Explore the vast range of titles available.

We provide field data of coseismic ground deformation related to the 6 April Mw 6.3 L'Aquila normal faulting earthquake. Three narrow fracture zones were mapped: Paganica‐Colle Enzano (P‐E), Mt. Castellano‐Mt. Stabiata (C‐S) and San Gregorio (SG). These zones define 13 km of surface ruptures that strike at 130–140°. We mapped four main types of ground deformation (free faces on bedrock fault scarps, faulting along synthetic splays and fissures with or without slip) that are probably due to the near‐surface lithology of the fault walls and the amount of slip that approached the surface coseismically. The P‐E and C‐S zones are characterized by downthrow to the SW (up to 10 cm) and opening (up to 12 cm), while the SG zone is characterized only by opening. Afterslip throw rates of 0.5–0.6 mm/day were measured along the Paganica fault, where paleoseismic evidence reveals recurring paleo‐earthquakes and post‐24.8 kyr slip‐rate ≥ 0.24 mm/yr.

Background On September 28th, 2018, at 18:02 local time (10:02 UTC), a strong earthquake of magnitude Mw  = 7.5 struck Central Sulawesi Province, Indonesia. The epicenter was located at 0.256 o south latitude and 119.846 o east longitude, around 77 km from Palu city, and 20 km below the ground surface. To understand the damage caused by the earthquake, and find a solution to mitigate the geo-disasters in Indonesia, a preliminary investigation on the 2018 Sulawesi earthquake was conducted from 16 to 20 November 2018. This quick report focuses on ground displacements induced by fault movement and large-scale ground flow. Results During the survey, there is some geotechnical damage were found, such as ground displacement induced by fault movement, liquefaction, landslides, and large-scale ground flow in some certain areas. Large ground displacement was found in some particular areas, such as Kedondong, Pipa Air, Pangeran Diponegoro and Cemara streets in Palu city. The earthquake also triggered large-scale ground flow in some different sites, such as Balaroa and Petobo districts in Palu city and Jono Oge and Sibalaya Villages. Conclusions The locations of large ground displacements appeared at surface coincide well with the estimated fault line. Therefore the large ground displacements were seems to be induced by the fault movement. Large ground flow caused severe damage to not only human but also houses and buildings. The mechanism of the large ground flow should be clarified in near future.

We present a 1:25,000 scale map of the coseismic surface ruptures following the 30 October 2016 M w 6.5 Norcia normal-faulting earthquake, central Italy. Detailed rupture mapping is based on almost 11,000 oblique photographs taken from helicopter flights, that has been verified and integrated with field data (>7000 measurements). Thanks to the common efforts of the Open EMERGEO Working Group (130 people, 25 research institutions and universities from Europe), we were able to document a complex surface faulting pattern with a dominant strike of N135°-160° (SW-dipping) and a subordinate strike of N320°-345° (NE-dipping) along about 28 km of the active Mt. Vettore-Mt. Bove fault system. Geometric and kinematic characteristics of the rupture were observed and recorded along closely spaced, parallel or subparallel, overlapping or step-like synthetic and antithetic fault splays of the activated fault systems, comprising a total surface rupture length of approximately 46 km when all ruptures were considered.

Surface faulting earthquakes are known to cluster in time from historical and palaeoseismic studies, but the mechanism(s) responsible for clustering, such as fault interaction, strain-storage, and evolving dynamic topography, are poorly quantified, and hence not well understood. We present a quantified replication of observed earthquake clustering in central Italy. Six active normal faults are studied using 36 Cl cosmogenic dating, revealing out-of-phase periods of high or low surface slip-rate on neighboring structures that we interpret as earthquake clusters and anticlusters. Our calculations link stress transfer caused by slip averaged over clusters and anti-clusters on coupled fault/shear-zone structures to viscous flow laws. We show that (1) differential stress fluctuates during fault/shear-zone interactions, and (2) these fluctuations are of sufficient magnitude to produce changes in strain-rate on viscous shear zones that explain slip-rate changes on their overlying brittle faults. These results suggest that fault/shear-zone interactions are a plausible explanation for clustering, opening the path towards process-led seismic hazard assessments. The mechanisms responsible for clustering of surface fault earthquakes are often unclear. Here the authors find that differential stress fluctuates during fault/shear-zone interactions which can produce changes in strain-rate and slip-rate changes leading to earthquake clustering.

Large-scale loss of life and property occurred in Kahramanmaraş and its districts, which are the city center where the epicenters of the earthquake couples that occurred on February 6, 2023, in Türkiye. Major damage has occurred in different structural systems due to the earthquake. In addition, fault traces that are the source of the earthquake were clearly observed on the ground surface. In this study, the effects of both earthquakes on soil, reinforced concrete, masonry, prefabricated, and other structural systems were evaluated observationally in Kahramanmaraş and its districts. Comparisons were made on the last two earthquake maps used in Türkiye for the locations of strong ground motion measuring devices in Kahramanmaraş. The masonry structures, which are common in rural areas in the epicenter, have been heavily damaged because they have not received engineering service. However, it is seen that the concrete buildings have insufficient strength and ductility. A similar situation is also present in industrial precast structures, and it has been observed that the damaged and collapsed in these structures are manufactured without complying with the type connection details given for prefabricated reinforced concrete structures in the codes. It has also been observed that the soil-structure interaction is the most determining parameter in the structure’s performance in these earthquake couples. Especially in weak soils, the damage to the structures has been quite heavy. The field data obtained from the earthquakes showed that some of the conditions of the current earthquake code should be discussed again.

