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Obtaining geological and landform dislocation features, as well as the measured stratigraphic activity age, provides direct evidence to evaluate fault activity, which is more difficult to do in areas with low tectonic activity, such as eastern and central China. A detailed investigation of the fault activity, trenching, drilling joint geological profile, geological survey, and chronological analysis were used to obtain the spatial geometry, fault kinematics, and activity chronology of the Jiulong fault. The conclusions are as follows: (1) The Jiulong fault was a fracture zone composed of four branch faults, with a width of around 30–40 m and good extendibility, while the maximum surface rupture length was 373 m. (2) The Jiulong fault has many strata dislocations, and the dislocation distance decreased from bottom to top, demonstrating synsedimentary structure characteristics, with a maximum stratigraphic dislocation distance of 18.2 m. (3) Preliminary analysis suggested the Jiulong fault as a secondary fracture of the Xiangfan-Guangji fault zone and provided evidence of the southeastward extension of the Xiangfan-Guangji fault. A preliminary hypothesis purported the Xiangfan-Guangji fault as the seismogenic fault of the Ms 5.0 magnitude earthquake in 1911. (4) According to OSL and ESR dating analyses, the upper breakpoint of the Jiulong fault cuts into the Late Pleistocene Xingang Formation (Qp3x) strata, and the latest active age of the Jiulong fault was 57.6 ka. The chronology analysis confirmed an active fault from the Late Pleistocene and identified a weak tectonic in Jiujiang Province, which represents the largest active fault outcrop uncovered in the area so far. This study provides evidence and research materials for the evaluation of fault activity and seismic stability in this region. [ABSTRACT FROM AUTHOR]

We conducted large-depth Ground-Penetrating Radar investigations of the seismogenic Casamicciola fault system at the volcanic island of Ischia, with the aim of constraining the source characteristics of this active and capable fault system. On 21 August 2017, a shallow (hypocentral depth of 1.2 km), moderate (Md = 4.0) earthquake hit the island, causing severe damage and two fatalities. This was the first damaging earthquake recorded on the volcanic island of Ischia from the beginning of the instrumental era. Our survey was performed using the Loza low-frequency (15–25 MHz) GPR system calibrated by TDEM results. The data highlighted variations in the electromagnetic signal due to the presence of contacts, i.e., faults down to a depth larger than 100 m below the surface. These signal variations match with the position of the synthetic and antithetic active fault system bordering the Casamicciola Holocene graben. Our study highlights the importance of employing large-depth Ground-Penetrating Radar geophysical techniques for investigating active fault systems not only in their shallower parts, but also down to a few hundred meters' depth, providing a contribution to the knowledge of seismic hazard studies on the island of Ischia and elsewhere. [ABSTRACT FROM AUTHOR]

Large-scale surface rupture caused by destructive earthquakes causes serious damage to major projects and requires the estimation of the permanent displacement of the ground surface caused by seismic rupture to take effective measures to reduce the effect of disasters. Therefore, in this paper, we propose a system for assessing the permanent displacement of the ground surface due to seismic rupture, which will be applicable to earthquake engineering. The system takes the physical process of earthquake occurrence as the theoretical basis, comprehensively analyzes the seismic activity, seismic geologic environment, fault activity characteristics, tectonic stress field, and GPS observation data, and evaluates the strong earthquake-prone sections of active faults through motion dynamics simulation. Then, referring to the statistical relationships between historical earthquakes, modern earthquakes, and ancient earthquakes, a model of earthquake occurrence is determined. We combine it with the results of seismic hazard analysis and select different methods of evaluating permanent surface displacements caused by seismic rupture at near-fault sites and far-from-fault sites through suitability analysis. We apply the proposed assessment system for example validation and find that the characteristics of the obtained permanent displacement field of the ground surface caused by seismic rupture are basically consistent with actual engineering laws. [ABSTRACT FROM AUTHOR]

The Periadriatic Fault system (PAF) ranks among the largest post-collisional structures of the European Alps. Recent geodetic data suggest that a fraction of the Adria–Europe convergence is still being accommodated in the Eastern Alps. However, the historical seismicity records along the easternmost segment of the PAF are ambiguous, and instrumental records indicate that seismotectonic deformation is mostly concentrated in the adjacent Southern Alps and Dinarides. Both electron spin resonance (ESR) and optically stimulated luminescence (OSL) dating methods can be used to date coseismic slip (with a combined range covering a few decades to a couple of million years) in slowly deforming fault zones, such as the PAF. Since the saturation doses of the quartz ESR signals are larger than quartz and feldspar OSL, ESR enables establishing a maximum age of the last resetting event of the system, while OSL allows constraining their minimum age when the signal is in saturation. We collected fault gouge samples from three localities along the easternmost segment of the PAF. For ESR, we measured the signals from the Al center in quartz comparing the results from the single aliquot additive dose (SAAD) and single aliquot regenerative (SAR) dose protocols. For OSL, we recorded the infrared stimulated luminescence signal at 50°C (IR50) and post-infrared infrared-stimulated luminescence signal at 225 °C (pIRIR225). Our dating results indicate that the studied segment of the PAF system accommodated seismotectonic deformation during the Quaternary, with a maximum age for the last resetting event of the system ranging from 1075 ± 48 to 552 ± 26 ka (ESR SAR) and minimum ages in the range from 196 ± 12 to 281 ± 16 ka (saturation of pIRIR225). The obtained ages suggest that the studied segment of the PAF could be considered at least as a potentially active fault. [ABSTRACT FROM AUTHOR]

