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EN
Lower Cambrian Mt Currie conglomerate at Kata Tjuta bornhardts (Central Australia) bears numerous fractured clasts. Clast-cutting fractures are restricted to particular clasts, the matrix of the conglomerate is not fractured. The fractures are tectonic joints of two sets. The joints were formed due to either seismic or aseismic deformation. In the former case, the fractures may result from Early Paleozoic earthquakes.
EN
The seismic elastomeric bearings reinforced with fibre is considered as a new technology in comparison to other conventional isolator systems in civil engineering. In this type of bearing, recycled fibres replaced traditional steel plates used in common bearings. Therefore, this type of bearing has been studied in recent years due to both environmental and cost-saving advantages. The shortage of references about the application of this type of bearing in the bridge industry, and particularly the continuous-span bridges, prompted the researchers in this study to investigate the performance of the isolated reinforced concrete box girder bridges with continuous spans. Reducing the acceleration transmission from the substructure to the superstructure is one of the main advantages of using seismic bearings. Based on the study of the structural models, it was found that, in most cases, elastomeric bearings reinforced with fibres showed a suitable performance and reduced the acceleration applied to the superstructure by absorbing the earthquake energy.
3
Content available remote Assessment of Emergencies Threatening a Particular Region
EN
The paper focuses on emergencies in a particular region of the Slovak Republic. The focus is mainly on describing the emergencies to which the region is most vulnerable and classifying them, as well as specific locations or businesses where there is a high risk of an emergency occurring. From the point of view of the effects of possible emergencies on the district of Bratislava, the most likely situations are natural disasters (floods from precipitation and watercourses, hailstorms, storms, landslides, ice) and accidents (fires, explosions and releases of dangerous substances). When planning rescue work, it is necessary to start from the worst-case scenario of the emergency, while the most important measure to protect the population is issuing warnings and possible evacuation. Special attention should be paid to the following measures: checking the safety measures around hydrological structures and watercourses, carrying out checks on legal entities and natural persons – entrepreneurs who manufacture, store and handle hazardous substances, preparing controlling organizations, forces and resources to carry out rescue work, preparing the population for self-protection and mutual assistance in the event of emergencies, mutual cooperation of rescue teams in preparation for emergencies, exchange of experience and knowledge with neighbouring districts.
PL
Dostęp do mocy obliczeniowej super komputerów oraz możliwość wykorzystania nowoczesnych systemów, np. takich jak Ls-Dyna, pozwala na uzyskanie niezwykle szczegółowych rozwiązań bardzo skomplikowanych problemów inżynierskich.
EN
The article presents some remarks on the dynamic simulations of bridges in the Ls-Dyna system. Some results of two dynamic problems are presented. The first example concerns a viaduct that was hit by a vehicle passing under it. The second one relates to the design of a concrete multi-span bridge subjected to earthquakes of various intensity.
EN
Crevasse-splay microdelta deposits and their soft-sediment deformation structures (SSDS) are described from a tectonically active lignite-bearing area. These strongly deformed siliciclastic deposits, situated between two lignite benches, are typical of a crevasse-splay microdelta. They accumulated in the overbank zone of a Middle Miocene river system (backswamp area) where shallow ponds or lakes occasionally existed. The deformation takes the form of deformed lamination and load (load casts and flame structures) structures as well as seismic breccias within the first Mid-Polish lignite seam. Ductile deformation structures were generated first by liquefaction and then the breccia was formed under brittle conditions. The brecciation followed a sudden tectonic collapse resulting in an increase in pore pressure rel ated to upward water movement. The occurrence in a tectonic graben and characteristic morphological features suggest an origin of these deformational structures with seismic shocks; thus, they can be called seismites. Hence, we provide strong evidence for accumulation of crevasse-splay sediments in the standing water of a backswamp area, and for tectonic activity in central Poland as the Middle Miocene lignite accumulated.
