Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, Northwest Alaska

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Auteurs principaux: Lenz, Josefine, Grosse, Guido, Jones, Benjamin M, Walter Anthony, Katey M, Bobrov, Anatoly A, Wulf, Sabine, Wetterich, Sebastian
Format: Dataset Open Access
Langue:en
Publié: PANGAEA 2015
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author Lenz, Josefine
Grosse, Guido
Jones, Benjamin M
Walter Anthony, Katey M
Bobrov, Anatoly A
Wulf, Sabine
Wetterich, Sebastian
author_facet Lenz, Josefine
Grosse, Guido
Jones, Benjamin M
Walter Anthony, Katey M
Bobrov, Anatoly A
Wulf, Sabine
Wetterich, Sebastian
collection Datos científicos de ciencias marinas y ambientales
contents Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyze a ~4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemistical, geochronological, micropaleontological (ostracoda, testate amoeba) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for Central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP, which drained catastrophically in spring 2005. The present study emphasizes that Arctic lake systems and periglacial landscapes are highly dynamic and permafrost formation as well as degradation in Central Beringia was controlled by regional to global climate patterns and as well as by local disturbances.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_845556
institution PANGAEA
language en
publishDate 2015
publisher PANGAEA
record_format pangaea
spellingShingle Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, Northwest Alaska
Lenz, Josefine
Grosse, Guido
Jones, Benjamin M
Walter Anthony, Katey M
Bobrov, Anatoly A
Wulf, Sabine
Wetterich, Sebastian
AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI
Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyze a ~4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemistical, geochronological, micropaleontological (ostracoda, testate amoeba) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for Central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP, which drained catastrophically in spring 2005. The present study emphasizes that Arctic lake systems and periglacial landscapes are highly dynamic and permafrost formation as well as degradation in Central Beringia was controlled by regional to global climate patterns and as well as by local disturbances.
title Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, Northwest Alaska
topic AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI
url https://doi.org/10.1594/PANGAEA.845556