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Real-time magnitude estimation using MEMS-based accelerometers
Colosimo, Francesco ; Kuna, Václav (advisor) ; Doubravová, Jana (referee)
III Abstract Earthquakes can be catastrophic events and disrupt people's lives in a significant and uncontrollable ways. Earthquake early warning (EEW) can help to reduce earthquake's impact and provide people with a technology that gives them time for action before destructive waves strike. This thesis contributes to the development of OpenEEW/Grillo system, by improving an algorithm for magnitude estimation. The thesis consists of two parts, the first part explains the concept of EEW and compares different approaches to EEW and various magnitude estimation algorithms. The second part is observational and uses seismic data from Grillo/OpenEEW network in Mexico. We use data from 1559 earthquakes recorded at the network from 2017 to 2021 and analyse the peak ground displacement with respect to the earthquake magnitude. We observe that earthquake magnitude correlates well with the peak ground displacement and the length of the P-wave segment used in the analysis. We estimate linear regression parameters for P-wave segments up to 10 s long and express earthquake magnitude as the function of peak ground displacement and the length of the P-wave segment. This work improves the magnitude estimation in the Grillo/OpenEEW system and enables the system to calculate the magnitude using the entire P-wave segment...
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Relocation of the 1962 earthquake swarm in West Bohemia
Konrádová, Diana ; Fischer, Tomáš (advisor) ; Doubravová, Jana (referee)
Since the swarm at the turn of 1985/86 the current activity of seismic swarms in western Bohemia takes place mainly in the area of Nový Kostel at the eastern edge of the Cheb basin. However, the location of previous activities, where only more remote seismic stations were in operation, is not exactly known. This also applies to the swarm of 1962, which this bachelor thesis is focused on. Seismic bulletin data are available from eight seismic stations at a suitable distance for sufficient localization quality for this swarm. The theoretical part of the thesis presents research results of fundamental existing localization methods and their properties. In the practical part, the location of the earthquake epicenter of swarm 1962 is presented.
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Relocation of the 1962 earthquake swarm in West Bohemia
Konrádová, Diana ; Fischer, Tomáš (advisor) ; Doubravová, Jana (referee)
Since the swarm at the turn of 1985/86 the current activity of seismic swarms in western Bohemia takes place mainly in the area of Nový Kostel at the eastern edge of the Cheb basin. However, the location of previous activities, where only more remote seismic stations were in operation, is not exactly known. This also applies to the swarm of 1962, which this bachelor thesis is focused on. Seismic bulletin data are available from eight seismic stations at a suitable distance for sufficient localization quality for this swarm. The theoretical part of the thesis presents research results of fundamental existing localization methods and their properties. In the practical part, the location of the earthquake epicenter of swarm 1962 is presented.
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Relative earthquake locations
Jeschkeová, Zuzana ; Bachura, Martin (advisor) ; Doubravová, Jana (referee)
This bachelor thesis concerns the issues related to techniques of earthquake locations. The methods can be divided into a two groups: absolute (Geiger method, grid search) and relative (master-event, hypoDD) ones. A greater emphasis is put on the latter ones - the relative methods. In these methods make use of so-called differential times - absolute time differences between phase arrivals of two earthquakes. The differential times can be estimated by the means of waveform cross-correlations. Our main objective was to compare cross-correlated differential times with the real ones and determine their accuracy. The analysis revealed that the difference - bias in differential time is present and for tho earthquakes with different magnitude it can reach 0.06 s. Keywords: locations, earthquakes, cross-correlation, seismograms
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Projekt "Seismologie ve školách"
Zedník, Jan ; Jedlička, Petr ; Doubravová, Jana
Projekt Seismologie ve školách si klade za úkol vývoj jednoduchého seismometru a registračního zařízení a vytvoření školní seismické sítě v České republice. Školní seismometr a další osvědčené pokusy bude možné používat na středních školách jako fyzikální pomůcku pro výuku věd o Zemi. K zařízení bude dodáván i jednoduchý zpracovatelský program a příručka pro studenty i pedagogy.
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New interactive software for seismic data processing
Doubravová, Jana ; Horálek, Josef
Seismon is an open source software package under GNU General Public Li- cense developed by Stefan Mertl (TU Wien). It is designed as a modular pro- gram with de ned interface for speci c types of modules. This gives program- mer rules how to add new tools easily without disturbing the program integrity. Seismon is written in MATLAB and all input and output data are stored in MySQL database which can be accessed by more Seismon users simultaneously. Seismon is initially equipped with tools for communication with the database, various waveform le conversions, and basic tools for data analysis and visual- ization. To use this software for routine processing of data from local seismic network in West Bohemia (WEBNET), some adaptations had to be done, and the modi ed program was called Seismon_WB. There had to be put a great emphasis on user friendliness which required to de ne keyboard shortcuts, add status bars directly displaying current possibilities and properties, or extract the most important functions out of structured menus to main window as GUI components.
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