Strong Earthquakes Research Articles

Degree of twist in the Achilles tendon interacts with its length and thickness in affecting local strain magnitude: a finite element analysis.

The relationship between the twisting of the three subtendons of the Achilles tendon (AT) and local strain has received attention in recent years. The present study aimed to elucidate how the degree of twist in the AT affects strain using finite element (FE) analysis, while also considering other geometries (e.g., length, thickness, and width) and their combinations. A total of 59 FE models with different degrees of twist and geometries were created. A lengthening force (z-axis) of 1,000N was applied to each subtendon (total: 3,000N). The average value of the first principal Lagrange strain was calculated for the middle third of the total length of the model. Statistical (stepwise) analysis revealed the effects of the degree of twist, other geometries, and their combinations on AT strain. The main findings were as follows: (1) a greater degree of twist resulted in higher average strains (t = 9.28, p < 0.0001) and (2) the effect of the degree of twist on the strain depended on dimensions of thickness of the most distal part of the AT (t = -4.49, p < 0.0001) and the length of the AT (t = -3.82, p = 0.0005). Specifically, when the thickness of the most distal part and length were large, the degree of twist had a small effect on the first principal Lagrange strain; however, when the thickness of the most distal part and length were small, a greater degree of twist results in higher first principal Lagrange strain. These results indicate that the relationship between the degree of twist and local strain is complex and may not be accurately assessed by FE simulation using a single geometry.

The 1912 Seismic Swarm in Guadalajara, Mexico: An Example of Intense and Unusual Seismicity in the Trans-Mexican Volcanic Belt

Abstract The residents of the Guadalajara, Mexico metropolitan area awakened on 8 May 1912 to a strong earthquake. In the next two months, ∼1500 shocks followed this first event. Two additional clusters of microearthquakes occurred in July and September. Although no significant structural damage was reported, several churches, public buildings, and private dwellings in the cities of Guadalajara and Zapopan suffered damage. Based on the macroseismic data, the intensity of the larger earthquakes was modified Mercalli intensity (MMI) VI–VII. The area that strongly felt the earthquakes and where the damage was concentrated is contained within a radius of ∼5 km. We assume that the swarm took place within this circle. Based on the relations of MMI versus peak ground acceleration (PGA), it is estimated that the PGA during the swarm was ∼190 gals. The magnitude of the largest earthquakes in the swarm was initially estimated as Mw 5.7, using a published PGA-to-Mw relation. However, this relation was based on earthquakes located 20 km away from downtown Guadalajara. Considering that the distance of the swarm from the city was ∼5 km, the magnitude of the largest events in the swarm was recalibrated as Mw 4.7. A second estimate of the magnitude was based on ground-motion models to calculate the PGA resulting from an earthquake located 5 km away, at a depth of 1 km. The resulting magnitude is Mw 5.3 ± 0.5. Thus, we suggest that the largest earthquakes of the swarm had an approximate magnitude of Mw 5.0. The location of the swarm suggests the presence of active faults underlying the metropolitan area of Guadalajara, where no seismicity has been recorded. This should be carefully considered to assess the seismic hazard of this important city of over 5 million people.

Seismic mitigation of porcelain cylindrical electrical equipment using synergistic concept with base isolation and tuned mass damper

Porcelain cylindrical electrical equipment (PCEEs), such as potential and current transformers, are critical components of electrical substations and essential to power supply networks. Nevertheless, previous strong earthquakes have rendered high vulnerability and poor performance of PCEE during seismic occurrences. To improve seismic performance of PCEE and alleviate adverse seismic impacts, an innovative synergistic mitigation method based on base isolation (BI) and tuned mass damper (TMD) was proposed and subsequently employed to PCEE. Combining BI with TMD allows for a greater utilization of each technology’s capabilities while also circumventing some of the limits of each. While TMD effectiveness is sensitive to input ground motion frequencies, BI could act as a filter to tune input frequency and help TMD fulfill better damping effectiveness. TMD could in return help BI achieve better stability under long-period dominant or pulse-like ground motions. The BI-TMD effectiveness and robustness were investigated using finite element modeling and nonlinear time history analysis. A comprehensive parametric study that considers variable PCEE frequencies, BI periods, TMD mass ratios, and TMD control frequencies was conducted. Results show that the proposed BI-TMD method can significantly enhance the effectiveness and robustness beyond BI single control in mitigating seismic responses of PCEE.

