Change search
Refine search result
12 1 - 50 of 71
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bark, Glenn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ericsson, Magnus
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Söderholm, Patrik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Norrbottens malm- och mineralresurs och dess potentiella betydelse för innovation, samhälle och miljö2014Report (Other academic)
    Abstract [sv]

    Gruvindustrins betydelse för samhällsutveckling och infrastruktur i Sverige och inte minst i Norrbottens län är mycket stor. De geologiska förutsättningarna att hitta nya brytvärda förekomster i Norrbotten är goda. Länet är tillsammans med Västerbotten en av Europas viktigaste regioner för utvinning av metaller. Det syns också i den nyligen framtagna regionala mineralstrategin för Norrbotten och Västerbotten. Visionen för den regionala mineralstrategin: ”Genom långsiktigt hållbart nyttjande av Norrbottens och Västerbottens läns mineralresurser har ytterligare tillväxt skapats i regionen och hela Sverige. Vi har utvecklat och stärkt vår ställning som ledande gruv- och mineralnation.”Eftersom framtidspotentialen för gruvnäringen är mycket god men okunnigheten hos både allmänhet och beslutsfattare om näringens betydelse för innovation och samhällsutveckling är stor, kopplat med en utbredd oro för miljöpåverkan, måste dessa viktiga framtidsfrågor belysas. Med finansiering från Länsstyrelsen i Norrbotten bedrevs därför under första hälften av 2014 en förstudie som syftade till att sammanfatta kunskapsläget om framtidens gruvindustri i Norrbotten. Resultaten av förstudien redovisas i den här rapporten. En viktig slutsats är att det under nästa strukturfondsperiod (med start 2015) behövs ett framtidsinriktat forskningsprogram för att belysa de möjligheter som finns. Denna förstudie utgör grund för en kommande ansökan till strukturfonderna. Kompetensen som finns vid Luleå tekniska universitet, Sveriges centrum för gruvrelaterad forskning och utbildning, bör användas för att studera troliga framtidsmöjligheter och hur de ska kunna användas för att få en så positiv utveckling som möjligt för länet. Projektet bör innehålla följande tre huvudinriktningar, som naturligtvis hör ihop:Vilka malm- och mineralresurser finns det potential för i Norrbotten, och vilka kommer sannolikt att exploateras i framtiden?Vad kommer den exploateringen att ha för betydelse för innovation och samhällsutveckling?Vad kommer den exploateringen att få för miljöeffekter och hur ska man göra för att minska miljöbelastningen?En annan slutsats är att nedlagda gruvområden inte måste ses som förstörd natur. Betydande mervärden som gruvturism skulle kunna skapas om vilja, kreativitet och beslutsamhet finns. Detta är ett givet utvecklingsområde där småföretag och entreprenörer kan göra stor insats om de politiska och myndighetsmässiga förutsättningarna finns. Dessa aspekter skulle också kunna belysas i det föreslagna forskningsprogrammet eller i ett eget projekt.

  • 2. Andersson, Per
    et al.
    Gustafsson, Örjan
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Porcelli, Don
    Widerlund, Anders
    Colloid-particle dynamics and transport of U-isotopes through the low-salinity (2002Conference paper (Other academic)
  • 3. Andersson, Per
    et al.
    Gustafsson, Örjan
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Roos, Per
    Colloid-particle dynamics and element transport through the low-salinity (2001Conference paper (Other academic)
  • 4.
    Andersson, Per S.
    et al.
    Swedish Museum of Natural History.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Land, Magnus
    Widerlund, Anders
    Dahlqvist, Ralf
    Swedish Museum of Natural History.
    Gustafsson, Örjan
    Stockholm University.
    Weathering, transport, and sedimentation of rare earth elements and Nd-isotopes in a boreal river basin: brackish bay area2000In: Vol. 5, no 2, p. 146-Article in journal (Other academic)
  • 5.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The fate of nitrogen in a lake occupied by Phragmites australis: a stable isotope tracer study2013In: Vol. 56, no 2-3, p. 139-141Article in journal (Refereed)
  • 6.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Using DGT to estimate soluble reactive phosphorus in a stream receiving nutrient rich mine water2013Conference paper (Refereed)
  • 7.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Husson, Eva
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Frauke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Effects on nutrient regime in two recipients of nitrogen-rich mine effluents in northern Sweden2013In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 31, p. 12-24Article in journal (Refereed)
    Abstract [en]

    The question of the limiting nutrient(s) for production of phytoplankton and macrophytes was explored in two contrasting freshwater systems receiving N- and P-rich mine effluents from the Boliden and Kiruna mine sites, northern Sweden. For both sites, total N (TN), total P (TP) and TN:TP mass ratios in water, sediment and macrophytes were used to examine (1) spatial variations within the systems, (2) differences between the systems and (3) seasonal variations. The TN concentration from the discharge point at the Kiruna site was about seven times higher than at the Boliden discharge point, while the TP concentration was 10 times lower than in the discharge point at the Boliden site. The majority of the studied lakes showed elevated biomass of phytoplankton, with maximum values found in Lake Bruträsket (Boliden). Mining activities have affected the nutrient regime of the two recipients by contributing to elevated TN and TP concentrations and TN:TP mass ratios as well as elevated production of phytoplankton and macrophytes compared to the reference sites. Depending on the NH4 concentration in the effluent at the Boliden site, water column TN:TP mass ratios shifted from being >22, indicating P-deficiency, to between 9 and 22, indicating a transition from N- to P-deficiency (co-limitation). However, water column TN:TP mass ratios at the Kiruna site always indicated P-deficiency, while TN:TP mass ratios of macrophytes indicate that both sites may vary from N- to P-limitation. The study suggests that for the design of efficient monitoring programmes and remediation measures, it is important to consider the major N and P species in water, phytoplankton, sediment and macrophytes.

  • 8.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Siergieiev, Dmytro
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Frauke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Husson, Eva
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Modelling nitrogen transformations in waters receiving mine effluents2011In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 409, no 21, p. 4585-4595Article in journal (Refereed)
    Abstract [en]

    This paper presents a biogeochemical model developed for a clarification pond receiving ammonium nitrogen rich discharge water from the Boliden concentration plant located in northern Sweden. Present knowledge about nitrogen (N) transformations in lakes is compiled in a dynamic model that calculates concentrations of the six N species (state variables) ammonium-N (Nam), nitrate-N (Nox), dissolved organic N in water (Norg), N in phytoplankton (Npp), in macrophytes (Nmp) and in sediment (Nsed). It also simulates the rate of 16 N transformation processes occurring in the water column and sediment as well as water–sediment and water–atmosphere interactions. The model was programmed in the software Powersim using 2008 data, whilst validation was performed using data from 2006 to 2007. The sensitivity analysis showed that the state variables are most sensitive to changes in the coefficients related to the temperature dependence of the transformation processes. A six-year simulation of Nam showed stable behaviour over time. The calibrated model rendered coefficients of determination (R2) of 0.93, 0.79 and 0.86 for Nam, Nox and Norg, respectively. Performance measures quantitatively expressing the deviation between modelled and measured data resulted in values close to zero, indicating a stable model structure. The simulated denitrification rate was on average five times higher than the ammonia volatilisation rate and about three times higher than the permanent burial of Nsed and, hence, the most important process for the permanent removal of N. The model can be used to simulate possible measures to reduce the nitrogen load and, after some modification and recalibration, it can be applied at other mine sites affected by N rich effluents.

