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This study delves into the repercussions of the 2023 earthquake in Turkey, particularity its impact on air pollution. A year post-event, it is evident that scientific literature has paid limited attention to monitoring the situation. However, the release of hazardous substances, such as asbestos, lead, and other toxins, from damaged structures poses a significant threat by contaminating nearby air, soil, and water sources, thereby jeopardizing ecosystems and public well-being. The improper disposal of waste post-earthquake and the presence of mining and oil refinery sites in the region contribute to potential air pollutants. These circumstances create challenging environments conducive to the spread of respiratory diseases, with potential long-term health and social consequences. Unfortunately, existing data gaps hinder a comprehensive understanding of the situation. This paper pioneers the reporting and analysis of data regarding potential sources of air pollution resulting from the earthquake in Turkey. It also pinpoints gaps in knowledge, outlining areas that demand further investigation. To effectively prevent and mitigate air pollution risks and associated health concerns linked to earthquakes, strategic recommendations are proposed. A key suggestion is the establishment of post-disaster air pollution monitoring systems capable of swiftly identifying emerging health issues, facilitating efficient responses, and curtailing potential long-term effects of the disaster. The paper underscores the necessity for continuous health monitoring of the affected population to mitigate possible adverse impacts on human health. These strategies play a pivotal role in reducing the likelihood of air pollution, supporting emergency response and recovery initiatives, and fostering new dedicated scientific studies., (© 2024. The Author(s).)

The massive earthquakes experienced in August and November 1999 affected thousands of people in the Marmara region, the most densely populated and industrialized part of Turkey. The humanitarian and economic cost was so enormous, and these earthquakes have changed the Turkish disaster management system and the Turkish people's approach to disasters. Marmara earthquakes are also considered as a milestone in the provision of psychosocial services for disaster victims. This paper aims to review the psychosocial interventions targeting children, adolescents, and their families after the 1999 earthquakes in Turkey. The progression from initial responses to more organized psychosocial interventions is outlined. Conducting the interventions at schools has ensured that thousands of children, teachers, and parents are reached in the most efficient and effective way possible. The significance of the school context in designing psychosocial interventions is highlighted and implications of the lessons learned for traumatic experiences of children and parents are also explored. It is evaluated that these inferences obtained from the Marmara earthquake in Turkey can be used in disasters around the world., Competing Interests: Declaration of Competing Interest The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: >50,000 people died in the February 2023 earthquakes in Türkiye. The aim of this study was to identify the factors affecting mortality rates of the trauma patients who were presented to the emergency department (ED) after the earthquake and provide suggestions for better preparedness strategies for future natural disasters., Methods: This retrospective, cross-sectional study encompassed data from 955 trauma patients out of 3072 patients aged 18 years and above who sought assistance in the ED. Patients were divided into two groups: the survivor group and the exitus group. Age, gender, the city where patients came from, type of presentation, injured organ systems and mechanisms of injury, laboratory findings, the diagnoses in the ED, time spent in the ED, surgical intervention, and hemodialysis sessions were analyzed. The characteristics of those who could not be identified at the presentation to the ED were subjected to additional analysis., Results: Out of 955 patients, 75.9% had extremity injuries, with crushing injuries (23.6%) being predominant. There were no significant differences in age or gender between the survivor and exitus groups (p = 0.776, p = 0.522), nor in the province of admission (p = 0.249). Clinical factors indicated that the exitus group were more likely to lack identification documents (29.6%), have spent longer trapped under debris, and have a higher frequency of ambulance transportation. Injuries such as chest and abdominal trauma, specific injury types, and amputation or open wounds were notably more frequent in the exitus group. Diagnoses revealed that metabolic causes were more common in exitus group (p < 0.001). While no significant difference existed in the need for emergency surgical intervention (p = 0.939), a higher frequency of emergency hemodialysis was observed among exitus group (p = 0.001). Laboratory findings indicated higher levels of various markers and lower calcium, base excess, and pH levels among those in the exitus group., Conclusion: In the aftermath of a devastating earthquake, this study underscores the formidable challenges faced by healthcare systems during natural disasters. To prepare for future disasters, healthcare systems must enhance resilience, develop rapid identification techniques, and adopt a holistic patient care approach., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Throughout its history, Operational Research has evolved to include methods, models and algorithms that have been applied to a wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first summarises the up-to-date knowledge and provides an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion and used as a point of reference by a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes. [ABSTRACT FROM AUTHOR]