Previous studies take less account of analytical solution analysis for buried pipeline under the action of active fault. Furthermore, current theoretical studies of fault‐pipeline interactions generally treat the structure as continuous pipeline, with less attention given to the effect of joints. This paper provides an analytical method to estimate the deformation and internal force of jointed pipelines under normal and reverse fault. By introducing the simplified soil deformation model and error function, the soil greenfield deformation curves under the influence of normal and reverse fault are obtained. Considering the interaction between the pipeline structure and the disturbed soil, the two‐parameter Pasternak foundation model is adopted to analyze the forces on pipeline infinitesimal elements. Then, the mechanical response of the jointed pipeline structure due to the fault additional load is solved by finite difference method. The accuracy of the presented analytical solution is verified by comparisons with observed data of model test and 3D numerical simulation results. Finally, the parametric analyses are performed to estimate the influence for the characteristics of the foundation, fault and joint, including subgrade shear stiffness, subgrade reaction coefficient, fault dip, joint rotational stiffness, joint spacing, and intersection of fault and pipeline. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract With the rapid development of Chinese transportation networks, such as the Sichuan-Tibet railway, numerous tunnels are under construction or planned in mountainous regions. Some of these tunnels must traverse or be situated near active fault zones, which could suffer damage from fault slip. In this study, the seismic response of a mountain tunnel subjected to coseismic faulting was analyzed using a fault-structure system in a two-step process. Firstly, a nonuniform slip model was proposed to calculate the ground deformations and internal displacements induced by a specific active fault on a geological scale, considering nonuniform slips on the fault plane. The 1989 Loma Prieta and 2022 Menyuan earthquakes were chosen as case studies to validate the proposed slip model. Secondly, the calculated displacement of the Menyuan earthquake was used as the input load for the discrete–continuous coupling analysis of the Daliang tunnel on an engineering scale. The simulated deformation of the Daliang tunnel aligned with the on-site damage observations following the Menyuan earthquake. Lastly, the effects of different fault conditions on the tunnel seismic response were investigated. The results indicate that the distribution of the peak longitudinal strain of the lining is governed by fault mechanisms, and the degree of fault slip significantly influences the response of the tunnel. A tunnel passing through an active fault with a wider fault fracture zone and smaller dip angle experience less damage.

Abstract Earthquake prevention and disaster mitigation are crucial aspects of social welfare that significantly impact national public security. This paper presents a seismic risk assessment and hazard prediction of the Hunhe Fault in the Shengyang-Fushun (Shen-Fu) New District. The target area is at risk of seismic damage due to two major branch ruptures, namely, F9 and F1; these ruptures have the potential to generate maximum earthquakes with a magnitude of 6.0 in the next 50 to 100 years. A three-dimensional underground velocity structure and asperity source model were established for the target faults. Subsequently, a hybrid technique combining deterministic and empirical approaches was employed to simulate the broadband strong ground motion of the target region in anticipation of the occurrence of expected scenario earthquakes. The distributions of peak ground acceleration (PGA), peak ground velocity (PGV) and peak ground displacement (PGD) for the area are provided, and the results indicate that densely populated urban areas could experience PGA values close to 280 cm/s2 along the fault traces. This study provides a reliable basis for engineering construction and urban planning in the Shen-Fu New District.

Abstract The Periadriatic Fault system (PAF) ranks among the largest post-collisional structures of the European Alps. Recent geodetic data suggest that a fraction of the Adria–Europe convergence is still being accommodated in the Eastern Alps. However, the historical seismicity records along the easternmost segment of the PAF are ambiguous, and instrumental records indicate that seismotectonic deformation is mostly concentrated in the adjacent Southern Alps and Dinarides. Both electron spin resonance (ESR) and optically stimulated luminescence (OSL) dating methods can be used to date coseismic slip (with a combined range covering a few decades to a couple of million years) in slowly deforming fault zones, such as the PAF. Since the saturation doses of the quartz ESR signals are larger than quartz and feldspar OSL, ESR enables establishing a maximum age of the last resetting event of the system, while OSL allows constraining their minimum age when the signal is in saturation. We collected fault gouge samples from three localities along the easternmost segment of the PAF. For ESR, we measured the signals from the Al center in quartz comparing the results from the single aliquot additive dose (SAAD) and single aliquot regenerative (SAR) dose protocols. For OSL, we recorded the infrared stimulated luminescence signal at 50°C (IR50) and post-infrared infrared-stimulated luminescence signal at 225 °C (pIRIR225). Our dating results indicate that the studied segment of the PAF system accommodated seismotectonic deformation during the Quaternary, with a maximum age for the last resetting event of the system ranging from 1075 ± 48 to 552 ± 26 ka (ESR SAR) and minimum ages in the range from 196 ± 12 to 281 ± 16 ka (saturation of pIRIR225). The obtained ages suggest that the studied segment of the PAF could be considered at least as a potentially active fault. Graphical abstract

Objective The Qinghai-Tibet Plateau is one of the most seismically active regions along the Mediterranean-Himalayan seismic belt. Understanding the earthquake-controlling effect of the active tectonic system in this region is crucial for analyzing regional strong earthquake hazards. Methods We analyzed earthquake activity with MW≥6.0 since 1990 and their tectonic mechanism around the Tibetan Plateau, focusing on the continental collision-extrusion tectonic system. Results The results show that the system plays a significant role in governing regional strong earthquake activity. Specifically, MW≥6.5 earthquakes primarily occur along the main boundary fault zone of this tectonic system, exhibiting a relatively regular spatio-temporal migration process. Moreover, the multi-layered extrusion-rotation active tectonic system in the eastern Tibetan Plateau constitutes the primary earthquake-controlling structure of the strong earthquake process since 1990, followed by the thrust faults of the Himalayan foreland. Therefore, the extrusion tectonic system of the Qinghai-Tibet Plateau should be the focus for the trend analysis of the strong earthquake activity in the future, especially the most active secondary extrusion tectonic units such as the Bayan Har block. Comparative analysis of strong earthquake activities in and around the Anatolian plate reveals similar continental collision-extrusion tectonic systems and earthquake-controlling effects in this area, indicating that this tectonic system is a typical earthquake-controlling structure in the intracontinental orogenic belt. Conclusion Further comprehensive analysis suggests that the active tectonic system can significantly control regional strong earthquake activity. Firstly, most of the strong earthquake events occur in the main boundary fault zone of the fault block in the tectonic system. Secondly, the strong earthquake events along different structural zones in the tectonic system often have linkage effects or mutual triggering relationships, and the complex or particular structural sites are often where double earthquakes or earthquake swarm activities easily occur. Thirdly, when a certain structural unit or tectonic zone in the tectonic system is in an active stage, strong earthquake clustering phenomena occur. Significance A thorough understanding of the coordinated deformation relationships between major active faults in the tectonic system, the segmented rupture behavior of strong earthquake activity in active fault zones, and the characteristics of "long period, quasi-periodicity and clustering" of strong earthquake recurrence in situ on active faults will assist in more accurately assessing the future seismic hazard of active fault zones when analyzing the future trend of strong earthquake activity based on the active tectonic system.