  • 9.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Carbon and nitrogen concentrations and isotopic composition in sediments of lakes receiving nitrogen rich mine effluents2011Conference paper (Refereed)
  • 10.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Interaction between nitrogen and phosphorus cycles in mining-affected aquatic systems-experiences from field and laboratory measurements2013In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, no 8, p. 5722-5736Article in journal (Refereed)
    Abstract [en]

    The main objectives of this study were to (a) study the interaction between N and P cycles in mining-affected aquatic systems and (b) to quantify release rates of sedimentary soluble reactive phosphorus (SRP) that may be related to this interaction. Sediment cores and water from Lake Bruträsket (Boliden, northern Sweden) were collected and a time series of water sampling and flow measurements was conducted in the Brubäcken stream connected to the lake. Factors affecting SRP release were studied in a sediment incubation experiment and water column experiments. Field and laboratory measurements indicated that pH and dissolved oxygen are two important factors for SRP release. At the end of the low-oxygen incubation, an SRP concentration of 56 μg L-1 resulted in a sedimentary flux of 1.1 mg SRP m-2 day-1. This is ∼10 times higher than the flux of 0.12 mg SRP m-2 day-1 obtained from depth integration of vertical SRP profiles measured in the lake, and ∼100 times higher than the external flux of 0.014 mg SRP m-2 d-1 into the lake (based on catchment area). Field measurements indicated that oxidation of organic matter and mining-related chemicals (ammonium and thiosulphates) may result in increased internal SRP flux from the sediment. Increased P loading in the lake as a result of low-oxygen conditions could change water column total nitrogen/total phosphorus ratios from 27 to 17, consequently changing the lake from being P-limited to be co-limited by N and P. The obtained findings point to possible interaction between the cycles of nitrogen (oxygen consumption) and P (flux from sediment) that may be important for nutrient regulation in mine water recipients.

  • 11. Chlot, Sara
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nitrogen uptake and cycling in Phragmites australis in a lake-receiving nutrient-rich mine water: a 15 N tracer study2015In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 74, no 7, p. 6027-6038Article in journal (Refereed)
    Abstract [en]

    Uptake and cycling of nitrogen (N) in the littoral zone of a lake-receiving nutrient-rich mine water located in Boliden, northern Sweden, was investigated. Stable isotope tracer solutions of 15N as NH4 + (NAM mesocosm) or NO3 − (NOX mesocosm) were added to mesocosms enclosing plants of common reed (Phragmites australis). The 15N abundance in various plant parts was measured at pre-defined time intervals over an experimental period of 22 days. During the course of the experiment, plant parts from the NAM mesocosms were significantly more enriched in 15N than plant parts from the NOX mesocosms. On day 13, Δδ15N values of the fine roots from the NAM mesocosms had reached +8220 ‰, while the maximum Δδ15N value in NOX roots was considerably lower at +4430 ‰. Using 15N values in macrophyte tissues present at the end of the experiment enabled calculations of uptake rates and % of tracer N recovered in the plant (%tracerNrecov). Maximum tracer uptake rates were higher for the NAM mesocosms (1.4 µg g−1 min−1 or 48 mg N m−2 d−1) compared to the NOX mesocosms (0.23 µg g−1 min−1 or 8.5 mg N m−2 d−1). Calculations of %tracerNrecov indicated that 1–8 and 25–44 % of added N was assimilated by plants in the NOX and NAM mesocosms, respectively. Hence, P. australis was more effective in assimilating NH4 +, and a larger portion of the tracer N accumulated in the roots compared to the other plant parts. Consequently, macrophyte N removal is most effective for cold-climate aquatic systems receiving mine water dominated by NH4 +. For permanent removal of N, the whole plant (including the roots) should be harvested.

  • 12.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Studying nitrogen cycling and uptake by macrophytes using 15N tracer techniques2011Conference paper (Refereed)
  • 13. Frandsen, Sara
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Herbert, Roger
    Institutionen för geovetenskaper, Uppsala Universitet.
    Öhlander, Björn
    Nitrogen effluents from mine sites in Northern Sweden: environmental effects and removal of nitrogen in recipients2009In: 8th International Conference on Acid Rock Drainage (ICARD) and Securing the Future: Mining, Metals & the Environment in a Sustainable Society 2009: Skelleftea, Sweden, 22 - 26 June 2009, Red Hook, NY: Curran Associates, Inc., 2009Conference paper (Refereed)
  • 14. Gustafsson, Ö.
    et al.
    Andersson, Per
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Roos, P.
    Colloid-particle dynamics and element transport through the low-salinity zone of a stable boreal northern shield estuary: insights from short-lived 234Th and sampling with high salinity resolution1998In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 62A, p. 553-554Article in journal (Refereed)
  • 15.
    Gustafsson, Örjan
    et al.
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Per S
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Roos, Per
    Department of Radiation Physics, Lund University.
    Ledin, Anna
    Department of Environmental Science and Engineering, Technical University of Denmark.
    Colloid dynamics and transport of major elements through a boreal river - brackish bay mixing zone2000In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 71, no 1-2, p. 1-21Article in journal (Refereed)
    Abstract [en]

    A range of biogeochemical methodologies were applied to investigate how aggregation processes affected the phase distribution and mixing of Fe, Si, and organic carbon between the Kalix River and the Bothnic Bay, northernmost Baltic Sea (salinity≤3; the low-salinity zone (LSZ) was stretching over 60 km in the spring). During the dynamic springflood conditions studied, small 238U-234Th disequilibria, low sediment trap fluxes, laboratory mixing experiments, as well as results from an independent two-box, two-dimensional mixing model combine to suggest that no significant removal of Fe, Si, or organic C was occurring in the highly-resolved LSZ. While no conclusions may be drawn based solely on property-salinity plots over narrow salinity ranges, apparently linear graphs for Fe and Si over 3 separate years also suggest minimal removal in this regime. At the same time, size distributions both of elements -from cross-flow ultrafiltration - and of bulk suspended solids - from light scattering (photon correlation spectroscopy [PCS]) - indicated that significant aggregation was taking place.The aggregation-without-significant-settling scenario in this low-salinity mixing regime, with a geochemistry similar to that of neighboring Russian Arctic rivers, is hypothesized to result from a comparatively high organic-to-detrital matter characteristic of the aggregates. While first principles would indeed suggest that decreasing electrostatic repulsion during mixing lead to aggregation, a low specific density of mineral-poor amorphous organic aggregates may lead to transport of these authigenic particles further away from the river mouth. The role of detrital "sinkers" on vertical removal of suspended organic matter is discussed in the wider context of scavenging mechanisms in the ocean.

