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Moment tensors of the largest events of the 2016 Central Italy earthquake sequence
Labuta, Martin ; Gallovič, František (advisor) ; Adamová, Petra (referee)
Title: Moment tensors of the largest events of the 2016 Central Italy earthquake sequence Author: Martin Labuta Department: Institute of Hydrogeology, Engineering Geology and Applied Geophysics Supervisor: doc. RNDr. František Gallovič, Ph.D., Department of Geophysics, Faculty of Mathematics and Physics, Charles University Abstract: Central Italy was stuck by an earthquake sequence in 2016, with the largest earthquake of moment magnitude Mw 6.5. 300 people have died after the first earthquake on August 24th, Mw 6.1 and the city Amatrice was heavily damaged. Utilizing the software ISOLA, the low-frequency centroids are found of selected earthquakes with Mw above 4.5. Using these results, the multiple point finite seismic sources are obtained in order to determine fault irregularities. Afterwards, there is a comparison of these results with other academic papers and earthquake catalogs. Keywords: earthquake, ISOLA, moment tensor, centroid
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Statistical analysis of natural and induced seismicity catalogues
Mazanec, Martin ; Eisner, Leo (advisor) ; Adamová, Petra (referee)
The main goal of this thesis is to analyze the statistical properties of seismic catalogues of natural and induced seismicity, identify similarities and differences. We compare statistical temporal and magnitude information contained in different types of earthquake catalogues. Six seismostatistical criteria used for identification of natural swarms and mainshock- aftershock earthquake sequences are applied to 10 different catalogues of natural and induced seismicity. We did not find a method to reliably distinguish between natural and induced seismicity based only on temporal and magnitude information contained in catalogues. We show that induced seismicity catalogues are similar to natural earthquake swarms. We report how the set of 6 criteria presented here can be used for distinguishing between mainshock-aftershock sequences and swarm seismicity. We also show that none of the tested criteria can be used independently for distinguishing between different types of seismicity.
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Focal mechanisms of earthquakes in the secondary focal zones in West Bohemia
Müller, Jozef ; Bachura, Martin (advisor) ; Adamová, Petra (referee)
Recent research on earthquake swarms in West Bohemia (Czechia) has been focused on the Novy Kostel Focal Zone, where, during the last decades, majority of the earthquake swarms has been observed. In this work we focus on earthquake activity surrounding this fault zone. To this purpose we estimated focal mechanisms from P-wave of earthquakes located to the west of the Novy Kostel Focal Zone, using the FOCMEC software. Dozens of earthquakes have been analysed, of which 20 produced reliable focal mechanisms (with at least 8 favourably positioned stations used). The resulting mechanisms revealed dominance of horizontal movements, which agreed well with fault orientations mapped by earthquake relocations. Results also imply the existence of normal faulting in the studied region.
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Moment tensors of the largest events of the 2016 Central Italy earthquake sequence
Labuta, Martin ; Gallovič, František (advisor) ; Adamová, Petra (referee)
Title: Moment tensors of the largest events of the 2016 Central Italy earthquake sequence Author: Martin Labuta Department: Institute of Hydrogeology, Engineering Geology and Applied Geophysics Supervisor: doc. RNDr. František Gallovič, Ph.D., Department of Geophysics, Faculty of Mathematics and Physics, Charles University Abstract: Central Italy was stuck by an earthquake sequence in 2016, with the largest earthquake of moment magnitude Mw 6.5. 300 people have died after the first earthquake on August 24th, Mw 6.1 and the city Amatrice was heavily damaged. Utilizing the software ISOLA, the low-frequency centroids are found of selected earthquakes with Mw above 4.5. Using these results, the multiple point finite seismic sources are obtained in order to determine fault irregularities. Afterwards, there is a comparison of these results with other academic papers and earthquake catalogs. Keywords: earthquake, ISOLA, moment tensor, centroid
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Statistical analysis of natural and induced seismicity catalogues
Mazanec, Martin ; Eisner, Leo (advisor) ; Adamová, Petra (referee)
The main goal of this thesis is to analyze the statistical properties of seismic catalogues of natural and induced seismicity, identify similarities and differences. We compare statistical temporal and magnitude information contained in different types of earthquake catalogues. Six seismostatistical criteria used for identification of natural swarms and mainshock- aftershock earthquake sequences are applied to 10 different catalogues of natural and induced seismicity. We did not find a method to reliably distinguish between natural and induced seismicity based only on temporal and magnitude information contained in catalogues. We show that induced seismicity catalogues are similar to natural earthquake swarms. We report how the set of 6 criteria presented here can be used for distinguishing between mainshock-aftershock sequences and swarm seismicity. We also show that none of the tested criteria can be used independently for distinguishing between different types of seismicity.
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Earthquake source models
Adamová, Petra ; Šílený, Jan (advisor) ; Fischer, Tomáš (referee) ; Gallovič, František (referee)
The earthquake source is routinely modeled by moment tensor description. In many cases we need more information about the source process and for that reason we occupy with higher degree moments. This approach allows us to esti- mate non-point characteristics (including some dynamic parameters): geometry of the source, duration of the source process, average slip on the fault, spatial and temporal centroid and rupture velocity vector within the point source ap- proach. This description includes 20 parameters - 6 parameters for standard moment tensor (MT) and 14 parameters for second degree moments (SDM). First, we studied synthetic tests. Large amount of significant earthquakes con- tains false non-DC component which can be caused by approximation finite source by point source. This hypothesis was proved on the case of unilateral rupture. Standard MT contains more than 20 % non-DC components which was reduced to 6 %. In the second part we applied this procedure to real data. We chose large earthquakes (Mw>6) with large non-DC component. We estimated second degree moments for them and compared them with previous studies. Moreover we restitute higher degree moments from data and proved that false non-DC component were caused by source finiteness. In the last part we applied this method to mining data and...
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