Objective The Litang-Yidun fault is a left-lateral strike-slip active fault zone extending approximately 130 km in the Sichuan-Yunnan rhombic block in the Holocene. As a significant seismogenic structure controlling seismic activity in the Litang area of western Sichuan, research on both paleoseismicity and surface ruptures primarily focuses on the Litang and Damaoyaba sections, with relatively limited study on the Cuopuhu section in the northern part. Detailed investigation of the Cuopuhu section can provide fundamental information on its activity characteristics, paleoseismic events, and slip rates. Methods The Cuopuhu section of the Litang-Yidun fault was investigated using field surveys, high-precision mapping, trenching, and 14C dating methods to explore its slip rate and paleoseismic events. Two trench sites were excavated at the foothills of Dongou Mountain to identify the relationships between faulting and strata, sedimentary characteristics, and fault motion. Conclusion Four paleoseismic events were identified: Event Ⅰ occurred before BC 3382±60 a; Event Ⅱ occurred between BC 3382±60 a and BC 1094±51 a; Events Ⅲ and Ⅳ occurred after AD 1330±44 a. The recurrence intervals of the four earthquakes are approximately 0.4±0.3 ka, 2.42±0.1 ka, and 2.40±0.1 ka, respectively. Based on the calculated intervals, Events Ⅰ and Ⅱ, and Events Ⅱ and Ⅲ, Ⅳ, have recurrence intervals of about 2.4 ka. Events Ⅲ and Ⅳ occurred after AD 1330±44 a, making it difficult to determine their sequence and exact timing. It can be inferred that the Cuopuhu section of the Litang-Yidun fault likely has a recurrence interval of about 2.4 ka for paleoseismic events, with a possibility of seismic events with recurrence intervals of 0.4±0.3 ka. By comparing the research data between the Cuopuhu section and the Litang and Damaoyaba segments, differences in paleoseismic events between the Cuopuhu section and the other sections are evident. However, the seismic activity of different fault sections has shown a sustained strengthening trend since the Holocene. Based on mapped fault scarps and moraine ridges from the last glacial period, the average slip rate of the Cuopuhu section since the Late Pleistocene is estimated to be 4.15±0.5 mm/a, similar to the slip rates of different branches of the Litang-Yidun fault in the late Quaternary period. Significance This study provides information on the tectonic features, paleoseismicity, and slip rates of the Litang-Yidun fault, aiding in a better understanding of the seismic history and structural deformation patterns in the area and giving more data for medium- and long-term earthquake prediction in the future. It also contributes to the seismic risk assessment of relevant projects along the Sichuan-Tibet Railway.

Objective Widely distributed active faults are natural carriers that produce surface-rupture events; multidisciplinary observations have revealed that geometric changes in active faults significantly influence surface-rupture development. However, previous studies on the interaction between the geometric characteristics of active faults and the underlying rock geology have been relatively limited and only confined to observing high-temperature and high-pressure experiments. Methods With the development of high-resolution geographic technology and quantitative research methods for active faults, it is now possible to finely characterize the geometric structure of large-scale faults and recognize multiparameter displaced landform characteristics. In this study, we utilized high-resolution topographic data (0.5 m) from the Fodongmiao-Hongyazi Frontal thrust (FFT) on the northeastern margin of the Tibetan Plateau, spanning approximately 120 km in length to identify and compare the parameters and characteristics of the faulted landform with the underlying bedrock geology. Result The research results indicate that the geometric characteristics of the fault are segmented and synchronized with the geological background of the bedrock. The shallow geometric structures of the eastern and western sections of the FFT are relatively simple and continuous, and the changes in parameters such as the strike, roughness, and deformation zone width of the fault are relatively small. The fault's geometric structure was rougher in the middle section of the fault, where Silurian granite is located, and the shallow deformation zone was broader than that in the eastern and western segments. The step-width distribution also varied more drastically along the fault. Conclusion This study revealed a significant correspondence between faulted landform parameter changes, the boundary of fault segments, and zones of vertical separation attenuation. Additionally, this study suggests that bedrock geology may exert substantial control over the shallow structural deformation of thrust faults. Significance The potential impact of the underlying geology should be considered for thrust faults and when analyzing seismic hazards related to active faults.

