TY - JOUR AU - Pasiecznik, Damian AU - Greenwood, Andrew AU - Bleibinhaus, Florian AU - Hetényi, György TI - Seismic structure of the Balmuccia Peridotite from a high-resolution refraction and reflection survey JF - GEOPHYSICAL JOURNAL INTERNATIONAL J2 - GEOPHYS J INT VL - 238 PY - 2024 IS - 3 SP - 1612 EP - 1625 PG - 14 SN - 0956-540X DO - 10.1093/gji/ggae239 UR - https://m2.mtmt.hu/api/publication/35300712 ID - 35300712 AB - In anticipation of a forthcoming scientific deep drilling initiative within the Western Alps near Balmuccia, Italy, a high-resolution seismic survey is performed at the proposed drill site. This site is situated within the Ivrea Verbano Zone (IVZ), characterized by lower crustal materials and fragments of upper-mantle rocks exposed adjacent to the Insubric Line. The 2-km-long seismic survey crosses an isolated km-scale outcrop of peridotite near the town of Balmuccia. Applying P-wave traveltime tomography, a substantial contrast in seismic velocities is identified, with velocities in the range of 1–8 km s−1. The peridotite displays velocities ranging from 6 to 8 km s−1. The higher velocities near 8 km s−1 are consistent with laboratory measurements on small-scale samples, while the low-velocity areas within the peridotite body reflect the influence of fractures and faults. The mean velocity derived for the peridotite body is ca. 7 km s−1. The reflection seismic analysis reveals subvertical reflectors positioned at the peridotite boundaries mapped at the surface, converging at a depth of ca. 0.175 km b.s.l. which images a lens-like structure for the peridotite body. However, the area beneath the imaged lens and the deeper Ivrea Geophysical Body (IGB) suggested by earlier studies is not well imaged, which leaves room for other interpretations regarding the relationship of these two bodies. Prior geophysical investigations provide only approximate depth estimates for the top of the IGB, spanning between 1–3 km depth b.s.l. Although the reflection data do not exhibit a series of continuous reflectors beneath the peridotite, a prominent reflection at ca. 1.3 km depth may indicate the top of the IGB. LA - English DB - MTMT ER - TY - JOUR AU - Greenwood, Andrew AU - Hetényi, György AU - Baron, Ludovic AU - Zanetti, Alberto AU - Müntener, Othmar TI - Active seismic surveys for drilling target characterization in Ossola Valley: International Continental Scientific Drilling Program (ICDP) project Drilling the Ivrea–Verbano zonE (DIVE) phase I JF - SCIENTIFIC DRILLING J2 - SCI DRIL VL - 33 PY - 2024 IS - 2 SP - 219 EP - 236 PG - 18 SN - 1816-8957 DO - 10.5194/sd-33-219-2024 UR - https://m2.mtmt.hu/api/publication/35300705 ID - 35300705 AB - Abstract. Drilling target locations of the International Continental Scientific Drilling Program (ICDP) project Drilling the Ivrea–Verbano zonE (DIVE) have been initially proposed based on geological knowledge of surface outcrops and the structural context of the Ivrea–Verbano zone (IVZ) and of the Insubric Line. For the determination of the exact locations of drilling sites as well as for drilling geometry planning, we have carried out a series of active seismic experiments to image the subsurface at high resolution. The two drilling sites of project DIVE in Ossola Valley, one near Ornavasso and the other in Megolo di Mezzo, in the central part of the Ivrea–Verbano zone have been surveyed with site-specific velocity models and a seismic data processing chain. The findings have been interpreted in relation with the outcropping structures. These suggest a reasonable continuity from the surface. They also guide the planned borehole orientations: near-vertical at DT-1B (Ornavasso) into the tightly folded Massone Antiform and at 15–20° from the vertical in Megolo across a flank of the broad Proman Anticline. The seismic surveys indicate that the sedimentary overburden is up to 50 m deep at the specific drill sites and can be minimized by relocating the proposed locations. The seismic surveys also indicate that the center of the Ossola Valley contains about 550 m of sedimentary infill, defining the interface of bedrock and Quaternary glacial