Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden
A composite sediment sequence, consisting of a Russian core and an overlapping freeze core, comprising the uppermost meter of the sediment record, was retrieved from Lake Inre Abborrtjärn in the Torneträsk valley in Lappland, northern Sweden. The core was subsampled for analysis of organic matter co...
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Lunds universitet/Geologiska institutionen
2006
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ftulundlupsp:oai:lup-student-papers.lub.lu.se:2338818 2023-07-30T03:55:22+02:00 Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden Nilsson, Anders 2006 application/pdf http://lup.lub.lu.se/student-papers/record/2338818 eng eng Lunds universitet/Geologiska institutionen http://lup.lub.lu.se/student-papers/record/2338818 geography geology limnological responses late Holocene permafrost dynamics Stordalen mire Abisko northern Sweden Earth and Environmental Sciences H1 2006 ftulundlupsp 2023-07-11T20:09:06Z A composite sediment sequence, consisting of a Russian core and an overlapping freeze core, comprising the uppermost meter of the sediment record, was retrieved from Lake Inre Abborrtjärn in the Torneträsk valley in Lappland, northern Sweden. The core was subsampled for analysis of organic matter content, inorganic carbon content and analysis of the sediment composition using a technique known as structural analysis, resulting in a high-resolution data set spanning the last 2000 years. The chronology of the sediment sequence is based on radiocarbon dating and 210Pb dating of the uppermost sediments. The aims of the study were to evaluate possible connections between sediment stratigraphic changes and variations in permafrost in the adjacent mire complex at Stordalen, with a main focus on variations in the presence of calcareous laminations in the sediments and their coupling to water chemistry (pH and alkalinity) of the lake. Since both Lake Inre Abborrtjärn and the Stordalen mire are situated in an area with abundant carbonate-rich bedrock exposures, the impacts of modern catchment hydrology as well as the influence on pH exerted by ombrotrophic mires and fens were assessed based on a water chemical survey. The stratigraphic records were also compared to meteorological data from the Abisko Scientific Research Station and temperature reconstructions from the Torneträsk area and the Northern Hemisphere beyond the short instrumental records. The study shows that the calcareous laminations originate from calcium carbonate precipitation by Characean algae (Chara sp.) as a result of photosynthesis during the summer months. The precipitation of calcium carbonate is dependent on lake-water pH and thus related to variations in the chemical composition of catchment runoff. From c. 1240 AD an expansion of ombrotrophic peat and permafrost aggradation at the Stordalen mire lowered the pH of the lake-water as a result of increased inflow of humic waters and DOC. Two periods of permafrost expansion were recognized in the ... Other/Unknown Material Abisko Lappland Northern Sweden permafrost Lund University Publications Student Papers (LUP-SP) Lappland ENVELOPE(18.067,18.067,65.900,65.900) Abisko ENVELOPE(18.829,18.829,68.349,68.349) Stordalen ENVELOPE(7.337,7.337,62.510,62.510) Torneträsk ENVELOPE(18.861,18.861,68.392,68.392) |
institution |
Open Polar |
collection |
Lund University Publications Student Papers (LUP-SP) |
op_collection_id |
ftulundlupsp |
language |
English |
topic |
geography geology limnological responses late Holocene permafrost dynamics Stordalen mire Abisko northern Sweden Earth and Environmental Sciences |
spellingShingle |
geography geology limnological responses late Holocene permafrost dynamics Stordalen mire Abisko northern Sweden Earth and Environmental Sciences Nilsson, Anders Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden |
topic_facet |
geography geology limnological responses late Holocene permafrost dynamics Stordalen mire Abisko northern Sweden Earth and Environmental Sciences |
description |
A composite sediment sequence, consisting of a Russian core and an overlapping freeze core, comprising the uppermost meter of the sediment record, was retrieved from Lake Inre Abborrtjärn in the Torneträsk valley in Lappland, northern Sweden. The core was subsampled for analysis of organic matter content, inorganic carbon content and analysis of the sediment composition using a technique known as structural analysis, resulting in a high-resolution data set spanning the last 2000 years. The chronology of the sediment sequence is based on radiocarbon dating and 210Pb dating of the uppermost sediments. The aims of the study were to evaluate possible connections between sediment stratigraphic changes and variations in permafrost in the adjacent mire complex at Stordalen, with a main focus on variations in the presence of calcareous laminations in the sediments and their coupling to water chemistry (pH and alkalinity) of the lake. Since both Lake Inre Abborrtjärn and the Stordalen mire are situated in an area with abundant carbonate-rich bedrock exposures, the impacts of modern catchment hydrology as well as the influence on pH exerted by ombrotrophic mires and fens were assessed based on a water chemical survey. The stratigraphic records were also compared to meteorological data from the Abisko Scientific Research Station and temperature reconstructions from the Torneträsk area and the Northern Hemisphere beyond the short instrumental records. The study shows that the calcareous laminations originate from calcium carbonate precipitation by Characean algae (Chara sp.) as a result of photosynthesis during the summer months. The precipitation of calcium carbonate is dependent on lake-water pH and thus related to variations in the chemical composition of catchment runoff. From c. 1240 AD an expansion of ombrotrophic peat and permafrost aggradation at the Stordalen mire lowered the pH of the lake-water as a result of increased inflow of humic waters and DOC. Two periods of permafrost expansion were recognized in the ... |
format |
Other/Unknown Material |
author |
Nilsson, Anders |
author_facet |
Nilsson, Anders |
author_sort |
Nilsson, Anders |
title |
Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden |
title_short |
Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden |
title_full |
Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden |
title_fullStr |
Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden |
title_full_unstemmed |
Limnological responses to late Holocene permafrost dynamics at the Stordalen mire, Abisko, northern Sweden |
title_sort |
limnological responses to late holocene permafrost dynamics at the stordalen mire, abisko, northern sweden |
publisher |
Lunds universitet/Geologiska institutionen |
publishDate |
2006 |
url |
http://lup.lub.lu.se/student-papers/record/2338818 |
long_lat |
ENVELOPE(18.067,18.067,65.900,65.900) ENVELOPE(18.829,18.829,68.349,68.349) ENVELOPE(7.337,7.337,62.510,62.510) ENVELOPE(18.861,18.861,68.392,68.392) |
geographic |
Lappland Abisko Stordalen Torneträsk |
geographic_facet |
Lappland Abisko Stordalen Torneträsk |
genre |
Abisko Lappland Northern Sweden permafrost |
genre_facet |
Abisko Lappland Northern Sweden permafrost |
op_relation |
http://lup.lub.lu.se/student-papers/record/2338818 |
_version_ |
1772814881718796288 |