ABSTRACT Local geological and geotechnical conditions strongly influence the intensity and frequency content of seismic ground shaking. Seismic codes often use an amplification factor (AF) to adjust the rock-level response spectrum based on subsurface parameters. However, using a single parameter such as Vs30 or broad site classes may overlook regional variability, introducing bias in hazard assessments. In this study, we conducted nonlinear ground response analysis on 52 soil profiles from the Saguenay region , using six eastern Canadian ground motions scaled to five NBCC 2020 hazard levels. We examined how shear-wave velocity, total soil thickness, and till layers affect nonlinear amplification. We also evaluated different site proxies – Vs30, average shear-wave velocity (Vsavg), soil thickness (Hsoil), and fundamental site period (T0) – in capturing amplification behavior. Our results show that shear-wave velocity, soil thickness, and till layers significantly influence site response. Nonlinear soil behavior reduces amplification at high shaking levels, especially in stiff and shallow profiles, and shifts predominant periods. While Vs30 effectively captures short-to-medium period responses, T0 better represents long-period amplification. A comparison reveals that NBCC 2020 often overestimates amplification and underscores the need for site-specific micro-zonation using optimal site proxies.

ABSTRACT In this study, we simulate ground motions for three major earthquakes that occurred in Central Italy: the 2009 Mw 6.3 L’Aquila earthquake and the two largest events of the 2016 Amatrice–Visso–Norcia sequence, the Mw 6.2 Amatrice and Mw 6.5 Norcia earthquakes. These events caused widespread damage, intense ground shaking, and casualties, making them key cases for evaluating and improving ground-motion modeling techniques, especially given the high-quality recordings available from near-source stations. We use the frequency–wavenumber (f-k) method to generate broadband synthetic ground motions ≤7 Hz. This approach balances computational efficiency with physical accuracy, making it well suited for regional-scale applications. Green’s functions are computed from the Central Italian Apennines 1D layered velocity model (Herrmann et al., 2011), and kinematic rupture models are generated using the methodology of Graves and Pitarka (2016; hereafter, GP16), implemented into the f-k framework. Site response is incorporated using frequency-dependent nonlinear amplification factors (Borcherdt, 1994). We evaluate the simulations through a detailed comparison with observed ground motions using RotD50 spectral acceleration and a goodness-of-fit analysis. In addition to simulations at recorded stations, we compute ground motions over a dense grid of virtual sites to assess spatial variability and source-related effects such as rupture directivity and regional amplification. Results are benchmarked against predictions from the empirical ground-motion model ITA18 (Lanzano et al., 2019). Our findings demonstrate that the f-k method can reproduce key features of observed ground motion with good agreement, capturing both near-fault effects and broader regional trends. This study demonstrates that the f-k approach offers a computationally efficient and physically robust alternative for deterministic ground-motion simulation, bridging empirical models and 3D simulations for practical use in hazard scenarios and urgent computing workflows.

The 2023 Kahramanmaraş earthquake sequence significantly impacted southeastern Türkiye. A comprehensive field investigation of 40 cone penetration tests and 7 seismic cone penetration tests was conducted to characterize the subsurface conditions of several areas affected by liquefaction in the port city of İskenderun. The investigations were performed at a key seismic station in the area, five areas with differing liquefaction-induced building settlements, and three lateral spread sites. The reclaimed shoreline area, which exhibited the most significant liquefaction effects, is underlain by thick medium dense clean sand deposits. Ground shaking characteristics in the investigated areas are estimated and essential subsurface data for developing high-quality field case histories are developed to support studies of liquefaction triggering and effects in İskenderun. In this context, it contributes to advancing liquefaction engineering and informs seismic hazard mitigation strategies in urban areas.

Abstract Understanding earthquake‐induced secondary hazards is critical for effective disaster mitigation and risk reduction. However, while most research focuses on hazards triggered by major earthquakes, moderate‐magnitude events can also cause severe disasters in specific geo‐environmental configurations. The 2023 Ms 6.2 (Mw 6.0) Jishishan earthquake, occurring in the transition zone between the Qinghai‐Tibet Plateau and the Loess Plateau in China, serves as an ideal case to investigate this “moderate quake but numerous hazards” phenomenon. To systematically characterize its impacts, we generated a comprehensive inventory of 16,544 co‐seismic landslides through visual interpretation utilizing high‐resolution spaceborne and airborne remote sensing images, and illuminated the driving factors of landslide evolution by machine learning methods. Random Forest and Light Gradient Boosting Machine models, which achieve an area under the receiver operating characteristic curve (ROC AUC) >0.96, are effective in landslide susceptibility assessment. Our results demonstrate that the occurrence of co‐seismic landslides is primarily controlled by large peak ground acceleration and the distribution of sedimentary lithology (loess). The proxy for ground disturbance derived from interferometric synthetic aperture radar (InSAR) data succeeds in highlighting the spatial pattern of earthquake damage. Furthermore, multi‐source remote sensing analysis of an enormous lateral spread disaster triggered by this earthquake revealed that flood irrigation over sandy soils, indicated by Sentinel‐2 soil moisture indices, is assumed to induce a liquefied process under ground shaking, subsequently leading to lateral spread. Our findings advance the understanding of landslide occurrence and multi‐hazard interaction in moderate seismic events within vulnerable landscapes.

The study was conducted to evaluate the potential liquefaction and foundation settlement in the supporting soils of the University of Southeastern Philippines Obrero Campus buildings. The Philippines is prone to ground shaking or earthquakes caused by fault movement or volcanic activity, and it has recently experienced destructive earthquakes with magnitudes ranging from 6.1 to 7.3. Making an evaluation of the effects of seismic events is a useful tool for developing risk-reduction strategies and will expand current knowledge of how high-magnitude earthquakes will affect the supporting soils of the buildings. In this study, data were collected from the USeP Physical Development Division (PDD) and utilized a descriptive quantitative non-experimental design to evaluate the supporting soils of the buildings. The techniques offered by Youd and Idriss (2001) and Liu (1995) were used to evaluate the potential liquefaction and foundation settlement in the buildings. The study showed that the Administrative, Graduate School, and TBI buildings are prone to liquefaction and eventual foundation settlement for earthquake magnitudes 7, 8, and 9, whereas the Engineering Laboratory and Arts and Sciences have some liquefaction-safe depths.

Many immersed tunnels are constructed in alluvial formations within earthquake-prone regions, making seismic resistance a critical aspect of their safety design. During an earthquake, tunnel displacements can lead to slippage between the tunnel and surrounding soil and may be further amplified by liquefaction. This phenomenon can cause severe structural damage, including tunnel flotation. This paper examines the seismic performance of immersed tunnels, starting with an overview of the deformation mechanisms affecting tunnels, including those induced by ground shaking and failure. Given its significance in large foundation deformations and its impact on tunnel integrity, liquefaction is analyzed alongside potential mitigation strategies. The seismic design process for immersed tunnels is discussed in detail, covering analytical approaches, numerical modeling techniques (such as finite element and finite difference methods), and physical modeling. Real-world examples are provided to illustrate key concepts. Finally, this paper summarizes the core factors influencing the seismic response of immersed tunnels and highlights future research directions to enhance their resilience in seismic environments.

Abstract We conducted a systematic search for earthquake swarms in Eastern Indonesia (2012–2021) using BMKG’s (Badan Meteorologi, Klimatologi, dan Geofisika) finalized catalog, identifying 14 swarms across Bali, Lombok, Nusa Tenggara, Banda, Seram, Papua, Sulawesi, Maluku, and Halmahera. Swarms were detected based on distinct spatio-temporal clustering without preceding or subsequent M > 6 events. From this process, we identified 14 potential earthquake swarms located sporadically in eastern Indonesia. Seismic swarm activity in eastern Indonesia provides critical insight into diverse crustal stress-release mechanisms within this complex tectonic setting. Analysis of multiple swarms across five regions—Lombok-Nusa Tenggara, Sulawesi, Molucca Sea-Halmahera, Banda-Seram, and Papua—reveals consistent patterns: swarms occur at shallow depths (<20 km), exhibit tight magnitude ranges without a dominant mainshock, and are driven by varied triggers including volcanic unrest, tectonic faulting, subduction dynamics, and fluid migration. Key controls include subductionrelated crustal stretching, strike-slip fault activation, and magmatic-fluid interactions. These swarms amplify local seismic hazards due to their shallow, prolonged nature and occurrence on previously unidentified secondary faults. The findings emphasize the necessity of continuous monitoring and refined hazard assessments to address region-specific risks associated with swarm-induced ground shaking and their potential triggering by larger tectonic events.

Icicle-shaped features known as sand dikes form during ground shaking. New work reveals how these features can be used to date long-ago earthquakes.

Abstract Seismic slope displacement analyses are crucial for assessing the performance of earth systems and natural slopes under earthquake loading. Input ground motions are important components of such analyses and represent one of the main sources of variability in estimated values of slope displacement. Most studies on seismic slope displacement analyses have been conducted using shallow crustal earthquake motions. However, ground motions from subduction zones are known to have comparatively longer durations. This study proposes a framework to quantify the effects of ground-motion duration on slope displacements using short- and long-duration ground-motion suites from subduction zone earthquakes. Challenges in isolating duration effects from those associated with the amplitude and frequency content of ground motions are overcome by creating sets of ground motions with the same amplitude and similar spectral shape, but with different significant durations. These equivalent short- and long-duration suites of motions are then utilized in nonlinear finite-element analyses to evaluate their impact on slope displacement. The finite-element model is developed to numerically simulate the strength and stiffness degradation of soils under cyclic loading from strong ground shaking. We find that the long-duration motions in our dataset can cause larger permanent displacements compared to their short-duration counterparts (with similar spectral shape but different duration), especially at higher ground shaking intensity levels that can trigger nonlinear soil behavior. Comparisons with simplified analyses show that the simplified methods can result in biased estimates of permanent displacements from the long-duration motions in our study. This study provides a framework to develop ground motion sets that can enable more in-depth investigations of the role of duration on seismic slope displacements and the damage potential of ground motions, particularly from subduction events.

Abstract Macroseismic surveys are of great interest to both the scientific community and the authorities.The aim of the MACROSISDATA project is to safeguard, disseminate, and promote through an online database the macroseismic survey documents collected by the French Central Seismological Bureau between 1921 and 1996. During this period, a total of 1428 earthquakes were surveyed to estimate macroseismic intensities (severity of ground shaking) by sending paper forms to the municipal authorities. This unique collection of forms, letters, maps, newspaper articles, and macroseismic reports amounts to 29 linear meters of archival paper documents. The 5-year MACROSISDATA project (2020–2025) consisted of 9 stages, from inventorying archival documents to online publication of digitized documents on a national website. The last stage will be implemented at the end of 2025. The stages were developed with the support of the archives department of the University of Strasbourg, comply with French archive management rules, and adopt a strategy that makes the data easily findable, accessible, interoperable and reusable (FAIR). In this article, we describe each stage in detail.

Summary Earthquake early warning systems are designed to provide critical seconds of warning before strong ground shaking, facilitating emergency mitigation efforts. Existing methods, such as neural networks and ground motion prediction equation-based approaches, rely on manually defined parameters and physics-based computations, which introduce human bias and hinder the efficiency of real-time applications. Furthermore, current studies primarily focus on scalar metrics such as peak ground acceleration and peak ground velocity to evaluate earthquake impacts. These metrics are limited to measuring ground shaking intensity and fail to capture the spectral characteristics of ground motion. Therefore, a ground-motion and structural-oriented deep learning-based model is proposed to predict uniform hazard spectral acceleration values across 111 periods ranging from 0.01 to 20 seconds. The framework is initially trained and evaluated on 17,500 ground-motion records from the crustal Next Generation Attenuation West 2 project. Spectral acceleration values are predicted by two subsets: deep learning-based uniform hazard spectral acceleration models 1 and 2. These models effectively utilize feature information from the initial seconds of seismic waveforms, eliminating the need for empirically defined parameters. Two deep learning-based models are developed for two datasets representing two distinct broad geographical regions. Both models utilize a similar deep-learning architecture but vary in input settings and hyperparameters to account for regional seismic characteristics. To assess the model's goodness-of-fit between observed and predicted values, as well as its generalization ability, we rigorously compare the two models with the latest data from the U.S. Geological Survey Earthquake Hazard Toolbox and the Japanese Strong-Motion Earthquake Network, respectively. An explainable artificial intelligence technique has been applied to better understand the framework and analyze how individual input features influence the outputs of the trained models. Integrating cutting-edge deep learning technologies into ground motion and engineering seismology reveals the significant potential of the model in enhancing real-time early warning systems. This integration also provides valuable support to various end-users involved in seismic monitoring, facilitating well-informed decisions in both real-time and near-real-time scenarios.

In the earthquakes that occurred in the Pazarcık (Mw = 7.7) and Elbistan (Mw = 7.6) districts of Kahramanmaraş Province on 6 February 2023, many buildings collapsed in the Hayrullah neighborhood of the Onikişubat district. In this study, we investigated whether there was a soil amplification effect on the damage occurring in the Hayrullah neighborhood of the Onikişubat district of Kahramanmaraş Province. Firstly, borehole, SPT, MASW (multi-channel surface wave analysis), microtremor, electrical resistivity tomography (ERT), and vertical electrical sounding (VES) tests were carried out in the field to determine the engineering properties and behavior of soil. Laboratory tests were also conducted using samples obtained from bore holes and field tests. Then, an idealized soil profile was created using the laboratory and field test results, and site dynamic soil behavior analyses were performed on the extracted profile. According to The Turkish Building Code (TBC 2018), the earthquake level DD-2 design spectra of the project site were determined and the average design spectrum was created. Considering the seismicity of the project site and TBC (2018) criteria (according to site-specific faulting, distance, and average shear wave velocity), 11 earthquake ground motion sets were selected and harmonized with DD-2 spectra in short, medium, and long periods. Using scaled motions, the soil profile was excited with 22 different earthquake scenarios and the results were obtained for the equivalent and non-linear models. The analysis showed that the soft soil conditions in the area amplified ground shaking by up to 2.8 times, especially for longer periods (1.0–2.5 s). This level of amplification was consistent with the damage observed in mid- to high-rise buildings, highlighting the important role of local site effects in the structural losses seen during the Kahramanmaraş earthquakes.

At 16:10 (JST) on January 1, 2024, a magnitude Mj 7.6 earthquake struck the northern Noto Peninsula, Japan. The earthquake caused intense ground shaking, with the peak ground acceleration (PGA) reaching 2,828 gal, which is one of the highest values ever recorded. Over 2,300 landslides were triggered, causing severe damage to infrastructure. The Noto Peninsula has long been vulnerable to significant seismic activity and has experienced a sustained seismic swarm from November 2020 to May 2023, during which at least 20,000 earthquakes with magnitudes of Mj≥1.0 were recorded. In mountainous areas, earthquakes are often accompanied by coseismic landslides. Owing to the frequent seismic swarm activity in the Noto Peninsula, long-term vigilance is essential to mitigate the hazards of earthquake-induced landslides and related secondary disasters. This study focuses on the Okubo District of Wajima City, Ishikawa Prefecture, which experienced a high concentration of landslides during the earthquake, including the largest observed landslide. A 3D dynamic elastoplastic finite element method was applied to simulate seismic ground responses and reassess the landslides triggered by the earthquake. The simulation emphasizes the spatial distribution of shear stress and PGA during seismic loading. Comparing the simulation results with the observed landslide inventory reveals that zones of elevated shear stress and PGA generally correspond to documented landslide locations. These findings suggest that the proposed numerical modeling approach can effectively identify potentially high-hazard slopes over a wide area, thereby supporting the development of a landslide-susceptibility map for the earthquake-prone Noto Peninsula.

This article discusses different approaches to evaluate liquefaction exposure across road networks and inform decision-making processes regarding asset management, emergency preparation and response planning. Using the New Zealand State Highway network, liquefaction exposure is assessed based on ground shaking from two sources: (1) various return period shaking intensities from the National Seismic Hazard Model and (2) a suite of specific earthquake scenarios. The first approach considers the likelihood of liquefaction exposure at each location conditional on different levels of ground shaking, suitable for assessing individual network components. The second approach presents liquefaction exposure for a specific earthquake scenario, capturing the extent of exposure across a network. In addition, it offers a new indicator, the number of events (NoE), identifying network sections that could be affected by liquefaction manifestation across multiple earthquake scenarios. For both approaches, the extent of potential exposure (number of affected 100 m-segments) and the level of network disruption (number of affected links representing segments between intersections) are estimated at both national and regional scales. While the national-scale assessment helps to quantify liquefaction exposure across the entire network, providing valuable insight for asset management, the regional-scale assessments identify potential worst-case scenarios, identify locations affected by multiple events and allow for more informed emergency management decision-making. Future research should expand the multi-scenario approach, incorporate network related aspects, such as criticality or redundancy, and consider recurrence intervals for scenario weighting or perform a full probabilistic liquefaction hazard analysis to enhance the evaluation of potential impacts and to further support decision-making.

SUMMARY We analysed infrasound waves associated with the Gyeongju earthquake (ML 5.8) that occurred on 2016 September 12, in the southeastern Korean Peninsula. For infrasound wave detection, the Progressive Multichannel Correlation method was applied to the infrasound data set recorded at seven arrays operating in South Korea at epicentral distances ranging from 178 to 472 km. Based on the back-projection method constrained by array-dependent celerity and azimuth deviation models, the source regions were identified in both the epicentral and non-epicentral regions. Remarkably, the non-epicentral secondary sources of this earthquake were located in regions with shallow water depths: (i) the western coastal area in the Yellow Sea and (ii) the shallow ocean basin and bank in the East Sea. The location results obtained from the earthquake could be corroborated through its foreshock (ML 5.1), yielding location results consistent with those of the main shock. The generation of infrasound waves over shallow water depths was fortuitously validated by direct recordings of dominant single-frequency (~0.3 Hz) infrasound waves at close range via temporary sensors near the ocean basin and bank. We interpreted that low-frequency infrasound signals could be generated from interactions among the ocean floor, shallow seawater and atmosphere. We performed numerical simulations of seismoacoustic fields to predict ground motions on the seafloor and acoustic transmission efficiency between the water and air interface. The simulations quantified the energy transfer through different media and clarified our observational results. We found that because this solid Earth‒water‒atmosphere coupled air wave has a relatively low frequency (~0.3 Hz), it can survive propagation over long distances compared with high-frequency infrasound waves generated in inland and mountain regions. In this study, we extend our understanding of water‒atmosphere coupling and the monitoring framework for earthquake-associated non-epicentral infrasound waves, encompassing not only inland ground shaking but also shallow sea regions located far from the epicentre.

Abstract Lacustrine paleoseismology has evolved into one of the most prominent techniques to establish long and high-resolution records of past earthquakes, particularly in subduction zones. A thorough understanding of the relation between the various components of strong ground motion and the resulting sedimentary signature is, however, still missing. Therefore, characterization of the source parameters of paleoearthquakes, such as magnitude and location, up to now relies solely on qualitative or semiquantitative considerations, linking the occurrence or absence of coseismic imprints (e.g., turbidites) to seismic shaking strength. These intensity values are usually expressed on the macroseismic scale, as such information is more readily available compared to instrumental data, especially for the numerous historical earthquakes that outdate the first use of seismometers. However, these are relatively subjective ground-motion measures, unable to capture key aspects of strong ground motion (e.g., peak ground acceleration [PGA], peak ground velocity [PGV], and duration). In this study, we determine the relation between these quantitative ground-motion values calculated for the bottom of a lake and the sedimentary shaking imprints identified therein. To achieve this, we focus on the sedimentary signature of instrumentally recorded megathrust earthquakes in south-central Chile. This includes the 1960 Mw 9.5 Valdivia earthquake and the 2010 Mw 8.8 Maule earthquake. A compilation of existing sedimentological data shows that coseismic deposits related to either of these events are identified in over 20 lakes. For these deposits, PGV scales log–logistically to the relative abundance of turbidites in each lake (within a 13 and 40 cm/s minimum and maximum threshold, respectively), whereas the turbidite volume correlates to both strength (PGA and/or PGV) and duration of shaking. By linking lacustrine imprint characteristics for both earthquakes to local ground motions, we bridge the gap between sedimentology and seismology, opening perspectives toward quantitative characterization of paleoearthquakes based on the signature of their imprint in lake sediment sequences.

Tectonically active areas are commonly subject to the compound threats of seismic ground shaking and landslide occurrence triggered by earthquakes, resulting in devastating human and infrastructural loss. Herein, an integrated multi-hazard appraisal strategy is offered that mingles probabilistic and seismic hazard analysis (PSHA), Newmark displacement modelling, and GIS-based landslide susceptibility mapping to assess and space-quantify risk in seismically active areas. Utilizing original data gathered from 2020 to 2024 seismic event data, digital elevation models (DEM), remote sensing imagery (Sentinel-2, PlanetScope), and regional landslide inventories the study uses a logic-tree-based PSHA in open Quake to produce site-specific ground shaking estimates. Subsequent Newmark displacement calculation is performed on the basis of critical slope acceleration and peak ground acceleration (PGA) values to provide coseismal slope deformations estimates. Concurrently, an Analytic Hierarchy Process (AHP) blended with logistic regression is applied to create a landslide susceptibility model based on terrain, geology, hydrology, and land cover data layers. The produced A multi-hazard risk map delineates 14.6% of the study area as high-risk, where slope failures will be more than 15 cm in areas of high topography, weathered lithology, and increased seismic intensity. Validation with 2020–2024 landslide inventories had an accuracy of 87.4% and an ROC-AUC of 0.91, demonstrating exceptional predictability. The results confirm that traditional single-hazard estimates grossly underestimate compound risks, particularly in populated, slope-prone regions. The research provides a strong geospatial approach to disaster risk reduction, land-use planning, and infrastructure planning in seismically active areas and contributes towards multi-hazard mitigation practice as per the Sendai Framework for Disaster Risk Reduction (2015–2030).

Aceh is a region of tectonic activity, characterized by high seismicity. This inherent seismic hazard endangers the stability of vertical structures, such as mosque towers. The objective of this study is to analyze the dynamic characteristics of the Main Tower of the Baiturrahman Grand Mosque by estimating its natural frequencies and damping ratios. These parameters are used to evaluate the structural vulnerability of the mosque. The study obtained data from multilevel microtremor measurements on each floor of the tower. These measurements were analyzed using two methods. The Horizontal to Vertical Spectral Ratio (HVSR) method identified the dominant frequency in the basement. The Random Decrement Method (RDM) determined the natural frequency and damping ratios at each level of the structure. The results indicate that the natural frequency of the tower ranges from 1.16 to 4.32 Hz, with a damping ratio of 0.91% to 22.97%, which is within the established range for reinforced concrete structures. The substandard value can cause the building to oscillate easily when earthquake shocks occur. The analysis identified the upper floors, specifically 3 and 4, to be the primary sites of resonance, with ratios reaching 11-12%. The significant negative correlation between height and natural frequency indicates that the upper part of the structure is more prone to low-frequency earthquakes. The implications of this study are significant in light of their potential to enhance the understanding of the structural resonance risks and provide a technical basis for planning mosque towers in earthquake-prone areas.

Kapanewon Pundong is in an active tectonic zone and has experienced significant seismic events, including the 2006 Bantul earthquake (Mw 6.3), which caused extensive damage. Liquefaction was a key contributor to infrastructure failure during the event. This study aims to evaluate liquefaction potential in Kapanewon Pundong through integrated microtremor and geospatial analysis. The Horizontal-to-Vertical Spectral Ratio (HVSR) method assessed local site effects that influence ground shaking. Liquefaction probability was estimated using the model by Zhu et al. (2017), considering parameters such as Vₛ₃₀, PGV, water table depth (WTD), distance to water bodies (DW), and average annual precipitation. The research findings include Vₛ₃₀ values that range from 221 to 893 m/s, PGV values from 16 to 29 cm/s. Panjangrejo and Srihardono villages exhibit the highest liquefaction probabilities, up to 30%. The estimated Liquefaction Spatial Extent (LSE) in these areas reaches 5.1%. These findings identify high-risk zones for earthquake-induced liquefaction and provide a quantitative foundation for spatial planning and disaster mitigation strategies in the region.

The 7.8 magnitude earthquake in Kahramanmaraş, Türkiye, on February 6, 2023, exposed critical infrastructure deficiencies, particularly in areas near the East Anatolian Fault Zone. This study examines geological and structural factors that intensified the damage, including soil amplification reaching 2.5 in sedimentary basins, significantly increasing ground shaking. Structural assessments show that pre-1999 buildings had over 45% failure rates due to inadequate reinforcement and shear wall deficiencies. Using probabilistic seismic hazard analysis (PSHA) and structural performance assessments, the effectiveness of retrofitting solutions like buckling-restrained braces (BRBs) and base isolation is evaluated. A comparative analysis with Japan, the U.S. (California), and New Zealand highlights best practices for seismic resilience. The findings emphasize the need for integrating site-specific hazard assessments into Türkiye’s seismic codes and enforcing large-scale retrofitting programs to mitigate future earthquake risks.