We applied an interdisciplinary approach to analyze the late Quaternary activity of the Sava Fault in the Slovenian Southern Alps. The Sava Fault is an active strike-slip fault, and part of the Periadriatic Fault System that accommodated the convergence of Adria and Europe. It is one of the longest faults in the Southern Alps. Using high-resolution digital elevation models from lidar and photogrammetric surveys, we were able to overcome the challenges of assessing fault activity in a region with intense surface processes, dense vegetation, and relatively low fault slip rates. By integrating remote sensing analysis, geomorphological mapping, structural geological investigations, and near-surface geophysics (electrical resistivity tomography and ground penetrating radar), we were able to find subtle geomorphological indicators, detect near-surface deformation, and show distributed surface deformation and a complex fault pattern. Using optically stimulated luminescence dating, we tentatively estimated a slip rate of 1.8 ± 0.4 mm/a for the last 27 ka, which exceeds previous estimates and suggests temporal variability in fault behavior. Our study highlights the importance of modern high-resolution remote sensing techniques and interdisciplinary approaches in detecting tectonic deformation in relatively low-strain rate environments with intense surface processes. We show that slip rates can vary significantly depending on the studied time window. This is a critical piece of information since slip rates are a key input parameter for seismic hazard studies. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University / Dongnan Daxue Xuebao is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The active tectonics of northern Central Mongolia is studied between two largest W–E-trending left lateral fault zones: the Khangai Fault and the Tunka–Mondy. These strike-slip zones are part of a single ensemble of active faults in the Mongol–Baikal region, formed under conditions of maximum northeastern compression and maximum northwestern extension. Their ENE-trending Erzin–Agardag and Tsetserleg faults with a dominant sinistral component extend between these zones. A series of the N-trending graben basins (Busiyngol, Darkhat, and Khubsugul) are located between the eastern end of the Erzin–Agardag strike-slip fault and the western part of the Tunka–Mondy strike-slip zone. The basins form a sinistral deformation zone, which is kinematically similar with the strike-slip faults, which follow the latter. In contrast to the largest boundary strike-slip faults, this structural paragenesis formed under conditions of N–S-trending relative compression and N–S-trending extension. A change in the orientation of the axes of the principal normal stress may be caused by the rotation of the block between the boundary faults. The area of graben-shaped basins is located above the top of a vast volume of low-velocity mantle, which we have identified as the Khangai plume. The lithospheric mantle above this rise is reduced; the remaining part of the lithosphere is heated and softened. The large active strike-slip faults are located above areas of subsidence of the low-velocity top of the mantle. Our trenching of the active faults showed that strong earthquakes repeated in the area of graben-shaped basins more often than in the large strike-slip zones, but they were characterized by lower magnitudes. [ABSTRACT FROM AUTHOR]

Establishing the absolute age of palaeoearthquakes is of great significance for the assessment of the seismicity and seismic hazards of a region. As such, several different geochronological techniques to date earthquake-related material have been developed to provide answers on the time of past earthquakes. The present study is part of a wider palaeoseismic research project conducted in the Nojima Fault Zone (NFZ), where the 1995 Mw 6.9 Kobe (Japan) earthquake was triggered, to assess the suitability of the isothermal thermoluminescence (ITL) dating technique on fine-grained quartz and medium-grained feldspar and to provide a sequence of ages for fault-rock samples separated from a drilled core that was retrieved from a depth of ~506 m. Our analysis reveals that ITL can produce consistent dating results and can be considered a reliable luminescence technique for the absolute dating of fault-gouge material. The produced ITL ages signified the existence of repeated seismic events within the NFZ that took place through the late Pleistocene period, with gouge ages spanning from 78.6 ± 4.2 to 13.4 ± 1.4 ka; however, overestimation of the produced ITL dating results may be apparent. Nonetheless, even though some degree of overestimation is considered, ITL dating results denote the oldest possible age boundary of formation (or luminescence signal resetting) of the collected fault-gouge layers. [ABSTRACT FROM AUTHOR]

During the 2021 La Palma strombolian and fissure eruption, two faults were identified that controlled the spatial distribution of earthquake hypocenters and effusive eruptive vents. One of these faults has a NW-SE trend (Tazacorte Fault: TZF) and the other one shows an ENE-WSW trend (Mazo Fault: MZF). Previous works on fault structural analysis in La Palma indicated that the eruption zone was compatible with an extensional tectonic strain ellipsoid which activated normal-strike-slip directional faults at the confluence of TZF and MZF. These fractures were activated during the 2021 Tajogaite eruption, determining the NW-SE and WSW-ENE spatial distribution of vents. Both faults were mapped in real time during the volcanic eruption from fieldwork and remote sensing imagery (aerial drone images). We have collected more than 300 fracture data associated with the effusive vents and post-eruption seismic creep. Since the affected area was densely inhabited, most of these fractures affect houses and infrastructures. Some of the houses affected by the TZF were damaged 9 months after the eruption, although they were not damaged during the eruption. Surprisingly, these houses already had repairs made to the same fractures since 1980, giving information of previous fault creep movement. During the 2021 Tajogaite eruption, shallow seismicity was spatially related to both faults, suggesting a seismic behavior instead of the precedent creep movement. However, the lack of seismicity after the eruption indicates that the faults went back to creep aseismic behavior, similarly to 1980. The mapping and monitoring of these faults (TZF and MZF) is relevant bearing in mind that they have been active since 1980 and the post-eruptive phase of the 2021 volcanic eruption, which has to be included in the land use planning in areas affected by the volcanic eruption and creep movement. Furthermore, both faults could act as seismogenic sources triggering volcanic earthquakes with potential high macroseismic intensities and mass movements. The data presented here show the importance of having this type of study before the onset of the eruption, thus allowing a better interpretation of seismic data during volcanic unrest. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Active faults are generally defined as faults that have moved in the past and will continue to be active in the future. They are expected to cause deformation and potential disasters if they are localized close to human activities. The definition and classification of active faults are important bases for evaluating the risk. This paper summarizes and compares the history, status, and progress of their definition and classification schemes used in representative countries and regions, as well as in some relevant standards, in active fault mapping, in the construction of spatial databases, and in some other aspects. It is concluded that the current geodynamic setting, existing technical means, geological operability, application purpose, and social acceptability of active faulting hazard in a specific area comprehensively determine the selection of the definition and classification. The key parameter in defining active faults is the time limit. It usually involves four time scales, i.e., Neotectonic (post-Neogene), Quaternary, Late Quaternary, and Holocene. The definition using a short time scale, such as Late Quaternary and Holocene, is usually suitable for the plate boundary zone, which has a high strain rate, but active faults in the intraplate deformation region and stable continental region should be defined with a long time scale, such as the Quaternary and Neotectonics. In addition, the magnitude standard can determine the activity intensity of active faults, which most generally includes three classes, namely, M ≥ 5.0 damaging earthquakes, M ≥ 6.0 strong earthquakes, and M ≥ 6.5 earthquakes that may produce surface displacement or deformation. The M ≥ 5.0 earthquake is generally applicable to regional earthquake prevention and risk mitigation in many countries or regions, but the M ≥ 6.5 earthquake magnitude benchmark is generally used as the standard in rules or regulations regarding active fault avoidance. The most common classification schemes in many countries or regions are based on fault activity, which is reflected mainly by the fault slip rate and fault recurrence interval (FRI), as well as by the last activation time. However, when determining the specific quantitative parameters of the different activity levels of faults, it is necessary to comprehensively consider the differences in activity and ages of the faults in the study region, as well as the amount and validity of existing data for the purpose of classifying different active levels of faults effectively. [ABSTRACT FROM AUTHOR]