In this paper, I discuss how the earthquake risk is exploited by 'disaster capitalism', in order to convert Istanbul to a massive construction site. The shock of the 1999 Marmara Earthquake has been effectively used by the neoliberal market and government as 'a shock therapy' to implement a construction‐led development model for Turkey and to favour the construction sector by introducing new incentives, exceptional rights and interventions, which otherwise might be challenged. The current Turkish government justify the ongoing massive urban transformation and new mass housing projects as an improvement of the housing stock to make residential buildings stronger and more resilient to earthquakes. However, areas actually under earthquake risk do not match the areas that are officially declared under disaster risk by the government. The Disaster Law #6306 that granted the government the absolute right to expropriate land based on the justification of 'protecting residents against earthquakes and other natural disasters' was applied in a selective way to seize valuable land in Istanbul. In the paper I explore how the disaster was quickly converted to an opportunity for economic growth. To do that I introduce stories of three different neighbourhoods in Istanbul, namely Moda, Tozkoparan and Fikirtepe, each of which experience the ongoing massive urban transformation differently based on the land value of the neighbourhoods, class position of the residents, and residents' capacity to organise in order to protect their rights. I describe, how disaster capitalism is lived and experienced differently in these three neighbourhoods. Although the massive construction projects are indifferent to life's sustainability, those projects are justified as interventions in terms of public health and safety through making housing resilient to earthquakes. I critically discuss how in each case biopolitics presents disaster capitalism's massive urban transformation projects as a manifestation of liveliness. [ABSTRACT FROM AUTHOR]

When evaluating an area's seismic risk or resilience, it is necessary to use the spatial correlation to analyze the ground motion parameters of multiple sites together in an earthquake. These two large earthquakes in Türkiye provided the possibility for spatial correlation analysis of ground motion intensity measurements in this area. Based on the strong motion records provided by The Disaster and Emergency Management Authority of Türkiye (AFAD), this study uses the local ground motion prediction equation in Türkiye to give spatial correlation analysis of Intensity Measurements. This study gives an exponential model based on a semivariogram and compares it with the correlation model obtained from previous studies. [ABSTRACT FROM AUTHOR]

On 6 February 2023, an earthquake doublet occurred, the first at Kahramanmaraş Pazarcık district ( M w = 7. 7) at local time 04:17 and the second, which approximately 9 hours after the first earthquake, occurred at Kahramanmaraş Elbistan district ( M w = 7. 6) at local time 13:24 in Türkiye. It is a disaster affected 11 cities in the eastern region in Türkiye and is referred as "Disaster of the Century". Earthquake disasters allow humanity to investigate seismic behavior under related construction details and revising the seismic codes. The authors conducted observational research to obtain interpretive information and digital data by investigating structural damages of moderately and heavily damaged buildings from earthquake sites. In this paper, performance evaluation is done based on existence of soft storey, weak column-strong beam, deficiencies and pounding effect. Damages are classified as beam, column, beam-column joint and shear wall, infill wall, roof and scaffolding damages. Ampleness of soft storey, column damages, inadequate joint reinforcement, inadequate structural ductility and low capacity, strong beam-weak column effect, and infill wall damages have been observed from the field. As a result of field observation, structural deficiencies, irregularities and mismatching capacity design principles have been concluded as common problems of reinforced concrete buildings in the Kahramanmaraş earthquake site. [ABSTRACT FROM AUTHOR]

Southeastern Turkey perished by the M w 7.8, Kahramanmaras earthquake on February 6, 2023, at 01:17 UT (04:17 LT). The Kahramanmaras-centered event, hit by the break of the East Anatolian Fault Line, is felt in Syria, Egypt, Lebanon, Iraq, and Cyprus on the border of Turkey. Together with Syria, it causes loss of lives and severe damage in 10 cities. This work is dedicated to the people of the region. The study discusses the causality of anomalies by conducting ionospheric anomaly research via the interpolated TEC map obtained from the CODE according to the coordinates of the epicenter of the earthquake (latitude, longitude). The TEC amplitudes are observed by evolving the time-domain TEC map into the frequency-domain with the Fourier transform. The peaks of the amplitudes allow preliminary information for the anomaly days. For the anomaly, the TEC (TECU) boundaries are drawn by the statistical specification. The TEC map outside these boundaries is marked as an anomaly. The causality of abnormalities is tried to be read through the triad of the geomagnetic storm(s) , solar activity , and the earthquake effect. One can find seven anomaly days in the paper. January 30, February 2, 3, 11, 15, 16, and 21 are the anomaly days. The essay probably detects the anomaly before 3 days related to the Southeastern earthquake. • Reads the causality of the earthquake in southeast Turkey (Mw 7.8), through the ionosphere-earth crust relationship. • Notices potential anomalies by presenting the time-domain TEC atlas in the frequency domain with Fourier spectral analysis. • Considering all possible TEC anomaly essentials detect the precursors of the earthquake 3 days before the event day. [ABSTRACT FROM AUTHOR]

