Magnetometry as a tool to estimate the pollution of marine environment around the small shipwrecks (Gulf of Gdańsk) (original) (raw)
Related papers
Acta Geophysica, 2016
Magnetic properties of deposits around the shipwrecks ("Munin" and "Abille") in the Gulf of GdaĔsk were investigated. Values of magnetic susceptibility (Ȥ) are relatively low; however, they reveal significant differences between investigated sites. The values of Ȥ around "Abille" wreck were 5-8×10-8 m 3 /kg. Around "Munin" wreck results were more diversified reaching value of Ȥ between 3.07×10-8 m 3 /kg and 12.92×10-8 m 3 /kg. The spatial variability of Ȥ coincided with near-bottom water currents distribution in the Gulf of GdaĔsk. Magnetic minerals were identified by thermomagnetic analysis. Around "Abille" wreck we have found magnetite with small amount of maghemite or hematite. The "Munin" sediments include only one magnetic phase; in several samples it is magnetite, in the others-maghemite. Day-Dunlop plot shows that "Abille" set is shifted towards lower magnetization ratio and higher coercivity ratio. The correlation between the distribution of Ȥ and hydrodynamic condition around shipwrecks allows to determine the direction of contaminant transport.
Journal of Soils and Sediments
Purpose This study is aimed at analyzing the spatial distribution of magnetic susceptibility and the content of potentially toxic elements (PTEs) in the surface layer of bottom sediments in the Vistula estuary (Gulf of Gdańsk, Poland) in relation to local sedimentary conditions. We also assessed the usefulness of magnetic susceptibility measurements to identify changes in sediment properties caused by anthropogenic factors. Materials and methods Bottom sediments were collected along three transects using the Van Veen grab sampler. The following properties were determined: granulometric composition, organic matter and carbonate content, pH, electrical conductivity, and heavy metal content (Cd, Cr, Cu, Fe, Ni, Pb, and Zn). Specific (mass) magnetic susceptibility (χ) was measured using the MS2 Bartington® laboratory magnetic susceptibility meter. To characterize the conditions of the sedimentary environment in the study area, statistical analysis was performed on selected parameters of...
Publications of the Institute of Geophysics, Polish Academy of Sciences; Geophysical Data Bases, Processing and Instrumentation
This work aims to evaluate the use of thermomagnetic curves to identify the presence of iron oxyhydroxysulfates (jarosite type minerals) by their transformation at high temperatures to ferrimagnetic iron oxides. Samples consist of fluvial sediments from a creek that was affected by a leak of sulfuric acid solution coming from a mine leachates dam, in Cananea, Sonora, Mexico. Measurements of volume magnetic susceptibility (κ) vs temperatures were performed in air, heating samples from 30 to 700 °C, and cooling back to 50 °C. Samples of the acid solution dam precipitates exhibited an important increase of magnetic susceptibility during heating, starting at 330 °C, and reaching its maximum (4 times the initial κ values) at 430 °C, followed by a drastic decrease; an even bigger increase of magnetic susceptibility during cooling was also observed. A very similar behavior was observed in samples of fluvial sediments from the affected basin, showing increases from 3 to 6 times the initial κ value during heating. Samples of not affected materials from the same area exhibited a contrasting behavior, presenting a decrease of κ during heating at 550 °C, and lower susceptibility values during cooling. The temperature at which the magnetic susceptibility increase occurs in affected samples coincides with the temperature reported for the desulphation of jarosite and its transformation to maghemite (Frost et al. 2005, 2007). This transformation at high temperatures can be used to infer the presence of material coming from the leak and delineate the affected area along the basin.
