Autonomous underwater vehicle (AUV) observations of recent tidewater glacier retreat, western Svalbard
Recent studies have highlighted the need to improve our understanding of the relationship between glacial-front bathymetry and oceanography in order to better predict the behaviour of tidewater glaciers. The glaciomarine fjords of western Svalbard are strongly influenced by temperate Atlantic Water...
| Published in: | Marine Geology |
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| Main Authors: | , , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2019
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| Subjects: | |
| Online Access: | https://pure.uhi.ac.uk/en/publications/7228fb71-f609-4154-b59b-5cfd1443a470 https://doi.org/10.1016/j.margeo.2019.106009 https://pureadmin.uhi.ac.uk/ws/files/3756937/AUV_Glaciers_Svalbard_Howe_July_MinorRev_Clean_2_.docx |
| Summary: | Recent studies have highlighted the need to improve our understanding of the relationship between glacial-front bathymetry and oceanography in order to better predict the behaviour of tidewater glaciers. The glaciomarine fjords of western Svalbard are strongly influenced by temperate Atlantic Water advected from the West Spitsbergen Current. Marine terminating (tidewater) glaciers locally influence many Svalbard fjords through fluxes of sediments, nutrients and freshwater, however their response to ocean warming and the imprint left by their recent retreat on the seabed remains unresolved. Here we present glacial front data collected by an autonomous underwater vehicle (AUV) from four tidewater glaciers; Fjortende Julibreen (Krossfjorden), Conwaybreen, Kongsbreen and Kronebreen (Kongsfjorden). The seabed adjacent to the glacial terminus has been mapped providing high-resolution bathymetry (0.5m-1.0m grid cell size), side-scan and photographs with additional simultaneous oceanographic observations. The aim being to survey the glacial front submarine landforms, to identify the water mass structure and to observe any melt water plume activity. The bathymetry data displays a diverse assemblage of glacial landforms including numerous retreat moraines, glacial lineations, crevasse-squeeze ridges and sediment debris flows reflecting the dynamic depositional environment of the glacial front. The age of the features and the annual rate of retreat have been estimated using satellite remote sensing imagery to digitise the glacial front positions over time. The glacial landforms have been produced by the last few years of retreat as these glaciers gradually become land-terminating. The AUV also observed in-situ subglacial meltwater plumes at the two most active glaciers (Kongsbreen and Kronebreen) and an associated signature of warm Atlantic Water occurring at the glacier face. The presence of relatively warm, oceanic waters enhances subsurface melting, accelerating the ablation rate, while fresh (melt) water injection at ... |
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