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Campos-Durán D, Alvarado GE, Martí J. Upper holocene tephro-chronostratigraphy of Irazú Volcano, Costa Rica. Sci Rep 2024; 14:7100. [PMID: 38532066 DOI: 10.1038/s41598-024-57962-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 03/23/2024] [Indexed: 03/28/2024] Open
Abstract
Irazú is one of the largest and most active volcanoes in Costa Rica. We present the tephro-chronostratigraphy of the last 2.6 ka of the Irazú volcano based on detailed field work and C14 radiometric dating, as well as a revision of the geological and historical records. In the stratigraphic record we identified at least 30 tephra units. Eight of them corresponding to the historical period (i.e., after 1700 A.D.), separated by repose periods of different durations. The distribution of the deposits, the volcanic morphologies (craters and pyroclastic cones) and the radiometric ages indicate that most of this recent eruptive activity has occurred from the summit of Irazú along an E-W fissure (~ 4 km long). Toward the west of the summit, near the Sapper hill may be the source of the oldest eruptions at 200 A.D., while the La Laguna cone, located to the east of the summit, could have formed around 1540 A.D., and Main Crater to the west could have formed around sixteenth-seventeenth century. Since then, the historical eruptions (i.e., 1723-1724, 1917-1921, 1924, 1928, 1930, 1933, 1939-1940 and 1963-1965) have been sourced from this crater, but not all of them are registered in the stratigraphy. The eruption frequency of Irazú during this period ranges from 23 to 100 years, with a major event about every 80 years. Irazu's eruptions have been mainly phreatomagmatic and Strombolian, including some phreatic explosions. We present a detailed tephro-chronostratigraphy that will help to building temporal analysis for hazard assessment and risk management plans to face future eruptions at Irazú.
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Affiliation(s)
- Daniela Campos-Durán
- Escuela de Ciencias Geográficas, Universidad Nacional de Costa Rica, Heredia, Costa Rica
| | - Guillermo E Alvarado
- Geociencias, Instituto Costarricense de Electricidad (ICE), San José, Costa Rica
| | - Joan Martí
- Department of Geosciences, IDAEA, CSIC, Barcelona, Spain.
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Bansal S, Creed IF, Tangen BA, Bridgham SD, Desai AR, Krauss KW, Neubauer SC, Noe GB, Rosenberry DO, Trettin C, Wickland KP, Allen ST, Arias-Ortiz A, Armitage AR, Baldocchi D, Banerjee K, Bastviken D, Berg P, Bogard MJ, Chow AT, Conner WH, Craft C, Creamer C, DelSontro T, Duberstein JA, Eagle M, Fennessy MS, Finkelstein SA, Göckede M, Grunwald S, Halabisky M, Herbert E, Jahangir MMR, Johnson OF, Jones MC, Kelleway JJ, Knox S, Kroeger KD, Kuehn KA, Lobb D, Loder AL, Ma S, Maher DT, McNicol G, Meier J, Middleton BA, Mills C, Mistry P, Mitra A, Mobilian C, Nahlik AM, Newman S, O’Connell JL, Oikawa P, van der Burg MP, Schutte CA, Song C, Stagg CL, Turner J, Vargas R, Waldrop MP, Wallin MB, Wang ZA, Ward EJ, Willard DA, Yarwood S, Zhu X. Practical Guide to Measuring Wetland Carbon Pools and Fluxes. Wetlands (Wilmington) 2023; 43:105. [PMID: 38037553 PMCID: PMC10684704 DOI: 10.1007/s13157-023-01722-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/24/2023] [Indexed: 12/02/2023]
Abstract
Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions. Supplementary Information The online version contains supplementary material available at 10.1007/s13157-023-01722-2.