6
Content available remote Geologiczne uwarunkowania rozwoju osuwisk w rejonie Krynicy-Zdroju
EN
The paper presents the final results of mapping work of the Polish Geological Institute - National Research Institute, carried out in the Krynica-Zdrój area in 2010-2012. In the Beskid Niski and Sądecki there are numerous landslides of surface sediments. They also occur in the spa zone of Krynica-Zdrój, posing a threat to its functioning. The basic problem is to recognise the nature of these geohazards and their occurrence in this region. For these reasons, a landslide inventory map was constructed for the whole study area (urban-rural commune). As a result of the analysis, a large variation in the distribution, type and range of landslides has been documented. The landslide surface index and the landslide density index were calculated, concluding that the two indexes differ from each other depending on the geographical position of the analysed area. Both indicators are 2.5-3 times higher for the Krynica-Zdrój town area than for the rural commune area. This variability is associated with different lithologies, tectonics, and geomorphologic features in the area. Krynica-Zdrój lies in the area predisposed to the development of landslides, where the overlapping effects of several passive factors causes mass movements. The Krynica-Zdrój area is composed of thick-bedded sandstones of the Krynica Sandstone Member and the Piwniczna Sandstone Member. They are underlain by variegated shales and thin-bedded turbidites of the Zarzecze Formation. In addition, tectonics of the deep basement is very important. Under the town, there is a deep Krynica fault zone additionally cut by sets of strike-slip faults that altogether cause severe disintegration of the subsurface material and the weakening of cohesive force. The area with the dense sets of faults is an active stress zone. Epicentres of earthquakes probably clustered along all these faults, causing the development and rejuvenation of many landslides in the Krynica-Zdrój area.
EN
The purpose of the article is to carry out a complex analysis of conditions and natural factors forming the hydrogeological regime as well as to integrate the existing information and groundwater monitoring data in Ivano-Frankivsk region for further creating the unified automated system to collect, process, analyze and store the monitoring observation data. The authors offer methodology, which is based on the geoinformation approach, for organizing and monitoring of the groundwater. The structure of spatial and attributive data that afford to systemize the existing schemes of the hydrogeological zoning as well as the results of long-term observations over variability of the groundwater levels and factors forming the hydrogeological regime were developed. The new approaches for improving the techniques to forecast the groundwater level with due consideration of temporal patterns for changes in water level, the Moon phases and seismic activity, are proposed. The obtained results are considered as an informational basis for reorganization of the state hydrogeological monitoring on the example of Ivano-Frankivsk region.
EN
A number of recent studies suggest that atmospheric changes that precede an earthquake might offer the hope of providing early warning. This study attempts to examine seismo-atmospheric anomalies around the time and the location of some of the major earthquakes in Greece in the period 2001–2015. Daily values of aerosol optical depth (AOD) and total ozone column (TOZ) obtained from satellite observations are used, in the time window between 25 days before and 14 days after each of these events, in a 1° × 1° area centred on the epicentre of each earthquake. For some of these earthquake events, abnormal increases in time series of AOD and TOZ data were detected before and after the occurrence of the earthquake. Nevertheless, in other cases, no clear anomalies were observed around the earthquake date. In addition, examining the statistics of AOD and TOZ daily values, there were many cases of prominent abnormal variations, without, however, being associated with an earthquake event. Therefore, no clear association was found between AOD and TOZ fluctuations and recent earthquakes in Greece.
EN
We investigate the structural properties of a spatio-temporal network of earthquake events that incorporates magnitude information between the connected events. The network creates temporally directed links from an origin event towards a later event if it breaks the record closest distance from the origin among all the events in the catalog so far. Additionally, the links are conditionally classified based on the magnitude difference between connected events: “up” (“down”) connections point from a weaker (stronger) to a stronger (weaker) event. Using earthquake records from the Philippines from 1973 to 2012 and southern California from 1982 to 2012, we observe that the out-degree distributions show slight deviations from the corresponding Poisson distribution of the same mean. The space and time separations of connected earthquakes both show power-law regimes, suggesting spatio-temporal (self)organization. More importantly, the conditional distributions of “up” and “down” connections in space, time, and network structure point to a higher likelihood of a stronger event triggering a nearby weaker event for the first few connections, as in the case of aftershocks. The results are captured by a sandpile-based model where a small but finite probability of preferentially targeting the most susceptible grid site is introduced. Our analysis, coupled with the discrete model analog, provides a quantitative picture of the spatio-temporal and magnitude organization of seismicity beyond just the successive events. The technique may be extended to further characterize similar long-period earthquake records to yield a more complete picture of the underlying processes involved in seismicity.