This paper explores the applicability of one-dimensional (1D) nonlinear (NL) and equivalent-linear (EL) site response analyses (SRA) for characterizing site effects at selected strong ground motion stations impacted by the February 6, 2023 Türkiye earthquakes. The 1D NL simulations generally underestimate site response at softer sites and for long periods likely due to basin effects and the uncertainties associated with site properties and the 1D approximation. The inclusion of the high-frequency spectral decay parameter (κ 0) in 1D simulations decreases the prediction bias of nonlinear SRA, especially at soft sites for short periods. Moreover, the theoretical transfer functions (TTFs) are demonstrated to capture the fundamental site period through in horizontal-to-spectral vertical ratio (HVSR) using ground motion data before and after the February 6, 2023 main event. • The performance of 1D site response approach in capturing site effects at stations affected by 2023 Türkiye events was tested. • 1D assumption underestimates the observed PSA for periods greater than site period probably due to basin effects at Hatay. • The use of κ 0 to adjust D min values of soils was found to slightly reduce the bias in 1D predictions for short periods. • ETFs and TTFs show consistency in the location of peak amplifications while highlighting discrepancies in terms of amplitude. [ABSTRACT FROM AUTHOR]

On February 6, 2023, two heavy earthquakes with moment magnitudes (M W) of 7.7 and 7.6 hit the Kahramanmaraş region in southeast Türkiye. Aftershocks of moment magnitude of 6 occurred consequently. These earthquakes affected more than 14 million people, and caused severe damage to civil infrastructure including buildings, government offices, religious buildings, dams, bridges, airports, and roads. After the earthquakes, a group of researchers visited the Hatay province to assess the response of buildings. Hatay was one of the most heavily affected cities in the region. The researchers gathered data on damaged reinforced concrete buildings, steel structures, as well as masonry buildings. This paper focuses on discussing the findings and analyzing the gathered data from reinforced concrete buildings and steel structures. A wide variety of issues that resulted in heavy damage or, in some cases, complete collapse of the buildings are discussed. These problems include construction mistakes such as insufficient shear reinforcements, neglected corrosion, utilizing low-quality concrete, insufficient development length in flexural reinforcements, and strong beam- weak column failure. In addition, various design errors including excessive torsional response of buildings, rigidity difference in two orthogonal directions of east–west and north–south of the building plan, pounding effect, short column failure, and development of weak and soft stories are described using gathered pictorial data. Finally, recommendations were made, and conclusions were drawn based on previous experimental and numerical studies of the seismic behavior of buildings as well as Turkish Building Earthquake Code (TBEC- 2018) requirements. [ABSTRACT FROM AUTHOR]

The 6th February 2023 Pazarcık and Elbistan earthquakes (Mw = 7.7 and Mw = 7.6) caused great destruction in many cities and were the disaster of the century for Türkiye. The greatest destruction was caused in the provinces of Hatay, Kahramanmaraş, and Adıyaman during these earthquakes, which were independent of each other and occurred on the same day. Information about earthquakes and strong ground motion records is given within the scope of this study. Reinforced concrete (RC) structures which constitute a large part of the urban building stock in the earthquake region were exposed to structural damage at different levels. The structural damage in the RC structures in the city center, Gölbaşı, and Kahta districts of the province of Adıyaman was evaluated within the scope of earthquake and civil engineering after field investigations. Insufficient RC, low-strength concrete reinforcement problems, RC frame failure, heavy overhang, short columns, soft story, and pounding effect are the main causes of the earthquake damage. The presence of these factors that reduce the earthquake resistance of RC structures increased the damage level. In addition, the fact that the earthquakes occurred nine hours apart and the continuation of aftershocks during that period negatively affected the damage levels. It has been observed that structures that receive the necessary engineering services during the construction and project phases ensure the safety of life and property, even if the structure is slightly damaged. In this study, we also tried to reveal whether the target displacements were satisfactorily represented by numerical analysis for a sample RC structure. [ABSTRACT FROM AUTHOR]

Background: Identifying healthcare services and also strengthening the healthcare systems to effectively deliver them in the aftermath of large-scale disasters like the 2023 Turkey-Syria earthquakes, especially for vulnerable groups cannot be emphasized enough. This study aimed at identifying the interventions undertaken or proposed for addressing the health needs or challenges of vulnerable groups immediately after the occurrence of the 2023 Turkey-Syria earthquakes, as well as for prioritizing their healthcare service delivery in the post-Turkey-Syria earthquake. Methods: In this scoping review compiled with the five steps of the Arksey and O'Malley framework, five databases, including PubMed, Science Direct, Web of Science, OVID, and Google Scholar, were searched for studies published between March and April 2023 in line with the eligibility criteria. Interventions for enhancing post-earthquake healthcare services (PEHS) were grouped into seven (7) categories, adopted from previous guidelines and studies. Each one was assigned a default score of a value equal to one (1), which, in the end, was summed up. Results: Of the 115 total records initially screened, 29 articles were eligible for review. Different interventions they reported either undertaken or proposed to address the healthcare needs and challenges, especially faced by the most vulnerable groups in the aftermath of the Turkey-Syria earthquakes, were categorized into 7 PEHS. They were ranked with their scores as follows: humanitarian health relief (25); medical care (17); mental health and psychosocial support (10); health promotion, education, and awareness (9); disease surveillance and prevention (7); disability rehabilitation (7); and sexual and reproductive health (5). Conclusion: Since there are no proper guidelines or recommendations about the specific or most significant PEHS to prioritize for vulnerable groups after the occurrence of large-scale earthquakes, this scoping review provides some insights that can help inform healthcare service delivery and prioritization for vulnerable groups in the post-2023 Turkey-Syria earthquakes and other similar disasters. [ABSTRACT FROM AUTHOR]