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Affiliation(s)
- Sheel Bansal
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Irena F. Creed
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON Canada
| | - Brian A. Tangen
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Scott D. Bridgham
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR USA
| | - Ankur R. Desai
- Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI USA
| | - Ken W. Krauss
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Scott C. Neubauer
- Department of Biology, Virginia Commonwealth University, Richmond, VA USA
| | - Gregory B. Noe
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA USA
| | | | - Carl Trettin
- U.S. Forest Service, Pacific Southwest Research Station, Davis, CA USA
| | - Kimberly P. Wickland
- U.S. Geological Survey, Geosciences and Environmental Change Science Center, Denver, CO USA
| | - Scott T. Allen
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, Reno, NV USA
| | - Ariane Arias-Ortiz
- Ecosystem Science Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, CA USA
| | - Anna R. Armitage
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX USA
| | - Dennis Baldocchi
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA USA
| | - Kakoli Banerjee
- Department of Biodiversity and Conservation of Natural Resources, Central University of Odisha, Koraput, Odisha India
| | - David Bastviken
- Department of Thematic Studies – Environmental Change, Linköping University, Linköping, Sweden
| | - Peter Berg
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA USA
| | - Matthew J. Bogard
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB Canada
| | - Alex T. Chow
- Earth and Environmental Sciences Programme, The Chinese University of Hong Kong, Shatin, Hong Kong SAR China
| | - William H. Conner
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC USA
| | - Christopher Craft
- O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN USA
| | - Courtney Creamer
- U.S. Geological Survey, Geology, Minerals, Energy and Geophysics Science Center, Menlo Park, CA USA
| | - Tonya DelSontro
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON Canada
| | - Jamie A. Duberstein
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC USA
| | - Meagan Eagle
- U.S. Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA USA
| | | | | | - Mathias Göckede
- Department for Biogeochemical Signals, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Sabine Grunwald
- Soil, Water and Ecosystem Sciences Department, University of Florida, Gainesville, FL USA
| | - Meghan Halabisky
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA USA
| | | | | | - Olivia F. Johnson
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
- Departments of Biology and Environmental Studies, Kent State University, Kent, OH USA
| | - Miriam C. Jones
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA USA
| | - Jeffrey J. Kelleway
- School of Earth, Atmospheric and Life Sciences and Environmental Futures Research Centre, University of Wollongong, Wollongong, NSW Australia
| | - Sara Knox
- Department of Geography, McGill University, Montreal, Canada
| | - Kevin D. Kroeger
- U.S. Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA USA
| | - Kevin A. Kuehn
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS USA
| | - David Lobb
- Department of Soil Science, University of Manitoba, Winnipeg, MB Canada
| | - Amanda L. Loder
- Department of Geography, University of Toronto, Toronto, ON Canada
| | - Shizhou Ma
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK Canada
| | - Damien T. Maher
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW Australia
| | - Gavin McNicol
- Department of Earth and Environmental Sciences, University of Illinois Chicago, Chicago, IL USA
| | - Jacob Meier
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Beth A. Middleton
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Christopher Mills
- U.S. Geological Survey, Geology, Geophysics, and Geochemistry Science Center, Denver, CO USA
| | - Purbasha Mistry
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK Canada
| | - Abhijit Mitra
- Department of Marine Science, University of Calcutta, Kolkata, West Bengal India
| | - Courtney Mobilian
- O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN USA
| | - Amanda M. Nahlik
- Office of Research and Development, Center for Public Health and Environmental Assessments, Pacific Ecological Systems Division, U.S. Environmental Protection Agency, Corvallis, OR USA
| | - Sue Newman
- South Florida Water Management District, Everglades Systems Assessment Section, West Palm Beach, FL USA
| | - Jessica L. O’Connell
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO USA
| | - Patty Oikawa
- Department of Earth and Environmental Sciences, California State University, East Bay, Hayward, CA USA
| | - Max Post van der Burg
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Charles A. Schutte
- Department of Environmental Science, Rowan University, Glassboro, NJ USA
| | - Changchun Song
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Camille L. Stagg
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Jessica Turner
- Freshwater and Marine Science, University of Wisconsin-Madison, Madison, WI USA
| | - Rodrigo Vargas
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE USA
| | - Mark P. Waldrop
- U.S. Geological Survey, Geology, Minerals, Energy and Geophysics Science Center, Menlo Park, CA USA
| | - Marcus B. Wallin
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Zhaohui Aleck Wang
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Eric J. Ward
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Debra A. Willard
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA USA
| | - Stephanie Yarwood
- Environmental Science and Technology, University of Maryland, College Park, MD USA
| | - Xiaoyan Zhu
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun, China
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Gözel F, Belivermiş M, Sezer N, Kurt MA, Sıkdokur E, Kılıç Ö. Chronology of trace elements and radionuclides using sediment cores in Golden Horn Estuary, Sea of Marmara. Environ Pollut 2022; 315:120359. [PMID: 36216182 DOI: 10.1016/j.envpol.2022.120359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/28/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Trace elements and radionuclides are substantial pollutants in marine environment since they are non-biodegradable and can be harmful even in minute concentrations. The Golden Horn estuary, where is an inlet of Bosphorus and two creeks, has been seriously polluted by untreated municipal and industrial dischargers for several decades. Since 1998, a large restoration and rehabilitation efforts have been undertaken in the estuary to mitigate the pollution. In the present study, four sediment cores were taken from the Golden Horn estuary to assess the historical accumulation of trace elements and radionuclides. Radiometric dating was implemented by 210Pb and 137Cs radionuclides and CRS model. Sedimentation rates were calculated in the range of 0.92-0.97 cm yr-1 in the estuary. The distribution of radionuclides (40K, 226Ra, and 228Ra) indicated some slight variations which ascribes to the geological characteristics of sediment along the cores. The concentrations of the anthropogenic elements were relatively higher in the intensive industrialization period. Their concentrations reduced in the latest 15-20 years thanks to the large-scale rehabilitation project in the estuary. The pollution indices, namely EF, Igeo, CF, and PLI showed that the concentrations of Cd, Cr, Cu, Pb, Sb, and Sn were above the world averages. Our results provide an insight on the long-term accumulation trends of trace element in the Golden Horn, which revealed that the estuary remains moderately polluted. We suggest that preventive countermeasures are much more important than post pollution remediation in the case of metallic pollution in the estuaries.
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Affiliation(s)
- Furkan Gözel
- Vocational School of Health Services, Bahçeşehir University, Beşiktaş, 34353, Istanbul, Türkiye; Department of Biology, Faculty of Science, Istanbul University, Vezneciler, 34134, Istanbul, Türkiye.
| | - Murat Belivermiş
- Department of Biology, Faculty of Science, Istanbul University, Vezneciler, 34134, Istanbul, Türkiye
| | - Narin Sezer
- Medical Services and Techniques Department, Istanbul Arel University, 34295, Sefaköy, Istanbul, Türkiye
| | - Mehmet Ali Kurt
- Department of Environmental Engineering, Faculty of Engineering, 33343, Mersin University, Mersin, Türkiye
| | - Ercan Sıkdokur
- Department of Molecular Biology and Genetics, Koç University, 34450, Istanbul, Türkiye
| | - Önder Kılıç
- Department of Biology, Faculty of Science, Istanbul University, Vezneciler, 34134, Istanbul, Türkiye
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4
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Smythe KK, Cooke CA, Drevnick PE, Cornett RJ, Blais JM. Tracking historical sources of polycyclic aromatic compounds (PACs) in dated lake sediment cores near in-situ bitumen operations of Cold Lake, Alberta. Environ Pollut 2022; 294:118567. [PMID: 34838713 DOI: 10.1016/j.envpol.2021.118567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/19/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
Most bitumen in the Alberta oil sands (Canada) is extracted by thermal in-situ recovery. Despite the widespread use of in-situ bitumen extraction, little information is available on the release of petroleum hydrocarbons by this method to adjacent land and water. Here we analyzed the composition and abundance of parent and alkylated polycyclic aromatic compounds (PACs) in 11 radiometrically-dated lake sediment cores collected near in-situ operations at Cold Lake Alberta to assess potential petroleum contamination sources to surrounding lakes over the past century. Like open-pit mining areas, alkylated PACs in Cold Lake sediments were elevated compared to unsubstituted parent PACs and increased coeval with the onset of bitumen extraction in the area. Diagnostic ratios and pyrogenic indices showed that PAC sources to these lake sediments were dominantly pyrogenic, likely from historic forest fires, however they shifted to more petrogenic sources coeval with expanding oil sands extraction at Cold Lake. PACs in sediment from regional lakes are weakly correlated to their proximity to in-situ oil wells, once corrected for lake area. These results suggest that in-situ operations, via diesel-fueled vehicular emissions and the combustion of natural gas for steam generation, are a source of PACs to nearby lakes, but PACs did not exceed Canadian sediment quality guidelines for the protection of aquatic life.
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Affiliation(s)
- Kirsten K Smythe
- Department of Earth & Environmental Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Colin A Cooke
- Environment & Parks, Government of Alberta, Edmonton, Alberta, Canada; Department of Earth and Atmospheric Science, University of Alberta Edmonton, Alberta, Canada
| | - Paul E Drevnick
- Environment & Parks, Government of Alberta, Edmonton, Alberta, Canada
| | - Robert J Cornett
- Department of Earth & Environmental Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Jules M Blais
- Department of Earth & Environmental Sciences, University of Ottawa, Ottawa, Ontario, Canada; Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
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5
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Albuquerque PTF, Fredou T, Barcellos RL, Melo JTB, Arruda GN, De França EJ. Anthropogenic influences on sedimentary geochemistry of Itapessoca Estuarine Complex, Pernambuco, Brazil. Environ Monit Assess 2021; 194:43. [PMID: 34950980 DOI: 10.1007/s10661-021-09699-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
The Itapessoca Estuarine Complex is characterized by a history of intense economic activities developed on the banks of its tributary rivers, often exercised without any control or planning. In order to relate natural and/or anthropic events to the sediment age, radiometric dating method was performed by determining excess 210Pb in the sediment using the proportional gas flow technique. To investigate possible disturbances in recent sedimentation processes in studied area, 20 surfaces sediment samples and 2 sediment cores were collected for determination of concentrations of the chemical elements. Al, Ca, Fe, K, Mg, Mn, Ni, Pb, Si, Sr, Ti and Zn concentrations were determined by the energy-dispersive X-ray fluorescence (EDXRF) technique. Through the enrichment factors and ratios among some elements associated with geochronological data, it was possible identify geochemical changes in sedimentation of sampled points, with increase of minerals associated with fine fractions and decrease of the proportions of elements associated with coarse fractions. The radiometric dating reveals that Pb enrichment and the exacerbated increase of Ca and Sr enrichment factors are strongly related to the anthropic activity in the region.
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Affiliation(s)
- Paulo T F Albuquerque
- Departamento de Engenharia de Pesca E Aquicultura, Universidade Federal de Rondônia, Rua da Paz, 4376, 76.916-000, Presidente Médici, Porto Velho, RO, Brazil.
- Departamento de Pesca E Aquicultura, Universidade Federal Rural de Pernambuco, Rua Dom Manuel de Medeiros, s/n, Recife, PE, 52171-900, Brazil.
| | - Thierry Fredou
- Departamento de Pesca E Aquicultura, Universidade Federal Rural de Pernambuco, Rua Dom Manuel de Medeiros, s/n, Recife, PE, 52171-900, Brazil
| | - Roberto L Barcellos
- Departamento de Oceanografia, Universidade Federal de Pernambuco, Av. da Arquitetura, s/n, Recife, PE, 50740-550, Brazil
| | - Julyanne T B Melo
- Centro Regional de Ciências Nucleares Do Nordeste, Comissão Nacional de Energia Nuclear, Av. Prof. Luiz Freire 200, Recife, PE, 50740-545, Brazil
| | - Gilberto N Arruda
- Centro Regional de Ciências Nucleares Do Nordeste, Comissão Nacional de Energia Nuclear, Av. Prof. Luiz Freire 200, Recife, PE, 50740-545, Brazil
| | - Elvis J De França
- Centro Regional de Ciências Nucleares Do Nordeste, Comissão Nacional de Energia Nuclear, Av. Prof. Luiz Freire 200, Recife, PE, 50740-545, Brazil
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Williams RM, Irwin RP, Noe Dobrea EZ, Howard AD, Dietrich WE, Cawley J. Inverted channel variations identified on a distal portion of a bajada in the central Atacama Desert, Chile. Geomorphology (Amst) 2021; 393:107925. [PMID: 34785830 PMCID: PMC8587680 DOI: 10.1016/j.geomorph.2021.107925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In deserts, the interplay between occasional fluvial events and persistent aeolian erosion can form composite modern and relict surfaces, especially on the distal portion of alluvial fans. There, relief inversion of alluvial deposits by differential erosion can form longitudinal ridges. We identified two distinct ridge types formed by relief inversion on converging alluvial fans in the hyperarid Chilean Atacama Desert. Although they are co-located and similar in scale, the ridge types have different ages and formation histories that apparently correspond to minor paleoclimate variations. Gravel-armored ridges are remnants of deflated alluvial deposits with a bimodal sediment distribution (gravel and sand) dated to a minor pluvial phase at the end of the Late Pleistocene (~12 kyr). In contrast, younger (~9 kyr) sulfate-capped ridges formed during a minor arid phase with evaporite deposition in a pre-existing channel that armored the underlying deposits. Collectively, inverted channels at Salar de Llamara resulted from multiple episodes of surface overland flow and standing water spanning several thousand years. Based on ridge relief and age, the minimum long-term deflation rate is 0.1-0.2 m/kyr, driven primarily by wind erosion. This case study is an example of the equifinality concept whereby different processes lead to similar landforms. The complex history of the two ridge types can only be generally constrained in remotely sensed data. In situ observations are required to discern the specifics of the aqueous history, including the flow type, magnitude, sequence, and paleoenvironment. These findings have relevance for interpreting similar landforms on Mars.
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Affiliation(s)
- Rebecca M.E. Williams
- Planetary Science Institute, 1700 E. Fort Lowell, Suite 106, Tucson, AZ 85719, United States of America
| | - Rossman P. Irwin
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, PO Box 37012, MRC 315, Washington, DC 20013-7012, United States of America
| | - Eldar Z. Noe Dobrea
- Planetary Science Institute, 1700 E. Fort Lowell, Suite 106, Tucson, AZ 85719, United States of America
| | - Alan D. Howard
- Planetary Science Institute, 1700 E. Fort Lowell, Suite 106, Tucson, AZ 85719, United States of America
| | - William E. Dietrich
- Earth & Planetary Science, University of California—Berkeley, 307 McCone Hall, Berkeley, CA 94720, United States of America
| | - J.C. Cawley
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, PO Box 37012, MRC 315, Washington, DC 20013-7012, United States of America
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Yu C, Xiao W, Xu Y, Sun X, Li M, Lin H, Tong Y, Xie H, Wang X. Spatial-temporal characteristics of mercury and methylmercury in marine sediment under the combined influences of river input and coastal currents. Chemosphere 2021; 274:129728. [PMID: 33540304 DOI: 10.1016/j.chemosphere.2021.129728] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/01/2021] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
Mercury, especially in the form of methylmercury (MeHg), is a global pollutant, and aquatic products are considered the main sources of Hg exposure to humans. The Bohai and Yellow seas are two important epicontinental seas for marine fisheries and aquaculture in China. A decreasing trend of the THg in the Yellow River Estuary toward the outer edge was reported according to 83 surface sediments (27.3 ± 15.0 ng g-1) and 3 sediment cores from the Bohai Sea and Yellow Sea. The relatively higher THg levels in the central Yellow Sea can be primarily attributed to higher organic carbon levels and finer-grained sediment sizes and partly to the particulates from the riverine input of the Yellow River driven by the currents. An increasing trend in THg levels since industrialization in north China around the Bohai and Yellow seas, and a decreasing trend of Yellow River THg input in recent years were recorded by sediment cores. The spatial distribution pattern of surface sediments MeHg (161 ± 130 pg g-1) was different from that of THg. A higher MeHg content and MeHg/THg ratio were found in the Bohai and Yellow seas compared to the East China Sea, and extremely high MeHg levels (714 pg g-1) were found in the Yellow Sea Cold Water Mass (YSCWM) area, which is considered an important region for fishery and marine breeding, suggesting that more attention should be paid to the potential ecological and human health risks in the region due to mercury exposure.