Modern sediments as enviromagnetic archives. A case study: Danube Delta and northwestern Black Sea
… Water Observation and Information System for …, 2010
A vast enviromagnetic archive of modern sediments from this aquatic system has been sampled over three decades. The magnetic signatures identified in the sediments can be used to characterise and differentiate the depositional environments inside an extended, diversified, and, at the same time, unitary complex of fluvial, lacustrine, lagoonal, deltaic and marine ecosystems. The presence of the anthropogenic impact on the ecosystems is clearly demonstrated by the modified magnetic fingerprints recovered from the bottom sediments at different time intervals. To calibrate the modern sediments and to compare different magnetic fingerprints recovered from the various aquatic environments, an original Magnetic Susceptibility Scale was conceived by the authors and it is successfuly used in the present paper.
Environmental magnetic studies on surface sediments: a proxy for metal and hydrocarbon contamination
International Journal of Environmental Science and Technology, 2013
Visakhapatnam is one of the major port cities, and it is developed into a hub of many large-and mediumscale industries. Due to growing industrialization and urbanization, coast is vulnerable to both organic and inorganic micro-pollutants. Twenty-five surface sediments were collected along the Visakhapatnam coast for the measurement of texture size, petroleum hydrocarbons, trace metals and environmental magnetic parameters. The percentage of coarser particles was more in the northern region, whereas the percentage of fine particles was increased toward south. Elevated levels of petroleum hydrocarbons and trace metals were attributed due to marine and land-based sources, in particular, those were due to shipping activities, treated and partially treated sewage and industrial wastes. The concentrations of trace metals, petroleum hydrocarbons and magnetic minerals were decreased from nearshore to seaward. Our results revealed that the magnetic mineralogy is dominated by magnetite with a small proportion of hematite, and the grain size of magnetic minerals was in the range of pseudo-single domain to multidomain nature with detrital origin. From the principal component analysis, the magnetic concentration and mineralogy-dependent parameters co-vary with the heavy metal and PHC concentrations, suggesting that the inputs of magnetic minerals, petroleum hydrocarbons and heavy metals in the Visakhapatnam shelf sediments were derived from the same anthropogenic sources. Thus, the large magnetic dataset can be used to reduce the number of chemical analysis; hence, environmental magnetic parameters were used as a proxy for both organic and inorganic micro-pollutants.
Physics and Chemistry of The Earth, 1998
Recently, magnetic measurements have been used m outline areas with increased loading of toxic metals due to industrial activity. It is supposed that magnetic minerals, which are easily detectable, can cant toxic metals of anthropic origin. However, physical background of this relationship is not comprehended yet. In this study, we present our first results on statistical correlation of various magnetic parameters on one side and chemical composition on the other, obtained on sediments from the bottom of lake Nechranice, located in noRhern Bohemia; the captive area being typical for intensive industrial and mining activity (brown-coal basins, uranium mines, coalburning power plants). Our results suggest, that magnetic susceptibility, which has been used in other studies as indicator of increase pollution levels due to local sources, does not actually link to any of the toxic elements in concern. This finding can be explained in terms of complex inlet due to different types of pollution sources.
Physics and Chemistry of the Earth, Parts A/B/C, 2002
Four of the 38 sediment cores, collected from the northwestern part of the Black Sea (French-Romanian BLASON Programme, 1998), were analysed in order to study the major hydrological and environmental change of the sea during the Holocene. This change was caused by the inflow of the marine Mediterranean waters into the freshwater basin of the Black Sea. Two cores from the northwestern shelf and two from the deep part of the sea, representing distinct sedimentary environments along the same profile, were chosen. Lacustrine sediments from deep-water cores and uppermost marine sediments in all studied cores are characterised by the presence of pyrite (FeS 2 ), which indicates anoxic, sulphate reducing conditions in sediment and in water column (as it is observed now in the Black Sea). Pyrite formation in this anoxic environment takes place below the oxic/anoxic limit, by reduction and sulphidation of iron. The transition from freshwater to marine conditions is marked in all studied cores by the presence of ferrimagnetic iron sulphide--greigite (Fe 3 S 4 ). Greigite is an intermediate mineral in the pyritisation reactions during early diagenesis, which can be preserved in the sediment if pyritisation cannot be accomplished, due to a high Fe/S ratio. In shallow water cores from the shelf, where marine transgression is marked by a discontinuity, greigite is present below and above it. This suggests that the anoxic, sulphate reducing conditions, allowing preservation of greigite, started in the sediment after marine transgression. In cores from the deep part of the sea, the transgression is represented by a level of sediments with high organic matter content (sapropel). The greigite is present only in the lower part of this level and its formation is related to the arrival of marine water. The presence of pyrite in the upper part of the lacustrine sediments indicates that anoxic conditions probably prevailed here during marine transgression. These results show the sensitivity of magnetic parameters to major environmental change in the Black Sea, and allow a correlation between cores from different depths, by recognition of greigite in the sediments marking the marine transgression.
