Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard
Bulk runoff and meteorological data suggest the occurrence of two meltwater outburst events at Finsterwalderbreen, Svalbard, during the 1995 and 1999 melt seasons. Increased bulk meltwater concentrations of Cl during the outbursts indicate the release of snowmelt from storage. Bulk meltwater hydroch...
Main Authors: | , , , |
---|---|
Format: | Other Non-Article Part of Journal/Newspaper |
Language: | unknown |
Published: |
2001
|
Subjects: | |
Online Access: | https://figshare.com/articles/journal_contribution/Evidence_for_seasonal_subglacial_outburst_events_at_a_polythermal-based_glacier_Finsterwalderbreen_Svalbard/9485072 |
id |
ftloughboroughun:oai:figshare.com:article/9485072 |
---|---|
record_format |
openpolar |
spelling |
ftloughboroughun:oai:figshare.com:article/9485072 2023-05-15T16:22:10+02:00 Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard Jemma Wadham Richard Hodgkins Richard Cooper Martyn Tranter 2001-01-01T00:00:00Z https://figshare.com/articles/journal_contribution/Evidence_for_seasonal_subglacial_outburst_events_at_a_polythermal-based_glacier_Finsterwalderbreen_Svalbard/9485072 unknown 2134/3327 https://figshare.com/articles/journal_contribution/Evidence_for_seasonal_subglacial_outburst_events_at_a_polythermal-based_glacier_Finsterwalderbreen_Svalbard/9485072 CC BY-NC-ND 4.0 CC-BY-NC-ND Earth Sciences not elsewhere classified untagged Text Journal contribution 2001 ftloughboroughun 2022-01-01T20:51:56Z Bulk runoff and meteorological data suggest the occurrence of two meltwater outburst events at Finsterwalderbreen, Svalbard, during the 1995 and 1999 melt seasons. Increased bulk meltwater concentrations of Cl during the outbursts indicate the release of snowmelt from storage. Bulk meltwater hydrochemical data and suspended sediment concentrations suggest that this snowmelt accessed a chemical weathering environment characterized by high rock:water ratios and long rock–water contact times. This is consistent with a subglacial origin. The trigger for both the 1995 and 1999 outbursts is believed to be high rates of surface meltwater production and the oversupply of meltwater to areas of the glacier bed that were at the pressure melting point, but which were unconnected to the main subglacial drainage network. An increase in subglacial water pressure to above the overburden pressure lead to the forcing of a hydrological connection between the expanding subglacial reservoir and the ice-marginal channelized system. The purging of ice blocks from the glacier during the outbursts may indicate the breach of an ice dam during connection. Although subglacial meltwater issued continually from the glacier terminus via a subglacial upwelling during both melt seasons, field observations showed outburst meltwaters were released solely via an ice-marginal channel. It is possible that outburst events are a seasonal phenomenon at this glacier and reflect the periodic drainage of meltwaters from the same subglacial reservoir from year to year. However, the location of this reservoir is uncertain. A 100 m high bedrock ridge traverses the glacier 6Ð5 km from its terminus. The overdeepened area up-glacier from this is the most probable site for subglacial meltwater accumulation. Other Non-Article Part of Journal/Newspaper glacier Long Rock Svalbard Loughborough University: Figshare Finsterwalderbreen ENVELOPE(15.273,15.273,77.489,77.489) Long Rock ENVELOPE(-61.198,-61.198,-62.689,-62.689) Svalbard |
institution |
Open Polar |
collection |
Loughborough University: Figshare |
op_collection_id |
ftloughboroughun |
language |
unknown |
topic |
Earth Sciences not elsewhere classified untagged |
spellingShingle |
Earth Sciences not elsewhere classified untagged Jemma Wadham Richard Hodgkins Richard Cooper Martyn Tranter Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard |
topic_facet |
Earth Sciences not elsewhere classified untagged |
description |
Bulk runoff and meteorological data suggest the occurrence of two meltwater outburst events at Finsterwalderbreen, Svalbard, during the 1995 and 1999 melt seasons. Increased bulk meltwater concentrations of Cl during the outbursts indicate the release of snowmelt from storage. Bulk meltwater hydrochemical data and suspended sediment concentrations suggest that this snowmelt accessed a chemical weathering environment characterized by high rock:water ratios and long rock–water contact times. This is consistent with a subglacial origin. The trigger for both the 1995 and 1999 outbursts is believed to be high rates of surface meltwater production and the oversupply of meltwater to areas of the glacier bed that were at the pressure melting point, but which were unconnected to the main subglacial drainage network. An increase in subglacial water pressure to above the overburden pressure lead to the forcing of a hydrological connection between the expanding subglacial reservoir and the ice-marginal channelized system. The purging of ice blocks from the glacier during the outbursts may indicate the breach of an ice dam during connection. Although subglacial meltwater issued continually from the glacier terminus via a subglacial upwelling during both melt seasons, field observations showed outburst meltwaters were released solely via an ice-marginal channel. It is possible that outburst events are a seasonal phenomenon at this glacier and reflect the periodic drainage of meltwaters from the same subglacial reservoir from year to year. However, the location of this reservoir is uncertain. A 100 m high bedrock ridge traverses the glacier 6Ð5 km from its terminus. The overdeepened area up-glacier from this is the most probable site for subglacial meltwater accumulation. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
Jemma Wadham Richard Hodgkins Richard Cooper Martyn Tranter |
author_facet |
Jemma Wadham Richard Hodgkins Richard Cooper Martyn Tranter |
author_sort |
Jemma Wadham |
title |
Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard |
title_short |
Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard |
title_full |
Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard |
title_fullStr |
Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard |
title_full_unstemmed |
Evidence for seasonal subglacial outburst events at a polythermal-based glacier, Finsterwalderbreen, Svalbard |
title_sort |
evidence for seasonal subglacial outburst events at a polythermal-based glacier, finsterwalderbreen, svalbard |
publishDate |
2001 |
url |
https://figshare.com/articles/journal_contribution/Evidence_for_seasonal_subglacial_outburst_events_at_a_polythermal-based_glacier_Finsterwalderbreen_Svalbard/9485072 |
long_lat |
ENVELOPE(15.273,15.273,77.489,77.489) ENVELOPE(-61.198,-61.198,-62.689,-62.689) |
geographic |
Finsterwalderbreen Long Rock Svalbard |
geographic_facet |
Finsterwalderbreen Long Rock Svalbard |
genre |
glacier Long Rock Svalbard |
genre_facet |
glacier Long Rock Svalbard |
op_relation |
2134/3327 https://figshare.com/articles/journal_contribution/Evidence_for_seasonal_subglacial_outburst_events_at_a_polythermal-based_glacier_Finsterwalderbreen_Svalbard/9485072 |
op_rights |
CC BY-NC-ND 4.0 |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766010134846242816 |