  • 16.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Per S
    Widerlund, Anders
    Öhlander, Björn
    Gustafsson, Örjan
    Land, Magnus
    The Ce-anomaly in river suspended matter: An indicator of hydrogeochemical processes in a boreal catchment2000In: Vol. 5, no 2, p. 540-Article in journal (Other academic)
  • 17.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Malinovskiy, Dmitry
    Rodushkin, Ilia
    Baxter, Douglas
    Widerlund, Anders
    Andersson, Per
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Gustafsson, Örjan
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Iron isotope fractionation in river colloidal matter2006In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 245, no 3-4, p. 792-798Article in journal (Refereed)
    Abstract [en]

    Temporal variations in the iron isotopic composition, δ56Fe between − 0.13‰ and 0.31‰, have been measured in the suspended fraction in a Boreal river. The major mechanism behind these variations is temporal mixing between two types of particles–colloids, Fe-oxyhydroxides and Fe–C colloids. Data in this study indicate that these two types of colloids have different Fe-isotope composition. The Fe–C colloid has a negative δ56Fe value whereas the Fe-oxyhydroxide colloid is enriched in 56Fe. These two types of colloidal matter have different hydrogeochemical origin. The Fe–C colloid reaches the river during storm events when the upper sections of the soil profile (O and E horizons) are flooded by a rising water table. Colloidal Fe-oxyhydroxides reach the river via inflow and subsequent oxidation of groundwater enriched in dissolved Fe(II).

  • 18.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Suteerasak, Thongchai
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Elming, Sten-åke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Sequestering of phosphorus during freshening of a silled marine basin: Role of manganese2011Conference paper (Other academic)
  • 19.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Formation and chemical composition of Fe-Mn-rich suspended particles in the Kalix River1994In: Bottniska vikens miljö: [sammanfattning av forskningsresultat : Umeå 15-17 mars 1994 / Kommittén för Bottniska viken], 1994Conference paper (Other academic)
  • 20.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Uptake of alkali and alkaline-earth elements on suspended iron and manganese in the Kalix River, northern Sweden1994In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 58, no 24, p. 5433-5442Article in journal (Refereed)
    Abstract [en]

    Scavenging of alkali and alkaline-earth elements by suspended Fe and Mn in the Kalix River, northern Sweden, has been studied for a period of seventeen months. More than 95% (by weight) of suspended nondetrital concentrations of Ca, Mg, and Sr are scavenged on suspended nondetrital Fe throughout all seasons. Barium is correlated to suspended Fe during winter, but during the summer a significant fraction of nondetrital Ba is associated with Mn-rich particles. Porewater profiles for Ca, Mg, and Sr are similar to the dissolved Fe profile, suggesting desorption from a Fe-rich carrier phase. Compared with the river water concentration, Ba is enriched twenty-five times in porewater and shows, together with Mn, a post-depositional subsurface maximum in the solid sediment. The alkali elements Na and K show a linear correlation to suspended nondetrital Fe during the winter. However, the summer concentrations cannot be explained by scavenging onto Fe alone, and sediment and porewater data show no clear association with Fe or Mn. The distribution coefficients for the alkaline-earth elements are two orders of magnitude larger than coefficients obtained for model Fe-oxyhydroxides. This suggests that surface complexation occurs via other functional groups and/or the alkaline-earths are more firmly bound to the natural Fe-rich phase.

  • 21. Ingri, Johan
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Uptake of trace elements on suspended matter in the Kalix River1996In: Sixth V. M. Goldschmidt Conference : Heidelberg 1996: extended abstracts, Cambridge Publ. , 1996, p. 277-Conference paper (Other academic)
  • 22.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Land, M.
    Stockholms Universitet.
    Geochemistry of major elements in a pristine boreal river system: hydrological compartments and flow paths2005In: Aquatic geochemistry, ISSN 1380-6165, E-ISSN 1573-1421, Vol. 11, no 1, p. 57-88Article in journal (Refereed)
    Abstract [en]

    Once or twice weekly, water sampling was undertaken for a two and a half year period in the Kalix River, northern Sweden. Soil water, groundwater, water in tributaries and mire water were also sampled at several occasions. Samples were filtered and analysed for major dissolved elements and TOC. Although only 5 of the bedrock in the Kalix River drainage basin is situated in the Caledonian mountains (mostly schist, with some outcrops of dolomite and limestone), the chemical composition of the river, at the river mouth, is clearly influenced by water from the mountain areas. High dissolved Ca/Mg ratios in June and July indicate a large influence of water from the mountain areas during summer. The dissolved Si/Mg ratio increases when water from the woodland (bedrock consisting of Precambrian granitoids) predominates during snowmelt in May, but the ratio is low during summer when water from the mountains is increased. However, the low Si concentrations in the mountain areas are probably not primarily the result of the different rocks but more a reflection of the less intense weathering of silicate minerals in the mountains. High Si/Mg ratios are closely related to high TOC. All the major dissolved elements, except TOC, are diluted by snowmelt in May. However, the dilution varies for different elements. Based on the interpretations of major element ratios the melt water discharge in May reflects two major compartments in the woodland; peatland areas and the upper section of the soil. During summer and autumn storm events in the woodland most of the storm water originated from peatland. High K/Mg ratios in the river in May are related to water discharge from the upper section of the till. Low S/Mg ratios in the river indicate an influence of mire water from the woodland both during melt water discharge in May and during increased water discharge in autumn. The Ca/Mg ratios in tributaries in the woodland are consistently lower during melt water discharge compared with values in August. The lower Ca/Mg ratio in May probably reflects water that has been in contact with the B-horizon in the till during spring flood. Data show that the TOC discharged during spring flood originates from two major compartments in the landscape, the upper soil profile and peatland. Storm discharge of TOC during the rest of the year originates mostly from peatland.

  • 23.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Land, Magnus
    Luleå tekniska universitet.
    Dissolved major element ratios as tracers for hydrological compartments and flowpaths in the Kalix River catchment, northern Sweden1996Report (Other academic)
  • 24. Ingri, Johan
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Land, Magnus
    Luleå University of Technology.
    Gustafsson, Örjan
    Luleå University of Technology.
    Andersson, Per
    Luleå University of Technology.
    Öhlander, Björn
    Temporal variations in the fractionation of the rare earth elements in a boreal river: the role of colloidal particles2000In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 166, no 1-2, p. 23-45Article in journal (Refereed)
    Abstract [en]

    Rare earth element (REE) data from weekly sampling of the filtered (<0.45 μm) and suspended particulate phase during 18 months in the Kalix River, Northern Sweden, are presented together with data on colloidal particles and the solution fraction (<3 kDa). The filtered REE concentration show large seasonal and temporal variations in the river. Lanthanum varied between approximately 300 and 2100 pM. High REE concentration in the filter-passing fraction is related to increased water discharge and there is a strong correlation between the REE concentration, organic carbon, Al and Fe. Physical erosion of detrital particles plays a minor role for the yearly transport of particulate REE in this boreal river system. The suspended particulate fraction, which is dominated by non-detrital fractions, accounted for only 35% of the yearly total transport of La in the river. Approximately 10% of the REE were transported in detrital particles during winter. At spring-flood in May, about 30% of the LREE and up to 60% of the HREE where hosted in detrital particles. Ultrafiltration of river water during spring-flood shows that colloidal particles dominate the transport of filter-passing REE. Less than 5% of the filtered REE are found in the fraction smaller than 3 kDa. The colloidal fraction shows a flat to slightly LREE enriched pattern whereas the solution fraction (<3 kDa) show an HREE enriched pattern, compared with till in the catchment. Suspended particles show a LREE enriched pattern. Data indicate that the REE are associated with two phases in the colloidal (and particulate) fraction, an organic-rich phase (with associated Al-Fe) and an Fe-rich (Fe-oxyhydroxide) inorganic phase. The Ce-anomaly in the suspended particulate fraction in the river shows systematic variations, and can be used to interpret fractionation processes of the REE during weathering and transport. There was no anomaly at maximum spring-flood but during the ice-covered period the anomaly became more and more negative. The temporal and seasonal variations of the Ce-anomaly in the suspended particulate phase reflect transport of REE-C-Al-Fe-enriched colloids from the upper section of the till (and/or from mires) to the river at storm events.

