Search Results (50)

On 7 January 2025, a M_S 6.8 earthquake struck Dingri County, southern Tibet, within the extensional regime of the central Himalaya–southern Tibetan Plateau. Using ascending and descending Sentinel-1A SAR data, we applied a two-pass Differential InSAR (D-InSAR) approach with SRTM DEM data to retrieve high-precision coseismic deformation fields. We observed significant LOS deformation, revealing peak displacements of −1.06 m and +0.76 m, with deformation concentrated along the Denmo Co graben and clear offsets along its western boundary fault. Nonlinear inversion using the Okada elastic dislocation model and a quadtree down-sampled dataset yields a rupture plane 28.42 km long and 12.81 km wide, striking 183.51°, dipping 55.41°, and raking −71.95°, consistent with a predominantly normal-faulting mechanism with a minor left-lateral component. Distributed-slip inversion reveals that peak slip (4.79 m) was concentrated in the upper ~10 km of the fault, with the main asperity located in the central fault segment. The seismic moment is estimated to be 4.24 × 10¹⁹ Nm, which corresponds to a magnitude of M_W 7.05. Coulomb failure stress (ΔCFS) calculations indicate stress increases (>0.01 MPa) at the northern and southern rupture terminations (5–10 km depth) and the flanks at 15–20 km depth, suggesting elevated seismic potential in these regions. This integrated InSAR–modeling–stress analysis provides new constraints on the source parameters, slip distribution, and tectonic implications of the 2025 Dingri earthquake, offering important insights for regional seismic hazard assessment. Full article

This study investigates spatiotemporal b value variations and seismic interaction networks preceding the M_wg 7.1 Dingri earthquake that struck southern Tibet on 7 January 2025. Using relocated earthquake catalogs (2021–2025) and dual-method analysis combining b value mapping with Granger causality network modeling, we reveal systematic precursory patterns. Spatial analysis shows that the most significant b value reduction (Δb > 0.5) occurred north of the mainshock epicenter at seismogenic depths (5–15 km), closely aligning with subsequent aftershock concentration zones. Granger causality analysis reveals a progressive network simplification: from 73 causal links among 28 nodes during the background period (2021–2023) to 49 links among 34 nodes pre-mainshock (2023–2025) and finally to 6 localized links post-rupture. This transition from distributed system-wide interactions to localized “locked-in” dynamics reflects the stress concentration onto the primary asperity approaching critical failure. The convergence of b value anomalies and network evolution provides a comprehensive framework linking quasi-static stress states with dynamic system behavior. These findings offer valuable insights for understanding earthquake nucleation processes and improving seismic hazard assessment in the Tibetan Plateau and similar complex tectonic environments. Full article

Analyzing accident reports to absorb past experiences is crucial for construction site safety. Current methods of processing textual accident reports are time-consuming and labor-intensive. This research applied the LDA topic model to analyze construction accident reports, successfully identifying five main types of accidents: Falls from Height (23.5%), Struck-by and Contact Injuries (22.4%), Slips, Trips, and Falls (21.8%), Hot Work & Vehicle Hazards (18.1%), and Lifting and Machinery Accidents (14.2%). By mining the rich contextual details within unstructured textual descriptions, this research revealed that environmental factors constituted the most prevalent category of contributing causes, followed by human factors. Further analysis traced the root causes to deficiencies in management systems, particularly poor task planning and inadequate training. The LDA model demonstrated superior effectiveness in extracting interpretable topics directly mappable to engineering knowledge and uncovering these latent factors from large-scale, decade-spanning textual data at low computational cost. The findings offer transformative perspectives for improving construction site safety by prioritizing environmental control and management system enhancement. The main theoretical contributions of this research are threefold. First, it demonstrates the efficacy of LDA topic modeling as a powerful tool for extracting interpretable and actionable knowledge from large-scale, unstructured textual safety data, aligning with the growing interest in data-driven safety management in the construction sector. Second, it provides large-scale, empirical evidence that challenges the traditional dogma of “human factor dominance” by systematically quantifying the critical role of environmental and managerial root causes. Third, it presents a transparent, data-driven protocol for transitioning from topic identification to causal analysis, moving from assertion to evidence. Future work should focus on integrating multi-dimensional data for comprehensive accident analysis. Full article