The Repeating Major Earthquakes in the Mexican Subduction Zone Along Oaxaca: Implications for Future Events

Abstract The subduction zone along Oaxaca, Mexico, has experienced multiple Mw ≥ 7 earthquakes that ruptured in close proximity several decades apart in at least three locations along the coast. Similarity of waveform recordings from a few long-period seismic stations at teleseismic distances has provided evidence for up to three repeated failures of the same slip patches, or persistent asperities, in the region. The evidence from prior single-station comparisons is bolstered by considering azimuthally distributed sets of body-wave recording pairs for the 1968 and 2018 Pinotepa Nacional (western Oaxaca), and 1965 and 2020 La Crucecita (eastern Oaxaca) earthquakes, as viewed in the long-period World-Wide Standardized Seismograph Network instrument passband (&amp;gt;5 s period). Drawing on detailed slip inversions for the most recent events and observations of their relationships with regional slow-slip events, we note features to be alert for in central Oaxaca where prior repeating events in 1928 and 1978 occurred and there is potential for a similar future event.

Onsite Seismic Monitoring Behavior of Undamaged Dams During the 2023 Kahramanmaraş Earthquakes (M7.7 and M7.6).

On 6 February 2023, two major earthquakes struck Türkiye, with their epicenters in the Pazarcık (M7.7; focal depth: 8.6 km) and Elbistan (M7.6; focal depth: 7 km) districts of Kahramanmaraş city. Most of the dams in the earthquake region remained structurally safe and stable. However, 17 dams in Türkiye and 1 dam in Syria were damaged during the 2023 Kahramanmaraş earthquakes. The main objective of this study was to better understand the real seismic behaviors of the dams during the two mainshocks and significant aftershocks. An earthfill dam, a concrete-faced rockfill dam (CFRD), and a roller-compacted concrete (RCC) dam constructed in the disaster area were selected to identify the real seismic behaviors of different types of dams during strong earthquakes. Acceleration records measured at the crest, right and left abutments, and foundations of the selected dams during the 2023 Kahramanmaraş earthquakes were taken into account to determine the real seismic behavior of the dams before, during, and after the earthquakes. The results of this investigation provide valuable insights into the real seismic behaviors of different types of dams in the vicinity of fault lines during strong earthquakes.

Correlation Between Post-Traumatic Stress Disorder and Sleep Hygiene in Adults Surviving the 2023 Kahramanmaraş Earthquakes.

On February 6, 2023, two major earthquakes with magnitudes of 7,7 and 7,6 struck the Kahramanmaraş region in Turkey. Over 50.000 people lost their lives and more than half a million buildings were damaged as a result of these earthquakes. Earthquake survivors may develop post-traumatic stress disorder and sleep hygiene problems. This study aims to evaluate the correlation between post-traumatic stress and sleep hygiene among surviving adults six months after the February 6th Kahramanmaraş Earthquakes in Turkey. This study was conducted with 1004 earthquake survivors in 11 provinces influenced by the February 6th Kahramanmaraş earthquakes in Turkey. The data was collected with Personal Information Form, Impact of Events Scale-Revised, and the Sleep Hygiene Index. It has been determined that 54.1% of earthquake survivors scored ≥ 33 on the Impact of Events Scale-Revised. The level of post-traumatic stress disorder was high and their sleep hygiene index level was above average among earthquake survivors. A strongly significant positive correlation was observed between the Impact of Events Scale-Revised and the Sleep Hygiene Index. It is recommended to plan and implement community-based psychological interventions to reduce post-traumatic stress disorder and improve sleep hygiene among survivors after earthquakes.