  • 25.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Land, Magnus
    Öhlander, Björn
    Andersson, P.S.
    Gustafsson, Ö.
    Seasonal variations of the rare earth elements in a boreal river1998In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 62A, p. 681-682Article in journal (Other academic)
  • 26.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Suteerasak, Thongchai
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bauer, Susanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Elming, Sten-åke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Changes in trace metal sedimentation during freshening of a coastal basin2014In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 167, p. 2-12Article in journal (Refereed)
    Abstract [en]

    Holocene freshening has turned the Bothnian Bay, northern Baltic Sea into an oligotrophic basin. Sequestering of trace elements has changed significantly during the oligotrophication process. In principle, trace metals have been transferred from permanently buried sulfides to Fe–Mn-oxyhydroxides in the top layers of the sediment. The oxyhydroxide layers restrict the flux of trace metals from the sediment to the oxic bottom water. Hence, Fe–Mn cycling in the suboxic sediment enriches a number of trace metals in the surface sediment. Arsenic, Sn, Ge and Bi show enrichment in the Fe-oxyhydroxide layer, whereas Mo, Cd, Ni, Co, Cu, and Sb are enriched in the uppermost Mn-oxyhydroxide layer. This natural redox cycling in the sediment obscures pollution effects.The oligotrophication process started approximately 3500 years ago, reflected in decreasing deposition of Zn, a proxy for phytoplankton production, and formation of Mn oxyhydroxide layers. Similarly, Ba/Al data indicate a decrease in the pelagic input of plankton. Barium data also suggest that dissolved sulfide in the sediment never reached high concentrations. Germanium is closely related to Ba, suggesting that Ge can be used as a proxy for phytoplankton production. Vanadium, U, Re, and Mo all indicate that the bottom water never has been significantly sulfidic during the last 5500 years. Rhenium data indicate that the organic carbon oxidation rate has decreased during the last 5500 years. Cadmium follows the organic matter distribution, but started to increase 1000 YBP (years before present). The reason for this enhanced input of Cd is unclear.

  • 27.
    Kløve, Bjørn
    et al.
    Water Resources and Environmental Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu.
    Ala-Aho, Pertti
    Water Resources and Environmental Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu.
    Bertrand, Guillaume
    University of Neuchâtel.
    Boukalova, Zuzana
    GIS-Geoindustry s.r.o..
    Ertürk, Ali
    Istanbul Technical University.
    Goldscheider, Nico
    Karlsruhe Institute of Technology (KIT), Institute for Applied Geosciences, Department of Hydrogeology.
    Ilmonen, Jari
    Water Resources and Environmental Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu.
    Karakaya, Nusret
    Abant Izzet Baysal University.
    Kupfersberger, Hans
    Joanneum Research Forschungsgesellschaft mbH Elisabethsr.
    Kvœrner, Jens
    Bioforsk - Norwegian Institute for Agricultural and Environmental Research.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mileusnić, Marta
    University of Zagreb.
    Moszczynska, Agnieszka
    Universita Cattolica del SacroCuore.
    Muotka, Timo
    Water Resources and Environmental Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu.
    Preda, Elena
    University of Bucharest.
    Rossi, Pekka
    Water Resources and Environmental Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu.
    Siergieiev, Dmytro
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Šimek, Josef
    GIS-Geoindustry s.r.o..
    Wachniew, Przemysław
    AGH University of Science and Technology, Mickiewicza.
    Angheluta, Vadineanu
    University of Bucharest.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Groundwater dependent ecosystems: Part I: Hydroecological status and trends2011In: Environmental Science and Policy, ISSN 1462-9011, E-ISSN 1873-6416, Vol. 14, no 7, p. 770-781Article in journal (Refereed)
    Abstract [en]

    Groundwater dependent ecosystems (GDEs) include valuable ecosystems such as springs, wetlands, rivers, lakes and lagoons. The protection of these systems and services they provide is highlighted by international agreements, i.e. Ramsar convention on wetlands, and regional legislation, i.e. the European Water Framework Directive. Groundwater provides water, nutrients and a relatively stable temperature. However, the role of groundwater in surface ecosystems is not fully understood. The ecosystem can depend on groundwater directly or indirectly, and the reliance can be continuous, seasonal or occasional. This has implications for the vulnerability of ecosystems, as some may be easily affected by external pressure. Conceptual models and quantitative assessments of how groundwater interacts with the environment are needed. GDEs are also threatened by different land use activities and climate change. Hence, we need to understand how GDEs are affected by changes in groundwater quantity and quality, as severe groundwater changes have been observed in many regions. This study examines key aspects of GDEs (hydrogeology, geochemistry and biodiversity) in order to improve conceptual understanding of the role of groundwater in such ecosystems. The status and baseline of different types of GDEs are discussed, with particular emphasis on past evidence of environmental change and potential thresholds and threats in GDEs in various parts of Europe with different land use, climate and geology

  • 28.
    Lövgren, Lars
    et al.
    Department of Chemistry, Umeå University.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Kristineberg spearheads research into safe disposal of mine waste2007In: Mining, People and the Environment, ISSN 0969-4218, p. 20-22Article in journal (Other academic)
  • 29.
    Nilsson, Lino
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Modelling tool for predicting and simulating nitrogen concentrations in cold-climate mining ponds2018In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 380, p. 40-52Article in journal (Refereed)
    Abstract [en]

    A nitrogen model was developed with the aim to trace nitrogen cycling in a cold climate-mining pond at the Aitik copper mine in northern Sweden. The model contains 10 state variables and 19 nitrogen cycling reactions. The model also includes sediment and physical properties of the pond, such as evaporation, freezing and thawing. The model was written in Mathworks MATLAB and was calibrated and validated using environmental monitoring data for the clarification pond at the Aitik mine. The data used comprised monthly values of nitrogen speciation, phosphorous and water flow. The model accurately predicts ammonium (r2 = 0.84) and nitrate (r2 = 0.82) concentrations in a time series from February 2012–August 2014. The model did not accurately predict nitrate concentrations (r2 = 0.11), presumably due to high oxygen concentration in the pond water that prevented denitrification in the water column. The transport of organic material to the sediment was also limiting denitrification in the sediment. When allowing denitrification in the water column as well as increasing the rate of transport of organic material to the sediment the nitrate prediction capacity increased to a satisfactory level (r2 = 0.54). A sensitivity analysis for the system showed that the most sensitive reactions for the water column were oxic mineralisation as well as the nitrification rate.

