skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution

Abstract

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%). 14C 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 tomore » 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.« less

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3];  [1];  [4]
  1. Desert Research Inst. (DRI), Reno, NV (United States)
  2. Centre National de la Recherche Scientifique (CNRS), Toulouse (France)
  3. Technische Univ. Braunschweig (Germany)
  4. Desert Research Inst. (DRI), Reno, NV (United States); Univ. of Massachusetts, Lowell, MA (United States)
Publication Date:
Research Org.:
Univ. of Nevada, Reno, NV (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1539722
Alternate Identifier(s):
OSTI ID: 1461015
Grant/Contract Number:  
SC0014275; 1304305; 1739567
Resource Type:
Accepted Manuscript
Journal Name:
Global Biogeochemical Cycles
Additional Journal Information:
Journal Volume: 32; Journal Issue: 7; Journal ID: ISSN 0886-6236
Publisher:
American Geophysical Union (AGU)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences

Citation Formats

Olson, C., Jiskra, M., Biester, H., Chow, J., and Obrist, D. Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution. United States: N. p., 2018. Web. doi:10.1029/2017gb005840.
Olson, C., Jiskra, M., Biester, H., Chow, J., & Obrist, D. Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution. United States. doi:10.1029/2017gb005840.
Olson, C., Jiskra, M., Biester, H., Chow, J., and Obrist, D. Tue . "Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution". United States. doi:10.1029/2017gb005840. https://www.osti.gov/servlets/purl/1539722.
@article{osti_1539722,
title = {Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution},
author = {Olson, C. and Jiskra, M. and Biester, H. and Chow, J. and Obrist, D.},
abstractNote = {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%). 14C 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.},
doi = {10.1029/2017gb005840},
journal = {Global Biogeochemical Cycles},
number = 7,
volume = 32,
place = {United States},
year = {2018},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

Save / Share: