A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland

Paleoclimate reconstructions across Iceland provide a template for past changes in climate across the northern North Atlantic, a crucial region due to its position relative to the global northward heat transport system and its vulnerability to climate change. The roles of orbitally driven summer coo...

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Main Authors: Ardenghi, Nicolò, Harning, David John, Raberg, Jonathan Henrik, Holman, Brooke René, Thordarson, Thorvaldur, Geirsdóttir, Áslaug, Miller, Gifford H., Sepúlveda, Julio
Format: Text
Language:English
Published: 2023
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Online Access:https://doi.org/10.5194/cp-2023-74
https://cp.copernicus.org/preprints/cp-2023-74/
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spelling ftcopernicus:oai:publications.copernicus.org:cpd114803 2023-11-12T04:19:05+01:00 A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland Ardenghi, Nicolò Harning, David John Raberg, Jonathan Henrik Holman, Brooke René Thordarson, Thorvaldur Geirsdóttir, Áslaug Miller, Gifford H. Sepúlveda, Julio 2023-10-27 application/pdf https://doi.org/10.5194/cp-2023-74 https://cp.copernicus.org/preprints/cp-2023-74/ eng eng doi:10.5194/cp-2023-74 https://cp.copernicus.org/preprints/cp-2023-74/ eISSN: 1814-9332 Text 2023 ftcopernicus https://doi.org/10.5194/cp-2023-74 2023-10-30T17:24:16Z Paleoclimate reconstructions across Iceland provide a template for past changes in climate across the northern North Atlantic, a crucial region due to its position relative to the global northward heat transport system and its vulnerability to climate change. The roles of orbitally driven summer cooling, volcanism, and human impact as triggers of local environmental changes in the Holocene of Iceland, remain debated. While there are indications that human impact may have reduced environmental resilience during Late Holocene summer cooling, it is still difficult to resolve to what extent human and natural factors affected Iceland’s Late Holocene landscape instability. Here, we present a continuous Holocene fire record of northeastern Iceland from proxies archived in Stóra Viðarvatn sediment. We use pyrogenic polycyclic aromatic hydrocarbons (pyroPAHs) to trace shifts in fire regimes, paired with continuous biomarker and bulk geochemical records of soil erosion, lake productivity, and human presence. The molecular composition of pyroPAHs and a wind pattern reconstruction indicate a naturally driven fire signal that is mostly regional. Generally low fire frequency during most of the Holocene significantly increased at 3 ka and again after 1.5 ka BP, before known human settlement in Iceland. We propose that shifts in vegetation type caused by cooling summers over the past 3 kyr, in addition to changes in atmospheric circulation, such as shifts in North Atlantic Oscillation (NAO) regime, led to increased aridity and biomass flammability. Our results show no evidence of faecal biomarkers associated with human activity during or after human colonisation in the 9 th century CE. Instead, faecal biomarkers follow the pattern described by erosional proxies, pointing toward a negligible human presence and/or a diluted signal in the lake’s catchment. However, low post-colonisation levels of pyroPAHs, in contrast to an increasing flux of erosional bulk proxies, suggest that farming and animal husbandry may have suppressed ... Text Iceland North Atlantic North Atlantic oscillation Copernicus Publications: E-Journals
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collection Copernicus Publications: E-Journals
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language English
description Paleoclimate reconstructions across Iceland provide a template for past changes in climate across the northern North Atlantic, a crucial region due to its position relative to the global northward heat transport system and its vulnerability to climate change. The roles of orbitally driven summer cooling, volcanism, and human impact as triggers of local environmental changes in the Holocene of Iceland, remain debated. While there are indications that human impact may have reduced environmental resilience during Late Holocene summer cooling, it is still difficult to resolve to what extent human and natural factors affected Iceland’s Late Holocene landscape instability. Here, we present a continuous Holocene fire record of northeastern Iceland from proxies archived in Stóra Viðarvatn sediment. We use pyrogenic polycyclic aromatic hydrocarbons (pyroPAHs) to trace shifts in fire regimes, paired with continuous biomarker and bulk geochemical records of soil erosion, lake productivity, and human presence. The molecular composition of pyroPAHs and a wind pattern reconstruction indicate a naturally driven fire signal that is mostly regional. Generally low fire frequency during most of the Holocene significantly increased at 3 ka and again after 1.5 ka BP, before known human settlement in Iceland. We propose that shifts in vegetation type caused by cooling summers over the past 3 kyr, in addition to changes in atmospheric circulation, such as shifts in North Atlantic Oscillation (NAO) regime, led to increased aridity and biomass flammability. Our results show no evidence of faecal biomarkers associated with human activity during or after human colonisation in the 9 th century CE. Instead, faecal biomarkers follow the pattern described by erosional proxies, pointing toward a negligible human presence and/or a diluted signal in the lake’s catchment. However, low post-colonisation levels of pyroPAHs, in contrast to an increasing flux of erosional bulk proxies, suggest that farming and animal husbandry may have suppressed ...
format Text
author Ardenghi, Nicolò
Harning, David John
Raberg, Jonathan Henrik
Holman, Brooke René
Thordarson, Thorvaldur
Geirsdóttir, Áslaug
Miller, Gifford H.
Sepúlveda, Julio
spellingShingle Ardenghi, Nicolò
Harning, David John
Raberg, Jonathan Henrik
Holman, Brooke René
Thordarson, Thorvaldur
Geirsdóttir, Áslaug
Miller, Gifford H.
Sepúlveda, Julio
A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland
author_facet Ardenghi, Nicolò
Harning, David John
Raberg, Jonathan Henrik
Holman, Brooke René
Thordarson, Thorvaldur
Geirsdóttir, Áslaug
Miller, Gifford H.
Sepúlveda, Julio
author_sort Ardenghi, Nicolò
title A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland
title_short A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland
title_full A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland
title_fullStr A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland
title_full_unstemmed A Holocene history of climate, fire, landscape evolution, and human activity in Northeast Iceland
title_sort holocene history of climate, fire, landscape evolution, and human activity in northeast iceland
publishDate 2023
url https://doi.org/10.5194/cp-2023-74
https://cp.copernicus.org/preprints/cp-2023-74/
genre Iceland
North Atlantic
North Atlantic oscillation
genre_facet Iceland
North Atlantic
North Atlantic oscillation
op_source eISSN: 1814-9332
op_relation doi:10.5194/cp-2023-74
https://cp.copernicus.org/preprints/cp-2023-74/
op_doi https://doi.org/10.5194/cp-2023-74
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