Seismicity of Czorsztyn Lake Region: A Case of Reservoir Triggered Seismic Process?     

Wojciech Białoń  Ewa Zarzycka  Stanisław Lasocki 《Acta Geophysica》2015,63(4):1080-1089

Czorsztyn Lake is an artificial water reservoir backed up by the hydropower plant Niedzica earth dam on Dunajec River in south Poland. Its filling began in 1995 and ended in 1997. The reservoir of 234.5 million m3 capacity is shallow, between 20 to 50 m of water column, on average. Until 2011 the seismic activity in this region was sparse, some 1 event trimonthly. However, in November 2011 more than 60 events occurred. Such bursts of activity, separated by low activity periods, continue to appear. Since August 2013 the area is monitored by a local seismic network. The setup allows to accurately locate the epicenters and to determine source mechanisms for stronger events. The events are clustered and aligned along NE-SW direction and their mechanisms are very similar, indicating N-S strike slip faulting. This and the irregular pattern of activity suggest that this seismicity is triggered by the reservoir impoundment.  相似文献   

The long-term stability of extrasolar system HD 37124. Numerical study of resonance effects     

Krzysztof Go&#;dziewski  S&#;awomir Breiter  Wojciech Borczyk 《Monthly notices of the Royal Astronomical Society》2008,383(3):989-999

We describe numerical tools for the stability analysis of extrasolar planetary systems. In particular, we consider the relative Poincaré variables and symplectic integration of the equations of motion. We apply the tangent map to derive a numerically efficient algorithm of the fast indicator Mean Exponential Growth factor of Nearby Orbits (MEGNO), a measure of the maximal Lyapunov exponent, that helps to distinguish chaotic and regular configurations. The results concerning the three-planet extrasolar system HD 37124 are presented and discussed. The best-fitting solutions found in earlier works are studied more closely. The system involves Jovian planets with similar masses. The orbits have moderate eccentricities, nevertheless the best-fitting solutions are found in dynamically active region of the phase space. The long-term stability of the system is determined by a net of low-order two-body and three-body mean motion resonances. In particular, the three-body resonances may induce strong chaos that leads to self-destruction of the system after Myr of apparently stable and bounded evolution. In such a case, numerically efficient dynamical maps are useful to resolve the fine structure of the phase space and to identify the sources of unstable behaviour.  相似文献   

3D bearing capacity probabilistic analyses of footings on spatially variable c–φ soil     

Kawa  Marek  Puła  Wojciech 《Acta Geotechnica》2020,15(6):1453-1466

Acta Geotechnica - The paper examines three-dimensional (3D) analyses of the load bearing capacity of square and strip footings on a spatially variable cohesive–frictional (c–φ)...  相似文献   

Temporal and spatial variability of extreme river flow quantiles in the Upper Vistula River basin,Poland          下载免费PDF全文

Agnieszka Rutkowska  Patrick Willems  Charles Onyutha  Wojciech Młocek 《水文研究》2017,31(7):1510-1526

Temporal and spatial variability in extreme quantile anomalies of seasonal and annual maximum river flows was studied for 41 gauging stations at rivers in the Upper Vistula River basin, Poland. Using the quantile perturbation method, the temporal variability in anomalies was analysed. Interdecadal oscillating components were extracted from the series of anomalies using the Hilbert‐Huang transform method. Period length, part of variance of each component, and part of unexplained variance were assessed. Results show an oscillating pattern in the temporal occurrence of extreme flow quantiles with clusters of high values in the 1960–1970s and since the late 1990s and of low values in the 1980s and at the beginning of the 1990s. The anomalies show a high variability on the right bank of the Upper Vistula River basin during the summer season with the highest values in catchments located in the western and south‐western parts of the basin. River flow extreme quantiles were found to be associated with large‐scale climatic variables from the regions of the North Atlantic Ocean, Scandinavia, Eastern Europe, Asia, and, to a lesser extent, the Pacific Ocean. Similarities between temporal variability of river flows and climatic factors were revealed. Results of the study are important for flood frequency analysis because a long observation period is necessary to capture clusters of high and low river flows.  相似文献   

Simple two-dimensional kinematic framework designed to test warm rain microphysical models     

Marcin J. Szumowski  Wojciech W. Grabowski  Harry T. Ochs III 《Atmospheric Research》1998,45(4):299-326

This paper describes a two-dimensional kinematic framework designed to test warm rain microphysical models. The idealized flow field is based on a case study from the Hawaiian Rainband Project (1990). Analyses of radar and aircraft data collected in convective cells embedded in Hawaiian rainbands are included for model validation. A Cloud Condensation Nuclei (CCN) activation spectrum, a condensational growth equation including the CCN chemical composition, collection efficiencies, and terminal velocities of the growing drops, are all provided. A sample set of figures from the test run with bulk microphysical parameterization illustrates the desired format for comparisons between the detailed model results and for validation of the model output with observations. This simple yet realistic test formulation includes vertical and horizontal advection, and can be used to evaluate microphysical model performance without complexities resulting from dynamical–microphysical interactions in dynamic cloud models. Without such interactions, scientists can focus on key physical processes involved in the formation of warm rain. The accurate representation of these processes in detailed models is essential to successfully simulate the observed evolution of warm precipitating clouds.  相似文献   

Least squares collocation with uncorrelated heterogeneous noise estimated by restricted maximum likelihood   总被引：2，自引：1，他引：1  