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Affiliation(s)
- Chenghao Yu
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Wenjie Xiao
- College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China; Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China; Shenzhen Key Laboratory of Marine Archaea Geo-Omics, Shenzhen, 518055, China
| | - Yunping Xu
- College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China
| | - Xuejun Sun
- Key Laboratory of Tibetan Environmental Changes and Land Surface Process, Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| | - Mingyue Li
- Key Laboratory of Tibetan Environmental Changes and Land Surface Process, Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| | - Huiming Lin
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Yindong Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Han Xie
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Xuejun Wang
- Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
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Singh KK, Vasudevan S. Reconstruction of sedimentation rates based on the chronological framework of Lake Pykara, Tamil Nadu, India. Environ Monit Assess 2021; 193:428. [PMID: 34143316 DOI: 10.1007/s10661-021-09200-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 06/07/2021] [Indexed: 06/12/2023]
Abstract
This work presents a piece of initial information about the estimation of the sedimentation rate for Lake Pykara. In this investigation, a chronological sequence of sediment core was set up dependent on 137Cs and 210Pbex analysis to study sediment accumulation rates in Lake Pykara. Caesium-137 (Cs) is an artificial radionuclide and is regularly utilized in building up the chronology of lake sediments in the Anthropocene period. The unsupported 210Pb profile shows a non-exponential decline of 210Pb activity with sediment depth. Sedimentation rates dependent on global atmospheric nuclear weapon maximum fallout of 137Cs (1963) bolster the utilization of the consistent rate of 210Pb supply (CRS) model in core sediments. The geochronology studies of the core were performed using the 137Cs method, to evaluate the model of time changes in the sediment. The 137Cs radioactivity was resolved directly by gamma spectrometry and fluctuated from 13.11 ± 1.3 Bq kg-1 for top layers to 1.21 ± 0.1 Bq kg-1 for the bottom of the core. Two trademark peaks of 137Cs radioactivity identified with the global fallouts after atomic weapons testing and the Chernobyl mishap were observed and used to affirm the 210Pb dating method. Radioactivity of 210Pbex ranged from 8.00 ± 1.0 to 1.40 ± 0.1 Bq kg-1. The mean sedimentation rate evaluated from both models was 0.71 ± 0.06 cm year-1, while the estimated age of Lake Pykara was 514.08 years (137Cs) and 521.43 years (210Pbex), respectively.
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Benmhammed A, Laissaoui A, Mejjad N, Ziad N, Chakir E, Benkdad A, Bouh HA, El Yahyaoui A. Recent pollution records in Sidi Moussa coastal lagoon (western Morocco) inferred from sediment radiometric dating. J Environ Radioact 2021; 227:106464. [PMID: 33232850 DOI: 10.1016/j.jenvrad.2020.106464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/30/2020] [Accepted: 11/12/2020] [Indexed: 06/11/2023]
Abstract
The Sidi Moussa lagoon, located in western coastal Morocco and ranked as a wetland of biological and ecological importance (Ramsar site), is contaminated due to its proximity to the industrial phosphate plants and other anthropogenic activities around it. This study was carried out to assess the current environmental state of the lagoon as well as historical inputs of pollutants over several decades. Three sediment cores were collected and analyzed for the determination radionuclide activities (210Pb, 226Ra, 238U and 137Cs) by gamma spectrometry and element concentrations by Inductively Coupled Plasma - Mass Spectrometry. Age-depth relationships were established in two cores using 210Pb and 137Cs as chronometer and time-marker, respectively, and Constant Rate of Supply as radiometric dating model. 210Pb and 238U were present in sediment in activities much higher than those reported for non-contaminated coastal systems. Sediment accumulation rates showed a slight increase over time with a depth-averaged value of 0.16 g cm-2 y-1. Enrichment Factors and practically derived sediment quality guidelines were used to assess sediment contamination/pollution and toxicological effects linked with the measured concentrations of sediment-bound elements. The profiles of Cr, Co, Cu, As and Ni displayed maximums at depths matching the start of the phosphate industrial plants, and decreasing concentrations in the sections above the maximums, revealing the positive effects of the environmental management system adopted by the phosphate company since early 2000s.
