LUMINITA ARDELEANU
National Institute for Earth Physics, P.O. Box MG-2, Bucharest, Romania
The paper aims to evidence characteristic space and time patterns of the earthquake
occurrence in the Vrancea region. The normal and intermediate depth sequences
of low magnitude events are investigated by a method which is based on the
analysis of point patterns in two-dimensional space; the time series of subcrustal
moderate-size and strong earthquakes are studied using a parametrization
derived from the Weibull distribution. The results who a significant clustering
tendency of the seismic activity in the crustal seismogenic area, while the
intermediate depth low- and moderate-magnitude seismicity is modeled by the
completely random pattern; the sequences of strong subcrustal earthquakes
indicate a quasi periodical occurrence of the major events.
Key words: Vrancea seismic region, crustal seismicity, subcrustal
seismicity, space-time seismicity, patterns.