Geophysical Institute of the ASCR

More documents

Recommendations

Info

FeO 91% Al2O3 0,8% SiO2 0,2% MgO CdO ZnO Fig. 36. SEM images of typical magnetic spherules of anthropogenic origin, found in topsoil layers in industrially affected area near Ostrava, along with typical elemental composition. Present instruments and methods enable very sensitive determination of concentration of strong ferrimagnetics (for instance magnetite), in the order of ppm. Magnetic properties of soils have been recently beneficially used in examining industrial pollution. Methods of "environmental magnetism" are sensitive and enable detection of small changes in concentration of magnetic particles in soils (e.g., Petrovský and Ellwood, 1999). Deposited dust of anthropogenic origin comprises high portion (5 – 10%) of highly (ferri)magnetic particles, produced primarily during combustion of fossil fuels containing pyrite. Dissociation and oxidation processes during combustion form ferrimagnetic iron oxides from Fe ions. Resulting anthropogenic magnetite (Fe3O4) or maghemite (Fe2O3) form specific spherules with diameter from several micrometers to several tens of micrometers and their magnetic properties are different from particles of lithogenic origin. Besides combustion, industrial magnetic particles also result from, e.g., steel and cement industry and from road traffic (e.g., Petrovský and Ellwood, 1999). Magnetic susceptibility represents one of major parameters indicating concentration of (ferri)magnetic particles in soils and sediments. Magnetic mapping (measurements of magnetic susceptibility of top soil layers) can be thus used as fast, effective and low-cost method of approximate determination of contamination of soils due to atmospheric deposition of pollutants. In case of undisturbed soils this magnetically enhanced layer reaches depths of some 5 – 10 cm. In particular, the method can be advantageously used in outlining hot-spots for further (more expensive and time consuming) chemical analysis of contaminated soils. Magnetic susceptibility of contaminated top soils was measured in situ using a portable loop-shaped hand probe Bartington MS2D. Since these measurements are fast and easy, large data sets can be obtained on any grid of measuring points over the area of concern. The data are represented in a form of 2-D maps, delineating magnetic susceptibility of top soils. In order to determine the undesired effect of basement rock (lithogenic contribution), magnetic parameters in dependence of depth were studied on selected sites to depths of 30 – 60 cm. For this purpose, a new unique instrument SM400 was developed (Petrovský et al., 2004). Our recent studies focused mainly on magnetic discrimination between natural soil magnetic minerals of lithogenic origin and anthropogenic ones, produced through industrial processes. This research is a direct continuation of the studies performed within the EU 5FP Project MAGPROX. In cooperation with Polish colleagues from the Institute of Environmental Engineering PAN in Zabrze, large set of 53
vertical profiles of magnetic susceptibility in soils was analysed and 7 typical profiles were classified (Magiera et al., 2005). Based on these results, more detailed study of vertical profiles of soil magnetic susceptibility was accomplished on a border-crossing transect in the Třinec-Katowice area. The results confirmed the assumption that topsoil magnetic anomaly, observed in this region, is fully due to atmospheric deposition of industrially derived magnetic particles. Magnetic discrimination of lithogenic and anthropogenic magnetic particles was also subject of the study done in close cooperation with colleagues from Leoben, Austria. It was shown that using a combination of magnetic parameters, dominant populations of magnetic minerals of natural and anthropogenic origins can be distinguished from each other (Fialová 2005; Fialová et al., 2005). However, magnetic methods should be complemented by other observations, e.g. scanning electron microscopy (Fig. 36). Finally, we started investigation of vertical migration of atmospherically deposited magnetic particles. The results will greatly contribute to the reliability of magnetic mapping, related to soil pollution problems. Last but not least, magnetic susceptibility of agricultural soils from the whole of the Czech Republic was examined. The samples were obtained from a depository of the Central Institute for Supervising and Testing in Agriculture in Brno. Ploughed topsoils were compared with those from the depth of 40 cm. Magnetic susceptibility was compared with concentrations of heavy metals. The results suggest that, independent of the soil use, agricultural soils are mixed to such