Abstract:
The dataset consists of a single shapefile containing terminus positions of Jakobshavn Isbrae, Ilulissat Icefjord, Greenland, between 2022-2023. Jakobshavn Isbrae is a fast-flowing outlet glacier situated in central west Greenland and terminates in Ilulissat Icefjord, a deep fjord basin renewed by water from Disko Bay (Gladish et al., 2015). Each polyline feature in this dataset reflects a terminus position manually digitised using synthetic aperture radar (SAR) mosaics downloaded from the National Snow and Ice Data Center (NSIDC; Joughin, 2021). The dataset comprises 31 terminus positions in total, each digitised from imagery collected between 02/01/2022 and 28/12/2022.
Hannah Picton acknowledges funding from the E4 DTP (Edinburgh Earth, Ecology and Environment Doctoral Training Partnership), NE/S007407/1.
Keywords:
Greenland, Jakobshavn Isbrae, ice dynamics, outlet glacier, terminus position
Picton, H. (2024). Terminus Positions of Jakobshavn Isbrae, Greenland, 2022-2023 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/30f96898-c12a-4783-8a31-0628b74a616a
| Access Constraints: | Data under embargo until publication of the associated article. |
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| Use Constraints: | This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2024-06-20 |
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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 | Hannah J Picton |
| Role(s) | Investigator, Technical Contact |
| Organisation | University of Edinburgh |
| Parent Dataset: | N/A |
| Reference: | A reassessment of the role of atmospheric and oceanic forcing on ice dynamics at Jakobshavn Isbrae Ilulissat Icefjord. The Journal of Geophysical Research: Earth Surface. [to be submitted] Black, T. and Joughin, I. (2022) MEaSUREs Weekly to Monthly Greenland Outlet Glacier Terminus Positions from Sentinel-1 Mosaics, Version 1 [dataset], National Snow and Ice Data Center. https://doi.org/10.5067/DGBOSSIULSTD. Black, T. and Joughin, I. (2023) Weekly to monthly terminus variability of Greenland's marine terminating outlet glaciers. The Cryosphere, 17(1): 1-13. https://doi.org/10.5194/tc-17-1-2023. Gladish, C. V., Holland, D. M., Rosing-Asvid, A., Behrens, J. W., and Boje, J. (2015). Oceanic Boundary Conditions for Jakobshavn Glacier. Part I: Variability and Renewal of Ilulissat Icefjord Waters, 2001-14. Journal of Physical Oceanography, 45(1), 3-32. https://doi.org/10.1175/JPO-D-14-0044.1. Joughin, I. (2021) MEaSUREs Greenland Image Mosaics from Sentinel-1A and -1B, Version 4 [dataset], National Snow and Ice Data Center. https://doi.org/10.5067/WXQ366CP8YDE. Joughin, I., Smith, B., Howat, I., Moon, T., and Scambos, T. (2016) A SAR record of early 21st century change in Greenland. Journal of Glaciology, 62(231): 62-71. https://doi.org/10.1017/jog.2016.10. |
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| Quality: | Black and Joughin (2023) state that the typical uncertainty associated with such manually digitised terminus positions is typically 25 m, however this may be higher at heavily crevassed termini, or at tidewater glaciers which discharge into adjacent melange or sea ice. A quality flag is thus provided for each individual shapefile; a value of 0 indicates certainty regarding the digitisation, whilst a value of 1 indicates the uncertainty may be greater than 25 m. It should however be noted that, at Jakobshavn Isbrae, seasonal changes in terminus position greatly exceed this estimated uncertainty. | |
| Lineage: | Each terminus position was manually digitised within QGIS using Sentinel-1A and Sentinel-1B SAR mosaics (Joughin et al., 2016) downloaded from the NSIDC (Joughin, 2021). The details of each SAR mosaic from which a given terminus position was digitised is provided in the attribute table of the shapefile. | |
| Temporal Coverage: | |
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| Start Date | 2022-01-02 |
| End Date | 2022-12-28 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | 69 |
| Northernmost | 69.2 |
| Longitude | |
| Westernmost | -49.7 |
| Easternmost | -49.5 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Greenland |
| Detailed Location | Jakobshavn Isbrae, Ilulissat Icefjord |
| Sensor(s): |
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| Data Collection: | QGIS Version 3.22.6. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 148.8 kB |
| Distribution Format | SHP |
| Fees | N/A |
| Data Storage: | A 'READ ME' text file is provided, outlining the dataset and defining the variables provided for each given terminus position. The manually digitised terminus positions are provided as individual lines within a single shapefile. |