Background: An earthquake with a magnitude of 7.7 occurred in Pazarcık District of Turkey at 04.17 on February 6, 2023 and another earthquake of 7.6 occurred at 13.24 on the same day. This is the second largest earthquake to have occurred in Turkey. The aim of this study is to investigate the earthquake-related level of knowledge, attitudes and behaviours, general health and psychological status of survivors who were affected by the 2023 Kahramanmaraş Earthquake and who were living in Nurdağı District of Gaziantep after the earthquake. Methods: Data of 2317 individuals older than 18 years of age who were living in earthquake neighbourhoods, tents and containers in Nurdağı District of Gaziantep were examined. Variables were evaluated to find out the demographic characteristics and general health status of earthquake victims. General Health Questionnaire (GHQ-12) was used to find out psychological states of earthquake victims. Results: The rate of injuries was 14.2% and leg and foot injuries were the most common with 44.2%. The relationship between injury status; and age, marital status, and being trapped under debris was revealed (p < 0.05). Mean GHQ-12 score of the survivors was 3.81 ± 2.81 and 51.9% experienced psychological distress. In the evaluation with logistic regression, it was found that female gender, being injured in the earthquake, loss of first degree and second degree relatives (with a higher rate in loss of first degree relative), having a severely damaged -to be demolished house and having a completely destroyed house were correlated with higher level of psychological distress (p < 0.05). Conclusion: General characteristics, injury prevalence and affecting factors of earthquake survivors were evaluated in the present study. Psychological distress was found in victims. For this reason, providing protective and assistive services to fight the destructive effects of earthquake is vital. Accordingly, increasing the awareness of people residing in earthquake zones regarding earthquakes is exceptionally important. [ABSTRACT FROM AUTHOR]

The February 2023 Turkey‐Syria Earthquake doublet ruptured multiple segments of the East Anatolian Fault (EAF) Zone. Dominating seismicity focal mechanism shifted dramatically from strike‐slip to normal‐faulting after the doublet. To better understand this shift, here we derived a comprehensive 3D co‐seismic displacement field and performed the stress analysis. Abundant space geodetic data were used to generate high‐resolution 3D surface displacement, which provide tight constraints on fault geometry, slip distribution and stress field. Together with stress inversion from aftershock focal mechanisms, we show that the principal stress direction rotation in the region with the most normal‐faulting aftershocks is the staggering 29°. The induced heterogenous stress may explain the shift of the dominant focal mechanism toward normal faulting. We suggest that the extensional horsetail splay faults, likely formed through geologic time scale related to the releasing bend on the EAF, are the hosts of most of the normal faulting aftershocks. Plain Language Summary: Sudden dislocation of two sides of a fault, or the rupture of rocks, produces an earthquake. The dislocation direction relative to the fault traces reflects the direction of stress that are responsible for the earthquake. When dislocation direction is parallel to the fault strike, the earthquake is termed as strike‐slip type, and termed as normal‐faulting type when they are perpendicular. A remarkable feature for the 2023 Turkey‐Syria Mw7.8 & 7.7 earthquake doublet is that, background seismicity shifted dramatically from strike‐slip to normal type of faulting after the doublet. To unravel the physical process resulted in this feature, we use space geodetic measurements to derive the surface displacements and stress field associated with the doublet. The derived stress field shows a staggering 29° rotation occurred in a horsetail splay fault structure where many normal‐faulting earthquakes happened. The large stress rotation indicates the doublet released considerable stress and may result in a heterogeneous stress field due to the stress change. The combination of the identified horsetail structure and stress rotation can help better explain the occurrence of pervasive normal‐faulting earthquakes. Key Points: We map the 3D displacements, slip distribution, and stress fields related to the 2023 Turkey‐Syria Earthquake doubletDramatic stress rotation occurred after the Earthquake doublet, up to 29°Stress rotation and horsetail splay fault structure are potentially responsible for normal‐faulting aftershocks [ABSTRACT FROM AUTHOR]