EN
The aftershock records of the magnitude 7.1 earthquake that hit the island of Bohol in central Philippines on 15 October 2013 is investigated in the light of previous results for the Philippines using historical earthquakes. Statistics of interevent distances and interevent times between successive aftershocks recorded for the whole month of October 2013 show marked differences from those of historical earthquakes from two Philippine catalogues of varying periods and completeness levels. In particular, the distributions closely follow only the regimes of the historical distributions that were previously attributed to the strong spatio-temporal correlations. The results therefore suggest that these correlated regimes which emerged naturally from the analyses are strongly dominated by the clustering of aftershock events.
EN
The earthquake inter-event time distribution is studied, using catalogs for different recent aftershock sequences. For aftershock sequences following the Modified Omori’s Formula (MOF) it seems clear that the inter-event distribution is a power law. The parameters of this law are defined and they prove to be higher than the calculated value (2 – 1/p). Based on the analysis of the catalogs, it is determined that the probability densities of the inter-event time distribution collapse into a single master curve when the data is rescaled with instantaneous intensity, R(t; Mth), defined by MOF. The curve is approximated by a gamma distribution. The collapse of the data provides a clear view of aftershock-occurrence self-similarity.
EN
Ground motion prediction equations are essential for several purposes ranging from seismic design and analysis to probabilistic seismic hazard assessment. In seismically active regions without sufficiently strong ground motion data to build empirical models, hybrid models become vital. Georgia does not have sufficiently strong ground motion data to build empirical models. In this study, we have applied the host-totarget method in two regions in Georgia with different source mechanisms. According to the tectonic regime of the target areas, two different regions are chosen as host regions. One of them is in Turkey with the dominant strike-slip source mechanism, while the other is in Iran with the prevalence of reverse-mechanism events. We performed stochastic finite-fault simulations in both host and target areas and employed the hybrid-empirical method as introduced in Campbell (2003). An initial set of hybrid empirical ground motion estimates is obtained for PGA and SA at selected periods for Georgia.
EN
The article presents the likely cause of cracks in the continental and oceanic lithospheric plates, and the probable causes of earthquakes initiating Earth’s speed changes. As the root cause of one of the earthquakes, the author adopts a rotational speed of the globe (reasons: changes of the ocean level, convection currents, or a change in the ice cover) causing the formation of small d’Alambert’s forces with a latitudinal direction, which affect the tectonic plates. The author shows that there is a natural amplifier in the lithosphere, which converts the small d’Alambert’s forces into forces capable of moving tectonic plates on the asthenosphere. The energy to produce the drift of tectonic plates comes from the potential energy of water column in the oceans and some lakes. Thus, the author also explains where the continent-moving forces come from, unlike AlfredWegener who was not able tounravelthis. It should be emphasized that the earthquake in 2011 (Fukushima) occurred during theEarth’s speed change. Current hypotheses should be re-examined and the reason for tectonic plate drift should be re-considered taking into account the hydrostatic pressure – a factor influencing the water column in the oceans and some lakes, and affecting the change in rotation speed of the Earth. The author believes that it is appropriate to carry out work to identify a close relationship between the changes in the Earth’s speed and earthquakes initiated by these changes, which would allow to forecast some earthquakes.
PL
Wobec rozwoju metod opracowania coraz liczniejszych zbiorów obserwacji, np. w postaci „chmur punktów”, dystans interpretacyjny otrzymywanych wyników do rzeczywistości zwiększa się czasem tak znacznie, że zastosowany model trudno odróżnić od metafory. W niniejszej pracy powracamy do korzeni tych metod, pokazując, na konkretnym przykładzie – zaskakującego trzęsienia w pobliżu Waszyngtonu w sierpniu 2011 r., zastosowanie najprostszego modelu „naturalnego”, skracającego dystans interpretacyjny.
EN
Considering the development of processing methods of sets of observations of growing numbers of elements, such as "point cloud", it may be stated that the interpretation distance between obtained results and the reality is so increased that it is difficult to distinguish between the applied model and a metaphor. In this paper the authors return to the roots of those methods and present - using the selected example of the surprising earthquake which happened close to Washington in August 2011 - utilisation of the simplest "natural" model, which shortens interpretation distance.
