Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution
Tundra soils serve as major sources of mercury (Hg) input to the Arctic Ocean via river runoff and coastal erosion; yet little information is available on tundra soil Hg concentrations, pool sizes, origins, and dynamics. We present a detailed investigation of Hg in the active layer (upper ~100 cm su...
Published in: | Global Biogeochemical Cycles |
---|---|
Main Authors: | , , , , |
Language: | unknown |
Published: |
2023
|
Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1539722 https://www.osti.gov/biblio/1539722 https://doi.org/10.1029/2017gb005840 |
id |
ftosti:oai:osti.gov:1539722 |
---|---|
record_format |
openpolar |
spelling |
ftosti:oai:osti.gov:1539722 2023-07-30T04:01:18+02:00 Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution Olson, C. Jiskra, M. Biester, H. Chow, J. Obrist, D. 2023-06-29 application/pdf http://www.osti.gov/servlets/purl/1539722 https://www.osti.gov/biblio/1539722 https://doi.org/10.1029/2017gb005840 unknown http://www.osti.gov/servlets/purl/1539722 https://www.osti.gov/biblio/1539722 https://doi.org/10.1029/2017gb005840 doi:10.1029/2017gb005840 54 ENVIRONMENTAL SCIENCES 2023 ftosti https://doi.org/10.1029/2017gb005840 2023-07-11T09:34:54Z Tundra soils serve as major sources of mercury (Hg) input to the Arctic Ocean via river runoff and coastal erosion; yet little information is available on tundra soil Hg concentrations, pool sizes, origins, and dynamics. We present a detailed investigation of Hg in the active layer (upper ~100 cm subject to seasonal thaw) of tundra soils across 11 sites in Alaska. Soil Hg concentrations in organic horizons (151 ± 7 μg/kg) were in the upper range of temperate soil organic horizons, and concentrations in mineral horizons (98 ± 6 μg/kg) were much higher than in temperate soils. Soil Hg concentrations declined from inland to coastal sites, in contrast to a hypothesized northward increase expected because of proximity to coastal atmospheric mercury depletion events. Principle component analyses and elemental ratios results show that exogenic sources dominated over geogenic sources—in A-horizons (66 ± 4%) and mineral B-horizons (51 ± 1%). 14 C age-dating suggested recent origins of Hg in surface soils but showed that mineral soils (more than 7,300 years old) must have accumulated atmospheric inputs across millennia leading to high soil concentrations and pools. We estimated a total Northern Hemisphere active-layer tundra soil Hg pool of 184 Gg (range of 136 to 274 Gg), suggesting a globally important Hg storage pool. Tundra soils are subject to seasonal thaw and freeze dynamics, thereby providing large inputs to rivers, lakes, and the Arctic Ocean. Understanding processes that mobilize Hg from tundra soils will be critical to understanding future Arctic wildlife and human Hg exposures. Other/Unknown Material Arctic Arctic Ocean Tundra Alaska SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Arctic Arctic Ocean Global Biogeochemical Cycles 32 7 1058 1073 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Olson, C. Jiskra, M. Biester, H. Chow, J. Obrist, D. Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
Tundra soils serve as major sources of mercury (Hg) input to the Arctic Ocean via river runoff and coastal erosion; yet little information is available on tundra soil Hg concentrations, pool sizes, origins, and dynamics. We present a detailed investigation of Hg in the active layer (upper ~100 cm subject to seasonal thaw) of tundra soils across 11 sites in Alaska. Soil Hg concentrations in organic horizons (151 ± 7 μg/kg) were in the upper range of temperate soil organic horizons, and concentrations in mineral horizons (98 ± 6 μg/kg) were much higher than in temperate soils. Soil Hg concentrations declined from inland to coastal sites, in contrast to a hypothesized northward increase expected because of proximity to coastal atmospheric mercury depletion events. Principle component analyses and elemental ratios results show that exogenic sources dominated over geogenic sources—in A-horizons (66 ± 4%) and mineral B-horizons (51 ± 1%). 14 C age-dating suggested recent origins of Hg in surface soils but showed that mineral soils (more than 7,300 years old) must have accumulated atmospheric inputs across millennia leading to high soil concentrations and pools. We estimated a total Northern Hemisphere active-layer tundra soil Hg pool of 184 Gg (range of 136 to 274 Gg), suggesting a globally important Hg storage pool. Tundra soils are subject to seasonal thaw and freeze dynamics, thereby providing large inputs to rivers, lakes, and the Arctic Ocean. Understanding processes that mobilize Hg from tundra soils will be critical to understanding future Arctic wildlife and human Hg exposures. |
author |
Olson, C. Jiskra, M. Biester, H. Chow, J. Obrist, D. |
author_facet |
Olson, C. Jiskra, M. Biester, H. Chow, J. Obrist, D. |
author_sort |
Olson, C. |
title |
Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution |
title_short |
Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution |
title_full |
Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution |
title_fullStr |
Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution |
title_full_unstemmed |
Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution |
title_sort |
mercury in active-layer tundra soils of alaska: concentrations, pools, origins, and spatial distribution |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1539722 https://www.osti.gov/biblio/1539722 https://doi.org/10.1029/2017gb005840 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Tundra Alaska |
genre_facet |
Arctic Arctic Ocean Tundra Alaska |
op_relation |
http://www.osti.gov/servlets/purl/1539722 https://www.osti.gov/biblio/1539722 https://doi.org/10.1029/2017gb005840 doi:10.1029/2017gb005840 |
op_doi |
https://doi.org/10.1029/2017gb005840 |
container_title |
Global Biogeochemical Cycles |
container_volume |
32 |
container_issue |
7 |
container_start_page |
1058 |
op_container_end_page |
1073 |
_version_ |
1772812041496559616 |