Seismic Response Analysis of Hydraulic Tunnels Under the Combined Effects of Fault Dislocation and Non-Uniform Seismic Excitation

Hydraulic tunnels are prone to pass through faults and high-intensity earthquake areas, which will cause serious damage under fault dislocation and earthquake action. Fault dislocation and seismic excitation are often considered separately in previous studies. For tectonic earthquakes with higher frequency in seismic phenomena, fault dislocation and ground motion are often associated, and fault dislocation is usually the cause of earthquake occurrence, so it is limiting to consider the two separately. Moreover, strong earthquake records show that there will be significant differences in the mainland vibration within 50 m. The uniform ground motion inputs in previous studies are not suitable for long hydraulic tunnels. This paper begins with the simulation of non-uniform stochastic seismic excitations that consider spatial correlation. Based on stochastic vibration theory, multiple multi-point acceleration time-history curves that can reflect traveling wave effects, coherence effects, attenuation effects, and non-stationary characteristics are synthesized. Furthermore, a fault velocity function is introduced to account for the velocity effect of fault dislocation. Finally, numerical analyses of the response patterns of the tunnel lining under four different conditions are conducted based on an actual engineering project. The results indicate the following: (a) the maximum lining response values occur under the combined effects of fault dislocation and non-uniform seismic excitation, indicating its importance in the seismic resistance of the tunnel. (b) Compared to uniform seismic excitation, the peak displacement of the tunnel under non-uniform seismic excitation increases by up to 6.42%, and the peak maximum principal stress increases by up to 28%. Additionally, longer tunnels exhibit a noticeable delay effect in axial deformation during an earthquake. (c) Under non-uniform seismic excitation, the larger the fault dislocation magnitude, the greater the peak displacement and peak maximum principal stress at the monitoring points of the lining. The simulation results show that the extreme response values primarily occur at the crown and haunches of the tunnel, which require special attention. The research can provide valuable references for the seismic design of cross-fault tunnels.

Seismic evaluation of plan irregular reinforced concrete building equipped with comb teeth metallic passive damper

Active and passive damping devices exhibit significant energy dissipating behavior under seismic loads and are being used to control vibration in buildings worldwide. Comb Teeth Damper (CTD) is one of the most promising recent types of passive dampers which consist of steel plates with multiple teeth designed to dissipate seismic energy by in-plane flexural yielding. In this study, the CTD was modeled and analyzed under lateral cyclic load using the finite element analysis software, ABAQUS. The first phase of this investigation was a comprehensive parametric study on CTD with two different numbers of teeth, namely 4 teeth (4 CTD) and 5 teeth (5 CTD); each model with six different thicknesses, namely 5, 10, 15, 20, 25, and 30 mm. The parametric study showed that by increasing the number of teeth, the load-carrying capacity, initial stiffness, and energy dissipation capacity have increased considerably. A similar trend was observed when the thickness of the damper was increased. From the results of the parametric study, 5CTD with 15 mm thickness damper model was identified as a suitable model for utilizing in Reinforced Concrete (RC) buildings using optimization algorithm. In the second phase, a G + 14 storey plan irregular RC building was modeled in the structural engineering software ETABS and subjected to six different strong earthquake ground motions. The non-linear time history analysis was performed on the building with and without identified CTD and found that the building equipped with dampers reduced 56% top displacement, 60% inter-storey drift, and 33% energy dissipation.

Development of a Matrix for Seismic Isolators Using Recycled Rubber from Vehicle Tires.