sediments at about 300 m below sea level. LA - English DB - MTMT ER - TY - JOUR AU - Menegoni, Niccolò AU - Panara, Yuri AU - Greenwood, Andrew AU - Mariani, Davide AU - Zanetti, Alberto AU - Hetényi, György TI - Fracture network characterisation of the Balmuccia peridotite using drone-based photogrammetry, implications for active-seismic site survey for scientific drilling JF - JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING J2 - J ROCK MECH GEOTECH ENGIN VL - in press PY - 2024 SN - 1674-7755 DO - 10.1016/j.jrmge.2024.03.012 UR - https://m2.mtmt.hu/api/publication/35300687 ID - 35300687 AB - The presence of discontinuities (e.g. faults, fractures, veins, layering) in crystalline rocks can be challenging for seismic interpretations because the wide range of their size, orientation, and intensity, which controls the mechanical properties of the rock and elastic wave propagation, resulting in equally varying seismic responses at different scales. The geometrical characterisation of adjacent outcrop discontinuity networks allows a better understanding of the nature of the subsurface rocks and aids seismic interpretation. In this study, we characterise the discontinuity network of the Balmuccia peridotite (BP) in the Ivrea–Verbano Zone (IVZ), northwestern Italy. This geological body is the focus of the Drilling the Ivrea–Verbano zonE (DIVE), an international continental scientific drilling project, and two active seismic surveys, SEismic imaging of the Ivrea ZonE (SEIZE) and high-resolution SEIZE (Hi-SEIZE), which aim to resolve the subsurface structure of the DIVE drilling target through high-resolution seismic imaging. For fracture characterisation, we developed two drone-based digital outcrop models (DOMs) at two different resolutions (10−3–10 m and 10−1–103 m), which allowed us to quantitatively characterise the orientation, size, and intensity of the main rock discontinuities. These properties affect the seismic velocity and consequently the interpretation of the seismic data. We found that (i) the outcropping BP discontinuity network is represented by three more sets of fractures with respect to those reported in the literature; (ii) the discontinuity sizes follow a power-law distribution, indicating similarity across scales, and (iii) discontinuity intensity is not uniformly distributed along the outcrop. Our results help to explain the seismic behaviour of the BP detected by the SEIZE survey, suggesting that the low P-wave velocities observed can be related to the discontinuity network, and provide the basic topological parameters (orientation, density, distribution, and aperture) of the fracture network unique to the BP. These, in turn, can be used for interpretation of the Hi-SEIZE seismic survey and forward modelling of the seismic response. LA - English DB - MTMT ER - TY - JOUR AU - Hetényi, György AU - Baron, Ludovic AU - Scarponi, Matteo AU - Subedi, Shiba AU - Michailos, Konstantinos AU - Dal, Fergus AU - Gerle, Anna AU - Petri, Benoît AU - Zwahlen, Jodok AU - Langone, Antonio AU - Greenwood, Andrew AU - Ziberna, Luca AU - Pistone, Mattia AU - Zanetti, Alberto AU - Müntener, Othmar TI - Report on an open dataset to constrain the Balmuccia peridotite body (Ivrea-Verbano Zone, Italy) through a participative gravity-modelling challenge JF - SWISS JOURNAL OF GEOSCIENCES J2 - SWISS J GEOSCI VL - 117 PY - 2024 IS - 1 SN - 1661-8726 DO - 10.1186/s00015-023-00450-3 UR - https://m2.mtmt.hu/api/publication/35300663 ID - 35300663 AB - The Balmuccia peridotite exposes relatively fresh mantle rocks at the Earth’s surface, and as such it is of interest for geologists and geophysicists. The outcrop is a kilometre-scale feature, yet its extent at depth is insufficiently imaged. Our aim is to provide new constraints on the shape of the density anomaly this body represents, through 3D gravity modelling. In an effort to avoid personal or methodology bias, we hereby launch an invitation and call for participative modelling. We openly provide all the necessary input data: pre-processed gravity data, geological map, in situ rock densities, and digital elevation model. The expected