  • 30.
    Nilsson, Lino
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Tracing nitrogen cycling in mining waters using stable nitrogen isotope analysis2017In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 84, p. 41-51Article in journal (Refereed)
    Abstract [en]

    We show how we used stable nitrogen and oxygen isotopes in ammonium and nitrate to identify and quantify nitrogen transformation and nitrogen sources at the LKAB mining site in northern Sweden. Stable nitrogen isotope analysis worked as an excellent tool for tracing nitrogen cycling in rapidly moving process waters. The isotope analysis was performed on the mining process waters at seven different key points along the water flow and we identified nitrification, ammonia volatilisation, and ammonium adsorption as nitrogen transformation processes. The source of nitrogen is historically explained as undetonated ammonium-nitrate based explosives. We used nitrate nitrogen and oxygen isotopes to quantify four nitrogen sources in the accumulated water in the mine as well as three sources in an above ground process water reservoir. The nitrate isotope data showed that most of the nitrate (70–80%) in the accumulated water underground originated from a sampling point located close to the surface and only a minor fraction (5–20%) originated directly from undetonated explosives (direct dissolution of NH4NO3 and nitrification of NH4). Nitrate from natural groundwater formed roughly 12% of mine water nitrate. In the above ground process water reservoir isotope data indicated another source of nitrogen coming from undetonated explosives.

  • 31. Pearson, D.G.
    et al.
    Nowell, G.M.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Davison, W.
    Quantifying micro-niche behaviour in sediments: Precise and accurate measurements of DGT gels by laser ablation high resolution laser ablation ICPMS2006In: Vol. 70, no 18, Suppl. 1, p. A478-Article in journal (Refereed)
    Abstract [en]

    New developments in micron-scale measurements of trace metals and sulphur contents within sediments by DGT (diffusive gradients in thin-films) have revealed micro-niche structures. The origin of micro-niches is unclear and it is important to understand the relative roles played by inorganic and biological processes in the localised remobilisation of metals. We have undertaken a S and Fe isotope study of micro-niches, to better understand their mechanisms of formation. With their inbuilt pre-concentration, element selection and simple matrix, DGTs are an ideal medium for laser ablation ICPMS. In contrast to analysis of mineral phases, fully matrix-matched standards can be easily made. We have initially concentrated on the measurement of S isotopes and will also present experiments where Fe isotopes have been measured in DGT gels. S and Fe isotopes were measured on a Neptune at mass resolutions of >9000. A New-Wave UP-213 nm laser was used with Ar as the carrier gas. Instrumental mass bias (IMB) for S was corrected for using sample-standard bracketing. Ablation experiments on two S DGT gel standards, 10 Hz, 40% power, 170 μm wide line, scan speed 70 μms-1, show in-run δ34S precisions for DGT gels with 2.1 μmol/cm2 S (3 V of 32S) of <0.2‰ (2SE). There is no observed correlation between δ34S and 32S intensity. Reproducibility on δ34S for individual analytical sessions (4-8 standards) is better than 0.3‰ while the reproducibility over 4 sessions is 0.19‰. Further tests to mimic ablation over micro-niches (continuous ablation across a gel with two isotopic compositions) show similar internal precisions and only slightly worse reproducibility-0.48‰ (2SD; n = 6). The accuracy of the LA δ34S measurements on a BaSO4 gel relative to the reference value of the starting BaSO4, bracketed by a AgI gel of known isotopic composition, is better than 1‰, showing negligible S isotopic fractionation during gel deployment. δ34S variations in micro-niches can be easily resolved at the 1‰ level and 100 μm scale whereas variations in natural micro-niches are expected to be 10‰ or more. Fe measurements, using external normalisation to a 60Ni/61Ni ratio and an exponential law to correct for IMB, suggest internal precisions and external reproducibility of <0.15‰ (2SE) and 0.07‰ (2SD) should be possible.

  • 32.
    Pekka, Larisa
    et al.
    Luleå tekniska universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Mokrotovarova, Olga
    Murmansk Areal Department for Hydrometeorology and Environmental Monitoring.
    Riabtseva, Margarita
    Federal State Institution Murmansk Territorial Fund for geological Information, Apatity.
    Öhlander, Björn
    Geochemistry of the Kola River, northwestern Russia2004In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 19, no 12, p. 1975-1995Article in journal (Refereed)
    Abstract [en]

    The Kola River in the northern part of the Kola Peninsula, northwestern Russia, flows into the Barents Sea via the Kola Bay. The river is a unique place for reproduction of salmon and an important source of drinking water for more than 500,000 people in Murmansk and the surrounding municipalities. To evaluate the environmental status of the Kola River water, sampling of the dissolved (<0.22 μm) and suspended (>0.22 μm) phases was performed at 12 sites along the Kola River and its tributaries during 2001 and 2002. Major (Ca, K, Mg, Na, S, Si, HCO3 and Cl) and trace (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sr, Ti, and Zn) elements, total and particulate organic C (TOC and POC), N and P were analysed. Comparison with the boreal pristine Kalix River, Northern Sweden, shows that, except for Na, Cl, Al, Cu and Ni, which exceed the concentrations in the Kalix River by as much as 2–3 times, the levels of other major and trace elements are close to or even below the levels in the Kalix River. However, the results also demonstrate that pollutants from the three major sources: (1) the Cu–Ni smelter in Monchegorsk, (2) the open-pit Fe mine and ore concentration plant in Olenegorsk, and (3) the Varlamov, the Medveziy and the Zemlanoy creeks, draining the area of the large agricultural enterprises in the lower part of the watershed, have a major influence on the water quality of the Kola River.

  • 33.
    Rentz, Ralf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Öhlander, Björn
    Impact of urban stormwater on sediment quality in an enclosed bay of the Lule River, northern Sweden2009In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, suppl. 1, p. A1090-Article in journal (Other academic)
    Abstract [en]

    Sediment samples and porewater of an enclosed bay (Skutviken) affected by stormwater discharge near the centre of Luleå, northern Sweden, were analyzed for major and trace elements and 16 polycyclic aromatic hydrocarbons (PAHs), and compared to a reference site and local till. Among the studied metals, Cd, Cu, Pb and Zn were enriched at Skutviken. The use of trace metal ratios provided indications of pollutant sources for the sediment. Also, the PAH content was enriched, in particular for phenantrene, anthracene, fluoranthene and pyrene, which are regarded as common constituents in stormwater. Pb-210 dating was used to determine historical changes in metal and PAH fixation in the sediment. The bay Skutviken was enclosed by the construction of a road bank in 1962. The enclosure led to reduced water circulation in the bay, which promoted the occurrence of anoxic conditions with sulphate reduction within the bay. As a consequence of these conditions, metals are trapped in the sediments as sulphides. This study suggests that enclosed bays with restricted water circulation may be efficient traps for urban pollutants. In areas with postglacial rebound, where such bays are common, enclosure may have an important impact on water and sediment qualities. Due to the postglacial uplift, presently water covered sediments may rise above the groundwater level in the future. These sediments may then become a secondary pollution source if metal sulphides are oxidized.