Destructive earthquakes are frequently related to inland active faults. In recent years, a significant number of shallow earthquakes with low magnitude have occurred in southern Garut, West Java, Indonesia. Two earthquakes, with magnitudes of M4.2 and M3.9 in 2016 and 2017, respectively, have caused significant damage and were interpreted as indications of an active fault. We used publicly available gravity data to infer the subsurface structure that may be related to recent seismic activity. We used spectral analysis and filtering techniques for the regional-residual anomaly separation and anomaly enhancement to show the basin structure in the study area. 3D gravity inversion modelling was performed to obtain the subsurface density distribution. The result indicates the sedimentary layers with a density of 2.4 to 2.5 gr/cm3 with an underlying basement with a density of 2.65 gr/cm3. An intra-basin basement high with an NE-SW trend divides the basin into two sub-basins. This local basement high can be associated with a magmatic intrusion body and a series of young volcanic bodies located at the northeastern end of the basin. Our results emphasize a possible strong interaction between the tectonic and magmatic activities in this region.

Objective The Changle-Zhao'an fault zone is one of the primary active faults running along the coast of the Fujian Province. This fault zone has induced several destructive earthquakes and is thus a principal seismogenic structure in the Fujian Province. Therefore, tight constraints on the Late Quaternary activity of the Changle-Zhao'an fault zone has significant significance. Methods Based on field survey along the Dongshan segment of the eastern branch of the Changle-Zhao'an fault in the Dongshan County, Fujian Province, the timing for the motion of this fault portion was determined to be between (34.8±8.3) ka and (48.0±3.5) ka by using K-feldspar luminescence dating of the strata above the fault break point and footwall. Results This indicates that the fault remained active since the Late Pleistocene. Furthermore, we estimated the potential maximum seismicity along the fault using the empirical relationship between magnitude (M) and fault dislocation (D). Conclusion Determination of a Late Pleistocene active fault, along with the estimate of the maximum earthquake magnitude, provides precise chronological evidence for understanding the activity of the Changle-Zhao'an fault zone. Our results thus serves as an important basis for conducting urban safety assessments in Dongshan County.

The eastern margin of the Tibetan Plateau is composed of multiple secondary tectonic units which constitute typical “multi-level extrusion-rotation active tectonic system”. It is the tectonic transformation belt that regulates the eastward extrusion of plateau blocks, and contains high-density active faults. This area is characterized by frequent and high intensity strong earthquakes and complex geological and geomorphological features. Therefore, this region is one of the areas in China where the problem of earthquake disaster is particularly significant. In recent years, with the research deepening of the national earthquake disaster risk survey, active fault detection of urban，seismic experimental site construction, seismic safety evaluation of engineering sites, identification of active faults and evaluation of crustal stability in major projects sites and urban areas，and the wide application of high-precision remote sensing, tectonic geomorphology, paleoseismic and Quaternary chronology methods. The investigation of seismogenic structures around the eastern margin of the Tibetan Plateau and its adjacent areas has been significantly improved. In order to timely exchange the latest study results in this field support regional earthquake prevention and disaster reduction and geological safety evaluation of important projects sites and infrastructure construction, the journal editorial department of Progress in Earthquake Science organized the special topic “The strong earthquakes and seismogenic structures in eastern margin of Tibetan Plateau and adjacent areas”. More than 20 representative academic papers such as active faults and earthquakes, Jishishan earthquake in Gansu Province，and research reviews in related fields have been collected. In this issue, 10 papers are selected in the special topic I “The strong earthquakes and seismogenic structures in eastern margin of Tibetan Plateau and adjacent areas”. It is hoped that these newly study results may improve the understanding of characteristics of strong earthquake activity and seismogenic structural mechanism in the region, and provide scientific basis for regional strong earthquake risk analysis and effective prevention of strong earthquake disaster risk.

The sublatitudinal active fault on the Kronotsky Peninsula (Kamchatka) has been studied. The deformations of the Holocene soil-pyroclastic cover opened by the trench indicate reverse vertical movements along the fault plane. The northern fault side is relatively downthrown. Evidence for a horizontal component is less certain because of the small number of geomorphologic references, but together they indicate that it is left-latetal. The average rate of strike-slip movements can be estimated to be of the order of 10 mm per year. Two explanations for the existence of a arc-normal active fault seem possible: the fault as part of a transform left-lateral horizontal flexure connecting the collisional part of Kamchatka with its transverse extension-prone part, and the fault as a result of clockwise rotation of the Kronotsky Peninsula block. The second option implies that the Pacific plate is being pushed under Kamchatka at an angle to it and seems less likely.

In 2021, an unusual activities of earthquake swarm occurred for the first time in Lake Toba (Indonesia), one of the world's largest calderas. Despite the fact that the earthquakes occurred in a volcanic setting, the swarm activity could be connected to the tectonic activities from the Sumatra fault system. The swarm activity occurred at a very shallow depth and were felt by local peoples with the intensity of II-IV MMI. The aim of this study was to look into the characteristics of the earthquake swarm in the Toba Caldera using waveforms recorded by temporary stations between March and June 2021. In May and June 2021, a total of 26 seismic stations were deployed for two months. Automatic seismic wave detection is essential because it may be utilized in earthquake early warning systems and speeds up analysis of origin time, P-, and S arrival timings, and earthquake sites. We discovered characteristics of a non-swarm earthquake's spectrum waveform from low to high frequency, whereas the swarm earthquake generated high frequency seismograms. Furthermore, we successfully captured the hypocentre, which was spread in the SW - NE direction, and we may be able to identify the unknown geological system responsible for the swarm's activity.