On 8 June 2025, the Mw 6.4 Paratebueno earthquake struck the eastern foothills of the Eastern Andes, Colombia. The event occurred near the Guaicáramo fault, along the eastern margin of the Eastern Cordillera fold-and-thrust belt. To investigate its rupture characteristics and tectonic implications, we utilized ALOS-2 and Sentinel-1 SAR data to derive coseismic deformation fields. Source geometry and slip distribution were inverted with the Okada dislocation model, and static Coulomb failure stress change were calculated to assess the triggering relationship with the 2023 Mw 6.2 Meta-Cundinamarca earthquake. The results reveal maximum line-of-sight displacements of 43 cm, 23 cm and 32 cm, respectively, caused by a northwest-dipping blind reverse fault (strike ~213°, dip 58°) with ~5 m maximum slip concentrated at depths of 8–12 km, without surface rupture. Combining geological and stratigraphic evidence, including regional structures and sedimentary cover thickness, this event implies a transition from a normal fault to reverse fault due to ongoing shortening of fold-and-thrust belt, consistent with a thick-skinned tectonic origin. Coulomb stress modeling suggests the 2023 event promoted the 2025 rupture, and the combined effect of the two events further increased stress on the southeastern Guaicáramo fault, implying elevated seismic hazard. Full article

Mount Etna has a well-documented history of frequent eruptions and seismic activity, periodically causing significant damage to urban areas. On 26 December 2018, a Mw 4.9 shallow earthquake struck the volcano’s eastern flank, severely damaging approximately 3000 buildings. The post-earthquake recovery strategy aimed to enhance community resilience by addressing the hazardous nature of the affected territory. This objective was achieved through measures such as relocation and public use transformation. In areas impacted by active faults, the relocation of damaged buildings was encouraged, while cleared zones were repurposed for public use, transformed into gardens and open-air parking spaces. Despite these efforts, some relocated individuals experienced psychological distress. To address this challenge, government planners played a pivotal role in disseminating scientifically accurate information, raising public awareness, and facilitating adaptation. The approach implemented on Etna was later adopted in other post-earthquake recovery programs in Italy, evolving into a replicable strategy for risk mitigation in disaster-prone areas. Full article

The Lower Tagus Valley (LTV) region has the highest population density in Portugal, with over 3.7 million people living in the region. It has been struck in the past by several historical earthquakes, which caused significant economic and human losses. For a proper seismic hazard evaluation, the area needs detailed V_s30 and soil classification maps. Previously available maps are based on proxies, or an insufficient number of velocity measurements followed by coarse geological generalizations. The focus of this work is to significantly improve the available maps. For this purpose, more than 90 new S-wave seismic velocities measurements obtained from seismic refraction and seismic noise measurements, doubling the number used in previously available maps, are used to update available V_s30 and soil classification maps. The data points are also generalized to the available geological maps using local lithostratigraphic studies and, for the first time, satellite images of this area. The results indicate that lithological and thickness changes within each geological formation prevent a simple generalization of geophysical data interpretation based solely on geological mapping. The maps presented here are the first attempt to produce maps at a scale larger than 1:1,000,000 in Portugal, with direct shear wave velocity measurements. A tentative approach to produce more detailed maps using machine learning was also carried out, presenting promising results. This approach may be used in the future to reduce the number of shear wave measurements necessary to produce detailed maps at a finer scale. Full article

