Powerful Earthquake Research Articles

Navigation satellites capture far-reaching effects of two powerful earthquakes

Navigation satellites capture far-reaching effects of two powerful earthquakes

The Preparation Phase of the 2023 Kahramanmaraş (Turkey) Major Earthquakes from a Multidisciplinary and Comparative Perspective

On 6 February 2023, Turkey experienced its most powerful earthquake in over 80 years, with a moment magnitude (Mw) of 7.7. This was then followed by a second earthquake of Mw 7.6 just nine hours later. According to the lithosphere–atmosphere–ionosphere coupling (LAIC) models, such a significant seismic activity is expected to cause anomalies across various observables, from the Earth’s surface to the ionosphere. This multidisciplinary study investigates the preparatory phase of these two major earthquakes by identifying potential precursors across the lithosphere, atmosphere, and ionosphere. Our comprehensive analysis successfully identified and collected various anomalies, revealing that their cumulative occurrence follows an accelerating trend, either exponential or power-law. Most anomalies appeared to progress from the lithosphere upward through the atmosphere to the ionosphere, suggesting a sequential chain of processes across these geospheres. Notably, some anomalies deviated from this overall trend, manifesting as oscillating variations. We propose that these anomalies support a two-way coupling model preceding major earthquakes, highlighting the potential role of fluid chemistry in facilitating these processes.

High-Resolution Velocity and Seismic Anisotropy Structures of the 2021 Ms 6.0 Luxian Earthquake Zone in Sichuan Basin

Abstract The Ms 6.0 Luxian earthquake, which occurred in a shallow sedimentary cover on the southern margin of the Sichuan basin in China, stands as the most powerful earthquake ever recorded in this region. This study aims to integrate multiple seismological methods to comprehensively investigate the seismic nucleation environment. Using data from 91 densely distributed seismic stations within the Luxian earthquake zone, we constructed models for velocity, anisotropy, and interfaces. Our results suggest the presence of a detachment interface at depths of ∼4.0–5.0 km, which appears to function as a stress-decoupling layer. This is evidenced by a noticeable shift in the intensity and orientation of azimuthal anisotropy, transitioning from weak to strong, and altering its alignment from a northwest–southeast to a northeast–southwest orientation. The mainshock and aftershocks are predominantly clustered along the boundaries characterized by high- and low-velocity zones, as well as the boundary of VP/VS ratios beneath the detached layer. This suggests the likely existence of a pre-existing northwest–southeast-striking fault with a southwest dip, extending from the underlying basement to the overlying sedimentary cover. The radial anisotropy analysis reveals a predominance of negative values beneath the Huaying Mountain fault, whereas positive values are prominent in the Yujisi sedimentary syncline. This distinctive pattern implies tectonic movements related to fault activities within the fault zone. Based on our findings and previous research, we speculate that the Ms 6.0 Luxian earthquake may have been influenced by local stress fields and triggered by industrial activities.

Post liquefaction effect on 1 and 2-dimensional model: a case study of Pasigala raw water transmission structure

Abstract The Liquefaction phenomenon that occurred in Central Sulawesi in September 2018 was triggered by a powerful earthquake that caused extensive destruction and loss of life. Due to its location close to the most active fault in Central Sulawesi, Palu Koro fault, there is still a high probability of recurrence of liquefaction near the area. Ikhsan et al (2023) found that near Sigi regency, certain spots are susceptible to liquefaction occurrence, especially near Maranatha village. This research aims to find the effect after the liquefaction near the Pasigala raw water bridge transmission construction in Sigi Regency if a similar earthquake occurred. It needs to be done because Pasi gala raw water transmission is one of the main raw water supplies to central Sulawesi. Some geotechnical data were carried out in this research such as stratigraphy, SPT, groundwater level, and seismic data. The Post liquefaction analysis was carried out using Idriss and Boulanger (2008) to define one-dimensional settlement potential from the spatial distribution of the liquefaction zone. Numerical models were compared to analyze the settling behavior in a two-dimensional model. The Empirical and Numerical results indicate that the settlement near the abutment’s structure over the 2018 earthquake simulation exceeded the permissible limit of 15 centimeters. This finding may lead to the prediction of damage to the entire structure.

