Quality: | The raw data are presented here. The data have not been corrected for vertical datum and no tide model was applied. No quality check has been performed. Data are not to be used for navigation. | |
| Lineage/Methodology: | The multibeam bathymetry data presented here have been acquired from 2024-07-28 to 2024-08-13 as part of RRS Sir David Attenborough cruise SD041. RRS Sir David Attenborough is fitted with a hull-mounted Kongsberg EM712 multibeam echo sounder with 1 degree x 1 degree acoustic beam widths. Multibeam bathymetry data were collected occasionally primarily to map unsurveyed areas, provide bathymetric characterisation of the local surroundings and identify suitable deployments sites. The mid-water EM712 multibeam echosounder was only used occasionally on the cruise. The occasions when it was used tended to be when the ship was in shallow water, for example in 3-Miipugut Fjord. The system was upgraded to SIS 5 a few weeks before the cruise, with only a couple of days of testing. While it provided better quality data than previously seen, we encountered a ping fault error quite regularly, interrupting the smooth acquisition of data. This error meant that the computer had to be shut down as well as the processing unit.With the very frequent occurrence of these errors, the system was often turned off and used only infrequently. Due to regulations and technical issues, most of the data were acquired with an average ship speed of 5 knots. The data were acquired using the Seafloor Information System (SIS) software - version 5.12.2. The installation parameters were set up following the information from the Anko Maritime AS (2020) reference survey as follows: TX transducer: X = 19.926 m, Y=0.263 m, Z = 8.093 m, Roll: 0.13 deg, Pitch = -0.32 deg, Heading =359.83 deg RX transducer: X = 18.699 m, Y =0.965 m, Z = 8.085 m, Roll: -0.21 deg, Pitch =-0.13 deg, Heading = 359.79 deg No calibration was undertaken on the EM712 during the cruise because of time constraints. The last calibration was undertaken on 27-28/08/2022 to the north of the Butt of Lewis (Northwest Scotland).These values have been added on SIS in the offset angle section of the installation parameters. The following angular offsets from the previous cruise were used: Roll: 0.08 deg Pitch =0.25 deg Heading =0.15 deg The EM712 was always operated in external trigger mode via K-sync allowing multiple acoustic instruments to be operated at the same time. The multibeam system was monitored and the 'angular coverage', 'depth', 'ping mode' and 'mammal protection' parameters changed regularly to adapt to the water depth and sea conditions. In bad weather, to increase the quality of the data, the beam angles were reduced and the power set to maximum. The default values were used for the 'water column', 'absorption coefficient', 'auto tilt', and 'along direction' parameters. On several occasions during the cruise, the EM712 had to be restarted after a faulty ping error. The issue became more and more apparent during the cruise. While it first appeared only every 72 hours, it happened several times a day while in Ryberg fjord. The only solution found to this issue was to restart both the computer and processing unit. ** Sound velocity ** Sound velocity corrections are essential for accurate bathymetric depths. The multibeam systems have an input for a surface sound velocity value at the transducer and sound velocity profiles were regularly updated. Profiles were obtained from CTD casts throughout SD041 and used as the primary input for sound velocity. Surface sound velocity was also obtained from a Valeport miniSVP sensor installed in the uncontaminated seawater system. These values were monitored and when possible the profile was updated with new CTD values. In icy conditions, it is to be noted that the inlet was flushed and not providing accurate data. ** Survey information ** SD041_a - Transit from UK up to Icelandic EEZ waters - no data aquired. SD041_b - Greenlandic waters, mooring site, Kangerlussuaq Trough SD041_c - 3-Miippugut Fjord SD041_d - Transit from 3-Miippugut fjord to Kivioq fjord, Kivioq fjord and bay in front of Rosenborg Gletcher On a few occasions, mainly linked to acquisition close to glaciers, water column data were acquired to better map ice fronts. |
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Locality
| Temporal Coverage: | |
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| Start Date | 2024-01-28 |
| End Date | 2024-08-13 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | 67.64468 |
| Northernmost | 68.37033 |
| Longitude | |
| Westernmost | -32.5041 |
| Easternmost | -29.1 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | 36m |
| Max Depth | 1720m |
| Location: | |
| Location | Arctic Ocean |
| Detailed Location | N/A |
| Location | Greenland |
| Detailed Location | N/A |
Instrumentation
| Sensor(s): |
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| Source(s): |
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| Data Collection: | Data collected on board RRS Sir David Attenborough using a Kongsberg EM712 multibeam echosounder using SIS software (version 5.12.2) . |
Storage
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 15 GB |
| Distribution Format | N/A |
| Fees | N/A |
| Data Storage: | This dataset consists of bathymetry data collected as part of 3 surveys: - SD041_b: 126 .kmall files ~7.8 GB - SD041_c: 93 .kmall files ~5.8 GB - SD041_d: 27 files (3 .kmwcd and 23 .kmall files) ~1.7 GB |