Modelling the Velocity Field in a Regular Grid in the Area of Poland on the Basis of the Velocities of European Permanent Stations     

Janusz Bogusz  Anna Kłos  Piotr Grzempowski  Bernard Kontny 《Pure and Applied Geophysics》2014,171(6):809-833

The paper presents the results of testing the various methods of permanent stations’ velocity residua interpolation in a regular grid, which constitutes a continuous model of the velocity field in the territory of Poland. Three packages of software were used in the research from the point of view of interpolation: GMT (The Generic Mapping Tools), Surfer and ArcGIS. The following methods were tested in the softwares: the Nearest Neighbor, Triangulation (TIN), Spline Interpolation, Surface, Inverse Distance to a Power, Minimum Curvature and Kriging. The presented research used the absolute velocities’ values expressed in the ITRF2005 reference frame and the intraplate velocities related to the NUVEL model of over 300 permanent reference stations of the EPN and ASG-EUPOS networks covering the area of Europe. Interpolation for the area of Poland was done using data from the whole area of Europe to make the results at the borders of the interpolation area reliable. As a result of this research, an optimum method of such data interpolation was developed. All the mentioned methods were tested for being local or global, for the possibility to compute errors of the interpolated values, for explicitness and fidelity of the interpolation functions or the smoothing mode. In the authors’ opinion, the best data interpolation method is Kriging with the linear semivariogram model run in the Surfer programme because it allows for the computation of errors in the interpolated values and it is a global method (it distorts the results in the least way). Alternately, it is acceptable to use the Minimum Curvature method. Empirical analysis of the interpolation results obtained by means of the two methods showed that the results are identical. The tests were conducted using the intraplate velocities of the European sites. Statistics in the form of computing the minimum, maximum and mean values of the interpolated North and East components of the velocity residuum were prepared for all the tested methods, and each of the resulting continuous velocity fields was visualized by means of the GMT programme. The interpolated components of the velocities and their residua are presented in the form of tables and bar diagrams.  相似文献   

Estimating thermal conductivity from core and well log data   总被引：1，自引：1，他引：0  

Irena Gąsior  Anna Przelaskowska 《Acta Geophysica》2014,62(4):785-801

The aim of the presented work was to introduce a method of estimating thermal conductivity using well log data. Many petrophysical properties of rocks can be determined both by laboratory measurements and well-logs. It is thus possible to apply geophysical data to empirical models based on relationships between laboratory measured parameters and derive continuous thermal conductivity values in well profiles. Laboratory measurements were conducted on 62 core samples of Meso-Paleozoic rocks from the Carpathian Foredeep. Mathematical models were derived using multiple regression and neural network methods. Geophysical data from a set of seven well logs: density, sonic, neutron, gamma ray, spectral gamma ray, caliper and resistivity were applied to the obtained models. Continuous thermal conductivity values were derived in three well profiles. Analysis of the obtained results shows good consistence between laboratory data and values predicted from well log data.  相似文献   

Studies of aerosol optical depth with the use of Microtops II sun photometers and MODIS detectors in coastal areas of the Baltic Sea     

Olga Zawadzka  Przemysław Makuch  Krzysztof M. Markowicz  Tymon Zieliński  Tomasz Petelski  Vidmantas Ulevičius  Agata Strzałkowska  Anna Rozwadowska  Dorota Gutowska 《Acta Geophysica》2014,62(2):400-422

In this paper we describe the results of a research campaign dedicated to the studies of aerosol optical properties in different regions of both the open Baltic Sea and its coastal areas. During the campaign we carried out simultaneous measurements of aerosol optical depth at 4 stations with the use of the hand-held Microtops II sun photometers. The studies were complemented with aerosol data provided by the MODIS. In order to obtain the full picture of aerosol situation over the study area, we added to our analyses the air mass back-trajectories at various altitudes as well as wind fields. Such complex information facilitated proper conclusions regarding aerosol optical depth and Ångström exponent for the four locations and discussion of the changes of aerosol properties with distance and with changes of meteorological factors. We also show that the Microtops II sun photometers are reliable instruments for field campaigns. They are easy to operate and provide good quality results.  相似文献   