extent, that concentration of magnetic minerals and heavy metals in topsoils and subsoils correlates very well and disables distinction of lithogenic and anthropogenic contributions. It is obvious, that contrast in topsoil magnetic susceptibility can be interpreted in terms of lithogenic, anthropogenic or combined contributions, mainly using vertical distribution of magnetic susceptibility measured on soil cores or in situ (using a newly developed SM400 susceptibility meter), and using other laboratory methods (e.g., geochemical analysis). Magnetic method, once correlated with concentrations of heavy metals at specific site, can serve as fast and low-cost tool for approximate screening and monitoring the pollution load. References Fialová H., 2005. Magnetic Discrimination of Lithogenic and Anthropogenic Minerals in soils. PhD Thesis. Czech Technical University, Prague. Fialová H., Maier G., Petrovský E., Kapička A., Boyko T., Scholger R. and MAGPROX Team, 2005. Magnetic properties of soils from sites with different geological and environmental settings. J. Appl. Geophys., submitted. Kapička A., Petrovský E., Ustjak S. and Macháčková K., 1999. Proxy mapping of fly-ash pollution of soils around a coalburning power plant: a case study in the Czech Republic. J. Geochem. Explor., 66, 291-298. Kapička A., Jordanova N., Petrovský E. and Podrázský V., 2003. Magnetic study of weakly contaminated forest soils. Water, Air and Soil Pollution, 148, 31-44. Kapička A., Petrovský E., Jordanova N. and Podrázský V., 2001. Magnetic parameters of forest top soils in Krkonoše Mountains, Czech Republic. Phys. Chem. Earth A, 26, 917-922. Magiera T., Strzyszcz Z., Kapička A., Petrovský E. and MAGPROX TEAM, 2005. Discrimination of lithogenic and anthropogenic influences on topsoil magnetic susceptibility in Central Europe. Geoderma (in print). Petrovský E. and Ellwood B.B., 1999. Magnetic monitoring of air-land and water pollution. In: B.A.Maher and R.Thompson (Eds.), Quaternary Climates, Environments and Magnetism, Cambridge Univ. Press. Petrovský E., Hůlka Z., Kapička A., 2004. A new tool for in situ measurements of the vertical distribution of magnetic susceptibility in soils as basis for mapping deposited dust. Environ. Technol., 25, 1021-1029. Singer M.J., Verosub K.L. and Fine P., 1996. A conceptual model for enhancement of magnetic susceptibility of soils. Quatern. Int., 34-36, 243-248. Maher B.A., 1998. Magnetic properties of modern soils and Quaternary loessic paleosols: palaeoclimatic implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 137, 25-54. Stanjek H., Fassbinder J.W.E., Vali H., Wagele H. and Graf W., 1994. Evidence of biogenic greigite (ferrimagnetic Fe3S4) in soil. Eur. J. Soil. Sci., 445, 97-104. 54
Page 2:
Academy of Sciences of the Czech Re
Page 5 and 6: Estimates of P-wave anisotropy from
Page 7 and 8: Scientific Divisions of the ASCR Ma
Page 9 and 10: Organization Units of the Geophysic
Page 11 and 12: Staff of the Geophysical Institute,
Page 13 and 14: Observatories of the Geophysical In
Page 15 and 16: The air-ground temperature monitori
Page 17 and 18: Geographic locations of the observa
Page 19 and 20: fourth logging. A passage of the fr
Page 21 and 22: Fig. 3. The borehole climate change
Page 23 and 24: Fig. 5. Monitoring results (1995-20
Page 25 and 26: Fig. 6. Residual gravity anomalies
Page 27 and 28: Fig. 9. Example showing measured P-
Page 29 and 30: Fig. 10. A simplified sketch showin
Page 31 and 32: Deep structure, seismotectonics and
Page 33 and 34: References Špičák A., Hanuš V.
Page 35 and 36: etrieved by inversion of surface wa
Page 37 and 38: References Babuška V., Plomerová
Page 39 and 40: References Brož M., Hrubcová P.,
Page 41 and 42: consecutive event pairs occurring s
Page 43 and 44: Amplitude ratios for complete momen
Page 45 and 46: References Vavryčuk V., 2005. Foca
Page 47 and 48: Fig. 28. Projections of the 3D ray
Page 49 and 50: Fig. 30 shows comparison of QI (red
Page 51 and 52: Electromagnetic depth soundings A c
Page 53 and 54: with the maximum/minimum resistivit
Page 55: spectral methods (Hejda and Reshetn
Page 59 and 60: ) The rapidly varying geomagnetic f
Page 61 and 62: Let us try to answer the question w
Page 63 and 64: Drilling the Eger Rift in Central E
Page 65 and 66: provided by IAGA, was used to cover
Page 67 and 68: 2005 Fulbright Scholarship, Prof. G
Page 69 and 70: Structure of the budget of the Geop
Page 71 and 72: Project code Title Principal invest
Page 73 and 74: Selected publications Alcalá M.D.,
Page 75 and 76: Vavryčuk V., Hrubcová P., Brož M
Page 77 and 78: Art exhibitons at the Geophysical I
show all

Geophysical Institute of the ASCR

Create successful ePaper yourself

Delete template?

Save as template?