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Affiliation(s)
- A Benmhammed
- Facultés des Sciences, Université Ibn Tofail, Kenitra, Morocco
| | - A Laissaoui
- Centre National de l'Energie, des Sciences et des Techniques Nucléaire, B.P. 1382 RP 10001, Rabat, Morocco.
| | - N Mejjad
- Faculté des Sciences, Université Ben M'Sik, Casablanca, Morocco
| | - N Ziad
- Ecole National des Sciences Appliquées, Université Ibn Tofail, Kenitra, Morocco
| | - E Chakir
- Facultés des Sciences, Université Ibn Tofail, Kenitra, Morocco
| | - A Benkdad
- Centre National de l'Energie, des Sciences et des Techniques Nucléaire, B.P. 1382 RP 10001, Rabat, Morocco
| | - H Ait Bouh
- Centre National de l'Energie, des Sciences et des Techniques Nucléaire, B.P. 1382 RP 10001, Rabat, Morocco
| | - A El Yahyaoui
- Centre National de l'Energie, des Sciences et des Techniques Nucléaire, B.P. 1382 RP 10001, Rabat, Morocco
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Eppenberger PE, Čavka M, Radović S, Paar D, Buzjak N, Ahern JCM, Biedermann P, Gruber P, Novak M, Janković I. Radiographic analysis and virtual cleaning of a bioarchaeological remain enclosed in mineral deposits from a limestone cave. Eur Radiol Exp 2020; 4:41. [PMID: 32642831 PMCID: PMC7343914 DOI: 10.1186/s41747-020-00166-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/03/2020] [Indexed: 11/10/2022] Open
Abstract
In limestone caves, environmental processes often cause alterations of human or animal skeletal remains, complicating classical analytical methods. Exemplary, a proximal femoral skeletal fragment, enclosed by a thick layer of speleothemic calcite deposits, was discovered during the exploration of the Bedara cave in Žumberak, Croatia. An examination without removal of the surrounding mineral deposits, possibly leading to damage of the specimen, was, therefore, desirable.We describe and discuss the applied techniques, including clinical computed tomography, virtual cleaning by a specially developed segmentation protocol using an open-source DICOM viewer, and virtual visualisation and dimensioning using computer-aided design software, so that this "hidden" specimen could be non-invasively examined in great detail. We also report on the circumstances and origin of the find, the results of radiocarbon dating, and its anatomical and taxonomic identification, according to which, the bone fragment belonged to a wild boar (Sus scrofa) from the timeframe of the Middle Eneolithic Retz-Gajary culture in the region (4,781 ± 35 years before present). This study provides a reference for future paleontological and anthropological analyses, seeking to unlock the enormous potential of anatomical studies of comparable skeletal remains that are either petrified or enclosed in speleothemic deposits.
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Affiliation(s)
- Patrick E Eppenberger
- Institute of Evolutionary Medicine, University of Zurich, Winterthurerstr, 190, CH-8057, Zurich, Switzerland.
| | - Mislav Čavka
- Department of Diagnostic and Interventional Radiology, University Hospital Centre "Zagreb", Zagreb, Croatia.,School of Medicine, Chair of Social Medicine and Organization of Healthcare, University Zagreb, Zagreb, Croatia
| | - Siniša Radović
- Institute for Quaternary Paleontology and Geology, Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Dalibor Paar
- Department of Physics, Faculty of Science, University Zagreb, Zagreb, Croatia
| | - Nenad Buzjak
- Department of Geography, Faculty of Science, University Zagreb, Zagreb, Croatia
| | - James C M Ahern
- Department of Anthropology, University of Wyoming, Laramie, WY, USA
| | - Philipp Biedermann
- Institute of Evolutionary Medicine, University of Zurich, Winterthurerstr, 190, CH-8057, Zurich, Switzerland
| | - Philipp Gruber
- Institute of Evolutionary Medicine, University of Zurich, Winterthurerstr, 190, CH-8057, Zurich, Switzerland.,Department of Neuroradiology, Kantonsspital Aarau, Aarau, Switzerland
| | - Mario Novak
- Institute for Anthropological Research, Centre for Applied Bioanthropology, Zagreb, Croatia
| | - Ivor Janković
- Department of Anthropology, University of Wyoming, Laramie, WY, USA.,Institute for Anthropological Research, Centre for Applied Bioanthropology, Zagreb, Croatia
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Vermeersch PM. Radiocarbon Palaeolithic Europe database: A regularly updated dataset of the radiometric data regarding the Palaeolithic of Europe, Siberia included. Data Brief 2020; 31:105793. [PMID: 32577447 PMCID: PMC7300123 DOI: 10.1016/j.dib.2020.105793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/22/2020] [Accepted: 05/25/2020] [Indexed: 11/27/2022] Open
Abstract
At the Berlin INQUA Congress (1995) a working group, European Late Pleistocene Isotopic Stages 2 & 3: Humans, Their Ecology & Cultural Adaptations, was established under the direction of J. Renault-Miskovsky (Institut de Paléontologie humaine, Paris). One of the objectives was building a database of the human occupation of Europe during this period. The database has been enlarged and now includes Lower, Middle and Upper Palaeolithic sites connecting them to their environmental conditions and the available chronometric dating. From version 14 on, only sites with chronometric data were included. In this database we have collected the available radiometric data from literature and from other more restricted databases. We try to incorporate newly published chronometric dates, collected from all kind of available publications. Only dates older than 9500 uncalibrated BP, correlated with a "cultural" level obtained by scientific excavations of European (Asian Russian Federation included) Palaeolithic sites, have been included. The dates are complemented with information related to cultural remains, stratigraphic, sedimentologic and palaeontologic information within a Microsoft Access database. For colleagues mainly interested in a list of all chronometric dates an Microsoft Excel list (with no details) is available (Tab. 1). A file, containing all sites with known coordinates, that can be opened for immediate use in Google Earth is available as a *.kmz file. It will give the possibility to introduce (by file open) in Google Earth the whole site list in "My Places". The database, version 27 (first version was available in 2002), contains now 13,202 site forms, (most of them with their geographical coordinates), comprising 17,022 radiometric data: Conv. 14C and AMS 14C (13,144 items), TL (678 items), OSL (1050 items), ESR, Th/U and AAR (2150 items) from the Lower, Middle and Upper Palaeolithic. All 14C dates are conventional dates BP. This improved version 27 replaces the older version 26.
