Rupturing of small natural earthquakes in West Bohemia investigated by source scanning

2022 ◽  
Author(s):  
Vojtěch Lávička ◽  
Tomáš Fischer
Keyword(s):  
West Bohemia ◽  
Natural Earthquakes

Marie Ulčová and her Contribution to the West Bohemian Museums

2018 ◽  
Vol 56 (1) ◽  
pp. 13-23
Author(s):  
Nela Štorková
Keyword(s):  
Twentieth Century ◽  
Second World War ◽  
World War ◽  
The West ◽  
West Bohemia ◽  
Long Time ◽  
Second World

While today the Ethnographic Museum of the Pilsen Region represents just one of the departments of the Museum of West Bohemia in Pilsen, at the beginning of the twentieth century, in 1915, it emerged as an independent institution devoted to a study of life in the Pilsen region. Ladislav Lábek, the founder and long-time director, bears the greatest credit for this museum. This study presents PhDr. Marie Ulčová, who joined the museum shortly after the Second World War and in 1963 replaced Mr. Lábek on his imaginary throne. The main objective of this article is to introduce the personality of Marie Ulčová and to evaluate the activity of this Pilsen ethnographer and the museum employee with an emphasis on her work in the Ethnographic Museum of the Pilsen Region. The basic aspects of the ethnographic activities, not only of Marie Ulčová but also of the Ethnographic Museum of the Pilsen Region in the years 1963–1988, are described through her professional and popularising articles, archival sources and contemporary periodicals.

scholarly journals Seismic rocking effects on a mine tower under induced and natural earthquakes

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Piotr Adam Bońkowski ◽  
Juliusz Kuś ◽  
Zbigniew Zembaty
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Ground Surface ◽  
Tall Buildings ◽  
Earthquake Ground Motion ◽  
Seismic Action ◽  
Seismic Effects ◽  
Copper Ore ◽  
Rotational Components ◽  
Natural Earthquakes

AbstractRecent research in engineering seismology demonstrated that in addition to three translational seismic excitations along x, y and z axes, one should also consider rotational components about these axes when calculating design seismic loads for structures. The objective of this paper is to present the results of a seismic response numerical analysis of a mine tower (also called in the literature a headframe or a pit frame). These structures are used in deep mining on the ground surface to hoist output (e.g. copper ore or coal). The mine towers belong to the tall, slender structures, for which rocking excitations may be important. In the numerical example, a typical steel headframe 64 m high is analysed under two records of simultaneous rocking and horizontal seismic action of an induced mine shock and a natural earthquake. As a result, a complicated interaction of rocking seismic effects with horizontal excitations is observed. The contribution of the rocking component may sometimes reduce the overall seismic response, but in most cases, it substantially increases the seismic response of the analysed headframe. It is concluded that in the analysed case of the 64 m mining tower, the seismic response, including the rocking ground motion effects, may increase up to 31% (for natural earthquake ground motion) or even up to 135% (for mining-induced, rockburst seismic effects). This means that not only in the case of the design of very tall buildings or industrial chimneys but also for specific yet very common structures like mine towers, including the rotational seismic effects may play an important role.

scholarly journals A seismologically motivated survey of blasting activity in the northern Rhine area

2000 ◽  
Vol 79 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Klaus-G. Hinzen ◽  
Stefan Pietsch
Keyword(s):  
Charge Weight ◽  
Time Interval ◽  
Maximum Charge ◽  
Comprehensive Test Ban Treaty ◽  
Comprehensive Test ◽  
Explosive Charges ◽  
Chemical Explosions ◽  
Working Day ◽  
Test Ban ◽  
Natural Earthquakes

AbstractDiscrimination between quarry blasts and earthquakes has gained importance due to signature of the Comprehensive Test Ban Treaty. In this context, large chemical explosions are significant. In the routine analysis of data from local seismograph networks, discrimination between smaller blasts and micro-earthquakes is not always clear. Many quarries are in operation and blasts far outnumber natural earthquakes in the highly industrialized northern Rhine area.We compiled a list of active quarries in the Northern Rhine Area and mapped their locations. We then created a database from a questionnaire sent out to all quarries on the list. From the 33% of questionnaires that were returned, we discerned some representative values for the main blasting parameters and explosive consumption. In the study area of 72,000 km2, approx. 21,000 blasts are fired per year (80 per working day). Most of the blasts (72%) have total explosive charges between 400 and 4500 kg. Shots with charges above 10 tons are rare (20-30 per year). Some 80% of the blasts are ripple-fired with a nominal firing time interval of 20 ms.Based on empirical amplitude vs. distance curves from vibration control measurements, a relation between maximum charge weight per delay time, L (kg), and a ‘quarry blast’ magnitude, MQB, is derived: MQB = 0.6·log10(L) + 0.131. Using this relation and extrapolating the database from the questionnaire shows that for magnitudes between 1 and 2, blasts occur 200–250 times more frequently than micro-earthquakes in the Northern Rhine area.

