Remote sensing data for seismic activity in SW Bulgaria

Numerous faults, photolineaments and concentric structures are established based on field research and interpretation of Landsat 1 remote sensing data. The territory of SW Bulgaria was and is the most seismically active in this country. The concentration of weak earthquake epicenters (1990-2002) and several cases of their migration take place in small blocks, limited by faults (photolineaments), in the concentric structures or along the faults and photolineaments. The results of our complex analysis indicate that: (i) the seismic manifestations migrate in several predominant directions; (ii) the epicenter distribution corresponds to the direction of main lineaments and concentric structures, (iii) the activated volumes cover consecutive segments of certain photolineaments, concentric structures and/or the blocks between them.