On February 6, 2023, the Republic of Turkey experienced a rare occurrence of two successive earthquakes, each with a magnitude exceeding 7.0. The Disaster and Emergency Management Agency (AFAD) swiftly shared the strong motion records, thereby enriching the global database of near‐fault strong motion records. Identification of permanent displacement is essential for effectively utilizing these records. In this study, we refined the permanent displacement identification method, which combines the Hermit interpolation baseline correction with flatness determination by incorporating a low‐pass filter. Following this, we compared four permanent displacement identification methods, including our improved approach. We applied these to the strong motion record of station 4404 and compared the results with the Global Positioning System coseismic displacement. At the same time, we used field investigation data to verify the effectiveness of our improved method, studying its applicability for both single‐wave packet and multiwave packet records. The conclusions are the following: the improved method provides a more reasonable and effective means of identifying permanent displacement. When the peak ground acceleration (PGA) exceeds 1 g, the permanent displacement identifications from the four methods differ significantly. The discrepancy in permanent displacements identified by the four methods in the horizontal direction is larger than that in the U−D direction. For the record with the largest PGA (station 4614), our improved method yields more reasonable results compared with other techniques. Furthermore, the choice of segmentation time nodes in the velocity time history significantly affects the identification of permanent displacement. [ABSTRACT FROM AUTHOR]

This study focuses on the identification of collapsed buildings in satellite images after earthquakes through deep learning-based image segmentation models. The performance of four different architectures, namely U-Net, LinkNet, FPN, and PSPNet, was evaluated using various performance metrics, such as accuracy, precision, recall, F1 score, specificity, AUC, and IoU. The study used satellite images taken from the area located in the south and southeast of Türkiye covering the eleven provinces which are most affected by the Mw 7.7 Pazarcık (Kahramanmaraş) and Mw 7.6 Elbistan (Kahramanmaraş) earthquakes. The results indicated that FPN and U-Net were the best-performing models depending on the performance metric of interest. FPN achieved the highest accuracy and specificity scores, as well as the best precision score, while U-Net achieved the best recall and F1 score values, as well as the best AUC and IoU scores. The training and validation accuracy and loss curves were analyzed, and the results indicated that all four models achieved an accuracy value of over 96%. The FPN model outperformed the others in terms of accurately segmenting images while maintaining a low loss value. This study provides insights into the potential of deep learning-based image segmentation models in disaster management and can be useful for future research in this field. [ABSTRACT FROM AUTHOR]

Seismic phase picking and magnitude estimation are fundamental aspects of earthquake monitoring and seismic event analysis. Accurate phase picking allows for precise characterization of seismic wave arrivals, contributing to a better understanding of earthquake events. Likewise, accurate magnitude estimation provides crucial information about an earthquake's size and potential impact. Together, these components enhance our ability to monitor seismic activity effectively. In this study, we explore the application of deep-learning techniques for earthquake detection and magnitude estimation using continuous seismic recordings. Our approach introduces DynaPicker, which leverages dynamic convolutional neural networks to detect seismic body-wave phases in continuous seismic data. We demonstrate the effectiveness of DynaPicker using various open-source seismic datasets, including both window-format and continuous recordings. We evaluate its performance in seismic phase identification and arrival-time picking, as well as its robustness in classifying seismic phases using low-magnitude seismic data in the presence of noise. Furthermore, we integrate the phase arrival-time information into a previously published deep-learning model for magnitude estimation. We apply this workflow to continuous recordings of aftershock sequences following the Turkey earthquake. The results of this case study showcase the reliability of our approach in earthquake detection, phase picking, and magnitude estimation, contributing valuable insights to seismic event analysis. [ABSTRACT FROM AUTHOR]

Here, we employ natural time analysis of seismicity together with non-extensive statistical mechanics aiming at shortening the occurrence time window of the Kahramanmaraş-Gazientep M7.8 earthquake. The results obtained are in the positive direction pointing to the fact that after 3 February 2023 at 11:05:58 UTC, a strong earthquake was imminent. Natural time analysis also reveals a minimum fluctuation of the order parameter of seismicity almost three and a half months before the M7.8 earthquake, pointing to the initiation of seismic electrical activity. Moreover, before this earthquake occurrence, the detrended fluctuation analysis of the earthquake magnitude time-series reveals random behavior. Finally, when applying earthquake nowcasting, we find average earthquake potential score values which are compatible with those previously observed before strong ( M ≥ 7.1 ) earthquakes. The results obtained may improve our understanding of the physics of crustal phenomena that lead to strong earthquakes. [ABSTRACT FROM AUTHOR]

