Full Moment Tensor Inversion as a Practical Tool in Case of Discrimination of Tectonic and Anthropogenic Seismicity in Poland

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• 作者：Grzegorz Lizurek
• 关键词：Anthropogenic seismicity ; moment tensor ; focal mechanism ; induced seismicity ; intraplate seismicity
• 刊名：Pure and Applied Geophysics
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：174
• 期：1
• 页码：197-212
• 全文大小：4125KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Geophysics/Geodesy;
• 出版者：Springer International Publishing
• ISSN：1420-9136
• 卷排序：174

文摘

Tectonic seismicity in Poland is sparse. The biggest event was located near Myślenice in 17th century of magnitude 5.6. On the other hand, the anthropogenic seismicity is one of the highest in Europe related, for example, to underground mining in Upper Silesian Coal Basin (USCB) and Legnica Głogów Copper District (LGCD), open pit mining in “Bełchatów” brown coal mine and reservoir impoundment of Czorsztyn artificial lake. The level of seismic activity in these areas varies from tens to thousands of events per year. Focal mechanism and full moment tensor (MT) decomposition allow for deeper understanding of the seismogenic process leading to tectonic, induced, and triggered seismic events. The non-DC components of moment tensors are considered as an indicator of the induced seismicity. In this work, the MT inversion and decomposition is proved to be a robust tool for unveiling collapse-type events as well as the other induced events in Polish underground mining areas. The robustness and limitations of the presented method is exemplified by synthetic tests and by analyzing weak tectonic earthquakes. The spurious non-DC components of full MT solutions due to the noise and poor focal coverage are discussed. The results of the MT inversions of the human-related and tectonic earthquakes from Poland indicate this method as a useful part of the tectonic and anthropogenic seismicity discrimination workflow.