Wojciech Jarmołowski 《Journal of Geodesy》2015,89(6):577-589

  相似文献   

The concept of cryo-conditioning in landscape evolution — Comment to the paper published by Ivar Berthling and Bernd Etzelmüller,Quaternary Research 75 (2011) 378–384     

Wojciech Dobiński 《Quaternary Research》2012,77(1):211-212

The term “cryo-conditioning,” proposed by the authors for classifying specific landform association in periglacial landscapes, needs to be defined more precisely. A starting point could be the proper understanding of the term “Cryo-” in the various compound words found in various disciplines. This is also important for a correct understanding of the proposed concepts, since it concerns one of the most important processes in nature: the phase transition of water between solid and liquid. Cold-temperate transition surfaces in polythermal glaciers and at the permafrost base in their forelands can act as a specific hub between the glacial and periglacial domains.  相似文献   

Malacological and palynological evidence of the Lower Pleistocene cold phase at the Carpathian Foothills (Southern Poland)     

Ewa Stworzewicz  Wojciech Granoszewski  Antoni Wójcik 《Quaternary Research》2012,77(3):492-499

Early Pleistocene sediments bearing gastropod shells and pollen flora were found during coring at Jawornik (South Poland) at a depth interval of 54.30–39.00 m, beneath the oldest till of the Carpathians. Thirteen land-snail taxa identified in 55 samples of the core formed two molluscan assemblages. In the bottom part, typical cold-loving snails were found (e.g. Vallonia tenuilabris, Pupilla loessica, Vertigo genesii, Columella columella), whereas in the upper part only Semilimax kotulae was present. The succession of molluscan assemblages may suggest that at the site of deposition, after a phase of tundra, steppe-tundra or forest-steppe landscape with patches of wet habitats in cold climate, the climate became slightly milder but still cool, favourable to the spreading of boreal (coniferous) woodlands. Pollen analysis was performed only for the upper part of the profile. The pollen spectra, besides the Tertiary (Miocene) elements, contained sporomorphs common to the Tertiary and Quaternary floras. Among them, the highest percentages were noted for Pinus haploxylon t., P. diploxylon t., Picea, Quercus, Ericaceae, Betula, and Ulmus. The fact that the sediments with organic remains underlie the oldest Scandinavian till suggests that they are older than the oldest glacial unit of the South-Polish Complex (Narevian = Menapian, ~ 1.2 Ma).  相似文献   

Evidence of probable paleotsunami deposits on Kho Khao Island, Phang Nga Province, Thailand     

Supawit Yawsangratt  Witold Szczuciński  Niran Chaimanee  Sirapapa Chatprasert  Wojciech Majewski  Stanis?aw Lorenc 《Natural Hazards》2012,63(1):151-163

The 2004 tsunami deposits and probable paleotsunami deposits were studied at the southern Kho Khao Island, on Andaman Sea coast of Thailand. The 2004 tsunami laid down about 8?cm of fining upward medium sand and locally about 40?cm of massive coarse sand with common mud clasts. The sediments were characterized by the presence of marine foraminiferal assemblage; however, already after 5?years many of carbonate foraminiferal tests were partly or completely dissolved. The probable paleotsunami deposits form layer about 1?m thick. It consists of massive very coarse sand with common big shells and mud clasts. Its composition suggests a marine origin and the presence of mud clasts, and similarity to the 2004 tsunami deposits suggests that the layer was left by paleotsunami, which took place probably during the late Holocene, even though two shells within the layer gave ¹⁴C ages of 40,000?years or more.  相似文献   

Development of an incised valley‐fill at an evolving rift margin: Pleistocene eustasy and tectonics on the southern side of the Gulf of Corinth,Greece     

Katarina Gobo  Massimiliano Ghinassi  Wojciech Nemec  Eivind Sjursen 《Sedimentology》2014,61(4):1086-1119

This study from the southern margin of the Gulf of Corinth documents a Late Pleistocene incised valley‐fill succession that differs from the existing facies models, because it comprises gravelly shoal‐water and Gilbert‐type deltaic deposits, shows strong wave influence and lacks evidence of tidal activity. The valley‐fill is at least 140 m thick, formed in 50 to 100 ka between the interglacials Marine Isotope Stage 9a and Marine Isotope Stage 7c. The relative sea‐level rise left its record both inside and outside the incised valley, and the age of the valley‐fill is estimated from a U/Th date of coral‐bearing deposits directly outside the palaeovalley outlet. Tectonic up‐warping due to formation of a valley‐parallel structural relay ramp contributed to the valley segmentation and limited the landward extent of marine invasions. The valley segment upstream of the ramp crest was filled with a gravelly alluvium, whereas the downstream segment accumulated fluvio‐deltaic deposits. The consecutive deltaic systems nucleated in the ramp‐crest zone, forming a bathymetric gradient that promoted the ultimate growth of thick Gilbert‐type delta. The case study contributes to the spectrum of conceptual models for incised valley‐fill architecture. Four key models are discussed with reference to the rates of sediment supply and accommodation development, and it is pointed out that not only similarity, but also all departures of particular field cases from these end‐member models may provide valuable information on the system formative conditions. The Akrata incised valley‐fill represents conditions of high sediment supply and a rapid, but stepwise development of accommodation that resulted from the spatiotemporal evolution of normal faulting at the rift margin and overprinted glacioeustatic signals. This study adds to an understanding of valley‐fill architecture and provides new insights into the Pleistocene tectonics and palaeogeography of the Corinth Rift margin.  相似文献