  • 34.
    Rentz, Ralf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Impact of urban stormwater on sediment quality in an enclosed bay of the Lule river, northern Sweden2011In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 218, no 1-4, p. 651-666Article in journal (Refereed)
    Abstract [en]

    Sediment and porewater samples from an enclosed bay receiving stormwater discharge (Skutviken) near the centre of Luleå, northern Sweden were analysed for major and trace elements and 16 polycyclic aromatic hydrocarbons (PAHs). Among the studied metals Cd, Cu, Pb and Zn were enriched at Skutviken. Also, the PAH content was enriched, in particular for phenantrene, anthracene, fluoranthene and pyrene which are regarded as common constituents in stormwater. The use of trace metal ratios provided indications about pollutant sources for the sediment. Cs-137 dating was used to determine historical changes in metal and PAH fixation in the sediment. The bay Skutviken is enclosed through the construction of a road bank since 1962. The enclosure led to reduced water circulation in the bay that promotes the occurrence of anoxic conditions with sulphate reduction within the bay. As a consequence of these conditions, metals are trapped in the sediments as sulphides. This study suggests that enclosed bays with restricted water circulation may be efficient traps for urban pollutants, reducing the present-day input of pollutants to the sea. In areas with postglacial land uplift, where such bays are common, bay sediments are a potential future source of pollutants when uplift results in erosion and oxidation of the sedi

  • 35.
    Siergieiev, Dmytro
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hyporheic water exchange in a large hydropower regulated boreal river: directions and rates2014In: Hydrology Research, ISSN 1998-9563, Vol. 45, no 3, p. 334-348Article in journal (Refereed)
    Abstract [en]

    Widespread river regulation is known to modify river-aquifer interactions, influencing entire watersheds, but knowledge of the hyporheic flowpath along regulated rivers is limited. This study measured the hydraulic conductivity of the river bed and the aquifer, water levels and seepage fluxes in the heavily regulated Lule River in Northern Sweden, with the aim of characterising water exchange across the river-aquifer interface. While pristine rivers in the area are gaining, the Lule River was recharging the aquifer during 10% of the time. Daily river level fluctuations (typically ±0.25 m) directed ~3% of the total orthogonal flux across the river bed towards the aquifer, while during ~2% of the time the orthogonal fluxes were negligible (≤10–4 m d–1). A clogging layer on the river bed, most likely formed due to the modified river discharge, restricted river-aquifer exchange. The hyporheic zone had higher electrical conductivity than the river and the aquifer and electrical conductivity occasionally decreased following rising river water levels, with 3–5 hours delay. Overall, hydropower regulation has severely altered the hydrological regime of the hyporheic zone in the Lule River.

  • 36.
    Siergieiev, Dmytro
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    “Clogging layer” at regulated river beds - implications for river-groundwater exchange2013Conference paper (Other academic)
    Abstract [en]

    Within the EU-project GENESIS (2013), aiming to provide scientific basis and technical guidance for the update of the EU Groundwater Directive, Luleå University of Technology is investigating possible effects of hydropower regulation on surface water (SW)- groundwater (GW) exchange. The study compares SW, GW and hyporheic processes for the unregulated Kalix River and the regulated Lule River. Hydropower has long been regarded a fairly green energy source but today negative effects have become obvious (Renöfält et al. 2010).The hyporheic zone (HZ) accommodates most of the SW-GW exchange of solutes just beneath and along a river, dampens heat fluxes, processes pollutants and is essential for ecosystems.The study observes SW and GW (in wells orthogonal to the river) at one site in each river. In these, hydrological (water level, hydraulic conductivity, tracer test) and geochemical (temperature, electrical conductivity, water/soil chemistry) measurements were performed during several seasons.The presence of natural high-flow events in the Kalix River removes fines from the river bed, maintaining good SW-GW connectivity that favours hyporheic exchange (Brunke and Gonser 1997). Altered discharge of the regulated river (reduced flow peaks and velocity, daily discharge fluctuations) facilitated deposition of fine sediments at the river bed forming a “clogging layer” (Blaschke et al. 2003). The bed in the regulated river has two orders of magnitude lower hydraulic conductivity than that at the unregulated site and restricts the SW-GW exchange.Reduced hydraulic connectivity between SW and GW at the regulated Lule River site suggests decreased fluxes across the river-aquifer interface (Siergieiev et al. 2013), and thus reduced size of the HZ which is not always the case in regulated rivers (Sawyer et al. 2009).Decreased hyporheic velocities led to increased residence time and favored prolonged contact between water and soil matrix that stimulated biogeochemical transformations. As a result, the electrical conductivity of hyporheic water of the Lule River was higher than that of the surrounding water.Deteriorated connectivity and extended travel time reduced the dissolved oxygen concentration, which is functionally ecologically essential for hyporheic habitat. In addition, complete consumption of nitrate found at the regulated site, suggests formation of a suboxic zone extending several meters inland which promotes metals release reflected in high dissolved Fe and Mn in the HZ. The conditions of SW-GW exchange control nutrients processing and their export to SW. Thus, the HZ in the Lule River acts as a source of dissolved metals, while in the Kalix River much of the metals are removed by hyporheic processes due to good SW-GW connectivity.SW-GW connectivity plays an important role for hyporheic exchange and hyporheic water quality. Hydropower regulation in the Lule River has altered this connectivity, which may have far reaching implications for biogeochemical processes in the river.

  • 37.
    Siergieiev, Dmytro
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wang, Zhiqing
    Hydropower regulation impact on river-groundwater interaction and the riparian zone: a geochemical approach2010Conference paper (Refereed)
    Abstract [en]

    Natural rivers, including their riparian zones, belong to the most diverse, dynamic, and complex ecosystems on the world’s continents, and they play key roles in the regulation and maintenance of biodiversity in the landscape (Dynesius and Nilsson, 1994). Hydropower has a major macro-economic impact since it supplies more than 50% of national electricity production in 65 countries (Koch, 2002). Today about two-thirds of the fresh water flowing to the oceans is obstructed by approximately 40,000 large dams and more than 900,000 smaller ones (Petts, 1984; McCully, 1996). Hydropower regulation of river bodies was for a long time considered to be an environmentally friendly source of energy (Renöfält et al., 2009). However, damming of rivers has later been recognized as one of the most dramatic anthropogenic impacts on the natural environment (Petts, 1984). A comparison between one regulated and one pristine river with similar features, both located in Northern Sweden, has been conducted (Collomp 2001). The Luleå River comprises 15 reservoirs and has been regulated for almost a century (72 % of the annual river runoff can be stored in its reservoirs) (Dynesius and Nilsson, 1994). The Kalix River, the last major unregulated river in Europe, is used as a reference for geochemical conditions in a pristine river.Water storage in reservoirs affects seasonal water discharge, water temperature, conductivity and concentrations of nutrients, dissolved oxygen, organic matter and metals. Spring peaks are truncated and postponed and average base flow is higher than that under pristine conditions. Due to increased sedimentation in the reservoirs, the transport of Fe, Si, Al, Mn, DOC, P and N has decreased (Drugge, 2003). The aim of the outlined study is to increase knowledge regarding the effect of river regulation on riparian groundwater geochemistry by:a) analysing river water measurements with respect to river-groundwater exchangeb) measuring riparian groundwater quality at one site in each of the two riversIn both rivers, sampling sites were chosen approximately 100 km upstream of the river mouth. The geological settings and climatic conditions are similar in the two chosen areas, with precipitation rates of about 400 mm/year. In the regulated Luleå River, frequent water level fluctuations cause continuous mixing of river water and groundwater. Land use in both areas is equally non-intensive, and hydropower exploitation of the Luleå River is the only notable difference in land use in the two areas. The monitoring program at each site includes installation of 2-3 groundwater wells, with data loggers continuously recording groundwater levels, temperature, pH, conductivity, DO and ORP. Water samples will be taken weekly or bi-weekly for metal and nutrient analyses, and the hydraulic conductivities at the sites will be determined in soil samples. Expected outcome: Improved knowledge regarding river regulation impact on riparian groundwater, based on comparison of a one-year cycle of seasonal variations in groundwater flow and quality in a heavily regulated and a nearby pristine river.

