37th General Assembly of the European Seismological Commission

We would like to invite you to submit an abstract to the session “S14: Imaging and modeling 3D fault complexities in FAULT2SHA” at the 37th General Assembly of the European Seismological Commission.The ESC will be held virtually on 19-24 September 2021. (https://www.erasmus.gr/microsites/1193).
The deadline for the abstracts submission is on April 19, 2021.

The form for abstract submission is available at the following link:

S14: Imaging and modeling 3D fault complexities in FAULT2SHADefining the 3D geometries of faults and their structural and rheological complexities not only presents challenges for field geologists, but also for seismic hazard assessment (SHA). Roughness of the fault plane, friction, asperities and bends constitute primary controlling parameters in physics based earthquake rupture models. Advanced seismic-cycle and earthquake rupture simulations incorporating these variables in 3D models have shown the occurrence of complex earthquake ruptures. Meanwhile, structural and field geologists are analyzing data at micro- and macro-scales, revealing that microscale observables can influence earthquake ruptures, or that, for example, strain partitioning, propagation of earthquake rupture or the seismic/creeping behavior can be influenced by steps, bends, gaps and barriers within and between faults. Modeling the 3D geometry incorporating the variability of these fault parameters along-strike and down-dip is the new frontier that earthquake scientists are beginning to explore, and a key scientific target of the Fault2SHA community. Finally, as the assessment of seismic hazard is ultimately concerned with the expected ground motion, to what extent are empirical ground motion prediction equations and physics-based ground motion simulations capable of capturing these complexities? This session welcomes contributions from: (i) earthquake geologists, seismologists and structural geologists exploring fault geometry and behavior, including detailed imaging of fault properties along-strike and down-dip; (ii) simulations of complex ruptures and earthquake recurrence through dynamic and multi-cycle simulations; (iii) incorporation of characteristic of 3D fault based ruptures into SHA; (iv) and ground motion modelers (empirical and physics-based) investigating the influence of such complex micro- and macroscale 3D complexities.

Conveners: Francesco Visini, Bruno Pace, Laura Peruzza, Oona Scotti and Graeme Weatheril


A first week of field survey after the Petrinja earthquake (Croatia) confirms surface rupturing

On December 29, 2020, an earthquake of magnitude Mw 6.4 shook the region of Petrinja in northern Croatia, 45 km south of Zagreb.

Considering the high magnitude of the earthquake and the potential occurrence of coseismic deformations over large areas, we contacted our Croatian colleagues from the Geological Institute of Croatia (HGI) to participate in the field investigations and establish the first bases for scientific collaboration. After several on-line meetings, the « EU team » planned a first series of field surveys, despite the sanitary crisis and the cold winter, in order to collect the data before their erosion.

The first week of geological surveys, focused on the surface fracture, has just ended. A second will begin and will develop the recognition of the liquefaction features, numerous in this particularly humid zone of the Kupa river catchment, a tributary of the Sava River. French (Lucilla Benedetti, Adrien Moulin, Maxime Henriquet, Stéphane Baize), Italian (Paolo Boncio, Bruno Pace, Francesco Iezzi, Alessio Testa) and Slovenian (Petra Jamšek Rupnik, Matevž Novak, Rok Brajkovič, Jure Atanackov, Bogomir Celarc, Ana Novak) geologists therefore joined the Croatian colleagues in the field (Branko Kordić, Matija Vukovski, Marko Budić, Marko Špelić, Nikola Belić), to complete the mapping of the rupture already largely advanced by the Croatian colleagues alone. This dataset will enrich the existing database of surface ruptures (SURE ; Baize et al., 2019).

The mapping program was regularly coordinated between the various partners who split into several groups every day. This collective work made it possible to confirm the existence of a rupture of moderate dimension for such an earthquake, with a rupture length of several km and maximum offsets of 15-20 cm, to discuss in the field and to think about future joint actions to improve knowledge of the seismogenic potential of the Pokupsko / Petrinja fault and associated structures, which are still largely unknown and which threaten this populated region of the territory. STAY TUNED!


Fault2SHA Learning Series: first lecture

Cosmogenic nuclides as a tool to constrain rates of deformation

Lucilla Benedetti, CEREGE-CNRS, Aix en Provence, France

11th January 2021 15:00 Central European Time

The use of cosmogenic nuclides has revolutionized the quantification of fault motion by filling a critical gap between short-term geodetically recorded slip-rates and geological-long term- slip rates. In this lecture I will present 1-the important aspects to be understood when dealing with cosmogenic nuclides from sampling strategy to getting exposure ages, 2-several applications such as the use of depth profiles to date the emplacement of morphological surfaces, fault scarp dating to unravel past seismic events, relief building and denudation rates, and a novel application on triangular facet to assess normal fault slip-rates.

Click here for Zoom Link for session