The NW–SE-trending Firenze-Pistoia Basin (FPB) is an intermontane tectonic depression in the Northern Apennines (Italy) bounded to the northeast by a SW-dipping normal fault system. Although it has moderate historical seismicity (maximum estimated Mw 5.5 in 1895), the FPB lacks detailed characterization of its recent tectonic structures, unlike those of nearby basins that have produced Mw > 6 events. This study focuses on the southeastern sector of the basin, including the urban area of Florence, using tectonic geomorphology derived from remote sensing, in particular LiDAR data, field verification, and high-resolution geophysical surveys such as electrical resistivity tomography and seismic reflection profiles. The integration of these techniques enabled interpretation of the subdued and anthropogenically masked tectonic structures, allowing the identification of Holocene activity and significant, although limited, surface vertical offset for three NE–SW-striking normal faults, the Peretola, Scandicci, and Maiano faults. The Scandicci and Maiano faults appear to segment the southeasternmost strand of the master fault of the FPB, the Fiesole Fault, which now shows activity only along isolated segments and cannot be considered a continuous active fault. From empirical relationships, the Scandicci Fault, the most relevant among the three active faults, ~9 km long within the basin and with an approximate Late Quaternary slip rate of ~0.2 mm/year, might source Mw > 5.5 earthquakes. These findings highlight the need to reassess the local seismic hazard for more informed urban planning and for better preservation of the cultural and architectural heritage of Florence and the other artistic towns located in the FPB.

Field surveys focused on detailed mapping and measurements of coseismic surface ruptures along the causative fault of the 6 February 2023, Mw 7.8 Kahramanmaraş earthquake. The aim was filling gaps in the previously available surface-faulting trace, validating the accuracy of data obtained from remote sensing, refining fault offset estimates, and gaining a deeper understanding of both the local and overall patterns of the main rupture strands. Measurements and observations confirm dominating sinistral strike-slip movement. An integrated and comprehensive slip distribution curve shows peaks reaching over 700 cm, highlighting the near-fault expressing up to 70% of the deep net offset. In general, the slip distribution curve shows a strong correlation with the larger north-eastern deformation of the geodetic far field dislocation field and major deep slip patches. The overall rupture trace is generally straight and narrow with significant geometric complexities at a local scale. This results in transtensional and transpressional secondary structures, as multi-strand positive and negative tectonic flowers, hosting different patterns of the mole-tracks at the outcrop scale. The comprehensive and detailed field survey allowed characterizing the structural framework and geometric complexity of the surface faulting, ensuring accurate offset measurements and the reliable interpretation of both morphological and geometric features.

We use a comprehensive dataset of field observations, high spatial resolution drone orthomosaics and digital terrain models (DTMs) to map, quantify and characterize the extensive ground fracturing related to the 2021 seismo-tectonic and volcanic activity in the Reykjanes Peninsula (Iceland). The dataset, spans an area of about 30 km 2 , where we map nearly 20 000 ground cracks with metric to decametric lengths and centimetric extensional offsets, revealing a dominant dextral shear, in agreement with published seismic data. Although striking in a direction similar to the volcanic systems in the Reykjanes Peninsula (N030–040), most fractures appear as en-échelon structures globally aligned along N-S-striking fault zones up to 3–4 km long. By examining the timing of ground fracturing through repeated field observations, seismic data and InSAR images, we associate a fracture zone with most earthquakes of M ω ≥ 5.0 that occurred in the month preceding the March 2021 Fagradalsfjall eruption. We describe three preexisting N-S fault zones, with fault segments that were reactivated up to three times during the pre-eruptive seismic activity, while the magma intrusion did not trigger graben-related ground fractures typically observed during magmatic injections. Our depiction of a system dominated by strike-slip tectonic features helps in understanding the geometry and bookshelf-mode of tectonic activity along a diffuse and highly oblique extensional plate boundary. Evidence of transient fracturing is typically quickly lost because of erosion or lava flow burial, highlighting a potential under-representation of diffuse fracturing when studying old tectonic and volcanic systems.

We present a 1:10,000 scale map of the coseismic surface ruptures following the 26 December 2018 Mw 4.9 earthquake that struck the eastern flank of Mt. Etna volcano (southern Italy). Detailed rupture mapping is based on extensive field surveys in the epicentral region. Despite the small size of the event, we were able to document surface faulting for about 8 km along the trace of the NNW-trending active Fiandaca Fault, belonging to the Timpe tectonic system in the eastern flank of the volcano. The mapped ruptures are characterized in most cases by perceivable opening and by a dominant right-oblique sense of slip, with an average slip of about 0.09 m and a peak value of 0.35 m. It is also noteworthy that the ruptures vary significantly in their kinematic expression, denoting locally high degree of complexity of the surface faulting.

The 2022 ( 6.8) Luding earthquake on the Xianshuihe Fault Zone (XFZ) caused severe casualties and property losses, and surface deformation and damage of which is crucial for studying the earthquake hazard assessment. However, few intensive scientific understanding has obtained to date because of widespread coronavirus transmission, strong vegetation coverage, and post-earthquake paralyzed traffic. By integrating high-resolution satellite images, large-scale geomorphic mapping, and UAV surveys, we constrain coseismic fractures and ruptures along an NW-SE-trending surface deformation zone, with discontinuous geomorphic scarps, cracks, and bulges concentrated in the areas of Yanzigou, Moxi, Menghugang, and Xingfu villages near the epicenter. Field observation also shows that the zone extends nearly parallel to the pre-existing XFZ with a length of ∼35 km with variable widths and a maximum vertical displacement of ∼100 ± 10 cm. The earthquake-induced surface coseismic effects, such as landslides, rock falls, and collapses, caused damage to the area. The amplification effect of the topography and the improper aseismic design and poor constructions may be responsible for the spatial distribution of MM Intensity IX, which is larger than other previous earthquakes that occurred in the surrounding area with a similar tectonic setting.