Twenty Years Seismic Monitoring of Induced Seismicity in Northern Albania

The northern part of Albania has been the focus of an intense effort by the Seismological Institute of Albania, for in this area two of the country’s biggest reservoirs are located. Three years before the impounding of the Fierza reservoir, a four-station network was installed around it. The possibility of induced seismicity continued after the impoundment of the Fierza reservoir in 1978 and the Komani reservoir, in 1985. The seismicity of the zone and some aspects of induced seismicity including: temporal correlation of seismicity with water level changes, spatial patterns in seismicity, frequency-magnitude relations, fault plane solutions etc., are studied during this period. The presence in this zone of a very important transverse fault, the Shkoder-Peja fault, makes the study of induced seismicity from Fierza and Komani reservoirs even more significant. The studies have shown that the impounding of the Fierza and Komani reservoirs has modified the natural course of microearthquake energy release, increasing the number of swarms in this area. The fluctuation of the water level in these two reservoirs, in due course, is a potentially important factor in the evaluation of seismicity for Northern Albania and especially in the hazard assessment of this region.