Trace metal and magnetic studies of sediments in greek estuaries and enclosed gulfs
Marine Chemistry, 1986
Minicores of seabottom sediments from typical coastal and estuarine areas of Greece (the Gulf of Elefsis and the estuaries of the Acheloos and Louros rivers), influenced in a widely varying degree by anthropogenic inputs, were analysed for trace metal content and measured for a series of magnetic properties (i.e., total magnetic susceptibility, frequency dependent susceptibility, isothermal remanent magnetization and demagnetization). Apparent linkages between trace metal content (total or in chemically leached fractions) and magnetic properties were found in cores from all areas. Variations in the relative importance of the non-leachable fraction of metals in the Elefsis Gulf sediments closely parallel changes in the percentage frequency dependent susceptibility, which can be considered as indicator of soil derived material. By combining chemical and magnetic data, very useful information was obtained on: (a) the origin (industrial) of the rapidly deposited sediments in the Gulf of Elefsis; (b) the deposition rate, which was estimated as 0.5 cm per annum; (c) the range and nature of the major natural particle assemblages present in the Acheloos and Louros estuaries; (d) the distinction between the assemblages deriving from the erosion of surface soils and from unweathered parent material; (e) the identification of particles acting as major trace metal carriers (viz. anthropogenic particulates and soil-derived Clays). In general the results confirm that integrated trace metal-magnetic studies can provide valuable data on the origin, transport and sedimentation mechanisms of trace metals associated in various ways with particles in coastal and estuarine systems. New perspectives are briefly discussed.
2020
Since the resume in 2005 of the systematic geophysical and geo-ecological investigation of the Romanian offshore, over 13,400 km of gravity lines and over 48,000 km of magnetic lines have been acquired on the entire surface of the Romanian maritime space and over most of the Bulgarian one. Based on this data numerous maps of the gravity and magnetic anomalies, at scales ranging from regional to the highest detail, have been compiled. If prior to 1990, marine gravity and magnetic researches were exclusively used for the study of the Romanian continental shelf deep geological structure and for the assessment of its hydrocarbon potential, the latter researches has expanded the range of topics addressed: deciphering of also near surface structures, marine site characterization, geo-archaeology, environmental geophysics, detection of submerged objects, maritime space security. Mainly during the last years, an increasing involvement of marine magnetometry in projects dedicated to the stud...
2016
The aim of the work was to investigate the influence of processes occurring during deposition of port sediments in dump sites on the bonding of metals in the sediment. About toxicity of polluted sediments are deciding not only concentration of macroand microelements but, also the chemical forms in which they exist. These forms have considerable influence on their assimilation of different trophic levels (including human). The results of the carried out investigations indicated that the concentration of the trace metals ware decreasing in sediments deposited on the dumping sites. Grain size analysis demonstrated a significant decrease of clay fraction in sediments from the dumping site by comparison with the depositing sediments. The sequential analysis proved that the percentage of the particular forms of the metals (especially Pb and Cd) was changing in the sediments deposited in the dumping site. The changes of salinity, mechanical mixing during excavation, oxygen concentration ma...