  • 38.
    Siergieiev, Dmytro
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Flow regulation effects on the hydrogeochemistry of the hyporheic zone in boreal rivers2014In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 499, p. 424-436Article in journal (Refereed)
    Abstract [en]

    River-aquifer interfaces are essential for ecosystem functioning in terms of nutrient exchange and biological habitat, but are greatly threatened world-wide. This study examined geochemical aspects of river-aquifer interaction in one regulated and one unregulated boreal river in Northern Sweden to determine whether the geochemical functioning of the hyporheic zone is affected by hydrological alterations, e.g. regulated river discharge and river-aquifer connectivity. In the unregulated Kalix River, the hyporheic pore water was well-oxygenated with orthogonal fluxes (≈0.6-0.7 m d-1) and acted as a sink for Fe, Mn, Al, NH4, and Ca, with fractional losses of 95%, 92%, 45%, 31%, and 15%, respectively. A corresponding elevation in the concentrations of these elements in the hyporheic sediment was observed, with higher saturation indices of Fe-, Mn-, and Al-bearing secondary minerals in hyporheic waters. In the regulated Lule River, hydraulic connectivity at the river-aquifer interface was altered by the presence of a clogging layer (0.04 m d–1). In addition, the river discharge oscillated daily, severely reducing exchange flows across the riverbed (<0.01 m d-1). As a result, the hyporheic pore water was suboxic, with elevated concentrations of filtered Fe and Mn (fractional increase of ≈3700% and ≈2500%, respectively) and other solutes (NH4, Si, S, Ca). A conceptual model revealed functional differences between geochemical features of the hyporheic zone of regulated and unregulated rivers. Overall, the results showed that hyporheic processes are altered along regulated rivers, with resulting impacts on the geochemistry of riverine, riparian and related marine ecosystems.

  • 39.
    Siergieiev, Dmytro
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Drugge, Lisbeth
    Collomp, Magali
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Impact of Hydropower Regulation on River Water Composition in Northern Sweden2014In: Aquatic geochemistry, ISSN 1380-6165, E-ISSN 1573-1421, Vol. 20, no 1, p. 59-80Article in journal (Refereed)
    Abstract [en]

    Using hydrogeochemical analysis of two large boreal rivers (pristine Kalix and hydropower regulated Lule) discharging into the Gulf of Bothnia, the major impacts of regulation on water discharge, element transport, and their seasonal redistribution have been assessed. The pre-regulation hydrogeochemical features were assumed to be similar for the two rivers. For the Lule River, the average maximum runoff was almost halved, while the average minimum was tripled as a result of the regulation. The fraction of winter transport of total organic carbon (TOC), Fe, Si, suspended Mn and P in the Lule River was, according to a conservative estimate, two to three times higher than in the pristine river. Longer residence time in the Lule River delayed arrival of the suspended Mn peak and dissolved Si decline to the river mouth. During summer, the suspended C/N ratio in the regulated river was 10-20 compared to <10 for the pristine, suggesting presence of predominantly old organic material. This was supported by a virtually constant suspended P/Fe ratio throughout the year in the Lule River, indicating low abundance of phytoplankton. TOC varied irregularly in the Lule River suggesting temporal disconnection between the river and the upper riparian zone. The disappearance of the spring flow maximum, a shift of element transport from spring to winter, and supply of mainly old organic material during the vegetation growth season may have a pronounced impact on the ecosystem of the Gulf of Bothnia and the river itself.

  • 40.
    Suteerasak, Thongchai
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Faculty of Technology and Environment, Prince of Songkla University, Thailand.
    Elming, Sten-Åke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Possnert, Göran
    Department of Physics and Astronomy, Uppsala University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Deposition rates and 14C apparent ages of Holocene sediments in the Bothnian Bay of the Gulf of Bothnia using paleomagnetic dating as a reference2017In: Marine Geology, ISSN 0025-3227, E-ISSN 1872-6151, Vol. 383, p. 1-13Article in journal (Refereed)
    Abstract [en]

    Three 6-m-long cores of sediments were collected in the northern, middle and southern part of the Bothnian Bay. The sediments were dated by paleomagnetic dating techniques, constrained by magnetic properties and geochemical data. The results indicate the ages of the sediments in the bottom part of the cores in the northern, middle and southern parts of the Bothnian Bay to be approximately 5300 years BP, 5350 years BP and 3500 years BP, respectively. The deposition rate calculated from the estimated ages at various depths show that the deposition rate was generally in the range 0.5–1.5 mm/year but it was higher in the southern part than in the middle and northern parts of the bay. There was a significant increase in the deposition rate at ca 2200 years BP, recorded in all three cores, a rate varying between 2.47 and 3.07 mm/year and lasting until ca 1840 years BP. A proposed constant uplift rate of the crust during the period ca 5500 years BP to present is thus not reflected by a constant deposition rate. The peaks in deposition rates at ca 2200–1840 years BP were followed by a decrease in salinity. This phenomenon is suggested to be caused by crustal uplift, with a threshold being formed in the southern part of the bay, thereby increasing the reactivation of bottom sediments and reducing the inflow of brackish water from the Bothnian Sea. The14C ages of the sediments reveal differences in age compared with the paleomagnetic ages. In the southern core, the 14C ages are ca 1350 years older, and in the north, the age offset is mixed. The reactivation and re-deposition of sediments is argued to be the reason for the apparent 14C age differences. This finding demonstrates that 14C cannot be used for the dating of Bothnian Bay sediments unless the radiocarbon age offset has been determined.

