1 Fac ulty of Min ing, Ge ol ogy and Pe tro leum En gi neer ing, Uni ver sity of Zagreb, Pierottijeva 6, Zagreb, Croatia Mt. Medvednica is an inselberg in NW Croatia, which lies at the in ter sec tion be tween the Southeastern Alps, Northwestern Dinarides and Tisza Mega-Unit of the Pannonian Ba sin. Due to the Pliocene-Quaternary N-S di rected short en ing, Mt. Medvednica ex pe ri enced 1500-2000 m of dif fer en tial up lift and now ex poses pre-Neo gene and Neo gene tec tonic and stratigraphic units that are sur rounded by Pliocene-Quaternary sed i ments. This pa per eval u ates a set of quan ti ta tive morphometry meth ods used to iden tify tec toni cally ac tive ar eas within this re gion characterized by low-rate ac tive fold ing and fault ing dur ing the Pliocene-Quaternary. Our anal y sis em ployed ex trac tion of hypsometric curves, cal cu la tion of a hypsometric in te gral, asym me try fac tor, and sta tis ti cal pa ram e ters of lon gi tu di nal stream pro files along 36 drain age bas ins de lin eated from a 25 m res o lu tion DEM of Mt. Medvednica area. De spite lithological het er o ge ne ity of the study area, the morphometric pa ram e ters we ob tain are good in di ca tors for dis crim i nat ing tec toni cally ac tive from in ac tive ar eas. We in terpret that the most tec toni cally ac tive ar eas are lo cated at the SW cor ner and in the cen tral part of Mt. Medvednica, where they are likely re lated to the North Medvednica Bound ary Fault, and to the Kašina Fault, re spec tively. The lat ter di vides the range into dis tinct NE and SW mor pho log i cal and struc tural ar eas.

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This study, involving remote sensing, seismology, and geology, revealed complex faulting during the mainshock of the Ston–Slano earthquake sequence (5 September, 1996, Mw = 6.0). The observed DInSAR interferogram fringe patterns could not be explained by a single fault rupture. Geological investigations assigned most of the interferogram features either to previously known faults or to those newly determined by field studies. Relocation of hypocentres and reassessment of fault mechanisms provided additional constraints on the evolution of stress release during this sequence. Available data support the scenario that the mainshock started with a reverse rupture with a left-lateral component on the Slano fault 4.5 km ESE of Slano, at the depth of about 11 km. The rupture proceeded unilaterally to the NW with the velocity of about 1.5 km/s for about 11 km, where the maximum stress release occurred. DInSAR interferograms suggest that several faults were activated in the process. The rupture terminated about 20 km away from the epicentre, close to the town of Ston, where the maximum DInSAR ground displacement reached 38 cm. Such a complicated and multiple rupture has never before been documented in the Dinarides. If this proves to be a common occurrence, it can pose problems in defining realistic hazard scenarios, especially in deterministic hazard assessment.

Terrestrial laser scanning (TLS) in combination with Unmanned Aircraft System (UAS) and modern computer based photogrammetry is currently the best approach for the acquisition of high-resolution 3D spatial information. Highly realistic 3D spatial data sets are becoming the basis for detailed geological studies, providing a multidisciplinary approach in the study and research of both underground and above ground sites. To emphasize the variety of possible implementations of these state-of-the-art methodologies, four characteristic and yet quite different case studies are presented where such geodetic techniques are successfully employed. The presented case studies demonstrate that TLS and UAS photogrammetry, as non-contact surveying methods, are able to reduce survey time and total project costs. As added value, they provide high-resolution data that can be analyzed in a virtual environment from a sedimentological or structural aspect. Stored digital documentation also allows future multi-temporal spatial data comparison at any timeframe and scale, thus enhancing any target geological data gathering and analyses at the studied sites.

The area of the Vinodol Valley and Bakar Bay represents a NW-SE oriented valley in the NW Adriatic characterised by prominent historical and instrumentally recorded seismicity. As part of the greater geodynamic domain including the Ilirska Bistrica-Rijeka-Senj seismogenic fault zone, new geological and structural data addressing the tectonic evolution of the area were collected in order to better understand the focal mechanisms of previous earthquakes and to enable identification of potential seismogenic sources. Mapped informal lithostratigraphic units mostly correspond to the Upper Cretaceous, Palaeogene and Quaternary successions described in other parts of the External Dinarides. However, a shorter stratigraphic range of the Gornji Humac fm., the youngest Cretaceous unit in the study area, was determined and suggests that the uplifted area in the central NW part of the Adriatic Carbonate Platform already comprised several thousand km 2 (from W and NW Istria to Krk and Vinodol area) at the end of the Turonian. Structural measurements of the fault planes in the study area generally correspond to the existing structural model of the tectonic evolution of the Dinarides. However, in contrast to the SW vergences typical of the Dinarides, NE-vergent reverse structures are common, especially along the SW margin of the Vinodol Valley. Cross-cutting relationships suggest that transpressional (NW-SE and NE-SW striking dextral and sinistral faults) and extensional features (NW-SE and NE-SW striking normal faults) are structurally concurrent or younger than the reverse faults, suggesting a change in the palaeostress field during the Neogene-Quaternary, with prevalent transpression and radial extension. Comparison of results of the palaeostress field analysis and the constructed synthetic focal mechanisms on one side, with available focal mechanism solutions for earthquakes within the Ilirska Bistrica-Rijeka-Senj seismogenic fault zone on the other, shows a favourable orientation of the observed NW-SE and NE-SW striking faults with respect to the recent compressional/transpressional stress field (N-S oriented P-axis), indicating these as potential seismogenic sources within the study area.