Moho depth determination from waveforms of microearthquakes in the West Bohemia/Vogtland swarm area

2013 ◽  
Vol 118 (1) ◽  
pp. 120-137 ◽  
Author(s):  
Pavla Hrubcová ◽  
Václav Vavryčuk ◽  
Alena Boušková ◽  
Josef Horálek
Keyword(s):  
Moho Depth ◽  
The West ◽  
Depth Determination ◽  
West Bohemia

On the scale dependence in the dynamics of rupture

2021 ◽  
Author(s):  
Federica Paglialunga ◽  
François Passelègue ◽  
Fabian Barras ◽  
Mathias Lebihain ◽  
Nicolas Brantut ◽  
...  
Keyword(s):  
Large Scale ◽  
Cohesive Zone Model ◽  
Experimental Studies ◽  
Stress Singularity ◽  
Scale Dependence ◽  
Zone Model ◽  
Stick Slip ◽  
Radiated Energy ◽  
Rupture Energy ◽  
Natural Earthquakes

<p>Potential energy stored during the inter-seismic period by tectonic loading around faults can be released through earthquakes as radiated energy, heat and rupture energy. The latter is of first importance, since it controls both the nucleation and the propagation of the seismic rupture. On one side, the rupture energy estimated for natural earthquakes (also called Breakdown work) ranges between 1 J/m<sup>2</sup> and tens of MJ/m<sup>2</sup> for the largest events, and shows a clear slip dependence. On the other side, recent experimental studies highlighted that at the scale of the laboratory, rupture energy is a material property (energy required to break the fault interface), limited by an upper bound value corresponding to the rupture energy of the intact material (1 to 10 kJ/m<sup>2</sup>), independently of the size of the event, i.e. of the seismic slip.</p><p>To reconcile these contradictory observations, we performed stick-slip experiments, as an analog for earthquakes, in a bi-axial shear configuration. We analyzed the fault weakening during frictional rupture by accessing to the on-fault (1 mm away) stress-slip curve through strain-gauge array. We first estimated rupture energy by comparing the experimental strain with the theoretical predictions from both Linear Elastic Fracture Mechanics (LEFM) and the Cohesive Zone Model (CZM). Secondly, we compared these values to the breakdown work obtained from the integration of the stress-slip curve. Our results showed that, at the scale of our experiments, fault weakening is divided into two stages; the first one, corresponding to an energy of few J/m<sup>2</sup>, coherent with the estimated rupture energy (by LEFM and CZM), and a long-tailed weakening corresponding to a larger energy not observable at the rupture tip.</p><p>Using a theoretical analysis and numerical simulations, we demonstrated that only the first weakening stage controls the nucleation and the dynamics of the rupture tip. The breakdown work induced by the long-tailed weakening can enhance slip during rupture propagation and can allow the rupture to overcome stress heterogeneity along the fault. Additionally, we showed that at a large scale of observation the dynamics of the rupture tip can become controlled by the breakdown work induced by the long-tailed weakening, leading to a larger stress singularity at the rupture tip which becomes less sensitive to stress perturbations. We suggest that while the onset of frictional motions is related to fracture, natural earthquakes propagation is driven by frictional weakening with increasing slip, explaining the large values of estimated breakdown work for natural earthquakes, as well as the scale dependence in the dynamics of rupture.</p>

scholarly journals Event couple spectral ratio Q method for earthquake clusters: application to North-West Bohemia

2018 ◽  
Author(s):  
Marius Kriegerowski ◽  
Simone Cesca ◽  
Matthias Ohrnberger ◽  
Torsten Dahm ◽  
Frank Krüger
Keyword(s):  
Wave Attenuation ◽  
Attenuation Factor ◽  
Source Region ◽  
Spectral Ratio ◽  
Ratio Method ◽  
Earthquake Swarms ◽  
North West ◽  
High Attenuation ◽  
West Bohemia ◽  
Spectral Ratio Method

Abstract. We develop an amplitude spectral ratio method for event couples from clustered earthquakes to estimate seismic wave attenuation (Q−1) in the source volume. The method allows to study attenuation within the source region of earthquake swarms or aftershocks at depth, independent of wave path and attenuation between source region and surface station. We exploit the high frequency slope of phase spectra using multitaper spectral estimates. The method is tested using simulated full wavefield seismograms affected by recorded noise and finite source rupture. The synthetic tests verify the approach and show that solutions are independent of focal mechanisms, but also show that seismic noise may broaden the scatter of results. We apply the event couple spectral ratio method to North-West Bohemia, Czech Republic, a region characterized by the persistent occurrence of earthquake swarms in a confined source region at mid-crustal depth. Our method indicates a strong anomaly of high attenuation in the source region of the swarm with an averaged attenuation factor of Qp 

scholarly journals Erosión ética en el trato con la inteligencia artificial

2020 ◽  
pp. 43-58
Author(s):  
Desireé Torres Lozano
Keyword(s):  
Artificial Intelligence ◽  
San Francisco ◽  
Mirror Neurons ◽  
Machine Intelligence ◽  
Publishing Company ◽  
Frankfurt Am Main ◽  
Modern Approach ◽  
Oxford University ◽  
Computing Machinery ◽  
West Bohemia

