Analysis of effects related to earthquakes and seismic oscillations appearing in rock deformation and gravimeter recordings

In rock-deformation monitoring measurements effects of earthquakes, and seismic events can be observed. From the point of view of the original aim of extensometric measurements these effects are usually considered as a noise however, further information can be achieved about the nature of these effects by studying various changes in the geological, rock-physical environment, complementing the analysis of seismograms.

In order to investigate the appearance of effects of earthquakes and seismic oscillations on rock-deformation data, authors choose recordings of significant (M>7) earthquakes observed by two long quartz-tube extensometers (azimuth angle difference is 76°) and a tidal monitoring gravimeter operating in the Matyashegy Gravity and Geodynamical Observatory in Budapest, furthermore by a three component STS-2 seismometer operating in the  Kövesligethy Radó Seismological Observatory in Budapest, nearby the gravity observatory. Authors present comparative results of an extensive spectral analysis of the three types of data.

Authors wish to express their thanks to OTKA (Hungarian Scientific Research Fund) for their support (OTKA-K101603, OTKA K109060).