Earthquake prediction using satellite data: Advances and ahead challenges

Due to the considerable loss of life and damages caused by powerful Earthquakes, along with the strengthening of structures and disaster management systems, many researches are being conducted associated with the possibility of creating Earthquake warning systems. However, no reliable scientific report on successful Earthquake prediction has been published so far. Although there are a couple of published scientific papers indicating the detection of unusual changes in physical and chemical parameters obtained from ground stations, but due to the limitations of in-situ measurement in terms of number, location, time and cost, there was no noticeable progress in Earthquake warning. After the advent of remote sensing satellites, the number of statistical studies related to Earthquake precursors increased significantly, and most of them emphasized the existence of abnormal behaviors in physical and chemical precursors around the time (about 1–30 days before) and locations of powerful Earthquakes. In this study, an attempt has been made to address the advances and challenges in the way of Earthquake prediction using satellite data and provide a perspective of the future of these researches. It should be noted that the increase in the number of satellites designed and launched specially for Earthquake studies, the variety of available Earthquake precursors (multi-precursor analysis), the development of classic and intelligent anomaly detection and predictor algorithms (multi-method analysis), the provision of intelligent systems for the integration of various precursors (fusion and decision systems), the creation of cloud storing and processing data services (Google Earth Engine, Giovanni, etc.) and the development of intelligent user interfaces for public, have made researchers more hopeful for the appearance of low-uncertainty Earthquake warning systems in the near future.

Coseismic deformation and fault slip distribution of the 2023 MW7.8 and MW7.6 earthquakes in Türkiye

On February 6, 2023, a devastating earthquake with a moment magnitude of MW7.8 struck the town of Pazarcik in south-central Türkiye, followed by another powerful earthquake with a moment magnitude of MW7.6 that struck the nearby city of Elbistan 9 h later. To study the characteristics of surface deformation caused by this event and the influence of fault rupture, this study calculated the static coseismic deformation of 56 stations and dynamic displacement waveforms of 15 stations using data from the Turkish national fixed global navigation satellite system (GNSS) network. A maximum static coseismic displacement of 0.38 m for the MW7.8 Kahramanmaras earthquake was observed at station ANTE, 36 km from the epicenter, and a maximum dynamic coseismic displacement of 4.4 m for the MW7.6 Elbistan earthquake was observed at station EKZ1, 5 km from the epicenter. The rupture-slip distributions of the two earthquakes were inverted using GNSS coseismic deformation as a constraint. The results showed that the Kahramanmaras earthquake rupture segment was distinct and exposed on the ground, resulting in significant rupture slip along the Amanos and Pazarcik fault segments of the East Anatolian Fault. The maximum slip in the Pazarcik fault segment was 10.7 m, and rupture occurred at depths of 0–15 km. In the Cardak fault region, the Elbistan earthquake caused significant ruptures at depths of 0–12 km, with the largest amount of slip reaching 11.6 m. The Coulomb stress change caused by the Kahramanmaras earthquake rupture along the Cardak fault segment was approximately 2 bars, and the area of increased Coulomb stress corresponded to the subsequent rupture region of the MW7.6 earthquake. Thus, it is likely that the MW7.8 earthquake triggered or promoted the MW7.6 earthquake. Based on the cumulative stress impact of the MW7.8 and MW7.6 events, the southwestern segment of the East Anatolian Fault, specifically the Amanos fault segment, experienced a Coulomb rupture stress change exceeding 2 bars, warranting further attention to assess its future seismic hazard risk.