Optical properties of long-range transported volcanic ash over Romania and Poland during Eyjafjallajökull eruption in 2010     

Anca Nemuc  Iwona S. Stachlewska  Jeni Vasilescu  Anna Górska  Doina Nicolae  Camelia Talianu 《Acta Geophysica》2014,62(2):350-366

After Eyjafjallajökull volcano eruption on 14 April 2010, due to a complex air mass circulation, Romania was exposed to volcanic ash and its mixture with continental aerosols. Ash particles with an average Ångström (UV-VIS) exponent of 1.4 ± 0.2 and (VIS-IR) of 1.2 ± 0.3, a color ratio (VIS-UV) of 0.54 and (IR-VIS) of 0.49, an average particle depolarization value ～9.4%, and a lidar ratio of 50 sr were retrieved on 18 April from multiwavelength Raman lidar measurements in Bucharest. Mixed volcanic ash with mineral dust particles advected from Sahara, depolarization ～12%, Ångström (UV-VIS) exponent of 1.25 ± 0.25 and (VIS-IR) of 1.45 ± 0.25, an increased color ratio (VIS-UV) of 0.61, (IRVIS) of 0.39 and lidar ratio of 53 sr were identified on 28 April. From observations in Poland conducted by an elastic lidar at 532 nm and a ceilometer at 1064 nm we retrieved an average backscatter related Ångström (VIS-IR) exponent of 1.25 ± 0.35, and a color ratio (IR-VIS) of 0.53 in the layer at about 5.5 km during the night of 16/17 April, indicating fresh ash over Warsaw.  相似文献   

Extension of EGNOS ionospheric correction coverage area     

Anna Swiatek  Iwona Stanislawska  Zbigniew Zbyszynski  Beata Dziak-Jankowska 《Acta Geophysica》2014,62(1):259-269

Ionosphere coverage is likely to be a driver for the EGNOS coverage area. Hence, a study considering a dedicated ionosphere algorithm to improve the ionosphere coverage area has been conducted. The logic of the study is the following: the accuracy of the GPS signal depends mainly on the total electron content (TEC). At two close points, TEC changes in time in a very similar way; these are region dependent variables. This correlation decreases with growing distance between the observation points and is anisotropic. Based on TEC variogram analysis, the specific algorithm has been developed. This specific algorithm is presented and discussed.  相似文献   

Origin, enzymatic response and fate of dissolved organic matter during flood and non-flood conditions in a river-floodplain system of the Danube (Austria)     

Anna Sieczko  Peter Peduzzi 《Aquatic Sciences - Research Across Boundaries》2014,76(1):115-129

Spectroscopic techniques and extracellular enzyme activity measurements were combined with assessments of bacterial secondary production (BSP) to elucidate flood-pulse-linked differences in carbon (C) sources and related microbial processes in a river-floodplain system near Vienna (Austria). Surface connection with the main channel significantly influenced the quantity and quality of dissolved organic matter (DOM) in floodplain backwaters. The highest values of dissolved organic carbon (DOC) and chromophoric DOM (CDOM) were observed during the peak of the flood, when DOC increased from 1.36 to 4.37 mg l^?1 and CDOM from 2.94 to 14.32 m^?1. The flood introduced DOC which consisted of more allochthonously-derived, aromatic compounds. Bacterial enzymatic activity, as a proxy to track the response to changes in DOM, indicated elevated utilization of imported allochthonous material. Based on the enzyme measurements, new parameters were calculated: metabolic effort and enzymatic indices (EEA 1 and EEA 2). During connection, bacterial glucosidase and protease activity were dominant, whereas during disconnected phases a switch to lignin degradation (phenol oxidase) occurred. The enzymatic activity analysis revealed that flooding mobilized reactive DOM, which then supported bacterial metabolism. No significant differences in overall BSP between the two phases were detected, indicating that heterogeneous sources of C sufficiently support BSP. The study demonstrates that floods are important for delivering DOM, which, despite its allochthonous origin, is reactive and can be effectively utilized by aquatic bacteria in this river-floodplain systems. The presence of active floodplains, characterized by hydrological connectivity with the main channel, creates the opportunity to process allochthonous DOC. This has potential consequences for carbon flux, enhancing C sequestration and mineralization processes in this river-floodplain system.  相似文献   