ResumenEl presente artículo tiene como finalidad definir la IA y poner en discusión su injerencia social, así como las consecuencias éticas que esto conlleva, ya que la construcción del hombre contemporáneo debe tener en cuenta el trato con estos sistemas. Definiremos qué es la inteligencia, cómo es que se le ha llamado inteligencia a los procesos de las máquinas y podremos establecer un diálogo entre la influencia ética que conlleva el trato con las mismas. Palabras clave Inteligencia artificial; Ética; Sistemas; Tecnología; Hombre Referencias Aristóteles, De Anima, Madrid: Gredos, 2000. ___, Ética a Nicómaco, Madrid: Gredos, 2000. ___, Política, Madrid, Gredos, 2003. Aspe, V. Nuevos sentidos mimesis en la Poética de Aristóteles, en Tópicos, Revista de filosofía, México: Tópicos, 2005. Bellman, Richard, An Introduction To Artificial Intelligence, San Francisco: Boyd and Fraser Publishing Company, 1978. Büchner et al, Discovering Internet Marketing Intelligence through Web Log Mining, Antrin, Mine it, Newtownabbey: University of Ulster Shore Road, 1998. Corominas, Pascual, Diccionario Crítico Etimológico Castellano e Hispánico, Madrid, Gredos, 2002. Descartes, Meditaciones Metafísicas, Gredos, Madrid, 2000. Elaine Rich, Kevin Knight, Artificial Intelligence, New Delhi: McGraw-Hill, 1991. Bude, Gesellschaft der Angst, Hamburgo: Hamburger Edition HIS, 2014. Heidegger, Platon: Sophistes, Frankfurt: Vittorio Klostermann, 1992. ___, Über den Humanismus, Frankfurt: Vittorio Klostermann, 1949. ___, Was heisst denken?, Frankfurt Am Main: Vittorio Klostermann, 2002. Hickock, Gregory, The Myth of Mirror Neurons. The Real Neuroscience of communication and cognition, Nueva York: W. W. Norton & ­Company, 2014. J. Haugeland, Artificial Intelligence: The very idea, Cambridge: MIT Press, 1985. Kirk, G.S. y Raven, J. E., Los filósofos presocráticos, Madrid: Gredos, 1970. Kurzweil Raymond, The Age of Intelligent Machines, Cambridge: MIT Press, 1990. Mariarosaria Taddeo, Luciano Floridi, How AI can be a force for good, en Science, Vol. 361, Issue 6404, Oxford: Oxford University, 2018. Nils Johan Nilsson, Artificial Intelligence: A new synthesis, USA: Morgan Kaufmann, 1998. Platón, Cratilo, Madrid, Gredos, 2004. Poole David et al, Computational Intelligence, a Logical Approach, Oxford: Oxford University, 1998. Press, Gill, A Very Short History Of Artificial Intelligence (AI), USA: Forbes, 2016. Russell, Norvig, Artificial Intelligence, A Modern Approach, New Jersey, Pearson, 2010. Armstrong, S., & K. Sotala, ​How we​’re predicting AI​ or failing to,​ Beyond Artificial Intelligence, Machine Intelligence Research Institute, Pilsen: University of West Bohemia,2015. Turing Alan, MIND, Computing Machinery and Intelligence, Cambridge: A Quarterly Review of Psychology and Philosophy, 1950. Winston Patrick Henry, Artificial intelligence, USA: Addison Wesley, Publishing Company, 1992.

Induced versus natural earthquakes: Search for a seismic discriminant

1980 ◽  
Vol 70 (1) ◽  
pp. 269-281
Author(s):  
William A. Peppin ◽  
Charles G. Bufe
Keyword(s):  
Active Faults ◽  
P Wave ◽  
S Wave ◽  
Spectral Parameters ◽  
San Andreas ◽  
Time Period ◽  
Seismic Stress ◽  
Stress Drops ◽  
Natural Earthquakes ◽  
Steam Production

abstract A sizeable body (150 records) of three-component, wideband (0.2 to 50 Hz) digital seismic data has allowed a direct comparison between earthquakes at The Geysers geothermal area, California and along nearby active faults of the San Andreas system. An attempt has been made to find analog or spectral parameters which would permit discrimination between 12 events within the steam production field and 30 outside it. Results of the study for both classes of events are: (1) seismic moments vary with local magnitude ML as log M0 = (1.06 ± 0.11) ML + 16.9 ± 0.1; (2) the ratio of vertical P-wave to horizontal S-wave spectral corner frequencies is near unity; (3) seismic stress drops are low (1.0 to 10 bars); and (4) focal mechanisms are quite comparable during the time period of this study.

Sign in / Sign up

Export Citation Format

Share Document