Stimulation of the collective memory of the 1999 Turkey earthquake through the Turkish media coverage of the 2023 earthquake

Turkey has been struck by several powerful earthquakes. Since the 1999 earthquake was the most recent and devastating earthquake before the last one happened in February 2023, many of these media channels’ depictions of the 2023 earthquake in Turkey may have been impacted by the collective memory of the 1999 earthquake. Collective memory of disasters and conflicts frequently takes on special significance as a mechanism for society to cope with the catastrophic events they have witnessed. Collective memory aids societies in dealing with the consequences of such events by giving a feeling of continuity as well as a structure for interpreting and comprehending what occurred. The media and social media are important in developing and conveying collective memory. They play an important role in framing events, transmitting details, and providing a forum for public debate. Social media, in addition to traditional media, has emerged as an innovative platform for the construction and diffusion of collective memory. The purpose of this study is to investigate whether the Turkish media depicted the collective memory of the 1999 earthquake in the aftermath of the 2023 earthquake. If the collective memory of the 1999 earthquake is invoked in media coverage of the 2023 earthquake, how is it depicted in terms of lessons learned, public response, and influence on Turkish society? The study’s findings indicate that the analysis of Turkish media coverage pertaining to the 2023 earthquake has demonstrated a restricted collective recollection of the 1999 earthquake.

Socio-Economic Development of Tibet in the 11th Five-Year Plan (2006–2010). Part 9

The 11th Five-year Plan of the People's Republic of China was an important stage in the socio-economic development of both the whole of China and the TAR in its composition. The plan set an annual GDP growth rate of 7.5 %, which actually exceeded 10 %. Tibet, on the other hand, was developing at a rate of more than 12 % per year. During the five-year plan, Tibet experienced many serious trials: a series of powerful earthquakes that claimed thousands of lives. In 2008, when China was preparing to host the Olympic Games in Beijing in August, Western intelligence agencies provoked an uprising in Lhasa on March 18. The leaders of France (in 2008) and the United States (in 2010) distinguished themselves by provocations against China, meeting with the Dalai Lama, despite the vigorous objections of the Chinese authorities. Nevertheless, Britain officially recognized Tibet for the first time as an autonomous region within the PRC. Significant achievements have been made in the development of transport in the region and especially aviation. Tibet remained one of the twelve least developed western regions of the People's Republic of China, but its economy continued to develop dynamically. The authority of Tibet in the world community has significantly increased, one of the manifestations of this was the great success of Tibet at the world Exhibition in Shanghai in 2010.

Dynamic analysis of the Xiaoyan Pagoda in China: Mechanisms for resisting rare earthquakes

The Xiaoyan Pagoda in Xi'an stands as a UNESCO World Cultural Heritage site, having endured severe damage from numerous powerful earthquakes without collapsing. To comprehensively understand its behavior during earthquakes, a Block Discrete Element (3DEC) analysis method was employed. The numerical model underwent scrutiny aligned with in-situ dynamic test results. The dynamic response of the pagoda was calculated separately while subjected to the influence of three seismic waves under two conditions: rigid foundation and considering soil-structure interaction (SSI), and the damage process was analyzed. The calculation results reveal that under conditions of a rigid foundation, the ancient pagoda experiences displacement increases suddenly of each floor and eventual collapse when subjected to an intensity of 8-degree (PGA=0.40 g) earthquake. However, when accounting for the constructive characteristics of the foundation soil and considering soil boundary effects, the pagoda of dynamic characteristics differ, resulting in a seismic response lower than that of the rigid foundation scenario. During a rare earthquake of intensity of 9-degree (PGA=0.62 g), observed block detachment occurs at the top floor and the pagoda eaves of the middle floor, aligning with historical patterns of damage seen in the Xiaoyan Pagoda. These research outcomes offer valuable insights, serving as a reference for enhancing the seismic resilience of the Xiaoyan Pagoda structure and predicting its earthquake collapse risks.

