Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar
Proglacial icings accumulate in front of many High Arctic glaciers during the winter months, as water escapes from englacial or subglacial storage. Such icings have been interpreted as evidence for warm-based subglacial conditions, but several are now known to occur in front of cold-based glaciers....
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2011-03-01
|
| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/5/139/2011/tc-5-139-2011.pdf |
| _version_ | 1819154530077507584 |
|---|---|
| author | K. Bælum D. I. Benn |
| author_facet | K. Bælum D. I. Benn |
| author_sort | K. Bælum |
| collection | DOAJ |
| description | Proglacial icings accumulate in front of many High Arctic glaciers during the winter months, as water escapes from englacial or subglacial storage. Such icings have been interpreted as evidence for warm-based subglacial conditions, but several are now known to occur in front of cold-based glaciers. In this study, we investigate the drainage system of Tellbreen, a 3.5 km long glacier in central Spitsbergen, where a large proglacial icing develops each winter, to determine the location and geometry of storage elements. Digital elevation models (DEMs) of the glacier surface and bed were constructed using maps, differential GPS and ground penetrating radar (GPR). Rates of surface lowering indicate that the glacier has a long-term mass balance of −0.6 ± 0.2 m/year. Englacial and subglacial drainage channels were mapped using GPR, showing that Tellbreen has a diverse drainage system that is capable of storing, transporting and releasing water year round. In the upper part of the glacier, drainage is mainly via supraglacial channels. These transition downglacier into shallow englacial "cut and closure" channels, formed by the incision and roof closure of supraglacial channels. Below thin ice near the terminus, these channels reach the bed and contain stored water throughout the winter months. Even though no signs of temperate ice were detected and the bed is below pressure-melting point, Tellbreen has a surface-fed, channelized subglacial drainage system, which allows significant storage and delayed discharge. |
| first_indexed | 2024-12-22T15:22:32Z |
| format | Article |
| id | doaj.art-79cee3b426364f2dba748e3343af10c1 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-22T15:22:32Z |
| publishDate | 2011-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-79cee3b426364f2dba748e3343af10c12022-12-21T18:21:35ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242011-03-015113914910.5194/tc-5-139-2011Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radarK. BælumD. I. BennProglacial icings accumulate in front of many High Arctic glaciers during the winter months, as water escapes from englacial or subglacial storage. Such icings have been interpreted as evidence for warm-based subglacial conditions, but several are now known to occur in front of cold-based glaciers. In this study, we investigate the drainage system of Tellbreen, a 3.5 km long glacier in central Spitsbergen, where a large proglacial icing develops each winter, to determine the location and geometry of storage elements. Digital elevation models (DEMs) of the glacier surface and bed were constructed using maps, differential GPS and ground penetrating radar (GPR). Rates of surface lowering indicate that the glacier has a long-term mass balance of −0.6 ± 0.2 m/year. Englacial and subglacial drainage channels were mapped using GPR, showing that Tellbreen has a diverse drainage system that is capable of storing, transporting and releasing water year round. In the upper part of the glacier, drainage is mainly via supraglacial channels. These transition downglacier into shallow englacial "cut and closure" channels, formed by the incision and roof closure of supraglacial channels. Below thin ice near the terminus, these channels reach the bed and contain stored water throughout the winter months. Even though no signs of temperate ice were detected and the bed is below pressure-melting point, Tellbreen has a surface-fed, channelized subglacial drainage system, which allows significant storage and delayed discharge.http://www.the-cryosphere.net/5/139/2011/tc-5-139-2011.pdf |
| spellingShingle | K. Bælum D. I. Benn Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar The Cryosphere |
| title | Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar |
| title_full | Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar |
| title_fullStr | Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar |
| title_full_unstemmed | Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar |
| title_short | Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar |
| title_sort | thermal structure and drainage system of a small valley glacier tellbreen svalbard investigated by ground penetrating radar |
| url | http://www.the-cryosphere.net/5/139/2011/tc-5-139-2011.pdf |
| work_keys_str_mv | AT kbælum thermalstructureanddrainagesystemofasmallvalleyglaciertellbreensvalbardinvestigatedbygroundpenetratingradar AT dibenn thermalstructureanddrainagesystemofasmallvalleyglaciertellbreensvalbardinvestigatedbygroundpenetratingradar |