ALBERT

Description: The Unified Scaling Law for Earthquakes (USLE), that generalizes the Gutenberg–Richter recurrence relation, has evident implications since any estimate of seismic hazard depends on the size of territory that is used for investigation, averaging, and extrapolation into the future. Therefore, the hazard may differ dramatically when scaled down to the proportion of the area of interest (e.g. a city) from the enveloping area of investigation. In fact, given the observed patterns of distributed seismic activity the results of multi-scale analysis embedded in USLE approach demonstrate that traditional estimations of seismic hazard and risks for cities and urban agglomerations are usually underestimated. Moreover, the USLE approach provides a significant improvement when compared to the results of probabilistic seismic hazard analysis, e.g. the maps resulted from the Global Seismic Hazard Assessment Project (GSHAP). In this paper, we apply the USLE approach to evaluating seismic hazard and risks to population of the three territories of different size representing a sub-continental and two different regional scales of analysis, i.e. the Himalayas and surroundings, Lake Baikal, and Central China regions.

Description: To dynamical study of the dams, the prediction of occurred deformation caused by hydrostatic and hydrodynamic pressures during the operation phase as well as the designing phase is necessary. The reservoir water changes also the permanent variations of atmospheric temperature especially in the areas where there are significant seasonal and circadian changes in conditions are important factors to “dynamic system” of the dams. The aim of this paper is to present an applied dynamic method to identify the body of the dam as a dynamic system and to predict its behavior in the variable environmental conditions based on the monitoring observations. Non-parametric methods such as cross-covariance and coherence method are applied for system identification of the dam based on time series of input signal of measured forces and output signal of deformation measurements. The main feature of this paper is using the weighting function method which enables “System Identification” of the dam as a dynamic system, to model the deformation of the dam. The applied weighting function method benefits from measurements of effective factors on system of the dam also the deformation monitoring measurements from different sensors. For practical applicability of the method for a dam, Masjed–Soleiman “earth–dam” in Iran has been chosen. A wide range of instruments has been installed inside the dam to control the deformation; therefore multiple measurements are available for analysis. Since changing atmospheric temperature has not an important role in geotechnical study of an earth-dam singly, the authors decided to investigate the environmental condition such as atmospheric temperature and reservoir water-level changes as input signal to the “dam-sensors-combination” system. Here the authors carried out their investigation using seven epochs of geodetic measurements between 2000 and 2008, moreover the measurements of four anchors inside an installed rod-extensometer between 2007 and 2013, settlement observations on settlement-plates in different levels between 2008 and 2013, and a long-time series of the daily observations of three installed soil-extensometers between 2005 and 2013. A significant correlation between temperature changes and soil-extensometer observations has been determined, besides the coherence method leads to common periods of 351 days between input and output time series. The weighting function method is applied to model the deformation of the dam using deformation measurements of installed soil-extensometer with temperature and water-level changes as effective sources. The RMS of difference between the estimated dam deformations from weighting function model compared to original measurements was calculated at 0.039 mm also from the point of correlation the original deformation measurements and modeled deformations are correlated at 95 %. The RMS of the difference between measurements and the predicted dam deformations using the weighting function model was calculated at 0.057 mm leading to a correlation value of 91 %. If the absolute values are transformed in percentage of the deformation, the maximum error of prediction is 10 %. The results show the success of weighting function method to model the deformation observations of the dam affected by input factors. One of the most important achievements of this paper is to draw a distinction between temperature as a systematic error sources and the other effective factors on the settlement observations of the earth-dam via comparison of the results of non-parametric methods on different sensors.

Description: The Vértes Hills are one of the most active seismic regions in Hungary. An \(\hbox {M}_\mathrm{L}~=~4.5\) magnitude earthquake shocked this area near to Oroszlány on January 29, 2011. The mainshock was followed by about four hundred aftershocks, and their magnitude varied from \(\hbox {M}_\mathrm{L}~=~-0.6\) to \(\hbox {M}_\mathrm{L}~=~3.5\) . Despite of the large number of aftershocks, the seismotectonic interpretation is very difficult because these earthquakes occurred in the vicinity of quarries. The waveform similarity analysis was proven a successful method to separate earthquakes and explosions, and revealed plus information about the aftershock sequence.

Description: The Fukushima nuclear catastrophe has led to a wide-spread international discussion on how seismic and tsunami hazards can be better predicted and adverse consequences be prevented. In some countries the event led to the complete phase-out of nuclear energy. The lessons drawn by different organisations including earth scientists, earthquake engineers, non-governmental and governmental organisations will be reviewed from an independent position. This review captures the following areas: (1) Hazard assessment, (2) Engineering design and defence in depth concepts, (3) Emergency preparedness. It is shown that not all important lessons from the catastrophe have been drawn, because some of the root causes of the accident are not yet addressed. Especially the need of a holistic approach towards hazard assessment and the implementation of defence in depth and diversity of design principles for critical infrastructures like nuclear power plants hast to be stronger emphasized to prevent similar disasters.

Description: Providing warning notification several seconds before dangerous earthquake waves arrive at a target site reduces the property damages and human casualties. Most earthquake early warning systems (EEWS) developed are either regional (“network based”) or on-site (“stand alone”) systems. The recent upgrade of the seismic network in Romania with high dynamic range accelerometers allows recording of moderate to large magnitude earthquakes at very close epicentral distances (less than 10–20 km). This allows an increase of the warning lead-time (the time difference between the alert notification time and the arrival time of potentially destructive waves at a given target). The seismicity of Romania is significantly affected by earthquakes produced by the Vrancea seismic source with intermediate depth events (three shocks/century with magnitude Mw greater than 7.0). In this paper we present the performance of the seismic network in rapidly locate events occurring in the Vrancea area. Since rapid location of earthquakes is the first step in issuing early warning notifications, by reducing the time of the first valid location will lead to an increase the lead-time interval. Also rapid location of events will allow a future upgrade of EEWS to cover the entire Romanian territory.