Open AccessAntipersistent dynamics in short time scale variability of self-potential signals
Author(s) -
V. Cuomo,
Maria Lanfredi,
V. Lapenna,
M. Macchiato,
Maria Ragosta,
Luciano Telesca
Publication year - 2000
Publication title -
annals of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 60
eISSN - 2037-416X
pISSN - 1593-5213
DOI - 10.4401/ag-3644
Subject(s) - variogram , scaling , statistical physics , scale (ratio) , scale invariance , temporal scales , fractal , detrended fluctuation analysis , series (stratigraphy) , range (aeronautics) , fractional brownian motion , physics , multifractal system , self similarity , brownian motion , geology , mathematics , statistics , mathematical analysis , kriging , geometry , materials science , ecology , paleontology , quantum mechanics , composite material , biology
Time scale properties of self-potential signals are investigated through the analysis of the second order structure function (variogram), a powerful tool to investigate the spatial and temporal variability of observational data. In this work we analyse two sequences of self-potential values measured by means of a geophysical monitoring array located in a seismically active area of Southern Italy. The range of scales investigated goes from a few minutes to several days. It is shown that signal fluctuations are characterised by two time scale ranges in which self-potential variability appears to follow slightly different dynamical behaviours. Results point to the presence of fractal, non stationary features expressing a long term correlation with scaling coefficients which are the clue of stabilising mechanisms. In the scale ranges in which the series show scale invariant behaviour, self-potentials evolve like fractional Brownian motions with anticorrelated increments typical of processes regulated by negative feedback mechanisms (antipersistence). On scales below about 6 h the strength of such an antipersistence appears to be slightly greater than that observed on larger time scales where the fluctuations are less efficiently stabilised