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Affiliation(s)
- Pierre M Vermeersch
- Department of Earth and Environmental Sciences, KU Leuven, Belgium.,Geo-Institute, Celestijnenlaan 200E, B-3001 Leuven, Belgium
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Mantero J, Abril Hernández JM, García-Tenorio R, Klubi E, Nyarko E. Experimental study on the use of granulometric speciation for the radiometric dating of recent sediments. J Environ Radioact 2019; 208-209:106016. [PMID: 31325733 DOI: 10.1016/j.jenvrad.2019.106016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 07/12/2019] [Accepted: 07/12/2019] [Indexed: 06/10/2023]
Abstract
Theoretical and experimental studies have shown that activity concentrations of fallout radionuclides (such as 137Cs and excess 210Pb) decrease with particles size in aqueous suspensions. This paper is aimed at reviewing the theoretical fundamentals for granulometric speciation of radionuclides, and at exploring its practical use in the analytical context of gamma spectrometry for the radiometric dating of recent sediments, with view to: i) improving the detection of 137Cs (since its use as independent chronostratigraphic mark is challenging in the southern hemisphere because its low fallout rate), ii) supporting refined CIC models and normalization techniques in 210Pb-based radiogeochronologies. The work uses surface sediments sampled from the Tinto Estuary (SW Spain), affected by mining and phosphate-fertilizer industries, and from the Ankobra Estuary (Ghana), affected by intensive artisanal gold-mining. Granulometric classes have been separated by a sieving column with decreasing mesh sizes and the obtained cumulative percentage of mass mathematically described by a Rosin-Rammler particle-size distribution. The target radionuclides for gamma spectrometry were 210Pb, 226Ra and137Cs, complemented with 40K, 234Th and 228Ra. Results revealed that, far from ideal experiments, under actual environmental conditions the increase in activity concentrations with decreasing particle sizes is too moderate, and in general they are affected by larger counting uncertainties due to the small available amount of mass. Indeed, there was no correlation between grain-size and 137Cs concentrations (p = 0.25), and similarly for excess 210Pb (p = 0.53). No effect of the organic matter content was observed in 137Cs (p = 0.58) and excess 210Pb (p = 0.85) concentrations. Present results pose some concerns to the general use of granulometric speciation in the context of gamma spectrometry for supporting the radiometric dating of recent sediments. A detailed discussion on the use of normalization methods is also presented.
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Affiliation(s)
- Juan Mantero
- Departamento de Física Aplicada II, Universidad de Sevilla. ETSA, Seville, Spain
| | | | - Rafael García-Tenorio
- Departamento de Física Aplicada II, Universidad de Sevilla. ETSA, Seville, Spain; Centro Nacional de Aceleradores (Univ. Sevilla- J. Andalucía-CSIC), Seville, Spain
| | - Emmanuel Klubi
- Department of Marine and Fisheries Sciences, University of Ghana, Legon, Ghana
| | - Elvis Nyarko
- Department of Marine and Fisheries Sciences, University of Ghana, Legon, Ghana; Vice Chancellor of the Regional Maritime University, Accra, Ghana
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Pappa FK, Tsabaris C, Patiris DL, Eleftheriou G, Ioannidou A, Androulakaki EG, Kokkoris M, Vlastou R. Temporal investigation of radionuclides and heavy metals in a coastal mining area at Ierissos Gulf, Greece. Environ Sci Pollut Res Int 2019; 26:27457-27469. [PMID: 31332681 DOI: 10.1007/s11356-019-05921-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
Vertical variations of radionuclides, trace metals, and major elements were determined in two sediment cores, which were collected in the marine environment of Ierissos Gulf near Stratoni's mining area. The enrichment factors (EFs) were also estimated and provided moderately severe to extremely severe enrichment for most trace elements and Mn, describing the anthropogenic influence in the gulf during the previous century. According to the applied dating models based on 210Pb and 137Cs, the effect in the marine sediment due to the exploitation of pyrite for the production of sulfuric acid during 1912-1920 was observed. Additionally, the decrease of mining activity during 1935-1945 due to the Second World War and the type of ore exploitation, the alteration of the exploited ores, and the construction and operation of Olympiada's floatation plant during 1950-1970 were identified. The end of tailing discharging into the marine environment during 1980-2010 was also noted.