EN
In the beginning of July 2010, a ground fissure was observed in the field near the village of Mavropigi (Northern Greece) and specifically in its NW side. Later on (early September), a second ground fissure was perceived, close and almost parallel to the first one and very close to the limits of the lignite exploitation mine (by the Public Power Corporation, PPC). It was observed that the village of Mavropigi slides away slowly towards the PPC lignite mine. Geological, seismological, as well as geotechnical survey in the field indicated that the phenomenon is related to the coal mining exploitation in the near vicinity of the village rather than to any seismotectonic activity in the surrounding area.
EN
The earthquake spatial distribution is being studied, using earthquake catalogs from different seismic regions (California, Canada, Central Asia, Greece, and Japan). The quality of the available catalogs, taking into account the completeness of the magnitude, is examined. Based on the analysis of the catalogs, it was determined that the probability densities of the inter-event distance distribution collapse into single distribution when the data is rescaled. The collapse of the data provides a clear illustration of earthquake-occurrence self-similarity in space.
EN
In recent year, there has been growing interest in the possible use of electromagnetic observations to study earthquakes and possible precursors prior to seismic activity, in response to the success in United States, Japan, Russia, China, and other countries using seismo-electromagnetic methods. We have established a new experimental setup (i.e., biopotential sensor) in Farah region (geographic coordinates: 27.17°N, 77.47°E), Mathura, India. The setup has started operating and analyzed the data since November 2011. The data have been tested by various methods and a good correlation with seismic events was found; thus, a real-time analysis from 21:00 p.m. through 8:00 a.m. every day was initiated. First, we recorded the amplitude enhancement in bio-potential and found positive correlation with seismic activities (near Delhi and Rajasthan) and analyzed the data with solar flares and magnetic storms during the same period, finding a negative correlation of these events. The studies of these events are in progress with statistical analysis of the data. We chose the observing site in Farah region because this region is well known for being a site of a conductive channel of seismic activity.
PL
W pracy tej proponuje się bezpośrednie wyznaczenie potencjału grawitacyjnego W=v2/2 przez pomiar czasu t swobodnego spadku ciała z wysokości h. Wyznacza się też natężenie pola grawitacyjnego g. Procedura ta opiera się na prawie fizycznym v=2vm, gdzie vm=h/t, które daje proste zależności: W=2(h/t)2 oraz g=2h/t2. Istnieje więc możliwość skonstruowania prostego potencjometru grawitacyjnego, a nawet gradientometru, jako dwóch sprzężonych potencjometrów. Efektywność tej procedury sprawdziliśmy w prostym eksperymencie symulacyjnym na poziomie precyzji mGal.
EN
In this paper we propose a direct calculation of gravitational potential W=v2/2 by measuring the free fall time t of an object from height h. The intensity of the gravitational field g is also calculated. The procedure is based on the physical law v=2vm, where vm=h/t, which gives W=2(h/t)2 and g=2h/t2. It is therefore possible to construct a simple gravitational potentiometer, and even a gradientometer, as two coupled potentiometers. The effectiveness of this procedure is verified by a simple simulation experiment at the level of precision of mGal.
EN
The time series of radon (222Rn) concentration in soil gas at a fault, together with the environmental parameters, have been analysed applying two machine learning techniques: (i) decision trees and (ii) neural networks, with the aim at identifying radon anomalies caused by seismic events and not simply ascribed to the effect of the environmental parameters. By applying neural networks, 10 radon anomalies were observed for 12 earthquakes, while with decision trees, the anomaly was found for every earthquake, but, undesirably, some anomalies appeared also during periods without earthquakes.
EN
At Cazzaso (Friuli) in northeast Italy, radon (222Rn) activity concentration in soil gas in a borehole at a depth of 80 cm has been monitored continuously (at a frequency of once an hour) since May 2004, using a Barasol probe (Algade, France). In addition, environmental parameters (air and soil temperature, barometric pressure) have been recorded. The results have been evaluated and the relationship between radon levels and seismic activity is discussed. Correlation between radon concentration and barometric pressure has been observed. Preliminary results have shown a distinct radon anomaly prior to some earthquakes.
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