RESILIENCE AND VULNERABILITY: THE HAOUZ EARTHQUAKE'S EFFECT ON HOUSING IN THE WESTERN HIGH ATLAS OF MOROCCO

This article delves into the vulnerability of traditional dwellings and cluster housing in the Western High Atlas region of Morocco, highlighting the major challenges they face during earthquakes. These houses, often built with natural materials such as earth, stone and wood, reveal structural limitations in the face of nature's relentless forces. More specifically, the article looks at the devastating Al Haouz earthquake of 2023, which marked the region's history as the most powerful earthquake in over a century. It left behind a tragic legacy of loss of life and considerable material damage. This underlines the imperative of understanding the seismic risks to which these traditional dwellings are exposed, particularly in a culturally and geologically rich and tectonically active region. The article goes beyond simply identifying the problems, highlighting the considerable efforts made by the government and civil society to rebuild and prepare the region for similar disasters in the future. It also highlights the need to strengthen the resilience of these traditional dwellings and to reconsider building standards to better cope with seismic risks.

Long‐Term Landslide Evolution and Restoration After the Wenchuan Earthquake Revealed by Time‐Series Remote Sensing Images

AbstractA powerful earthquake, particularly in mountainous regions, has the ability to trigger an immense number of landslides, resulting in severe damages. However, effectively assessing their recoveries in the years following the mainshocks has not yet been attempted due to the lack of continuously updated landslide inventories. Therefore, we proposed a novel detection framework utilizing time‐series Landsat images from 2000 to 2021, which enabled us to achieve a long‐term landslide inventory in the seismic zone for the first time. The response patterns of landslide development under different conditions were explored in detail. The restoration models were quantitatively established, revealing that the recoveries of post‐earthquake landslide activity and vital environmental indicators require a range from ∼5.29 to ∼25.00 years. This pioneering research is highly beneficial in comprehending the impact of earthquake‐induced hazards on short‐term land surface damage and long‐term ecological equilibrium.

Surface deformations of the 6 February 2023 earthquake sequence, eastern Türkiye.

Two powerful earthquakes struck Türkiye on 6 February 2023. The initial rupture was on the Dead Sea fault zone, yet maximum displacements and energy release [moment magnitude (Mw) 7.8] occurred 24 seconds later when rupture transferred to the East Anatolian fault zone (EAFZ). More than 7 hours later, a Mw 4.5 aftershock at the junction of the EAFZ with the east-west striking Çardak-Sürgü fault was followed 86 minutes later by the second large (Mw 7.5) earthquake, suggesting a causal relationship. We provide quantitative ground and aerial documentation of surface offsets and kinematics from the slipped faults, providing important data on surface deformation during large continental strike-slip earthquakes, rupture propagation mechanisms, and how slip may be transferred between complex fault systems. We also provide insight into how slip along linked fault systems accommodates global plate motions.

Observed failure modes in existing URM buildings after November 26, 2019 earthquake in Albania

This study explores the vulnerability of Unreinforced Masonry (URM) structures to seismic events, aiming to uncover the causes of failure and propose reconstruction strategies. Despite often being devastated in powerful earthquakes, URM buildings show damage even in mild to moderate seismic events. Field assessments after a magnitude 6.4 earthquake near Durres, Albania, in 2019, revealed severe damage in masonry buildings and adobe dwellings. Weak structural connections, insufficient roof support, and the absence of bond beams in load-bearing walls were identified as key contributors to the observed damage. The survival of masonry buildings post-earthquake does not guarantee seismic safety. The study recommends reinforcement techniques like shotcrete application, space reduction, and corner reinforcement, along with innovative methods such as Fiber Reinforced Polymer (FRP) use, for existing undamaged unreinforced buildings. These measures aim to prevent damage in the aftermath of destructive earthquakes, offering insights for the resilience of URM structures.

Extract and analysis of surface deformation caused by Mengyuan earthquake in Qinghai using ascending and descending tracks D-InSAR technology