Over recent decades, numerous strong earthquakes have caused widespread devastation, including citywide destruction, significant loss of life, and severe structural damage. Seismic base isolation is a well-established method for mitigating earthquake-induced risks in buildings; however, its high cost often limits its implementation in developing countries. Simultaneously, the global rise in vehicle numbers has led to the accumulation of discarded tires, intensifying environmental challenges. In response to these issues, this study investigates the development of a seismic isolator matrix using recycled rubber from vehicle tires, proposed as a sustainable and cost-effective alternative. Ten recycled rubber matrices were experimentally evaluated for their physical and mechanical properties. The matrix with optimal granulometry and binder content, demonstrating superior performance, was identified. This optimized matrix underwent further validation through compression and cyclic shear tests on reduced-scale prototypes of fiber-reinforced isolators, which included five prototype designs, two of which featured flexible reinforcement. The best-performing prototype comprised a recycled rubber matrix with 15% binder and glass fiber, exhibiting vertical stiffness and damping characteristics superior to those of natural rubber. Specifically, this prototype achieved a damping ratio of up to 22%, surpassing the 10% minimum required for seismic isolation, along with a vertical stiffness of 45 kN/mm, critical for withstanding the vertical loads transferred by buildings. These findings suggest that the recycled tire rubber matrix, when combined with glass fiber, is a viable material for the production of seismic isolators. This combination utilizes discarded materials, contributing to environmental sustainability.

Tectonic activation and the risk of Ilisu Dam collapse to Iraq through modelling and simulation using HEC-RAS

Floods caused by dam failures can cause huge losses of life and property, especially in estuarine areas and valleys. In spite of all the capabilities and great improvements reached by man in the construction of dams and their structures, they will remain helpless before the powerful forces of nature, especially those related to tectonic activation, and the occurrence of earthquakes of different intensities.The region extending from the Ilisu Dam in Turkey to the Mosul Dam in Iraq was chosen as an area for this study, and the HEC-RAS application was used to simulate the collapse of the Ilisu Dam due to a major earthquake, to know the magnitude of the risks and losses that could result from this. The Ilisu Dam was built very close to a highly tectonically active fault system, particularly the East Anatolian Fault (EAF), which is one of the largest tectonically active faults in the world with a length of 500 km. This region has witnessed past and present earthquakes of high magnitude (M > 7), especially in the EAF, so the construction of the Ilisu Dam near the EAF fault system is of great concern, as it was built in a basin with very complex seismic activity and geology.Using the HEC-RAS simulation application, the study found that the flood resulting from the collapse of the Ilisu Dam would reach the edges of the Mosul Dam Lake in just 13 h. With a flow of more than 100,000 m3/s, more than 10 billion m3 of water will flow into the Mosul Dam Lake within four days of the disaster. This will lead to the collapse of the Mosul Dam and direct the flood wave of the collapse of these dams towards Baghdad through Mosul, Tikrit, and Samarra. This could pose risks to all Iraqi cities located within the Iraqi sedimentary plain (Mesopotamia), from south of the Mosul Dam up to Basra, in a scenario similar to Noah’s Flood.

Initial response to the 2024 Noto earthquake by the university hospital closest to the disaster area

Major earthquakes have occurred frequently in Japan throughout history, and the 2024 Noto earthquake is no exception. However, such natural disasters differ in some respects, and specific problems related to these events have also become clear. Kanazawa Medical University Hospital, which was the closest university hospital to the disaster area of the 2024 Noto earthquake, played a crucial role in serving the local community in the wake of the earthquake. The first method used to identify disaster-related patients is to tag them when they are examined by a physician. After confirming that a patient was eligible at the disaster-related patient-determination meeting, patients’ medical information was extracted from the tag name. A total of 421 disaster-related patients were transported and hospitalized by day 31. Fifty-two (14.4%) and 48 (13.3%) patients were admitted for orthopedic surgery and respiratory medicine, respectively. Forty (11.1%) and 38 (10.5%) patients were admitted to cardiology and nephrology departments, respectively. These four departments account for 49.3% of the total. The number of hospitalized patients in the nephrology and orthopedic surgery departments was high immediately after the 2024 Noto Earthquake. We also describe new hospital-specific initiatives and recommendations to improve Kanazawa Medical University Hospital’s system while sharing another hospital experience.

