Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada)
Thermokarst lakes cover nearly one fourth of ice-rich permafrost lowlands in the Arctic. Sediments from an athalassic subsaline thermokarst lake on Herschel Island (69°36'N; 139°04'W, Canadian Arctic) were used to understand regional changes in climate and in sediment transport, hydrology,...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.886875 2023-05-15T14:53:12+02:00 Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) Fritz, Michael Unkel, Ingmar Lenz, Josefine Gajewski, Konrad Frenzel, Peter Paquette, Nathalie Lantuit, Hugues Körte, Lisa Wetterich, Sebastian LATITUDE: 69.600830 * LONGITUDE: -139.063060 * DATE/TIME START: 2009-04-29T00:00:00 * DATE/TIME END: 2009-04-29T00:00:00 2018-02-26 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.886875 https://doi.org/10.1594/PANGAEA.886875 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.886875 https://doi.org/10.1594/PANGAEA.886875 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Fritz, Michael; Unkel, Ingmar; Lenz, Josefine; Gajewski, Konrad; Frenzel, Peter; Paquette, Nathalie; Lantuit, Hugues; Körte, Lisa; Wetterich, Sebastian (2018): Regional environmental change versus local signal preservation in Holocene thermokarst lake sediments: A case study from Herschel Island, Yukon (Canada). Journal of Paleolimnology, 60(1), 77-96, https://doi.org/10.1007/s10933-018-0025-0 AWI Arctic Land Expedition CA-Land_2009_YukonLakes PCUWI PG1967 Piston corer UWITEC Yukon_Lakes_2009 Dataset 2018 ftpangaea https://doi.org/10.1594/PANGAEA.886875 https://doi.org/10.1007/s10933-018-0025-0 2023-01-20T07:34:07Z Thermokarst lakes cover nearly one fourth of ice-rich permafrost lowlands in the Arctic. Sediments from an athalassic subsaline thermokarst lake on Herschel Island (69°36'N; 139°04'W, Canadian Arctic) were used to understand regional changes in climate and in sediment transport, hydrology, nutrient availability and permafrost disturbance. The sediment record spans the last ~11,700 years and the basal date is in good agreement with the Holocene onset of thermokarst initiation in the region. Electrical conductivity in pore water continuously decreases, thus indicating desalinization and continuous increase of lake size and water level. The inc/coh ratio of XRF scans provides a high-resolution organic-carbon proxy which correlates with TOC measurements. XRF-derived Mn/Fe ratios indicate aerobic versus anaerobic conditions which moderate the preservation potential of organic matter in lake sediments. The coexistence of marine, brackish and freshwater ostracods and foraminifera is explained by (1) oligohaline to mesohaline water chemistry of the past lake and (2) redeposition of Pleistocene specimens found within upthrusted marine sediments around the lake. Episodes of catchment disturbance are identified when calcareous fossils and allochthonous material were transported into the lake by thermokarst processes such as active-layer detachments, slumping and erosion of ice-rich shores. The pollen record does not show major variations and the pollen-based climate record does not match well with other summer air temperature reconstructions from this region. Local vegetation patterns in small catchments are strongly linked to morphology and sub-surface permafrost conditions rather than to climate. Multidisciplinary studies can identify the onset and life cycle of thermokarst lakes as they play a crucial role in Arctic freshwater ecosystems and in the global carbon cycle of the past, present and future. Dataset Arctic Foraminifera* Herschel Herschel Island Ice permafrost Thermokarst Yukon PANGAEA - Data Publisher for Earth & Environmental Science Arctic Yukon Canada Herschel Island ENVELOPE(-139.089,-139.089,69.583,69.583) ENVELOPE(-139.063060,-139.063060,69.600830,69.600830) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
AWI Arctic Land Expedition CA-Land_2009_YukonLakes PCUWI PG1967 Piston corer UWITEC Yukon_Lakes_2009 |
spellingShingle |
AWI Arctic Land Expedition CA-Land_2009_YukonLakes PCUWI PG1967 Piston corer UWITEC Yukon_Lakes_2009 Fritz, Michael Unkel, Ingmar Lenz, Josefine Gajewski, Konrad Frenzel, Peter Paquette, Nathalie Lantuit, Hugues Körte, Lisa Wetterich, Sebastian Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) |
topic_facet |
