Figure 2
Panel a displays hypocenter relative locations (red dots) for the aftershocks that followed the M 5.1 earthquake of July 25, 2011. Locations were obtained using manual picks and the high-resolution P-wave velocity model described in Appendix 1. Triangles indicate OBS locations. Thick black line indicates the seismic profile collected in 2001 during the Seismarmara Cruise28,36 shown in Fig. 5. Thin black lines are for active faults7. Panels b anc c display the cross-sections of depth below sea-level along an East-West line crossing at 40.80°N and along a North-South line crossing at 27.78°E, respectively, with the aftershocks and the velocity structure extracted from the P-wave velocity grid (Appendix 1). The two iso-velocity lines at 4.2 and 5.2 km/s correspond to the syn-kinematic and post-kinematic basement, respectively28,31. Red star indicates the absolute location of the Mw 5.1 earthquake (the position obtained with land and sea-bottom stations is consistent within 0.5 km with the position obtained using OBSs only). First, absolute locations of all the events of the aftershock sequence were obtained using the NonLinLoc33 software package. Then relative locations were computed using NonLDiffLoc33 on a selection of “well-constrained” events, e.g.: number of stations ≥ 7; RMS < 250 msec; gap ≤150°; error in depth smaller than z. Image created with GMT software, Version 4.5.11.