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Affiliation(s)
- Filothei K Pappa
- Institute of Oceanography, Hellenic Centre for Marine Research, 46.7 km Athens-Sounio Ave, 19013, Anavyssos, Greece.
- Department of Physics, National Technical University of Athens, 15780, Zografou, Greece.
| | - Christos Tsabaris
- Institute of Oceanography, Hellenic Centre for Marine Research, 46.7 km Athens-Sounio Ave, 19013, Anavyssos, Greece
| | - Dionisis L Patiris
- Institute of Oceanography, Hellenic Centre for Marine Research, 46.7 km Athens-Sounio Ave, 19013, Anavyssos, Greece
| | - Georgios Eleftheriou
- Institute of Oceanography, Hellenic Centre for Marine Research, 46.7 km Athens-Sounio Ave, 19013, Anavyssos, Greece
| | - Alexandra Ioannidou
- Nuclear Physics and Elementary Particle Physics Division Department of Physics, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Effrosini G Androulakaki
- Institute of Oceanography, Hellenic Centre for Marine Research, 46.7 km Athens-Sounio Ave, 19013, Anavyssos, Greece
| | - Michael Kokkoris
- Department of Physics, National Technical University of Athens, 15780, Zografou, Greece
| | - Roza Vlastou
- Department of Physics, National Technical University of Athens, 15780, Zografou, Greece
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Gąsiorowski M, Sienkiewicz E. Bird population changes reconstructed from isotopic signals of peat developed in a nutrient enriched tundra. Sci Total Environ 2019; 646:1359-1366. [PMID: 30235621 DOI: 10.1016/j.scitotenv.2018.07.453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/25/2018] [Accepted: 07/31/2018] [Indexed: 06/08/2023]
Abstract
Five peat sequences were studied to identify the time the little auk Alle alle colonies originated in the Hornsund area (Spitsbergen). Elemental and stable isotope analysis of nitrogen and carbon was applied as markers for bird activity. The peat sequences were dated with 210Pb and radiocarbon methods. The results showed that peat development related to seabird activity is significantly older (at least 300 years old) in localities closer to the fjord's mouth (west) than those located deeper in the fjord (east), which are ~100 years old. Isotopic signals indicated that bird activity in the western localities decreased simultaneously with the growth of the eastern colonies. Colonization by birds of new localities correlated with the termination of the Little Ice Age and the meaningful decrease in the glacier area of the region. Hence, we suggest that the availability of new localities for nesting in talus cones, nival moraines and lateral moraines on gentle mountain slopes with south-eastern exposition attracted the little auk due to better thermal conditions, isolation from strong westerly winds and better protection from predation by gull Larus hyperboreus. The expansion of little auks to the new localities was fast (20-30 yrs), and there are no records of changes in bird impacts on the tundra environment after 1920.
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Affiliation(s)
- Michał Gąsiorowski
- Institute of Geological Sciences, Polish Academy of Sciences, Twarda St. 51/55, PL-00818 Warszawa, Poland.
| | - Elwira Sienkiewicz
- Institute of Geological Sciences, Polish Academy of Sciences, Twarda St. 51/55, PL-00818 Warszawa, Poland
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Gevao B, Bahloul M, Guijarro KM, Kannan K. Depositional time trends of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in a dated sediment core from the Northern Arabian Gulf. Mar Pollut Bull 2016; 112:195-200. [PMID: 27555483 DOI: 10.1016/j.marpolbul.2016.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 07/31/2016] [Accepted: 08/04/2016] [Indexed: 06/06/2023]
Abstract
The historical record of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) deposition was reconstructed from the analysis of a dated sediment core collected from a remote area in the northwestern Arabian Gulf not influenced by any point sources of contamination. The sedimentary record showed that PCDD/F concentrations started to increase above pre-industrial background levels in the mid-1960s. This was followed by an exponential increase in concentrations attaining a maximum of 7.5pg/g (dry wt) in the early 1980s and stayed fairly constant thereafter. The homolog profiles in sediments remained fairly consistent throughout the core with PCDD contributing 75% of the ΣPCDD/F concentrations. The homolog profile was dominated by OCDD which contributed approximately 55% of the total dioxins throughout the core. The consistency in the homolog patterns throughout the core suggests that the source of dioxins have remained fairly unchanged throughout the sedimentary record represented by the core.
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Affiliation(s)
- Bondi Gevao
- Environmental Pollution and Climate Program, Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat 13109, Kuwait.
| | - Majed Bahloul
- Environmental Pollution and Climate Program, Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat 13109, Kuwait
| | - Karell Martinez Guijarro
- Environmental Pollution and Climate Program, Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat 13109, Kuwait
| | - Kurunthachalam Kannan
- Wadsworth Center, New York State Department of Health, School of Public Health, State University of New York, Empire State Plaza, P. O. Box 509, Albany, NY 12201-0509, United States
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