  • 41.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Do suspended particulate Fe and Mn oxides in rivers carry trace metals into the Bothnian Bay?1996In: Abstracts of oral and poster presentations: 22:a Nordiska geologiska vintermötet ; The 22nd Nordic Geological Winter Meeting, 8-11 January 1996 in Turku-Åbo, Finland / [ed] Tuula Kohonen; Bo Lindberg, Åbo Akademi University Press, 1996, p. 233-Conference paper (Other academic)
  • 42.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Early diagenesis of arsenic in sediments of the Kalix River estuary, Bothnian Bay1993In: Abstracts of lectures and posters: 21:a Nordiska geologiska vintermötet 10-13 Januari 1994 Luleå / [ed] Jan-Anders Perdahl, Luleå: Högskolan i Luleå , 1993, p. 227-Conference paper (Other academic)
  • 43.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Early diagenetic remobilization of copper in near-shore marine sediments: a quantitative pore-water model1996In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 54, no 1-2, p. 41-53Article in journal (Refereed)
    Abstract [en]

    Solid-phase and pore-water Cu have been determined for two cores in the low-salinity (2-3‰) Kalix River estuary, Sweden. The pore-water Cu concentration in the oxidized surface layer of the sediment (32-42 nmol l-1) exceeded the Cu concentration in the overlying bottom water (10-11 nmol l-1) by a factor of 3-4. Assuming that organic matter degradation follows first-order kinetics, a multi-G model with two organic matter fractions of different reactivity was used to describe the early diagenetic decomposition of organic matter. An estimated Cu/C mole ratio of 5.10-5 was obtained from sediment trap data. By combining this ratio with a steady-state pore-water Cu model, the early diagenetic remobilization of Cu was linked to the decomposition of organic matter. The rate constant for the reaction that releases Cu could be set equal to the decay constant of the highly reactive organic matter fraction (2.0 yr-1). This highly reactive fraction was decomposing under aerobic conditions close to the sediment-water interface. Early diagenetic remobilization of Cu in these sediments thus appears to be entirely controlled by aerobic decomposition of organic matter. An estimate of the diffusive benthic efflux of Cu (2.9 nmol cm-2 yr-1) suggests that ˜ 3% of the amount of Cu being deposited is released back into the water column.The pore-water model supports the idea that the Redfield model for the biological control of nitrogen and phosphorus can be extended to certain bioreactive trace elements.

  • 44.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemistry of iron and arsenic in sediments of the Kalix River estuary, northern Bothnian Bay1996In: Development of environmental technology in the Barents Region, 1996, p. 77-78Conference paper (Other academic)
  • 45.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemistry of iron and arsenic in sediments of the Kalix River estuary, northern Bothnian Bay1996In: Environmental geochemistry: selected papers from the 3rd International Symposium, Kraków, Poland, 12 - 16 September 1994 / [ed] Ron Fuge, Elsevier, 1996, p. 438-439Conference paper (Other academic)
  • 46.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    MiMi - Geokemiska transportprocesser för metaller i Laisan: sedimentation och elementtransport mellan sediment och vatten1999Report (Other academic)
  • 47.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Suspended particulate matter, sedimentation and early diagenetic processes in the Kalix River estuary, northern Sweden1996Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Many important reactions controlling the transfer of elements from the continents to coastal waters and the oceans are taking place in estuaries. For many elements, estuaries can act as filters, capable of reducing the river load of dissolved and particulate elements to the oceans. Although sedimentation is an important process in estuaries, early diagenetic processes in sediments may be responsible for the remobilization of redox-sensitive elements back into estuarine waters. This thesis focuses on the behaviour of suspended and settling particulate Fe - Mn oxides and organic matter in the stratified, low-salinity (< 3‰) Kalix River estuary. In addition, the early diagenetic cycling of Fe, Mn, organic C and trace metals was also studied. Samples of the dissolved (< 0.45 μm) and suspended phase were collected along vertical profiles at three stations in the estuary. Settling particulate matter was collected by the use of sediment traps. Pore-water and solid phase sediment data were used to study early diagenetic processes. The estuary appears to be relatively inefficient as a trap for river transported, particulate, oxide- and organic-associated elements. Suspended, slow-settling particles rich in Fe - Mn oxides and organic matter to a large extent are flushed through the estuary in the seaward flowing surface water. Organic matter is an important carrier of Cu, which appears to be due in part to biological uptake of Cu. Flocculation of dissolved Fe, Si and Al is of little or no significance, while Mn is desorbed from suspended particles early in the estuarine mixing of freshwater and brackish water. A study of the varved, undisturbed sediments deposited in the central part of the estuary shows that the deposition of trace metals has decreased since the late 1970's. Despite active post-depositional redox cycling of Fe and Mn, efficient oxidation processes in the surface sediment prevent diffusion of dissolved Fe and Mn back into the water column. Reduction/ dissolution of Fe oxides is a slow process, resulting in burial of Fe oxides in permanently deposited, anoxic sediments. Post-depositional mobilization of trace metals in the bottom sediment is controlled by the type of carrier phase and the redox conditions in the sediment. The post-depositional mobility of trace metals is low - moderate, except for As, which is associated with redox-sensitive Fe oxides. Copper is associated with with labile organic matter, and early diagenetic remobilization of Cu appears to be entirely controlled by oxic decomposition of organic matter close to the sediment - water interface.

  • 48.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Trace metal transport into the Bothnian Bay by particulate Fe-Mn oxides and organic matter1996In: Jubilee issue: short papers and abstracts for the Jubilee meeting "Current problems, ideas and results in geology" : Stockholm 16th-18th October 1996 at the celebration of the 125th anniversary of the Geological society of Sweden / [ed] Björn Sundquist, Geologiska föreningen , 1996, p. 91-Conference paper (Refereed)
  • 49.
    Widerlund, Anders
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Per S.
    Swedish Museum of Natural History.
    Strontium isotopic composition of modern and Holocene mollusc shells as a palaeosalinity indicator for the Baltic Sea2006In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 232, no 1-2, p. 54-66Article in journal (Refereed)
    Abstract [en]

    The 87Sr/86Sr isotope ratio in subfossil carbonate mollusc shells from raised-beach sediments is used as a palaeosalinity indicator for the Baltic Sea. The main purpose is to demonstrate the applicability of the method in a formerly glaciated area, using 87Sr/86Sr ratios found in modern shells (Mytilus edulis, Macoma baltica, and Radix balthica) to elucidate the parameters and conditions to be used for palaeosalinity determinations based on subfossil shells. Proxy salinity data are calculated assuming that the Sr concentration in Baltic Sea water is controlled by a two-component, conservative mixing between seawater and river water. Based on replicate determinations of the 87Sr/86Sr ratio in modern shells, proxy salinity data can be quantified with a relative precision of better than ± 5% for salinities up to ≈ 10‰. Comparison with measured, present-day salinities indicates that the accuracy is generally better than ± 5% for the proxy data. With this precision and accuracy, the present-day salinity differences between the major Baltic sub-basins (Bothnian Bay, Bothnian Sea, and Baltic Proper) can be detected. Palaeosalinities were determined using subfossil shells (M. edulis and M. baltica) with calibrated 14C ages of 6770-3070 cal BP. The shell deposits occur from 65 m a.s.l. down to the present-day sea level. The palaeosalinities determined for the Bothnian Bay (4.8-10.3‰) and the Bothnian Sea (7.3-10.3‰) are in good agreement with earlier estimates of the maximum Littorina Sea stage palaeosalinity in these sub-basins (8-10‰). At one locality, two different shell species from the same shell deposit were dated (M. edulis and M. baltica). The shells differed in age by 460 ± 70 14C years, a possible indication that the ecological conditions at a locality may have been favourable to different faunas at different times.

  • 50.
    Widerlund, Anders
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, P.S.
    Swedish Museum of Natural History.
    A Holocene strontium isotope record of palaeosalinity for the Littorina Sea stage of the Baltic Sea2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 15S, p. A1108-Article in journal (Other academic)
12 1 - 50 of 71
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf