Soil gas composition above gas deposits and perspective structures of the Carpathian Foredeep,SE Poland

In 2001 a surface geochemical survey was carried out in the Carpathian Foredeep, in the area between Jaros?aw and Radymno (SE Poland) where multihorizon gas deposits were discovered. These deposits accumulate microbial CH₄ with small amounts of N₂ and higher molecular weight gaseous hydrocarbons. Soil–gas composition in the hydrocarbon fields in the study area is relatively different from the original composition of natural gas occurring in the subsurface reservoir. In 449 analyzed soil gas samples collected from 1.2 m depth relatively low concentrations were found for CH₄ (median value 2.2 ppm) and its homologues (median value of total alkanes C₂–C₄ – 0.02 ppm). Alkenes were encountered in 36.3% of the analyzed samples (mean value of total alkenes C₂–C₄ – 0.015 ppm) together with distinctly higher concentrations of H₂ (maximum value – 544 ppm, mean value – 42 ppm) and CO₂ (maximum value – 10.26 vol.%, mean value – 2.27 vol.%). Individual, very high concentrations of CH₄ (up to about 35 vol.%) resulted from sub-surface biochemical reactions whereas higher alkanes detected in soil gases (up to about 68 ppm) originated from deep gas accumulations. Both the H₂ and alkenes may be indirect indicators of deep hydrocarbon accumulations. Carbon dioxide may also be useful for hydrocarbon exploration, revealing increased concentrations in those sampling sites where CH₄ concentrations are strongly depleted, presumably due to bacterial oxidation. These relationships are valid only for the study area and should not be extended as an universal principle.     

Studies of aerosols advected to coastal areas with the use of remote techniques

This paper presents the results of the studies of aerosol optical properties measured using lidars and sun photometers. We describe two case studies of the combined measurements made in two coastal zones in Crete in 2006 and in Rozewie on the Baltic Sea in 2009. The combination of lidar and sun photometer measurements provides comprehensive information on both the total aerosol optical thickness in the entire atmosphere as well as the vertical structure of aerosol optical properties. Combination of such information with air mass back-trajectories and data collected at stations located on the route of air masses provides complete picture of the aerosol variations in the study area both vertically and horizontally. We show that such combined studies are especially important in the coastal areas where depending on air mass advection directions and altitudes the influence of fine or coarse mode (in this case possibly sea-salt) particles on the vertical structure of aerosol optical properties is an important issue to consider.     

Influence of Elevation Data Source on 2D Hydraulic Modelling

The aim of this paper is to analyse the influence of the source of various elevation data on hydraulic modelling in open channels. In the research, digital terrain models from different datasets were evaluated and used in two-dimensional hydraulic models. The following aerial and satellite elevation data were used to create the representation of terrain–digital terrain model: airborne laser scanning, image matching, elevation data collected in the LPIS, EuroDEM, and ASTER GDEM. From the results of five 2D hydrodynamic models with different input elevation data, the maximum depth and flow velocity of water were derived and compared with the results of the most accurate ALS data. For such an analysis a statistical evaluation and differences between hydraulic modelling results were prepared. The presented research proved the importance of the quality of elevation data in hydraulic modelling and showed that only ALS and photogrammetric data can be the most reliable elevation data source in accurate 2D hydraulic modelling.     

Diversity and conservation status of large branchiopods (Crustacea) in ponds of western Poland

