Terminus data for: Multi-decadal retreat of Greenland's marine-terminating glaciers
Many marine-terminating glaciers draining the Greenland ice sheet have retreated over the past decade, yet the extent and magnitude of retreat relative to past variability is unknown. We measure changes in front positions of 210 marine-terminating glaciers using Landsat imagery spanning nearly four...
| Main Authors: | , |
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| Format: | Dataset |
| Language: | unknown |
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2020
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| Online Access: | https://zenodo.org/record/5027197 https://doi.org/10.5061/dryad.vhhmgqnq6 |
| Summary: | Many marine-terminating glaciers draining the Greenland ice sheet have retreated over the past decade, yet the extent and magnitude of retreat relative to past variability is unknown. We measure changes in front positions of 210 marine-terminating glaciers using Landsat imagery spanning nearly four decades and compare decadal-scale rates of change with earlier observations. We find that 90% of the observed glaciers retreated between 2000 and 2010, approaching 100% in the northwest, with rapid retreat observed in all sectors of the ice sheet. The current retreat is accelerating and likely began between 1992 and 2000, coincident with the onset of warming, following glacier stability and minor advance during a mid-century cooling period. While it is clear an extensive retreat occurred in the early 20th century, a period of increasing air temperatures, a comparison of our results with historical observations provides evidence that the current retreat is more widespread. The onset of rapid retreat with warming relative to the slow and lagged advance with cooling suggests an asymmetry in the response of marine fronts to external forcing. Details for the data are included in the manuscript. All observed values are included but time series for individual glaciers may differ based on image availability and quality. Datasets included are 1) the shapefiles for digitized glacier fronts and 2) a matlab data file. Funding provided by: National Aeronautics and Space AdministrationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000104Award Number: NNX08AQ83GFunding provided by: National Aeronautics and Space AdministrationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000104Award Number: NNX08AL98A The details are included in the manuscript and elements of the 'Ice-front change mapping' section are copied here, with minor edits: We mapped the change in ice-front position between image pairs using the 'box method' of Moon and Joughin (2008) and Howat and others (2010). On each image, we manually ... |
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