Seismic Tomography in the Targu Jiu Region (Romania): Relationships with Seismic Velocity Anomalies and Fault Activity  
[PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (C.N. ); [EMAIL_ADDRESS] (M.R.) [PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [PERSON]S] (M.A. ); [PERSON]] (C.N. ); [EMAIL_ADDRESS] (M.R.) [PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [EMAIL_ADDRESS] (M.A. ); [PERSON]] (C.N. ); [EMAIL_ADDRESS] (M.R.) [PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [PERSON]S] (M.A. ); [PERSON]] (C.N. ); [EMAIL_ADDRESS] (M.R.) [PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [PERSON]S] (M.A. ); [PERSON]] (C.N. ); [EMAIL_ADDRESS] (M.R.) [PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (C.N. ); [EMAIL_ADDRESS] (M.R.) [PERSON]  
1 National Institute for Earth Physics, Calugareni 12, 077125 Magurele, Romania; [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (R.D. ); [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (C.N. ); [EMAIL_ADDRESS] (M.R.) Footnote 1: email: {[PERSON]ADDRESS],mnihai.andrei@infp. River in the east and the Danube Valley in the west, with its southern boundary marked by the Pericarpathian Fault. The Getic Depression was formed as a result of large-scale transcurrent movements generated by the Paleogene to Early Miocene displacement and clockwise rotation of the Tisza-Dacia Unit around the western Moesia corner, followed by the Badenian-Sarmatian uplift of the South Carpathian units [4; 5]. The Getic Depression initially formed in the Late Paleogene-Early Miocene as a pull-apart basin, with its development controlled by the Timok-Cerna Jiu fault system [6]. Later, during the Sarmatian tectonic event, the pre-existing E-W fault system was inverted by an oblique compression generated by the eastward movement of the Tisza-Dacia tectonic block [7]. The tectonic molding around the Moesian platform of the South Carpathians observed west of Targu Jiu began in the Oligocene and was mostly shaped by dextral wrenching along the Cerna Fault [8]. The dextral wrenching continued into the Early Miocene, but more externally along the Timok Fault, with a dextral displacement of 65 km. In the Middle Miocene, dextral faults cut in the E-W and NW-SE direction the sedimentary cover of the Getic Depression [2; 9]. Beneath the sedimentary cover of the Getic depression and in the area lined up in the extension of the Timok Fault, a perpendicular normal fault system is found along the western edge of the Moesian Platform. The N-S fault system originates from the Permo-Triassic rift and a younger E-W normal fault system mostly formed during the Mid-Tertiary period [2]. The area around Targu Jiu city has been considered until 2023 an area of low seismic activity, not included in the seismogenic zones of Romania. Seismic activity in the Getic Depression (Figure 1) is generally manifested by earthquakes of moderate size, rarely exceeding magnitude Mw = 5 [11]. The most significant earthquakes before 2023 were recorded on 20 June 1943 (Mw = 5.2) produced east of Tismana, on 9 July 1912 (Mw = 4.5) about 9 km south of Targu Jiu, and on 4 May 1963 (Mw = 4.5), about 22 km NW of the same location. However, since February 2023, the area has experienced a significant intensification of seismic activity, highlighting more complex seismotectonic processes  
Figure 1: Tectonic framework of the Getic Depression in relation to Carpathian orogen and the Moesian Platform (modified after [10]) and location of the study area (Tárgu Jiu).