In 2023, two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye, causing severe casualties and economic losses. The damage to critical urban infrastructure and building structures, including highways, railroads, and water supply pipelines, was particularly severe in areas where these structures intersected the seismogenic fault. Critical infrastructure projects that traverse active faults are susceptible to the influence of fault movement, pulse velocity, and ground motions. In this study, we used a unique approach to analyze the acceleration records obtained from the seismic station array (9 strong ground motion stations) located along the East Anatolian Fault (the seismogenic fault of the MW7.8 mainshock of the 2023 Türkiye earthquake doublet). The acceleration records were filtered and integrated to obtain the velocity and displacement time histories. We used the results of an on-site investigation, jointly conducted by China Earthquake Administration and Türkiye's AFAD, to analyze the distribution of PGA, PGV, and PGD recorded by the strong motion array of the East Anatolian Fault. We found that the maximum horizontal PGA in this earthquake was 3.0 g, and the maximum co-seismic surface displacement caused by the East Anatolian Fault rupture was 6.50 m. As the fault rupture propagated southwest, the velocity pulse caused by the directional effect of the rupture increased gradually, with the maximum PGA reaching 162.3 cm/s. We also discussed the seismic safety of critical infrastructure projects traversing active faults, using two case studies of water supply pipelines in Türkiye that were damaged by earthquakes. We used a three-dimensional finite element model of the PE (polyethylene) water pipeline at the Islahiye State Hospital and fault displacement observations obtained through on-site investigation to analyze pipeline failure mechanisms. We further investigated the effect of the fault-crossing angle on seismic safety of a pipeline, based on our analysis and the failure performance of the large-diameter Thames Water pipeline during the 1999 Kocaeli earthquake. The seismic method of buried pipelines crossing the fault was summarized. [ABSTRACT FROM AUTHOR]

This study aims to obtain the viable parameters of base isolation systems that are utilized in buildings with seismic isolation and specially located in Turkey. To provide a more accurate representation of real-world scenarios, the study accounts for severe ground motion records simultaneously during the dynamic response analysis of the structure. Three records are taken from the 2023 Turkey earthquake (records for Elbistan, Nurdagi, and Pazarcik). The optimization model's objective function is to minimize the ratio of the roof acceleration to the peak ground acceleration. To ensure realistic outcomes, certain isolation parameters are constrained, such as maintaining the damping ratio and period within a predetermined range as well as the maximum lateral drift of the structure. An upgraded variant of the Butterfly Optimization Algorithm, known as the Fuzzy Butterfly Optimization Algorithm (FBOA), is employed to address the presented optimization model. The FBOA technique incorporates a fuzzy decision-making mechanism that adjusts its search strategy according to the prevailing conditions of the present problem. In addition, the FBOA method utilizes a new auxiliary vector called virtual butterfly, which provides information on the entire population based on each agent's quality. Consequently, FBOA transforms into a self-regulating search algorithm, eliminating the requirement for any external parameters. Results have verified the effectiveness of FBOA in detecting optimal parameters of the proposed isolation system. [ABSTRACT FROM AUTHOR]

Understanding earthquake phenomena is always challenging. The search for reliable precursors of earthquakes is important but requires systematic and long-time monitoring employing multi-disciplinary techniques. In search of possible precursors, we obtained commercially bottled spring waters dated before and after the earthquakes of 6 February 2023. Hydrogeochemical precursors have been detected in commercially bottled natural spring waters (Ayran Spring and Bahçepınar Spring), which are at a distance of about 100 and 175 km from the epicenters of the Mw 7.7 and Mw 7.6 Kahramanmaraş (Türkiye) earthquakes of 6 February 2023, respectively. The available water samples cover the period from March 2022 to March 2023. The pre-earthquake anomaly is characterized by an increase in electrical conductivity and major ions (Ca 2+ , Mg 2+ , K + , Na + , Cl - , and SO 42-) compared to the background for Ayran Spring water samples. The pre-earthquake anomaly lasted for at least 6 months. The anomaly in major ions sharply declined and the ion content approached the background values about 2 weeks after the earthquakes. Although only 6.5 km away from the Ayran Spring, the bottled water samples of the Bahçepınar Spring did not show any anomalies in electrical conductivity; therefore, the samples were not analyzed for ion content. Bahçepınar water is collected from shallow boreholes dug into alluvial deposits, which we believe are decoupled from the basement rocks, and this may be the reason for the lack of abnormal water chemistry prior to the earthquakes. This attests to the fact that sampling locations are very important in the detection of possible earthquake precursors. Results of the Ayran spring water samples indicate that spring water chemical anomalies of discrete samples may provide valuable information on pre-earthquake crustal deformation. Monitoring of spring waters, along with other monitoring techniques in a multidisciplinary network, and for a sufficiently long time, could potentially enable obtaining reliable proxy indicators of pre-earthquake crustal deformation. [ABSTRACT FROM AUTHOR]