We present the first magnetotelluric sounding (MTS) data acquired in the southern part of the Lena River delta which is a junction zone of the Siberian Craton and the Verkhoyansk fold-and-thrust belt, in the transition zone from the Eurasian Continent to the shelf of the Laptev Sea. The MTS data were used to construct a vertical section of the bulk electrical resistivity (ER) structure of the Earth's crust down to a depth of 8 km. The upper high-resistivity layer (320–1000 Ohm m) corresponds to the permafrost rocks ranging in thickness from 1 km to 400 m under the channels of the Lena River. The underlying deformed Mesoproterozoic–Lower Triassic rocks can vary in composition, but they are poorly differentiated in ER values (110–240 Ohm m). We detected three low-resistivity anomalies (10–60 Ohm m) related to the fluid-saturated core and damage zones of active faults. A deep-lying high-resistivity anomaly (320–350 Ohm m) identified at the northeastern part of the section can correspond to the Lower Proterozoic or Archean metamorphic rocks. [ABSTRACT FROM AUTHOR]

Along the southeastern margin of the Tibetan Plateau, an important boundary fault, known as the Red River Fault (RRF), formed during the extrusion of mantle and lower crustal materials beneath the Tibetan Plateau. The characteristics of RRF activity are important for understanding the tectonic evolution of the southeastern margin of the Tibetan Plateau. There is less knowledge about the strong earthquake recurrence interval in the southern segment of the RRF than about its northern segment. In this study, based on the characteristics of the active tectonic landform, three paleoseismic trenches were excavated in Adipo Village north of Honghe County in the southern segment of the RRF. In these trenches, three paleoseismic events that occurred in the middle and late Holocene were identified. According to the 14C dating results, these events were constrained to 785-504 BC, 26-492 AD, and 1,415-1857 AD. The average earthquake recurrence interval was determined to be approximately 960-1,320 a. [ABSTRACT FROM AUTHOR]

Destructive earthquakes are frequently related to inland active faults. In recent years, a significant number of shallow earthquakes with low magnitude have occurred in southern Garut, West Java, Indonesia. Two earthquakes, with magnitudes of M4.2 and M3.9 in 2016 and 2017, respectively, have caused significant damage and were interpreted as indications of an active fault. We used publicly available gravity data to infer the subsurface structure that may be related to recent seismic activity. We used spectral analysis and filtering techniques for the regional-residual anomaly separation and anomaly enhancement to show the basin structure in the study area. 3D gravity inversion modelling was performed to obtain the subsurface density distribution. The result indicates the sedimentary layers with a density of 2.4 to 2.5 gr/cm³ with an underlying basement with a density of 2.65 gr/cm3 . An intra-basin basement high with an NE-SW trend divides the basin into two sub-basins. This local basement high can be associated with a magmatic intrusion body and a series of young volcanic bodies located at the northeastern end of the basin. Our results emphasize a possible strong interaction between the tectonic and magmatic activities in this region. [ABSTRACT FROM AUTHOR]

The highway project from Weifang to Qingdao and its connection line, pass through the active Anqiu-Juxian fault zone. To ascertain the precise distribution, tectonic characteristics, and activity of the Anqiu-Juxian fault within the area of the project, the regional geological structures was firstly studied. It was initially deduced that the Anqiu-Juxian Fault passes through the project in the vicinity of Caocun, which served as the foundation for accurate fault positioning and activity identification. Secondly, through remote sensing, field geological investigation and mapping, the micro-geomorphology and outcrop features of distribution of the fault were discussed. Through seismic geophysical survey on the shallow strata, the distribution pattern of the fault inside the strata were conducted. Through drilling exploration, specific distribution features and activity of the fault were revealed and confirmed. Finally, further analysis of the fault's activity period was conducted by referencing to C14 dating and optically stimulated luminescence dating results from projects nearby. The research results show that, the eastern and western branches of the Anqiu-Juxian fault intersect with the highway project in the vicinity of K24 + 900 and K23 + 550 respectively. The fault's activity period dates back to the Late Pleistocene and Holocene epochs of the Quaternary period, and the F1 and F2 faults on either side are pre-Quaternary faults. After comprehensive analysis and deliberation, it has been established that the eastern and western branches of the Anqiu-Juxian fault show relatively stronger activity within the project area, posing significant influence on the proposed highway. While the activity of the F1 and F2 faults is relatively weaker, exerting less impact on the proposed highway. In accordance with the research results, the new highway adopts general subgrade to traverse distribution zone of the fault. [ABSTRACT FROM AUTHOR]

The Sichuan-Tibet transportation corridor is prone to numerous active faults and frequent strong earthquakes. While extensive studies have individually explored the effect of active faults and strong earthquakes on different engineering structures, their combined effect remains unclear. This research employed multiple physical model tests to investigate the dynamic response of various engineering structures, including tunnels, bridges, and embankments, under the simultaneous influence of cumulative earthquakes and stick-slip misalignment of an active fault. The prototype selected for this study was the Kanding No. 2 tunnel, which crosses the Yunongxi fault zone within the Sichuan-Tibet transportation corridor. The results demonstrated that the tunnel, bridge, and embankment exhibited amplification in response to the input seismic wave, with the amplification effect gradually decreasing as the input peak ground acceleration (PGA) increased. The PGAs of different engineering structures were weakened by the fault rupture zone. Nevertheless, the misalignment of the active fault may decrease the overall stiffness of the engineering structure, leading to more severe damage, with a small contribution from seismic vibration. Additionally, the seismic vibration effect might be enlarged with the height of the engineering structure, and the tunnel is supposed to have a smaller PGA and lower dynamic earth pressure compared to bridges and embankments in strong earthquake zones crossing active faults. The findings contribute valuable insights for evaluating the dynamic response of various engineering structures crossing an active fault and provide an experimental reference for secure engineering design in the challenging conditions of the Sichuan-Tibet transportation corridor. [ABSTRACT FROM AUTHOR]

