COMMENTS

The Dinarides are a wide NW-SE fold-and-thrust belt stretching from southwestern Slovenia to Montenegro along the Adriatic coast of Croatia and inland. The Dinarides formed as a consequence of subduction and collision processes in the border zone between Europe and Adria tectonic plates. Adria acted, and is still acting, as an indenter moving roughly towards stable Europe and causing the Meso-Cenozoic carbonate rocks of the Dinaric platform to over-ride onto the Adriatic lithosphere (e.g. Aljinovic et al., 1990; Prelogovic et al., 1995; Herak, 1999). The most prominent structures of the Dinarides are NW-SE oriented thrust faults (Mamuzic, 1975; Ivanovic et al., 1976; Herak, 1991, 1999). Present day tectonic rates are mostly obtained from GPS campaigns and display general NNE-SSW to NE-SW trends, with values of 2-2.5 mm/yr in northern Dalmatia (Grenerczy et al., 2005) and 4-4.5 mm/yr in central and southern Dinarides (Grenerczy et al., 2005; Bennett et al., 2008; Devoti et al., 2008).

Within the Dinarides the seismicity is distributed along the entire length of the belt. Data on both instrumental and historical seismicity show earthquake activity across the entire width of the thrust belt. Available focal mechanism solutions (Herak et al., 1995; Vannucci et al., 2004) and structural geological data show, that at its NW end the seismic deformation is dominated by right-lateral movement on NW-SE strike-slip faults. In the central and southern part of the belt, both in the off-shore and coastal parts, thrusting is the prevailing mode of seismic deformation whereas in the inner parts of the belt the fault planes are steeper and show more complex kinematics with reverse, strike-slip and oblique movements. Active processes in this region are mainly driven by NE oriented compression, documented from maximum compressive axis orientation of focal mechanisms (Anderson and Jackson, 1987; Pondrelli et al., 2006) and from long-term geological evidence (Prelogovic et al., 2003).

This Source coincides with the NW-SE oriented Jabuka-Andrija thrust, which is one of the most external structures of the Dinarides deforming Adria microplate with S to SW verging thrust displacements. We set the depth interval of the source taking into account regional structural data and earthquake locations (Herak et al., 2005). The only seismic sequence with good instrumental coverage for this fault is the 2003 sequence of Jabuka Island. The mainshock occurred on 29 March with a magnitude Mw 5.5 and was preceded by a foreshock of Mw 5.0 two days earlier.

The strike of the source was derived taking into consideration regional data on fault geometry (Ivancic et al., 2006) combined with available fault plane solution of earthquakes (Herak et al., 2005; Pondrelli et al., 2006). We obtained the average dip of the source considering existing data from seismic profiles (Grandic et al., 2007) and fault plane solutions of recent seismic events (Herak et al., 2005; Pondrelli et al., 2006). We set average rake values considering local and regional structural and geodynamic data. Such geometry fairly agrees with the orientation of the maximum horizontal compressive stress, which is between 340° N and 15° N (Prelogovic et al., 1999, 2003; Pribicevic et al., 2001).

Slip rate values range on the basis of horizontal velocities obtained by GPS campaigns (Devoti et al., 2008) and considering the geometry of the source. We assigned the maximum magnitude value after the magnitude of the 29 March 2003 event of Jabuka.