A survey on temporary ponds has been conducted in search for large branchiopod crustaceans (Anostraca, Notostraca, Spinicaudata and Laevicaudata) in Wielkopolska province (western Poland). 728 pools have been studied and large branchiopods have been found in 221 of them. Seven species have been recorded, including three anostracans: Branchipus schaefferi, Chirocephalus shadini and Eubranchipus grubii; two notostracans: Lepidurus apus and Triops cancriformis; one spinicaudatan, Cyzicus tetracerus and one laevicaudatan, Lynceus brachyurus. According to the analysis of co-occurrence, the species form three groups, differing in habitat preferences and conservation status. The number of species shows that the diversity of globally threatened large branchiopods is still relatively high in the region. On the other hand, their conservation status is highly diverse and in most species unfavourable. Distribution of all species is highly clustered: large branchiopods have been generally found in 33 UTM squares (10 × 10 km) of 96 squares studied. However, only two species, i.e. E. grubii and L. apus occurred in more than five such squares and could be assessed as moderately widespread. Most water bodies inhabited by large branchiopods occur in groups forming patches of suitable habitats which are dispersed among prevailing seemingly unsuitable areas. Sustaining the existence of large metapopulations seems, therefore, to be essential for conservation of branchiopod species diversity. Field observations also bring some examples of human activities unintentionally supporting the branchiopod conservation.     

Geostatistical evaluation of magnetic indicators of forest soil contamination with heavy metals

The goal of the study was the geostatistical evaluation of quantitative magnetic measures, which can be used for effective delineation of the extent of the area polluted with heavy metals. Several parameters of magnetic susceptibility, measured in the soil profile, were proposed as magnetic indicators of soil pollution and analyzed in detail. The following parameters were calculated: maximum magnetic susceptibility, magnetic susceptibility at the depth of 3 cm and 5 cm, and the area under the curve of magnetic susceptibility. Measurements were performed at two forested study areas, located in Upper Silesian Industrial Area (Poland). Analyses were performed using geostatistical methods, and the results were verified using dense chemical measurements. The results showed that the area under curve of magnetic susceptibility was the most effective magnetic indicator of soil contamination with heavy metals. It was possible to detect the entire polluted area, and only about 16% of the study area was assumed to be contaminated while being unpolluted. The results obtained with maximum magnetic susceptibility and magnetic susceptibility at the depth of 3 cm and 5 cm were less effective in comparison with the area under curve of magnetic susceptibility.     

Evolution of the palaeolake at Ruszkówek (central Poland) during the Eemian Interglacial based on isotope,cladoceran and diatom data

We present isotope, cladoceran and diatom results from investigations of Eemian sediments of the palaeolake at Ruszkówek, central Poland. Our analyses of the 15-m-thick sediments indicate that sandy silts occur on the bottom, followed by calcareous gyttja, interbedded with lake marl. The upper part of the sequence contains peat and peaty sands. Values of δ¹⁸O change from −9.4‰ to −3.3‰ and δ¹³C values oscillate between −3.2‰ and +7.0‰. Nine isotope zones (Is) were defined and characterized using stable isotope analysis of carbonates. Fifteen species of subfossil Cladocera were found and six faunal zones were distinguished (Cladocera zones). One hundred and twenty-three diatom taxa, representing 31 genera were identified, enabling us to discern six Diatom Assemblage Zones. The isotope, cladoceran, and diatom data correlate well with pollen data that define seven phases of evolution of the palaeolake at Ruszkówek. The palaeolake began during the final phase of the Wartanian (Late Saalian Glaciation). During the early Eemian, the palaeolake reached its maximum depth. During the Early Vistulian glaciation, the palaeolake declined. Changes in the cladoceran and diatom communities indicate initial oligotrophic conditions in the lake, then an increase to mesotrophy, and finally eutrophic conditions.     

Attenuation from microseismic datasets by the peak frequency method benchmarked with the spectral ratio method

Recently proposed peak-frequency method is used to estimate the P- and S-wave quality factors from microseismic events. We use a downhole monitoring dataset of 10 high signal-to-noise ratio microseismic events to calculate P- and S-wave effective attenuation of a carbonate reservoir. We benchmark these results with the spectral ratio method and obtain mutually consistent results. Additionally we develop and test two techniques of peak frequency determination. We show that the peak frequency method can be successfully used in the estimation of the quality factor and it provides precise measurements of attenuation.