The Astaneh Fault is one of the active and seismic faults in the Shahroud sinistral fault system. Fault gouges can be seen in a completely pristine and unchanged form in the portions of this fault that have affected the carbonate rocks. Fault gouges are the direct product of lithology and are formed as a result of the fault slip from the host rocks. Studying these rocks for type, composition, mineralogical phases and structure can provide results on how the fault slip and gouge process occurs. The result of a seismic slip in faults, and especially in gouges, are different types of deformations, such as mineralogical and compositional deformations, depending on the conditions of their formation. From this deformation model, we can mention the thermal decomposition of calcite and dolomite, as well as the presence of siderite in gouges. In this article, by studying the combined [aggregated] microstructures in the Astaneh fault gouge, their relationship with seismic slip has been investigated. According to previous research, the Astaneh Fault is certainly a seismic fault. The presence of the resulting thermal decomposition of calcite and dolomite (calcium and magnesium oxide or periclase) and the welding of particles due to heat may be the key to seismic slip in this fault. [ABSTRACT FROM AUTHOR]

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An analysis of the results of repeated geodynamic observations at the Buzachi peninsula field are presented. Comprehensive geodynamic monitoring includes leveling and gravimetric observations, GPS measurements, and repeated satellite radar interferometry data. A comprehensive analysis of the results shows the presence of systematic subsidence of the earth's surface in the central part of the field territory, induced by development. Based on leveling and gravimetric observations, two areas of local anomalies are identified, which are localized in zones of anomalous deformation activity of faults. Dangerous manifestations of gas gryphons have been repeatedly recorded at the field, which occurred in the area of the dynamic influence of fault zones. Deformations of the earth's surface alternating in sign (uplift and subsidence) are revealed, which precede the process of active formation of gryphons. Mathematical modeling of these processes is carried out and a generalized geomechanical model of the formation of anomalous and negative fluid dynamic manifestations is proposed. A calculation of local horizontal stresses shows that they are concentrated near active faults, forming paths for subvertical fluid migration and creating conditions for the formation of gryphons. A complex parameter is proposed to assess the level of geodynamic hazard of the field territory, and areal distribution diagrams of this parameter by year are constructed. Potentially dangerous zones of anomalous manifestation of recent deformation and fluid dynamic processes have been identified. [ABSTRACT FROM AUTHOR]

The Khangai plume is situated under Central and Eastern Mongolia and is a mantle volume with significantly reduced longitudinal (P) wave velocities. The plume has been identified as a result of the analysis of the MITP08 volumetric model of P-wave velocity variations, representing the deviations of P-wave velocities from the average values (δVp), given as a percentage. The lithospheric mantle is thinned to ca. 50 km above the plume. Especially low velocities (δVp ≤ –0.6%) are found in the sublithospheric mantle up to a depth of 400 km. The main body of the plume is located under the Khangai Highland and extends northward to the edge of Southern Siberia. The Khentei branch of the plume that is located SE of the Khentei Highland is connected with the main plume body at depths of 800–1000 km. Branches of the plume and its Khentei branch extend into Transbaikalia. The area of the plume decreases with depth, and its deepest part (1250–1300 km) is located under the southern Khangai Highland. The main body of the Khangai plume is expressed on the land surface by the Cenozoic uplift reaching 3500–4000 m in the southern Khangai Highland. From the SE, the Khangai plume and its Khentei branch territory are limited by Late Cenozoic troughs stretching along the southeastern border of Mongolia. From other sides, the Khangai uplift is bounded by a C-shaped belt of basins. The belt includes the southwestern part of the Baikal Rift Zone, the Tunka and Tuva Basins in the north, the Ubsu-Nur Basin and the Basin of Big Lakes in the west, and the Valley of Lakes in the south. The basins are filled with lacustrine and fluvial deposits of the Late Oligocene to Pliocene. In the Quaternary, the South and Central Baikal Basins, which existed as early as the Early Paleogene, became a part of the Baikal Rift, and the other basins were involved in the general uplift of the region. The structural paragenesis of the Khangai uplift and the surrounding basins is caused by the influence of the Khangai plume. On the territory above the plume, including its Khentei and Transbaikalia branches, the Cenozoic basaltic plume volcanism occurred, inheriting the Cretaceous volcanic manifestations in some places. The structural paragenesis associated with the Khangai plume is combined with the structural paragenesis produced by lithospheric plate interaction. The latter is expressed the best of all by active faults, but developed synchronously to the plume paragenesis. The active fault kinematics shows that the eastern and central parts of the region developed in the transpression conditions and the north-eastern part developed in conditions of extension and transtension. The Khangai plume is connected at depth with the Tibetan plume, which is situated under the central and eastern Tibetan Plateau north of the Lhasa block. The Tibetan plume has the shape of a funnel rising from depths of 1400–1600 km and is accompanied by thinning of the lithosphere and uplift of the land surface. The Khangai and Tibetan plumes represent a specific category of plumes. They rise from the upper Lower Mantle and differ by this from the Upper Mantle plumes and the African and Pacific superplumes rising from the core-mantle boundary. Data are presented on the possible connection of the Khangai and Tibetan plumes with the superplume branches, but independent origin of the plumes is also admitted. [ABSTRACT FROM AUTHOR]

