Regional and temporal evaluation of seismicity in the Vlora-Elbasani-Dibra Transversal Fault Zone, Albania

Abstract

Characteristics of seismic activity along the Vlora- Lushnja-Elbasani-Dibra (V-L-E-D) Transversal Fault Zone are analyzed between 1964 and 2015. There are a total of 2814 events in the time interval 1964 and 2015 with Md1.7. This study is focused on the correlation of seismotectonic b-value, precursory quiescence Z-value, and interrelationships between some other seismicity parameters. The distribution of the relatively low b-value coincides with the tectonic compression field which acts along the V-L-E-D Transversal Fault Zone. The distribution of the relatively low b-value coincides with the tectonic compression field which acts along the V-L-E-D Transversal Fault Zone. Anomalously low b-value areas coincide more or less with the spatial distribution of M≥5.0 earthquakes and their known rupture extents. Temporal changes in b-value may be related to the stress variations in these times before and after the main events. The lowest Z-values show that the variations in seismic activity rate are not significant, and the highest Z-values demonstrate a decrease in seismicity rate. In the Z-value maps for all parts of the V-L-E-D, three areas exhibit significant seismic quiescence: centered at 41.00°N-19.78°E (region A, around Lushnja), 40.99°N-20.03°E (region B, in the Cerriku), 40.81°N-19.86°E (region C, including Kucova). In addition to these three significant areas, there are some small quiescence areas in different parts of the V-L-E-D.