1. Revealing subtle active tectonic deformation: integrating lidar, photogrammetry, field mapping, and geophysical surveys to assess the Late Quaternary activity of the Sava Fault (Southern Alps, Slovenia)Petra Jamšek Rupnik, Jure Atanackov, Barbara Horn, Branko Mušič, Marjana Zajc, Christoph Grützner, Kamil Ustaszewski, Sumiko Tsukamoto, Matevž Novak, Blaž Milanič, Anže Markelj, Kristina Ivančič, Ana Novak, Jernej Jež, Manja Žebre, Miloš Bavec, Marko Vrabec, 2024, izvirni znanstveni članek Povzetek: We applied an interdisciplinary approach to analyze the late Quaternary activity of the Sava Fault in the Slovenian Southern Alps. The Sava Fault is an active strike-slip fault, and part of the Periadriatic Fault System that accommodated the convergence of Adria and Europe. It is one of the longest faults in the Southern Alps. Using high-resolution digital elevation models from lidar and photogrammetric surveys, we were able to overcome the challenges of assessing fault activity in a region with intense surface processes, dense vegetation, and relatively low fault slip rates. By integrating remote sensing analysis, geomorphological mapping, structural geological investigations, and near-surface geophysics (electrical resistivity tomography and ground penetrating radar), we were able to find subtle geomorphological indicators, detect near-surface deformation, and show distributed surface deformation and a complex fault pattern. Using optically stimulated luminescence dating, we tentatively estimated a slip rate of 1.8 ± 0.4 mm/a for the last 27 ka, which exceeds previous estimates and suggests temporal variability in fault behavior. Our study highlights the importance of modern high-resolution remote sensing techniques and interdisciplinary approaches in detecting tectonic deformation in relatively low-strain rate environments with intense surface processes. We show that slip rates can vary significantly depending on the studied time window. This is a critical piece of information since slip rates are a key input parameter for seismic hazard studies.
Ključne besede: active fault, lidar, photogrammetry, tectonic geomorphology, structural geology, geophysics, electrical resistivity tomography, ground penetrating radar, slip rate, Sava Fault
Objavljeno v DiRROS: 30.04.2024; Ogledov: 15; Prenosov: 3
 Celotno besedilo (53,23 MB) |
2. Transverse Dinaric zone of increased compression between the Kraški rob and Hrušica Regions, NE MicroadriaLadislav Placer, Igor Rižnar, Ana Novak, 2023, izvirni znanstveni članek Povzetek: The Kvarner fault divides the Microadria (Adria microplate, the Adria stable core) into the Po and Adria segments. The Istra block, which is sandwiched between the right-lateral Kvarner Fault and the left-lateral Sistiana Fault lies at the extreme eastern edge of the Po segment. Both faults run transversely to the Dinarides and reach their thrust boundary in the east. The Microadria has been moving towards the Dinarides since the Middle Miocene. The movement of the Istra block is exposed in relation to the neighbouring blocks, so an extensive pushed area (the Istra Pushed Area) was formed in the External Dinarides, which is bent towards the northeast. It is defined by two flexural zones, one lying in the extension of the Sistiana Fault and the other in the extension of the Kvarner Fault. The structure of the Dinaric thrust border on the north-eastern side of the Istra block is complex. Its prominent structural element is the Črni Kal Anomaly, due to which a zone of increased compression developed within the Istra Pushed Area and transversely to the Dinarides (Kraški rob – Hrušica Traverse), which lies between the Sistiana and Kvarner Flexural Zones. In terms of kinematics, it differs greatly from these two, and various geomorphologically responsive deformations have occurred within it. Mt. Vremščica (1027 m), which represents a transpressive anticline within the wider zone of the Raša Fault is the most prominent. In order to understand the genesis of the Classical Karst relief, it is important to know that the Mt. Vremščica ridge rose from the levelled karst surface.
Ključne besede: NE Microadria (Adria Microplate), Istra peninsula, Istra Pushed Area, Črni Kal Anomaly, Kraški rob – Mt. Hrušica Traverse, stacked structure, envelope fault
Objavljeno v DiRROS: 15.01.2024; Ogledov: 159; Prenosov: 130
Celotno besedilo (36,01 MB) |
3. Not another hillshade: alternatives which improve visualizations of bathymetric dataAna Novak, Sašo Poglajen, Marko Vrabec, 2023, izvirni znanstveni članek Povzetek: Increasing awareness of the importance of effective communication of scientific results and concepts, and the need for more accurate mapping and increased feature visibility led to the development of novel approaches to visualization of high-resolution elevation data. While new approaches have routinely been adopted for land elevation data, this does not seem to be the case for the offshore and submerged terrestrial realms. We test the suitability of algorithms provided by the freely-available and user-friendly Relief Visualization Toolbox (RVT) software package for visualizing bathymetric data. We examine the algorithms optimal for visualizing the general bathymetry of a study area, as well as for highlighting specific morphological shapes that are common on the sea-, lake- and riverbed. We show that these algorithms surpass the more conventional analytical hillshading in providing visualizations of bathymetric data richer in details, and foremost, providing a better overview of the morphological features of the studied areas. We demonstrate that the algorithms are efficient regardless of the source data type, depth range, resolution, geographic, and geological setting. The summary of our results and observations can serve as a reference for future users of RVT for displaying bathymetric data.
Ključne besede: bathymetry, RVT, visualization, hillshade, geomorphology, marine geology, multibeam
Objavljeno v DiRROS: 01.12.2023; Ogledov: 206; Prenosov: 67
Celotno besedilo (15,49 MB) |
4. Late-Quaternary evolution of the semi-confined alluvial megafan of Isonzo River (Northern Adriatic): where the fluvial system of the Southern Alps meets the karstLivio Ronchi, Alessandro Fontana, Ana Novak, Annamaria Correggiari, Sašo Poglajen, 2023, izvirni znanstveni članek Povzetek: The evolution of alluvial megafans has mainly been investigated in unconfined settings; however, at the boundary of these large depositional systems, the development of fluvial channels can be affected by structural constraints with regional extent. Here we present the study of the eastern sector of the megafan of Isonzo River, in the Gulf of Trieste, where this system fed through the southern Alps is constrained by the Karst and Istria cliffs. Although this area is now submerged under the northern Adriatic Sea, stratigraphy from seismo-acoustic profiles, drill cores and multi-beam bathymetry allows us to reconstruct the paleochannel system of the Isonzo River in detail, which was likely active within the period of 21–17.5 ka cal BP, at the end of LGM. This was reconstructed for over 50 km and currently represents the longest abandoned fluvial channel in the Mediterranean seabed. The occurrence of the mountain fringe and competition with nearby alluvial systems forced the paleochannel to follow the present coastline and conditioned the slope of its thalweg to decrease almost to null, resulting the transformation from the megafan to the undifferentiated alluvial plain.
Ključne besede: marine geology, CHIRP, stratigraphy, bathymetry, last glacial maximum, adriatic sea
Objavljeno v DiRROS: 31.05.2023; Ogledov: 281; Prenosov: 101
Celotno besedilo (8,68 MB) |