The Wenchuan earthquake, an unexpected magnitude 8.0 mega-earthquake that struck on 12 May 2008, significantly changed land cover (LC), particularly affecting vegetation and rock cover. However, the long-term effects of LC changes on ecosystem services (ESs) remain unclear in earthquake-affected regions, especially across different spatial scales. This study, focusing on Wenchuan County, employs a multi-model framework that integrates fractional vegetation coverage (FVC), rock exposure rate (FR), and ecosystem services (ESs), combining correlation analysis, geographically weighted regression (GWR), Self-organizing map (SOM) clustering, and XGBoost-SHAP model, to analyze the spatiotemporal dynamics, interrelationships, and driving mechanisms of land cover (LC) and ESs before and after the earthquake. Results show that: (1) From 2000 to 2020, FVC and FR fluctuated markedly under earthquake influence, with slight declines in habitat quality (HQ) and carbon storage (CS) and notable improvements in soil conservation (SC) and water yield (WY). (2) With increasing elevation, the FVC–CS–SC group exhibited a downward trend and synergy, while the FR–HQ–WY group increased and also showed synergy; trade-offs and synergies became more pronounced at larger scales, displaying strong spatiotemporal heterogeneity. (3) Elevation (explaining 10–60% of variance) was the main driver for LC and ESs, with land use, slope, human activities, climate, and geological conditions significantly impacting individual indicators. At the same time, the existing geological hazard points are mainly concentrated along both sides of the river valleys, which may be associated with intensified human–land conflicts. These findings offer valuable insights into ecological restoration and sustainable development in earthquake-affected regions. Full article

In 2011, a M 5.7, earthquake struck near Mineral, Virginia, about 130 km southwest of Washington, D.C., prompting studies on paleoliquefaction to better understand the earthquake potential of the Central Virginia seismic zone and the hazard it poses to the Mid-Atlantic region. Researchers identified earthquake-induced liquefaction features along the Appomattox and Rapidan rivers, dated sediment and estimated the ages of these liquefaction features as well as features previously found along several other rivers in the seismic zone, and evaluated scenario earthquakes to constrain the locations and magnitudes of past earthquakes. Evidence suggests that historical earthquakes (M 5.25–5.5) in 1758, 1774, and 1875 C.E. caused liquefaction along the Appomattox, James, and Pamunkey Rivers, and a paleoearthquake (M 6.5–6.75) around 2640 ± 80 yr B.P. near Wyndham Forest caused liquefaction along the Appomattox River and across the seismic zone. Similarly, an earthquake (M 5.5–5.75) around 1690 ± 50 yr C.E. may have triggered liquefaction along the Rapidan River. Full article

Aircraft hangars are essential in the aviation industry, providing crucial maintenance and protection for aviation assets. However, constructing these upper structures involves significant safety risks. Due to the complexity of upper structure construction, it is vital to prioritize safety to prevent workplace accidents. Ensuring construction safety is not only crucial for operational efficiency but also aligns with several Sustainable Development Goals (SDGs), such as Decent Work and Economic Growth (SDG 8) and Industry, Innovation, and Infrastructure (SDG 9). This study assesses the safety risks associated with hangar construction using activity-based failure modes and effects analysis (FMEA). A mixed-method approach is adopted, incorporating insights from five construction safety experts and data from 100 individuals directly involved in the upper structure construction of the spaceframe hangar. Descriptive data analysis was employed to establish the foundation for computing risk priority numbers (RPNs) using the FMEA technique. Three primary activities were identified as having extremely high risks: workers falling from heights during the lifting and erection of the space frame, workers falling from heights during basement excavation while installing floor slab formwork, and workers falling from heights during the casting of floor slabs. These activities present safety risks with RPN values ranging from 64 to 100, including incidents of workers falling from heights and being struck by materials. This study serves as a crucial reference for formulating construction safety plans that encompass risk identification, assessment, and control measures. The findings provide essential insights into various safety hazards in construction projects, particularly those related to military infrastructure. By identifying and assessing these risks, the research facilitates the development of more effective and comprehensive safety protocols. Implementing the recommended control measures ensures a proactive approach to mitigating potential accidents and injuries. Consequently, this research contributes to academic knowledge and enhances safety standards and practices within the construction industry. Full article

