Constraints on the Hydrologic Systems of Three Tidewater Glaciers using High Temporal and Spatial Resolution Satellite Imagery
Abstract
During summer, warm atmospheric temperatures around the margins of the Greenland Ice Sheet drive considerable melting on the surface of outlet glaciers. The resultant meltwater collects in ponds on the ice surface, which can drain to the bed, lubricate the bed, travel to the glacier's terminus, and discharge into the ocean. Glacial hydrology systems are complex, often rapidly changing, and perhaps most importantly, different in each glacier system. Here we use high spatial and temporal resolution imagery from Planet to investigate these processes on three tidewater glaciers: Kangerdlugssuaq, Rink, and Helheim. Utilizing Planet (Planet Team 2019; https://api.planet.com), we have been able to better discern and record timescales over which filling, drainage, and calving events occur.
We observe and measure the area of surface melt ponds, the surface expression of buoyant subglacial plumes near the terminus, and calving events over the summer seasons of 2016-2018 using geospatial software QGIS. We combine our melt pond measurements with surface DEMs and bed topographies to obtain a better understanding of the locations of individual ponds with respect to the system as whole. We also characterize behaviors of types of ponds observed across an individual glacier and provide a detailed description of the supraglacial systems of each glacier. Our observations support an association between calving events and rapid melt pond drainage events as well as exhibit behaviors predicted through past projects on the subglacial systems of each For example, our data at Helheim shows a pattern of pond drainage which allows us to put constraints on the internal dynamics of the hydrologic system. Through this study we can make estimates on the amount of melt water on the surface of each system as well as the relative change in volume during a drainage event. Overall, the high resolution and temporal coverage of the imagery has allowed us to make detailed measurements of the timing and characteristics of the surface hydrology of these three glaciers and improve connections between inferred glacial hydrologic system and major events. This study provides new insights into these dynamic and important parts of the climate system, by utilizing the improved repeat coverage available from Planet alongside other remote sensing platforms.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC043.0008U
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0726 Ice sheets;
- CRYOSPHERE;
- 0728 Ice shelves;
- CRYOSPHERE;
- 0730 Ice streams;
- CRYOSPHERE