Fluctuation analysis of the time dynamics of laser distance data measured in the medieval Jeron‎m Mine (Czech Republic)

Fractal tools are used to investigate the hourly time fluctuations of the ceiling height of a chamber located in the medieval Jeron‎m Mine, which is one of the Cultural National Heritage sites of the Czech Republic. The data were measured from 2008 to 2010 by a laser distance meter (Leica DISTO T M A 4 ). The scaling behavior is revealed by means of different statistics: the power spectrum method, the detrended fluctuation analysis, the Higuchi analysis and the mean distance spanned within time L . The values of the scaling exponents estimated by means of these methods indicate that the temporal fluctuations of the ceiling height are not typical of a purely random stochastic process (i.e. white noise), but evidence the presence of long-range correlations. Furthermore, it is found that these correlations are linear.