On 6 February 2023, the MW 7.8 Pazarcik and the MW 7.5 Elbistan earthquakes occurred in southeastern Turkey, close to the Syrian border, causing many deaths and a great deal of property destruction. The Pazarcik earthquake mainly damaged the East Anatolian Fault Zone (EAFZ). The Elbistan earthquake mainly damaged the Cardak fault (CF) and the Doğanşehir fault (DF). In this study, Sentinel-1A ascending (ASC) and descending (DES) orbit image data and pixel offset tracking (POT) were used to derive surface deformation fields in the range and azimuth directions induced by the Pazarcik and Elbistan earthquakes (hereinafter referred to as the Turkey double earthquakes). Utilizing GPS coordinate sequence data, we computed the three-dimensional surface deformation resulting from the Turkey double earthquakes. The surface deformation InSAR and GPS results were combined to invert the coseismic slip distribution of the EAFZ, CF, and DF using a layered earth model. The results show that the coseismic ruptures of the Turkey double earthquakes were dominated by left-lateral strike-slips. The maximum slip was 7.76 m on the EAFZ and about 8.2 m on the CF. Both the earthquakes ruptured the surface. The Coulomb failure stress (CFS) was computed based on the fault slip distribution and the geometric parameters of all the active faults within 300 km of the MW 7.8 Pazarcik earthquake's epicenter. The CFS change resulting from the Pazarcik earthquake suggests that the subsequent Elbistan earthquake was triggered by the Pazarcik earthquake. The Antakya fault experienced an increase in CFS of 8.4 bars during this double-earthquake event. Therefore, the MW 6.3 Uzunbağ earthquake on 20 February 2023 was jointly influenced by the Turkey double earthquakes. Through stress analysis of all the active faults within 300 km of the MW 7.8 Pazarcik earthquake's epicenter, the Ecemis segment, Camliyayla fault, Aadag fault, Ayvali fault, and Pula segment were all found to be under stress loading. Particularly, the Ayvali fault and Pula segment exhibited conspicuous stress loading, signaling a higher risk of future seismic activity. [ABSTRACT FROM AUTHOR]

Earth observations from remotely sensed data have a substantial impact on natural hazard surveillance, specifically for earthquakes. The rapid emergence of diverse earthquake precursors has led to the exploration of different methodologies and datasets from various satellites to understand and address the complex nature of earthquake precursors. This study presents a novel technique to detect the ionospheric and atmospheric precursors using machine learning (ML). We examine the multiple precursors of different spatiotemporal nature from satellites in the ionosphere and atmosphere related to the Turkey earthquake on 6 February 2023 (Mw 7.8), in the form of total electron content (TEC), land surface temperature (LST), sea surface temperature (SST), air pressure (AP), relative humidity (RH), outgoing longwave radiation (OLR), and air temperature (AT). As a confutation analysis, we also statistically observe datasets of atmospheric parameters for the years 2021 and 2022 in the same epicentral region and time period as the 2023 Turkey earthquake. Moreover, the aim of this study is to find a synchronized and co-located window of possible earthquake anomalies by providing more evidence with standard deviation (STDEV) and nonlinear autoregressive network with exogenous inputs (NARX) models. It is noteworthy that both the statistical and ML methods demonstrate abnormal fluctuations as precursors within 6 to 7 days before the impending earthquake over the epicenter. Furthermore, the geomagnetic anomalies in the ionosphere are detected on the ninth day after the earthquake (Kp > 4; Dst < −70 nT; ap > 50 nT). This study indicates the relevance of using multiple earthquake precursors in a synchronized window from ML methods to support the lithosphere–atmosphere–ionosphere coupling (LAIC) phenomenon. [ABSTRACT FROM AUTHOR]

The Central Anatolian Plateau with its volcanic provinces represents a broad transition zone between the compressional deformation in the east and the extensional regime in the west. The Central Anatolian Fault Zone separates the Kırşehir Block in the north and the Anatolide-Tauride block in the south within the plateau. A proper understanding of physical properties such as seismic attenuation in the crustal volume of this region can provide hints toward the possible source for the geodynamic events in the past and present that likely leads to the observed deformation. To model intrinsic and scattering attenuation separately, we perform a non-empirical coda wave modeling approach in which a fitting process between observed and synthetic coda wave envelopes is performed for each earthquake in multiple frequency bands. Here acoustic radiative transfer theory assuming multiple isotropic scattering was utilized for the forward modeling of the synthetic coda-wave envelopes of local earthquakes. Our findings generally highlight the prominent nature of intrinsic attenuation over scattering attenuation implying the presence of thick volcanic rocks with relatively high attenuation values beneath Central Anatolia. In overall the spatial distribution of the attenuation at varying frequencies marks the Kırşehir Massif distinctively with its considerable high attenuating character. Our findings together with early seismological and geo-electrical models suggest a possible partial melt beneath the most of Central Anatolian Volcanic Province and resultant zones of elevated fluid rich content exhibit high and dominant intrinsic attenuation. To the southeast, a gradual decrease in the observed attenuation coincides with the Central Tauride Mountains where high altitude is considered to be evolved following the slab break-off and resulting mantle upwelling. [ABSTRACT FROM AUTHOR]