Precision in uncovering the seismic source mechanism and conducting a thorough monitoring of deformation characteristics resulting from surface rupture is of paramount importance for geological comprehension, disaster management, and emergency response. This study employs both ascending and descending orbit Sentinel-1 data to capture the horizontal and vertical deformation traits of the Ms6.9 earthquake in Menyuan, Qinghai, on January 8, 2022, consequently exposing its seismogenic structure. The research outcomes suggest: the Menyuan earthquake generated an elliptical deformation zone measuring 30 × 20 km, with the maximum line-of-sight seismic displacement reaching 6.8 cm. And then, the vertical deformation field exhibited a range between -0.28 m and 0.42 m, while the horizontal deformation field ranged from -0.89 m to 0.94 m. This indicates that the earthquake's deformation is primarily oriented in the east-west direction. The left plate exhibited an upward trend with a NWW orientation, while the right plate displayed a downward trend with a SEE orientation, suggesting that the Menyuan earthquake can be classified as a "NWW-SEE" type. Furthermore, the seismic epicenter of this earthquake was predominantly concentrated in the western segment of the Lenglongling Fault. Two powerful earthquakes sequentially struck along this fault zone, intensifying the imperative for seismic geological research in the region. Additionally, this instance can serve as a benchmark for monitoring deformations and elucidating the seismic source mechanism in earthquakes with comparable seismogenic structures.

Structural damage observed in reinforced concrete buildings in Adiyaman during the 2023 Turkiye Kahramanmaras Earthquakes

Türkiye, located in a highly seismic region, has witnessed a history of devastating earthquakes, with unprecedented consequences noted in February 2023 when two powerful earthquakes near Pazarcik (Mw 7.7) and Elbistan (Mw 7.6) struck Southern Türkiye, resulting in extensive casualties, structural damage, and the compromised integrity of over 500,000 buildings. This study, centered on the Adiyaman region, scrutinizes the immediate structural damage to various reinforced concrete buildings, including both low-rise and tall structures. Many of the damages were attributed to structural deficiencies, including inadequate seismic reinforcement detailing, non-compliance with earthquake-resistant construction techniques, substandard concrete quality, and poor workmanship. The quality of building materials is considered a critical factor in structural resilience during earthquakes. Substandard materials or compromised quality can substantially impair a building's ability to withstand seismic forces. These key findings address a critical gap in understanding the vulnerabilities of reinforced concrete buildings in the aftermath of the 2023 Türkiye Kahramanmaraş Earthquakes. With professional rescue experience from the field, the authors bring unique insights.

Geofluids as a possible unconventional tool for seismic hazard assessment

In recent decades, phenomenological methods known as Recognition of Earthquake-Prone Areas (REPA) were set up for identifying potential sites of powerful earthquakes. The information on potential earthquake sources provided by the REPA method is an essential part of seismic hazard assessment methodology. For the first time, we have combined global-scale information on the geographic occurrence of geofluids with global-scale information on earthquake occurrence, heat flow distribution, and S-wave dispersion, to gain insights into the evolution of local stress-strain fields. We focused on areas characterized by the occurrence of thermal waters and/or by the release of deep-seated gases, as traced by the isotope composition of associated helium. We noticed that the geographic distribution of these geofluids could serve as an indirect indicator of crustal permeability anomalies generated by crustal deformation procedures. This study proposes adding geofluids to the list of fundamental geological parameters to be considered in hazard assessment research.

Seismogenic Structures in Sediments of Different Lithological Composition and their Position in Mesozoic–Cenozoic Sections of the Northern Caucasus

A comparative analysis of the morphological features of rock horizons affected by paleoearthquakes showed that seismites from lithologically different deposits differ significantly. Powerful earthquakes determine not only the destruction of the sedimentary structure of near-surface deposits and their chaotic mixing, but also actively affect the underlying layers to a depth of several tens of meters; since the degree of diagenetic lithification of rocks in different horizons varies with depth, the nature of their seismogenic changes also changes. It was found that major seismic events were associated with the time intervals of tectonic and paleogeographic restructuring of sedimentation basins, which consisted in the intensification of the process of bowing of the reservoir bed, changes in the material composition of sediments accumulated in the paleobasin. A special type of seismites was formed during the impact of earthquakes on siliceous deposits, in which the processes of diagenetic redistribution of authigenic mineral matter, which passed through the gel stage during diagenesis, actively proceeded.

