Statistical and spectral properties of the L’Aquila EQL in 2009

A great number of earthquake lights (EQL) were observed in association with the L’Aquila earthquake of April 6, 2009. A previous comparison of EQL locations and the geology of the epicentres showed some possible association of EQL types with ground characteristics, while the association between sighting and shock times divided the co-seismic EQL types into pre-seismic and post-seismic ones. In this report, EQL colours are considered with respect to EQL types, positions and times. A digital method, taking into account witness distribution, to correct the statistical properties of EQL distribution was proposed. A Radial Distribution Function and time distribution were calculated. Accelerating EQL time distribution and correlation length fluctuations with earthquake were observed when approaching the principal shocks. The power law model produced good fits for the distributions.