The Correlation between Serum Cortisol Concentration in Mammals and the Level of Global Seismic Activity.

A positive correlation was found between the level of global seismic activity and dynamics of cortisol concentration in blood serum of male rabbits (r=0.33, p=0.01) and Campbell's dwarf hamsters (r=0.38, p=0.04). For a small group of healthy volunteers (n=5), we also found a positive correlation between cortisol levels and the number of major earthquakes, excluding aftershocks (r=0.36, p=0.009) and a negative correlation with IL-18 levels (r=-0.28, p=0.04). The body response to earthquakes is not delayed, and the numerous aftershocks do not seem to affect the biological indicators under study. These facts showed that the earthquakes themselves do not affect the cortisol level via the changes of the environmental parameters. In contrast, the underlying biotropic factor is an unknown trigger responsible for an increase in the number of potent earthquakes. Evidently, it is important to take into account the level of global seismicity as a marker of this trigger provoking the rise of glucocorticoid hormones.

The 2024 Mw 7.0 Wushi Earthquake in Southern Tianshan Convergent Zone: Finite-Fault Model for the Coseismic Rupture and Aftershock

Abstract On 22 January 2024, an Mw 7.0 earthquake struck the oblique thrust Maidan fault (MDF) at the boundary between the Southern Tianshan and Tarim basin, making it the largest earthquake on the fault in the last 100 yr. Here, we use Interferometric Synthetic Aperture Radar (InSAR) to retrieve coseismic and aftershock deformation caused by the earthquake and then constrain fault geometry and slip distribution. Line-of-sight InSAR observations revealed a coseismic deformation area of 70 km × 60 km with a maximum value of ∼0.8 m and also captured the deformation from the aftershock event seven days after the mainshock. Our preferred two-segment coseismic fault model ruptures the MDF locked segment and deeper regions, exhibiting a homogeneous elliptical rupture with a maximum slip of ∼2.7 m on a rectangular plane with a dip angle of ∼60°, a length of ∼55 km, and a depth between 5 and 20 km. The aftershock formed a rupture plane of 10×8 km2 with the maximum slip of ∼0.3 m, causing slip in the shallow area of the fault where the coseismic ruptures were smaller, and supplementarily released the stress in the shallow part of the fault. The strong earthquake (Mw 7) return period on MDF inferred from the interseismic slip rate is 170–200 yr. Oblique thrust slip revealed by the slip distribution model is the result of long-term absorption of oblique convergence strain in the Southern Tianshan by the MDF and then concentrated release. The 2024 event resulted in a 60 km unruptured segment on the MDF being in a stress-triggering zone, increasing the potential seismic hazard, in contrast to the delayed seismicities on 100 km region of the southern Kalping fault (KPF).

Analyzing the seismic hazard of Jishishan earthquake based on multi-source data

Abstract. An Ms6.2 earthquake occurred in Jishishan County, Linxia Hui Autonomous Prefecture, Gansu Province on December 18, 2023, which is another strong earthquake event that occurred in the eastern and northeast margin of the Qinghai-Tibet Plateau after the Ms6.8 Luding earthquake in 2022. To determine the spatial characteristics and human casualties of the earthquake, this paper obtains the seismic spatial information based on remote sensing data. The results show that the earthquake has thrust characteristics and is a thrust-type earthquake, in which the line-of-sight deformation of the lifting and falling rail coseismic deformation fields are mainly uplifted, 7.51cm, and 7.91cm respectively. At the same time, the PSO-BiLSTM-Attention population casualty model is proposed, and 149 people are predicted to die, which is 2 people less than the actual 151 people, indicating that the model can well estimate the post-disaster death toll and can be used for the post-disaster death population assessment.