AWI Arctic Land Expedition CA-Land_2009_YukonLakes PCUWI PG1967 Piston corer UWITEC Yukon_Lakes_2009 |
description |
Thermokarst lakes cover nearly one fourth of ice-rich permafrost lowlands in the Arctic. Sediments from an athalassic subsaline thermokarst lake on Herschel Island (69°36'N; 139°04'W, Canadian Arctic) were used to understand regional changes in climate and in sediment transport, hydrology, nutrient availability and permafrost disturbance. The sediment record spans the last ~11,700 years and the basal date is in good agreement with the Holocene onset of thermokarst initiation in the region. Electrical conductivity in pore water continuously decreases, thus indicating desalinization and continuous increase of lake size and water level. The inc/coh ratio of XRF scans provides a high-resolution organic-carbon proxy which correlates with TOC measurements. XRF-derived Mn/Fe ratios indicate aerobic versus anaerobic conditions which moderate the preservation potential of organic matter in lake sediments. The coexistence of marine, brackish and freshwater ostracods and foraminifera is explained by (1) oligohaline to mesohaline water chemistry of the past lake and (2) redeposition of Pleistocene specimens found within upthrusted marine sediments around the lake. Episodes of catchment disturbance are identified when calcareous fossils and allochthonous material were transported into the lake by thermokarst processes such as active-layer detachments, slumping and erosion of ice-rich shores. The pollen record does not show major variations and the pollen-based climate record does not match well with other summer air temperature reconstructions from this region. Local vegetation patterns in small catchments are strongly linked to morphology and sub-surface permafrost conditions rather than to climate. Multidisciplinary studies can identify the onset and life cycle of thermokarst lakes as they play a crucial role in Arctic freshwater ecosystems and in the global carbon cycle of the past, present and future. |
format |
Dataset |
author |
Fritz, Michael Unkel, Ingmar Lenz, Josefine Gajewski, Konrad Frenzel, Peter Paquette, Nathalie Lantuit, Hugues Körte, Lisa Wetterich, Sebastian |
author_facet |
Fritz, Michael Unkel, Ingmar Lenz, Josefine Gajewski, Konrad Frenzel, Peter Paquette, Nathalie Lantuit, Hugues Körte, Lisa Wetterich, Sebastian |
author_sort |
Fritz, Michael |
title |
Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) |
title_short |
Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) |
title_full |
Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) |
title_fullStr |
Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) |
title_full_unstemmed |
Radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (PG1967) from Herschel Island (Yukon, Canada) |
title_sort |
radiocarbon dates, porewater hydrochemistry, calcareous microfossils and pollen data from a lake sediment core (pg1967) from herschel island (yukon, canada) |
publisher |
PANGAEA |
publishDate |
2018 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.886875 https://doi.org/10.1594/PANGAEA.886875 |
op_coverage |
LATITUDE: 69.600830 * LONGITUDE: -139.063060 * DATE/TIME START: 2009-04-29T00:00:00 * DATE/TIME END: 2009-04-29T00:00:00 |
long_lat |
ENVELOPE(-139.089,-139.089,69.583,69.583) ENVELOPE(-139.063060,-139.063060,69.600830,69.600830) |
geographic |
Arctic Yukon Canada Herschel Island |
geographic_facet |
Arctic Yukon Canada Herschel Island |
genre |
Arctic Foraminifera* Herschel Herschel Island Ice permafrost Thermokarst Yukon |
genre_facet |
Arctic Foraminifera* Herschel Herschel Island Ice permafrost Thermokarst Yukon |
op_source |
Supplement to: Fritz, Michael; Unkel, Ingmar; Lenz, Josefine; Gajewski, Konrad; Frenzel, Peter; Paquette, Nathalie; Lantuit, Hugues; Körte, Lisa; Wetterich, Sebastian (2018): Regional environmental change versus local signal preservation in Holocene thermokarst lake sediments: A case study from Herschel Island, Yukon (Canada). Journal of Paleolimnology, 60(1), 77-96, https://doi.org/10.1007/s10933-018-0025-0 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.886875 https://doi.org/10.1594/PANGAEA.886875 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.886875 https://doi.org/10.1007/s10933-018-0025-0 |
_version_ |
1766324614938492928 |