inversion results will be compared and jointly analysed with all participants. This approach should allow us to conclude on the shape of the Balmuccia peridotite body and the associated uncertainty. This crowd effort will contribute to the site surveys preparing a scientific borehole in the area in frame of project DIVE. LA - English DB - MTMT ER - TY - JOUR AU - Uthaman, Mita AU - Singh, Chandrani AU - Singh, Arun AU - Hetényi, György AU - Dutta, Abhisek AU - Kumar, Gaurav AU - Dubey, Arun Kumar TI - Complex Multi-Fault Dynamics in Sikkim Himalaya: New Insights From Local Earthquake Analysis JF - GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS J2 - GEOCHEM GEOPHY GEOSY VL - 25 PY - 2024 IS - 6 PG - 18 SN - 1525-2027 DO - 10.1029/2023GC011363 UR - https://m2.mtmt.hu/api/publication/35275784 ID - 35275784 LA - English DB - MTMT ER - TY - JOUR AU - Subedi, Shiba AU - Hetényi, György AU - Frederick, Massin AU - Adhikari, Lok Bijaya AU - Michailos, Konstantinos TI - Local earthquake monitoring with a low-cost seismic network: a case study in Nepal JF - EARTH PLANETS AND SPACE J2 - EARTH PLANETS SPACE VL - 76 PY - 2024 IS - 1 PG - 14 SN - 1343-8832 DO - 10.1186/s40623-024-02047-y UR - https://m2.mtmt.hu/api/publication/35275780 ID - 35275780 LA - English DB - MTMT ER - TY - JOUR AU - Bouscary, Chloe AU - King, Georgina E. AU - Grujic, Djordje AU - Lave, Jerome AU - Hetényi, György AU - Almeida, Rafael AU - Herman, Frederic TI - Sustained deformation across the Sub-Himalayas since 200 ka JF - GEOLOGY J2 - GEOLOGY VL - 52 PY - 2024 IS - 1 SP - 72 EP - 76 PG - 5 SN - 0091-7613 DO - 10.1130/G51656.1 UR - https://m2.mtmt.hu/api/publication/34954074 ID - 34954074 LA - English DB - MTMT ER - TY - JOUR AU - Schlömer, A AU - Hetényi, György AU - Plomerová, J AU - Vecsey, L AU - Bielik, M AU - Bokelmann, G AU - Csicsay, K AU - Czuba, W AU - Fojtíková, L AU - Friederich, W AU - Fuchs, F AU - Grad, M AU - Janik, T AU - Kampfová Exnerová, H AU - Kolínský, P AU - Malinowski, S AU - Meier, T AU - Mendecki, M AU - Papčo, J AU - Środa, P AU - Szűcs, E AU - Süle, B AU - Timkó, M AU - Gyarmati, A AU - Wéber, Z AU - Wesztergom, V AU - Žlebčíková, H TI - The Pannonian-Carpathian-Alpine seismic experiment (PACASE): network description and implementation JF - ACTA GEODAETICA ET GEOPHYSICA J2 - ACTA GEOD GEOPHYS VL - 59 PY - 2024 SP - 249 EP - 270 PG - 22 SN - 2213-5812 DO - 10.1007/s40328-024-00439-w UR - https://m2.mtmt.hu/api/publication/34815141 ID - 34815141 AB - The Pannonian-Carpathian-Alpine Seismic Experiment (PACASE) is a collaborative project based on a large, passive seismic network comprising 214 temporary stations. Among the primary aims are the imaging of the Earth’s crustal, lithospheric and upper mantle structure, including joint inversions; monitoring and mapping of seismic activity; and interpretation of the data from seismotectonic and geodynamic perspectives. The base of the cooperation is a high-quality, broadband seismic network covering the very centre of Europe: the Eastern Alpine and Western Carpathian Mountain ranges, the Bohemian Massif, and the sedimentary Molasse and Pannonian Basins. In this overview, we focus on the implementation and achieved field goals of PACASE, such as seismic station configuration, general network organization, data availability and access to the dataset. With selected seismological examples, we demonstrate the good usability of the records of earthquake detection, and a first publication attests to the structural imaging capability of the PACASE data. We assess the background noise level at various stations and its variations in time and space. Our aim is to collect all practical information relevant to serve as a long-term reference for the PACASE. LA - English DB - MTMT ER - TY - JOUR AU - Scarponi, M AU - Kvapil, J AU - Plomerová, J AU - Solarino, S AU - Hetényi, György TI - New constraints on the shear wave velocity structure of the Ivrea geophysical body from seismic ambient noise tomography (Ivrea-Verbano Zone, Alps) JF - GEOPHYSICAL JOURNAL INTERNATIONAL J2 - GEOPHYS J INT VL - 236 PY - 2024 IS - 2 SP - 1089 EP - 1105 PG - 17 SN - 0956-540X