Ordu Üniversitesi Uzaktan Eğitim Gören 2. Sinif Diş Hekimliği Öğrencilerinin 2022-2023 Güz Dönemi Anatomi Öz Yeterliliklerinin Belirlenmesi

OObjective: On 6 February 2023, a significant seismic event occurred in Kahramanmaraş, Turkey. The region was hit by strong earthquakes of high intensity. The first powerful earthquake occurred at 04:17 local time. It had a profound impact on the local population and infrastructure. The aim of this study is to investigate the anatomy self-efficacy of the students of the second semester of the Faculty of Dentistry who took a distance learning course after the earthquake in Kahramanmaraş. Methods: A total of 102 students participated in this cross-sectional study. Students participating in the study were administered the Anatomy Self-Efficacy Scale. The independent samples t-test was used to compare two independent groups of parametric data. For categorical data, the chi-squared test was used for multiple comparisons. Results: Mean total scale score of males is 78.73±10.64, and the subdimensions are 34.47±4.18, 21.42±3.85 and 22.83±3.78 from 1 to 3. The total score of females is 79.20±9.83, and in the sub-dimensions they are 34.58±3.73, 21.46 ± 3.39 and 23.15±4.35 respectively. For the total and sub-dimension scores, there was no statistically significant difference between the sexes. Conclusion: In the life of an academic institution, online education has become essential. In this study, whose population was second-year students at Ordu University Dentistry, students who receive online education for basic medical sciences, which includes intensive practical training such as anatomy instruction, can achieve an intermediate level of anatomy self-efficacy. While online education is ideal for improving self-efficacy in anatomy at an intermediate level, it is not sufficient for improving anatomy at a high level.

ICOLD 2023, Gothenburg Sweden: Turkish experience of the February 2023 seismic event

This technical briefing provides a summary of the findings and assessments presented by the DSI (State Hydraulic Works, Türkiye) team during the ICOLD 2023 meeting regarding the performance of embankment dams during the seismic events that occurred in February 2023. Two powerful earthquakes with moment magnitudes (Mw) initially estimated to be between 7.5 and 7.8 struck the eastern Anatolian Fault Line, impacting several embankment dams in the region. The seismic activity resulted in significant lateral displacements, settlements and cracks in the embankment dams structures. For the first earthquake, peak acceleration recorded at the nearest station (TK4614 – Pazarcik) was 2.21g, for the second earthquake, the peak acceleration recorded at the nearest station (TK4612 – Goksun) was 0.59g. The presentation at the conference, as reported here, provided valuable insights into the performance of the embankment dams during and after earthquakes.

Investigation of the LAIC mechanism of the Haiti earthquake (August 14, 2021) using CSES-01 satellite observations and other earthquake precursors

A powerful Mw = 7.2 earthquake occurred in Haiti on August 14, 2021 at 12:29:08 UTC (18.434° N, 73.482° W, depth ∼10 km). In this study, in a period of three months from June 1 to August 31, 2021, the variations in electron density and temperature parameters obtained from CSES-01 satellite measurements in the Dobrovolsky’s area the Haiti earthquake are considered. With the aim of investigating the proposed mechanisms for interactions between different layers of the Earth in the process of earthquakes (LAIC-Lithospheric Atmospheric Ionospheric Coupling), the behavior of 48 other precursors obtained from the data of other satellites in the same location and time period were analyzed. These precursors are 1) TEC obtained from GPS satellite data, 2) scalar and vector magnetic field data as well as electron density and temperature measured by the related sensors of three Swarm A, B and C satellites during day and night and 3) Variations in lithospheric and atmospheric parameters NO2 and SO2 obtained from OMI satellite measurements and also Ozone, carbon monoxide and surface temperature parameters obtained from AIRS data. By analyzing the above mentioned precursors, abnormal behaviors are observed around 30 and 50 days before the earthquake, and especially 1 to 15 days before the earthquake and by comparative study of the observed anomalies, possible LAIC mechanisms are discussed. The findings of this study can acknowledge the sequence of seismic anomalies observed in the lithosphere, then the atmosphere and finally the ionosphere. Therefore, this study once again emphasizes the necessity of performing multi-precursor analysis with the aim of justifying the LAIC mechanism and also observing seismically prone anomalies in the time period of about 10 days before powerful earthquakes.