Publications by authors named "Juho Junttila"

The aim of this study is to identify the environmental impact of drill cuttings (DC) released around three wells drilled in 1992, 2000 and 2012 in the SW Barents Sea. Foraminiferal assemblages are studied in cores taken along transects <250 m from wells. Well E-1992 shows no impact of DC on foraminifera indicating that low amounts of released DC limit environmental impact.

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Five stations (≤250 m from the well heads) from three exploration wells of different ages from the SW Barents Sea were studied to investigate the spreading of drill cuttings and sediment quality. Two of the wells were drilled before the restriction of use of oil-based drilling fluids (1993). Elevated concentrations of Ba were found in sediments near all the wells with the highest concentrations at ≤60 m from the well head.

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Repparfjorden in northern Norway has been partly designated for submarine mine tailings disposal when the adjacent Cu mine re-opens in 2019. In order to increase sedimentation, the flocculant, Magnafloc10 is planned to be added to the mine tailings prior to discharge into the fjord. This study investigated the feasibility of reducing the Cu concentrations (375 mg/kg) in the mine tailings by applying electrodialytic extraction, including potential optimisation by adding Magnafloc10.

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Metal concentrations, sediment properties and benthic foraminiferal assemblages were investigated in sediment cores in the SW Barents Sea, to reconstruct environmental baselines and natural variability of Atlantic Water inflow since 1800 CE. Metal concentrations correspond to no effect levels and do not influence the foraminifera. Increased Hg and Pb was linked to inflow of Atlantic Water.

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The present multiproxy investigation of marine sediment cores aims at: 1) Identifying dispersion of petroleum exploration related drill cutting releases within the Goliat Field, Barents Sea in 2006/07 and 2) Assessing past and present influence of drill cuttings on the marine environment. The cores were recovered 5, 30, 60, 125 and 250m from the drill site in the eastward downstream direction. Downstream dispersion of drill cuttings is evaluated by examining sediment grain size distribution and barium (Ba), heavy metal, total organic carbon and sulphur concentrations.

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Mining of Cu took place in Kvalsund in the Arctic part of Norway in the 1970s, and mine tailings were discharged to the inner part of the fjord, Repparfjorden. Metal speciation analysis was used to assess the historical dispersion of metals as well as their potential bioavailability from the area of the mine tailing disposal. It was revealed that the dispersion of Ba, Cr, Ni, Pb and Zn from the mine tailings has been limited.

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We investigate the state of sedimentological environment and contaminant status of Repparfjorden (N Norway) impacted by submarine disposal of mine tailings during the 1970s using sedimentological and geochemical properties of seventeen sediment cores. The impact of tailings disposal is mainly restricted to the inner fjord where the discharge occurred. Sediment cores retrieved from the inner fjord contain layers of mine tailings up to 9-cm thick, 3-9cm below the seafloor.

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We investigated benthic foraminiferal assemblages in contaminated sediments in a subarctic harbor of Northern Norway to assess their utility as indicators of anthropogenic impacts. Sediments in the harbor are repositories for POPs and heavy metals supplied through discharges from industry and shipping activities. Sediment contaminant concentrations are at moderate to poor ecological quality status (EcoQS) levels.

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The aim of this study is to establish pre-impact baseline conditions for an Arctic region where petroleum activities are projected to increase in the coming decades. We characterize the spatial distribution of living benthic foraminifera in the Tromsøflaket-Ingøydjupet region of the Barents Sea and relate this to sediment properties and their associated metal concentrations. Metal concentrations of the sediments did not exceed threshold levels of harmful environmental effects, indicating that the area exhibits pre-impact baseline conditions.

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