Effect of Wet‐Dry Cycles on the Loading–Unloading Damage of Granite

ABSTRACTInvestigating the effect of wet‐dry (W‐D) cycling on loading–unloading damage is crucial for ensuring the stability of granite slopes in mountainous areas prone to strong earthquakes. This study conducted a series of W‐D cycling and loading–unloading tests on granite samples, complemented by weight measurements, wave velocity assessments, and nuclear magnetic resonance (NMR) tests on samples subjected to W‐D cycling. The results indicated that W‐D cycling reduced the mechanical properties of granite and increased the irreversible strain, dissipated energy, and number of acoustic emission (AE) counts during loading–unloading. The increase in the number of W‐D cycles led to a significant rise in the number of small‐scale, intergranular, and transgranular microcracks and the gradual formation of middle‐scale and large‐scale microcracks. W‐D cycling weakened the granite because of crystal expansion and contraction as well as mineral dissolution, whereas loading–unloading damaged the granite through inconsistent deformation resulting from the varying hardness of different minerals. This study provides a foundation for understanding the formation mechanism of seismically cracked slopes under the combined effects of rainfall and earthquakes.

Nonlinear Finite Element Simulation and Analysis of Steel Frame Structures Considering Nonlinear Behavior

This paper focuses on investigating the nonlinear behavior of steel frame structures in practical engineering applications. Utilizing finite element analysis, the study simulates the response of structures under extreme loads such as strong earthquakes. By incorporating nonlinear material properties and contact effects, the numerical simulation and analysis explore phenomena such as plastic deformation, yield, and instability in frame structures. The research outcomes contribute to a deeper understanding of the energy dissipation and safety performance of these structures.

Impact of Carbon Fiber‐Reinforced Polymer Sheets and Bolt Diameter on the Seismic Performance Enhancement of Steel Beam‐Column Joints

ABSTRACTBeam‐column joints are pivotal for ensuring the resilience of prefabricated steel structures under various loading conditions. Following the major earthquakes of the 1990s, semi‐rigid bolted connections emerged as a promising alternative to traditional welded connections. This study investigates a fully prefabricated Intermediate Beam‐Column Joint (IBCJ) with extended endplates, renowned for its excellent seismic resistance. While significant progress has been made in existing research, there is still a need to thoroughly examine the tension capacity of IBCJs concerning bolt size and explore the potential of Carbon Fiber‐Reinforced Polymer (CFRP) sheets to enhance joint performance under seismic loading. Using the finite element method, this research evaluates the performance of IBCJ under both monotonic and cyclic loading conditions. After validation with experimental data, the study examines various bolt diameters to assess their tension capacity, ductility ratio, secant stiffness, and energy dissipation capacity. The findings indicate that larger bolts exhibit higher ultimate capacities and reduced deformation at failure. Additionally, the study investigates the optimal placement and configuration of CFRP sheets, identifying the backside of the endplates as the most effective location. The application of CFRP significantly enhances bolt tension capacity by up to 1.2 to 1.3 times, demonstrating its potential in reducing bolt failure risk and improving structural reliability under seismic conditions. The superior performance of CFRP‐strengthened bolts can play a crucial role in the design and retrofitting of prefabricated steel structures, potentially contributing to the improvement of existing standards and practices of seismic enhancement of IBCJ.