The first MW 7.7 and second MW 7.6 Kahramanmaraş earthquakes were the strongest tectonic events in Eastern Türkiye since the MW 7.9 Erzincan earthquake in 1939. The first and second events occurred on the Pazarcık and Çardak segments of the East Anatolian Fault System, respectively. A subsequent significant earthquake of MW 6.4 occurred in the Antakya fault zone. We summarize preliminary earthquake data and share our previous field observations to better understand the mechanism and provide scientific consequences for future investigations and layout planning. After combining the field observations, kinematic analysis of fault surfaces, investigations of orthophotos, characteristics of mainshocks, and differential interferometry analysis of Sentinel-1A synthetic aperture radar images are used to evaluate the surface deformation from an earth sciences point of view. As a result, field data, paleostress analysis, and deformation zones are found to be completely consistent with the focal mechanism solutions of recent earthquakes. Furthermore, the first MW 7.7 event would have been caused by motion along the Pazarcık and Amanos segments at the same time as a single seismic segment. [ABSTRACT FROM AUTHOR]

The Mw 7.7 Pazarcık earthquake on February 06, 2023, struck southern Türkiye, causing typical liquefaction along the shores of İskenderun Bay. This liquefaction was characterized by lateral spreading, subsidence, and flooding. Subsidence-triggered sand ejecta, water flows, and opening cracks were identified in areas spanning approximately 2 km in length and 300 m in width. Based on coastal references such as lighthouses or harbor platforms, settlements of 0.8 m and lateral spreading of 0.4% were recorded along the coastal zone following the Pazarcık earthquake. According to camera recordings, liquefaction-related water and silty sand outflows occurred 29 min after the earthquake. The largest water outlet observed had dimensions of 2 m in length, 1 m in width, and 0.5 m in depth. Images captured at the moment of liquefaction show water gushing for 2 m. Granulometric analysis of liquefied sand eruptions at 10 locations on the coast of İskenderun indicated the presence of silty sand (SM). No water entered the settlement area from the sea during or shortly after the earthquake. The waters that flooded the streets of İskenderun were largely drained or pumped out after remaining for 3 days. The liquefaction of the main soil zone played a crucial role in the collapse or tilting of tall buildings along the shores of İskenderun.Lateral spreading and collapse on the shores of İskenderun were further exacerbated by the MW 6.4 magnitude Defne earthquake that occurred 14 days after the initial major earthquake. Field observations made 25 days after the first earthquake revealed a settlement of 1.7 m and approximately 1% lateral spreading in the coastal zone of İskenderun. [ABSTRACT FROM AUTHOR]

Quantitative geomorphic analyses are usually powerful in identifying active tectonics across global orogenic belts. Our present study will focus on the Anatolian Plate which hosts a lot of recent catastrophic earthquakes in Türkiye. Six geomorphic indices for 100 sub-basins around Türkiye have been computed including local relief, slope, normalized steepness index (kSn)), hypsometric curve and integral (HI), transverse topographic symmetry factor (Tf), and the basin asymmetry factor (Af). The averaged kSn and Af values have shown four high-value anomalous zones, suggesting relatively high uplift rates featured by high river incision and regional tilting. The values of 0.35 - HI < 0.6 for basins with S-shaped curves imply intensive tectonic activities along the eastern part of the North Anatolian Fault Zone (NAFZ), the Northeast Anatolian Fault Zone (NEAFZ), the East Anatolian Fault Zone (EAFZ), and the Central Anatolian Fault Zone(CAFZ). All results of the geomorphic indices analysis suggest a relatively high degree of tectonic activity in the following four areas, the Isparta Angle, the Eastern Black Sea Mountains, the South-eastern Anatolia Region, and the Central Anatolian fault zone. We further suggest that the eastern part of the NAFZ, NEAFZ, EAFZ, and CAFZ will be more active in tectonic activities, with a greater potential for strong earthquake occurrence. [ABSTRACT FROM AUTHOR]

Both MW 7.8 and MW 7.5 earthquakes occurred in southeastern Türkiye on February 6, 2023, resulting in numerous buildings collapsing and serious casualties. Understanding the distribution of coseismic surface ruptures and secondary disasters surrounding the epicentral area is important for post-earthquake emergency and disaster assessments. High-resolution Maxar and GF-2 satellite data were used after the events to extract the location of the rupture surrounding the first epicentral area. The results show that the length of the interpreted surface rupture zone (part of) is approximately 75 km, with a coseismic sinistral dislocation of 2–3 m near the epicenter; however, this reduced to zero at the tip of the southwest section of the East Anatolia Fault Zone. Moreover, dense soil liquefaction pits were triggered along the rupture trace. These events are in the western region of the Eurasian Seismic Belt and result from the subduction and collision of the Arabian and African Plates toward the Eurasian Plate. The western region of Chinese mainland and its adjacent areas are in the eastern section of the Eurasian Seismic Belt, where seismic activity is controlled by the collision of the Indian and Eurasian Plates. Both China and Türkiye have independent tectonic histories. [ABSTRACT FROM AUTHOR]