Structural damage in the cities of Reggiolo and Carpi after the earthquake on May 2012 in Emilia Romagna   总被引：2，自引：2，他引：0  

Marco Andreini  Anna De Falco  Linda Giresini  Mauro Sassu 《Bulletin of Earthquake Engineering》2014,12(5):2445-2480

This paper addresses the structural damage to the main buildings of the cities of Reggiolo and Carpi after the primary earthquake shocks on May 20th and 29th, 2012, in Emilia Romagna. The damage survey, performed via form-based methods, highlights the different seismic behaviour of several types of buildings, especially those having historical features, and the consequences of the damage in terms of costs. Moreover, an analysis of some failure mechanisms activated in Reggiolo enables the evaluation of the local peak ground acceleration, due to the soil amplification.  相似文献   

Assessing coastal benthic macrofauna community condition using best professional judgement - Developing consensus across North America and Europe     

Heliana Teixeira  Ángel Borja  J. Ananda Ranasinghe  Daniel M. Dauer  Steven Degraer  Antoine Grémare  Roberto J. Llansó  João C. Marques  Anna Occhipinti-Ambrogi  Rafael Sardá  Ronald G. Velarde 《Marine pollution bulletin》2010,60(4):589-600

Benthic indices are typically developed independently by habitat, making their incorporation into large geographic scale assessments potentially problematic because of scaling inequities. A potential solution is to establish common scaling using expert best professional judgment (BPJ). To test if experts from different geographies agree on condition assessment, sixteen experts from four regions in USA and Europe were provided species-abundance data for twelve sites per region. They ranked samples from best to worst condition and classified samples into four condition (quality) categories. Site rankings were highly correlated among experts, regardless of whether they were assessing samples from their home region. There was also good agreement on condition category, though agreement was better for samples at extremes of the disturbance gradient. The absence of regional bias suggests that expert judgment is a viable means for establishing a uniform scale to calibrate indices consistently across geographic regions.  相似文献   

The influence of the 3D morphology and cavity network on the seismic response of Castelnuovo hill to the 2009 Abruzzo earthquake     

Lorenza Evangelista  Luigi Landolfi  Anna d’Onofrio  Francesco Silvestri 《Bulletin of Earthquake Engineering》2016,14(12):3363-3387

During the Abruzzo earthquake (6.IV.2009, M_W = 6.3), the village of Castelnuovo, lying on an elliptical hill about 60 m high, underwent an intensive damage (I_MCS = 9–10), that could be partly ascribed to the topographic amplification and to the presence of an underground cavity network. To verify these hypotheses, the seismic response of the hill was carefully investigated adopting both 2D and 3D finite difference numerical models. Analyses were carried out using a detailed geotechnical model, defined on the basis of a comprehensive field investigation (boreholes, DH, HVSR, ERT) and accurate laboratory tests (RC-TS). The reference input motion was reproduced considering the time history of the mainshock recorded at an accelerometric station close to the epicenter, conveniently deconvoluted to the bedrock and scaled in amplitude to the site of Castelnuovo. The results of the numerical analyses, expressed in terms of distribution of the amplification factor of peak acceleration and Housner intensity, proved that the topographic effects significantly influenced the ground motion at surface, whereas the role of cavities seemed to be negligible.  相似文献   

Microfungi Potentially Pathogenic for Humans Reported in Surface Waters Utilized for Recreation          下载免费PDF全文

Anna Biedunkiewicz  Katarzyna Góralska 《洁净——土壤、空气、水》2016,44(6):599-609

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