Application of newly developed rotational sensor for monitoring of mining induced seismic events in The Karvina region

Abstract

Classical Russian pendulum seismometer S-5-S was modified for recording of the rotational components of ground motion around the vertical or horizontal axes; the modified sensor is denoted here as S-5-SR. Experimental field testing of the S-5-SR sensor started in December 2010 in the Karvina coal region that is known as an area of intensive mining induced seismicity. First seismic station was installed in Doubrava village characterized by thick sedimentary layers. Next seismic station was installed in Orlova village, in different local geological conditions, i.e. in region without sedimentary layers. More than 200 mining induced seismic events were recorded on each seismic station during the period of six months of seismic monitoring. The recorded wave patterns confirm the existence of rotational ground motion components in this region; the strongest recorded value of this component exceeded 1 mrad.s-1. Analysis of the obtained records is presented in this paper.

Coherence spectra of rotational and translational components of mining induced seismic events

“…First records of rotational component of ground vibration velocity in the Karviná region were obtained during the experimental seismic monitoring in 2010 and 2011 that confirmed rotational component existence also for the mining induced seismic events (Kaláb et al 2013). The maximum measured value of rotational velocity exceeded value of 1 mrad s −1 at Doubrava locality (mining induced seismic event with epicentral distance 1 km and energy 5.3 E 5 J).…”

“…1). Evaluation of more distant events with epicentral distances longer than 10 km is not representative for the coherence spectra analysis due to quickly attenuated value of rotational velocity (Kaláb et al 2013).…”

Study of Site Effect at Seismic Station Located in Undermined Area of Karviná Region (Czech Republic)

“…These apparatuses provide digital records of measured signals in the frequency range of 0.5-30 Hz and sampling frequency of 100 Hz. Measurement of rotational component of vibrations, using newly developed S-5-SR sensor, was also performed in Orlová and Doubrava localities (Knejzlík et al 2012, Kaláb et al 2013, Lyubushin et al 2015. Results from seismological monitoring together with geotechnical studies are used also for evaluation of seismic loading of structures, e.g., Kaláb and Lednická (2012).…”

First deep underground observation of rotational signals from an earthquake at teleseismic distance using a large ring laser gyroscope

“…The need for a rotational sensor in geophysics was first claimed in a fundamental text about seismology (Aki and Richards (2009)), where the authors state that "... note the utility of measuring rotation near a rupturing fault plane (...), but as of this writing, seismology still awaits a suitable instrument for making such measurements". The search for such a sensor is of actual interest, as shown by many recent studies (Kaláb et al (2013); Brokešová and Málek (2010); Schreiber et al (2006a)). So far, RLGs allowed to achieve important results in a variety of disciplines, spanning from geodesy (Schreiber et al (2004)) to both regional and global seismology (Igel et al (2005); Pancha et al (2000); Simonelli (2014); Schreiber et al (2006a)).…”