DO - 10.1093/gji/ggad470 UR - https://m2.mtmt.hu/api/publication/34565490 ID - 34565490 AB - We performed seismic ambient noise tomography to investigate the shallow crustal structure around the Ivrea geophysical body (IGB) in the Ivrea-Verbano Zone (IVZ). We achieved higher resolution with respect to previous tomographic works covering the Western Alps, by processing seismic data collected by both permanent and temporary seismic networks (61 broad-band seismic stations in total). This included IvreaArray, a temporary, passive seismic experiment designed to investigate the IVZ crustal structure. Starting from continuous seismic ambient noise recordings, we measured and inverted the dispersion of the group velocity of surface Rayleigh waves (fundamental mode) in the period range 4–25 s. We obtained a new, 3-D vS model of the IVZ crust via the stochastic neighbourhood algorithm (NA), with the highest resolution between 3 to 40 km depth. The fast and shallow shear wave velocity anomaly associated with the IGB presents velocities of 3.6 km s−1 directly at the surface, in remarkable agreement with the location of the exposed lower-to-middle crustal and mantle outcrops. This suggests a continuity between the surface geological observations and the subsurface geophysical anomalies. The fast IGB structure reaches vS of 4 km s−1 at 20–25 km depth, at the boundary between the European and Adriatic tectonic plates, and in correspondence with the earlier identified Moho jump in the same area. The interpretation of a very shallow reaching IGB is further supported by the comparison of our new results with recent geophysical investigations, based on receiver functions and gravity anomaly data. By combining the new geophysical constraints and the geological observations at the surface, we provide a new structural interpretation of the IGB, which features lower crustal and mantle rocks at upper crustal depths. The comparison of the obtained vS values with the physical properties from laboratory analysis of local rock samples suggests that the bulk of the IGB consists of a combination of mantle peridotite, ultramafic and lower crustal rocks, bound in a heterogeneous structure. These new findings, based on vS tomography, corroborate the recent interpretation for which the Balmuccia peridotite outcrops are continuously linked to the IGB structure beneath. The new outcomes contribute to a multidisciplinary framework for the interpretation of the forthcoming results of the scientific drilling project DIVE. LA - English DB - MTMT ER - TY - JOUR AU - Hetényi, György AU - Subedi, Shiba TI - A Call to Action for a Comprehensive Earthquake Education Policy in Nepal JF - Seismica J2 - Seismica VL - 2 PY - 2023 IS - 2 SN - 2816-9387 DO - 10.26443/seismica.v2i2.242 UR - https://m2.mtmt.hu/api/publication/35300645 ID - 35300645 AB - Earthquakes in Nepal are among the most damaging natural hazards, claiming many lives and causing more widespread destruction than any other natural hazard. Yet, due to other difficulties and challenges, earthquakes are at the forefront of people’s attention only after major events, such as the 1934 or 2015 earthquakes. As a result, current preparedness of the population to earthquakes is far below the optimal level. This calls for an immediate and widespread educational effort to increase awareness and to raise the current young generation responsibly. After describing the current status of earthquake education at various school levels in Nepal, we here propose a series of actions to undertake towards an official education policy, starting from full openness and use of languages, via coordination and teacher's training, to the content, frequency and style of curriculum. We conclude on a timeline of actions, which have various lengths but should start today. We hope that by sharing our researcher and educational experience and thoughts, the actual preparation of the earthquake education policy for Nepal will start being developed under a dedicated team. Elements of the proposal presented here can be used and adapted to other regions at risk around the world. LA - English DB - MTMT ER -