Analysis of Seismicity in Elbasani Geothermal Zone during Five Last Decades

Abstract

During the last five decades since 1968, the Elbasani zone in Albania is dominated by low seismicity. This fault zone has evidenced some seismological phenomena. It is a transversal active fault zone with normal and strike-slip faults characterized by low-velocity layers. From instrumental seismicity in this area have been located 1831 seismic events, with magnitude ML > 1.1 Richter and 3 of them with magnitude ML > 5.0. Recently on May 19, 2014, a moderate earthquake ML5.2 occurred in the Elbasani seismogenic zone. This earthquake was located 6 km southeast of Belshi town and 18 km south of Elbasani town and was felt over Albania. The analysis of seismicity during the period of time 968-2022 years indicates that most earthquakes were located in the upper and middle earth crust and very few in the uppermost mantle. The focal mechanisms solution of some earthquakes indicates an extensional regime in this fault zone. The parameters of focal mechanisms indicate the predominance of normal fault motion and strike-slip fault motion is compatible with the present-day extension regime. The Elbasan zone has a complex geological structure with a significant number of geothermal water resources and some features of seismicity. The analysis of the features of seismicity during the five last decades provides us with correct interpretations of seismotectonic, low velocity lowers and understanding of geodynamic phenomena of the Earth's crust. The area of active faults of Elbasan presents a threat to the city of Elbasan and to the curative and tourist area of Llinxha-Hidrat.