The construction industry is considered one of the most hazardous industries. The accidents associated with construction equipment are a leading cause of fatalities in the U.S., with one-quarter of all fatalities in the construction industry due to equipment-related incidents, including collisions, struck-by events, and rollovers. While close collaboration among multiple equipment and humans is common, conventional collision alert mechanisms for equipment usually rely on distance sensors with static thresholds, often resulting in too many false alarms, causing drivers’ ignorance. Considering the collaborative operation scenario, this research proposes and develops a dynamic-threshold alert system by recognizing hazardous events based on the types of nearby objects with their orientation or postures and their distances to the system carrier equipment based on image-based recognition and Sim2Real techniques. Two experiments were conducted, and the results show that the system successfully reduced a large number of false near-collision alarms for the collaboration scenarios. Although the accuracy of object recognition and image-based distance estimation is feasible for practical use, it is also easily degraded in the self-obstruction scenario or for equipment with large and movable parts due to incorrect recognition of the bounding boxes of the target objects. Full article

On 5 September 2022, the moment magnitude (Mw) 6.7 Luding earthquake struck in the Xianshuihe Fault system on the eastern edge of the Tibet Plateau, illuminating the seismic gap in the Moxi segment. The fault system geometry and rupture process of this earthquake are relatively complex. To better understand the underlying driving mechanisms, this study first uses the Interferometric Synthetic Aperture Radar (InSAR) technique to obtain static surface displacements, which are then combined with Global Positioning System (GPS) data to invert the coseismic slip distribution. A machine learning approach is applied to extract a high-quality aftershock catalog from the original seismic waveform data, enabling the analysis of the spatiotemporal characteristics of aftershock activity. The catalog is subsequently used for fault fitting to determine a reliable fault geometry. The coseismic slip is dominated by left-lateral strike-slip motion, distributed within a depth range of 0–15 km, with a maximum fault slip > 2 m. The relocated catalog contains 15,571 events. Aftershock activity is divided into four main seismic clusters, with two smaller clusters located to the north and south and four interval zones in between. The geometry of the five faults is fitted, revealing the complexity of the Xianshuihe Fault system. Additionally, the Luding earthquake did not fully rupture the Moxi segment. The unruptured areas to the north of the mainshock, as well as regions to the south near the Anninghe Fault, pose a potential seismic hazard. Full article

On 23 January 2024, an M_w 7.01 earthquake struck the Wushi County, Xinjiang Uygur Autonomous Region, China. The occurrence of this earthquake provides an opportunity to gain a deeper understanding of the rupture behavior and tectonic activity of the fault system in the Tianshan seismic belt. The coseismic deformation field of the Wushi earthquake was derived from Sentinel-1A ascending and descending track data using Differential Interferometric Synthetic Aperture Radar (D-InSAR) technology. The findings reveal a maximum line-of-sight (LOS) displacement of 81.1 cm in the uplift direction and 16 cm in subsidence. Source parameters were determined using an elastic half-space dislocation model. The slip distribution on the fault plane for the M_w 7.01 Wushi earthquake was further refined through a coseismic slip model, and Coulomb stress changes on nearby faults were calculated to evaluate seismic hazards in surrounding areas. Results indicate that the coseismic rupture in the M_w 7.01 Wushi earthquake sequence was mainly characterized by left-lateral strike-slip motion. The peak fault slip was 3.2 m, with a strike of 228.34° and a dip of 61.80°, concentrated primarily at depths between 5 and 25 km. The focal depth is 13 km. This is consistent with findings reported by organizations like the United States Geological Survey (USGS). The fault rupture extended to the surface, consistent with field investigations by the Xinjiang Uygur Autonomous Region Earthquake Bureau. Coulomb stress results suggest that several fault zones, including the Kuokesale, Dashixia, Piqiang North, Karaitike, southeastern sections of the Wensu, northwestern sections of the Tuoergan, and the Maidan-Sayram Fault Zone, are within regions of stress loading. These areas show an increased risk of future seismic activity and warrant close monitoring. Full article

Construction workplaces often face unforeseen collision hazards due to a decline in auditory situational awareness among on-foot workers, leading to severe injuries and fatalities. Previous studies that used auditory signals to prevent collision hazards focused on employing a classical beamforming approach to determine equipment sounds’ Direction of Arrival (DOA). No existing frameworks implement a neural network-based approach for both equipment sound classification and localization. This paper presents an innovative framework for sound classification and localization using multichannel sound datasets artificially synthesized in a virtual three-dimensional space. The simulation synthesized 10,000 multi-channel datasets using just fourteen single sound source audiotapes. This training includes a two-staged convolutional recurrent neural network (CRNN), where the first stage learns multi-label sound event classes followed by the second stage to estimate their DOA. The proposed framework achieves a low average DOA error of 30 degrees and a high F-score of 0.98, demonstrating accurate localization and classification of equipment near workers’ positions on the site. Full article

On 14 November 2021, a doublet earthquake, each event of which had an Mw of 6.1, struck near Fin in the Simply Folded Belt (SFB) in southern Iran. The first quake occurred at 12:07:04 UTC, followed by a second one just a minute and a half later. The SFB is known for its blind thrust faults, typically not associated with surface ruptures. These earthquakes are usually linked to the middle and lower layers of the sedimentary cover. Identifying the faults that trigger earthquakes in the region remains a significant challenge and is subject to high uncertainty. This study aims to identify and determine the fault(s) that may have caused the doublet earthquake. To achieve this goal, we utilized the DInSAR method using Sentinel-1 to detect deformation, followed by finite-fault inversion and magnetic interpretation to determine the location, geometry, and slip distribution of the fault(s). Bayesian probabilistic joint inversion was used to model the earthquake sources and derive the geometric parameters of potential fault planes. The study presents two potential fault solutions—one dipping to the north and the other to the south. Both solutions showed no significant difference in strike and fault location, suggesting a single fault. Based on the results of the seismic inversion, it appears that a north-dipping fault with a strike, dip, and rake of 257°, 74°, and 77°, respectively, is more consistent with the geological setting of the area. The fault plane has a width of roughly 3.6 km, a length of 13.4 km, and a depth of 5.6 km. Our results revealed maximum displacements along the radar line of sight reaching values of up to −360 mm in the ascending orbit, indicating an unknown fault with horizontal displacements at the surface ranging from −144 to 170 mm and maximum vertical displacements between −204 and 415 mm. Aeromagnetic data for Iran were utilized with an average flight-line spacing of 7.5 km. The middle of the data observation period was considered to apply the RTP filter, and the DRTP method was used. We calculated the gradient of the residual anomaly in the N-S direction due to the direction of the existing faults and folds. The gradient map identified the fault and potential extension of the observed anomalies related to a fault with an ENE-WSW strike, which could extend to the ~ E-W. We suggest that earthquakes occur in the sedimentary cover of the SFB where subsurface faulting is involved, with Hormuz salt acting as an important barrier to rupture. The multidisciplinary approach used in this study, including InSAR and magnetic data, underscores the importance of accurate fault characterization. These findings provide valuable insights into the seismic hazard of the area. Full article

A multi-hazard analysis (seismic, landslide, flood) is conducted to verify the impact on the road network. The ENEA CIPCast platform is an innovative Decision Support System (DSS) that is used to implement the analyses using GIS. Using analytical and geoprocessing tools, the hazards were assessed and mapped. The overlapping of different geospatial layers allowed the implementation of a specific hazard map for the road network. Multi-hazard values were obtained using an appropriate matrix of single values, which were classified, and then summarized into four classes of values. The analyses were conducted at the regional (Campania region), provincial (Metropolitan City of Naples), and local scales (island of Ischia and municipality of Casamicciola Terme). In particular, the landslide event that struck Ischia island on 26 November 2022 and the municipality of Casamicciola Terme was considered as a case study to determine the impact on the road network, infrastructures, buildings, and jeopardizing inter-municipal connections. The results are mainly visualized through map processing and statistical summaries of the data. The management of the landslide debris, which can contain a multitude of fractions (waste, biomass and vegetation, sludge, soil, and rocks transported downstream by water), was also explored. This is a frontier issue for which international manuals and guidelines, as well as national and emergency acts, have been examined. A specific protocol for the sustainable management of the debris generated by floods and landslides is needed, and discussed in the present paper, to overcome emergencies after catastrophic events. Full article