Mitigation strategies and policies recommendation for the economic impact of the Sunda Strait Megathrust: Seismic risk probability assessment and cost loss estimates

This study investigates seismic risk and potential impacts of future earthquakes in the Sunda Strait region, known for its susceptibility to significant seismic events due to the subduction of the Indo-Australian Plate beneath the Eurasian Plate. The aim is to assess the likelihood of major earthquakes, estimate their impact, and propose strategies to mitigate associated risks. The research uses historical seismic data and probabilistic models to forecast earthquakes with magnitudes ranging from 6.0 to 8.2 Mw. The Gutenberg-Richter model helps project potential earthquake occurrences and their impacts. The findings suggest that the probability of a major earthquake could occur as early as 2026–2027, with a more significant event estimated to likely occur around 2031. Economic estimates for a 7.8–8.2 Mw earthquake suggest potential damage of up to USD 1.255 billion with significant loss of life. The study identifies key vulnerabilities, such as inadequate building foundations and ineffective disaster management infrastructure, which could worsen the impact of future seismic events. In conclusion, the research highlights the urgent need for comprehensive seismic risk mitigation strategies. Recommendations include reinforcing infrastructure to comply with seismic standards, implementing advanced early warning systems, and enhancing public education on earthquake preparedness. Additionally, government policies must address these issues by increasing funding for disaster management, enforcing building regulations, and incorporating traditional knowledge into construction practices. These measures are essential to reducing future earthquake impacts and improving community resilience.

Experimental and Numerical Research on Fracture Properties of Mass Concrete Under Quasi-Static and Dynamic Loading

The dynamic fracture behavior of mass concrete is crucial to the dynamic analysis and safety evaluation of concrete dams subjected to strong earthquake shocks in the framework of fracture mechanics. In the presented research, cylindrical specimens with a ring of preset cracks were cast by three-graded mass concrete, and direct tension tests were performed with two loading rates considered, i.e., 10−6/s for quasi-static loading and 10−3/s for dynamic loading. The load–crack mouth opening displacement (P-CMOD) curves were obtained, from which the fracture toughness, fracture energy, and characteristic length of the mass concrete were obtained. In this process, the influence of the eccentricity in the tests was compensated by the numerical modeling of the tests. Next, the crack propagation process of the mass concrete was modeled using the extended finite element method. From the test results, it is found that, under quasi-static loading, the crack generally propagates along the interface between the aggregates and the matrix, while, under dynamic loading, more aggregates are fractured. As compared to the case of quasi-static loading, the energy absorption capacity, fracture energy, and fracture toughness increase for dynamic loading, while the characteristic length decreases. Moreover, the numerically predicted P-CMOD curves agree reasonably well with the experimental measurements.

Ductile Versus Brittle Tectonics in the Anatolian–Aegean–Balkan System

It is hypothesized that the present tectonic setting of the Anatolian, Aegean and Balkan regions has been deeply influenced by the different deformation styles of the inner and outer belts which constituted the Oligocene Tethyan system. Stressed by the Arabian indenter, this buoyant structure has undergone a westward escape and strong bending. The available evidence suggests that in the Plio–Pleistocene time frame, the inner metamorphic core mainly deformed without undergoing major fragmentations, whereas the orogenic belts which flanked that core (Pontides, Balkanides, Dinarides and Hellenides) behaved as mainly brittle structures, undergoing marked fractures and fragmentations. This view can plausibly explain the formation of the Eastern (Crete–Rhodes) and Western (Peloponnesus) Hellenic Arcs, the peculiar time-space features of the Cretan basins, the development of the Cyprus Arc, the North Aegean strike-slip fault system, the southward escapes of the Antalya and Peloponnesus wedges and the complex tectonic setting in the Balkan zone. These tectonic processes have mostly developed since the late Late Miocene, in response to the collision of the Tethyan belt with the Adriatic continental domain, which accelerated the southward bending of the Anatolian and Aegean sectors, at the expense of the Levantine and Ionian oceanic domains. The proposed interpretation may help us to understand the connection between the ongoing tectonic processes and the spatio-temporal distribution of major earthquakes, increasing the chances of estimating the long-term seismic hazard in the study area. In particular, it is suggested that seismic activity in the Serbo–Macedonian zone may be favored by the post-seismic relaxation that develops after seismic crises in the Epirus thrust front and inhibited/delayed by the activations of the North Anatolian fault system.