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Kopili fault (KF) zone, one of the active faults in northeastern region (NER), has experienced large earthquakes in 1869 (Mw 7.4) and 1943 (Mw 7.2). In order to mitigate future occurrences of earthquakes in the KF, it is essential to understand its long-term seismic history and seismic hazard implications. Seismogenic liquefaction features were identified at three trench sites in the floodplain deposits of Kolong River, near KF. The liquefaction features include multiple sand dykes and sand sills and are direct response to liquefaction of saturated sediment induced during past seismic activity. A total of seven samples from marker horizons have been processed to constrain the chronology of liquefaction features using optically stimulated luminescence (OSL) dating technique. OSL age constraints from Trench 1 indicate two episodes of earthquake-induced liquefaction since perhaps AD 1692, one, possibly two episodes of liquefaction in Trench 2 since AD 1540 and Trench 3, suggest one liquefaction event during the past 1000–2000 years. From the present study, given the limited results of the dating available we can conclude that two earthquakes induced liquefaction in the vicinity of the Kopili fault zone during the past ~ 480 years. Additional excavations and dating of earthquake-induced liquefaction features are required to precisely evaluate the frequency of major earthquakes in the KF zone. [ABSTRACT FROM AUTHOR]

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Identifying the movement of the branches of the hidden Thakhek fault in Thailand is challenging due to the absence of evident landforms indicating an active fault. In this study, we analyzed a digital elevation model (DEM) to identify potential landforms. A 2D Electrical Resistivity Tomography (ERT) survey was conducted to locate the hidden Thakhek fault. The results reveal vivid images of resistivity contrast, interpreted as two reverse faults, with mudstone exhibiting low resistivity in the middle, flanked by thick sediment layers with higher resistivity. Three trenches were excavated perpendicular to the two interpreted reverse faults. The displacement of reverse faulting appears to have shifted mudstone over Quaternary sediments, with vertical offsets revealed in trenches NWY-1, NWY-2, and NWY-3. This movement could be identified as a positive flower structure. Additionally, lakes are identified as a negative flower structure along the traces. These features result from strike-slip strains under a locally appropriate compressional and extensional environment in a shearing strike-slip fault.

We conducted large-depth Ground-Penetrating Radar investigations of the seismogenic Casamicciola fault system at the volcanic island of Ischia, with the aim of constraining the source characteristics of this active and capable fault system. On 21 August 2017, a shallow (hypocentral depth of 1.2 km), moderate (Md = 4.0) earthquake hit the island, causing severe damage and two fatalities. This was the first damaging earthquake recorded on the volcanic island of Ischia from the beginning of the instrumental era. Our survey was performed using the Loza low-frequency (15–25 MHz) GPR system calibrated by TDEM results. The data highlighted variations in the electromagnetic signal due to the presence of contacts, i.e., faults down to a depth larger than 100 m below the surface. These signal variations match with the position of the synthetic and antithetic active fault system bordering the Casamicciola Holocene graben. Our study highlights the importance of employing large-depth Ground-Penetrating Radar geophysical techniques for investigating active fault systems not only in their shallower parts, but also down to a few hundred meters’ depth, providing a contribution to the knowledge of seismic hazard studies on the island of Ischia and elsewhere.

This article reflects on the management of active fault surface rupture hazard after the Canterbury and Kaiköura earthquakes. To understand mitigation barriers, interviews were conducted with planners and natural hazard risk specialists in selected districts with active faults, but without land use provisions. The interviews revealed issues with the interpretation and implementation of the Ministry for the Environment's Active Fault Guidelines, Planning for Development of Land on or Close to Active Faults: a guideline to assist resource management planners in New Zealand. The purpose and intended use of the New Zealand Active Faults Database (NZAFD) is also explored. [ABSTRACT FROM AUTHOR]

On January 18, 2021, a moderate earthquake (Mw 6.5) occurred ~ 45 km southwest of San Juan, a city in Central-Western Argentina, at a relatively shallow depth of ~ 20 km. The earthquake caused damage to the environment and infrastructure in the affected area, which is home to ~ 600,000 residents. To assess ground deformation, identify the seismogenic source, and evaluate the extent of secondary effects, we utilized Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques in combination with Sentinel-2 visible and infrared imagery, as well as field data. DInSAR results suggested centimeter-scale ground deformation around the epicenter, off-fault deformation linked to regional structures, and site effects, such as liquefaction and landslides. By combining the values extracted from a 3-year-long PSI and SBAS time series, we estimated a vertical displacement of approximately 4.5 cm near the epicenter. Off-fault deformation involves some degree of ground settling on top of a blind or buried section of the Papagallos fault system, the reactivation of a section of the Rinconada fault system, and liquefaction and ground settling processes in the Tulum Valley. Rockfalls were distributed throughout a geologically diverse terrain and along a NW swath, with their occurrence controlled by the shaking intensity. The total area affected by secondary effects was ~ 3800 km2. Based on the available focal mechanism solutions and the distribution of environmental damage, we propose a left-lateral strike-slip displacement in a blind NW-striking fault, although different interpretations are discussed. Finally, we estimated the epicentral depth from SBAS time series Bayesian Inversion and from differential travel times pP-P, obtaining a depth of 20–25 km. [ABSTRACT FROM AUTHOR]

The lithospheric structure of the Tibetan Plateau and its adjacent area is a hot topic in geodynamic research. It is important to reveal the mechanism of crustal deformation and tectonic evolution of the study area. In this study, the techniques of wavelet multiscale decomposition and field edge detection were used to study the discontinuities of the lithosphere revealed by multilevel Bouguer gravity anomalies. Specifically, we evaluated the depth characteristics of the major active faults in the study area and identified 15 deep major faults that cut through the lithosphere. They are Chaman fault, Shyok suture zone, Altyn-Tagh fault, Karakash fault, Karakoram fault, Talas-Fergana fault, Kashgarr-Yeshgar transfer system, Rushan-Pshart suture zone, Sangri-Nacuo fault, Main Frontal thrust, Burmese fold belt, Yadong-Gulu fault, Gaoligong fault, Sagaing fault and Nujiang fault. We have also elucidated the tectonic mechanisms of two famous geodynamic phenomena in the Pamir Plateau. The first is the intense intermediate depth seismicity beneath Pamir-Hindukush. It cannot simply be described as the rupture of a subducted residual plate, which could be divided into two distinct tectonic units. One belongs to the Indian plate, the other to the Eurasian plate. Secondly, the mechanism of intense seismicity confined to the western upper crust of the Pamir Plateau could be explained as significant fragmentation of crustal material. