Atypical seismic records of quarry blasts

Blasting operations cause vibrations. Seismograms are used to assess the effect of these vibrations on the surroundings. The seismic record of blasting usually has a very typical character - a sharp onset of the first wave followed by other groups of waves with a prominent group of surface waves. Detailed analysis of seismograms contributes to the study of the local subsurface geological structure, the evaluation of the effect of blasting, the proposal of optimizing the effect of blasting, etc. This character can be changed for various reasons, which is often caused by the "specific" local geological structure - the disruption of the rock environment. The paper presents the wave pattern of individual types of seismic waves in the vicinity of the realized blast and several examples of these atypical seismic records. Experimental measurements were carried out in several quarries in Slovakia and Czech Republic. As an example, the measured wave pattern in an open-pit lignite mine has an atypical character characterized primarily by the duration of vibrations of up to 35 seconds.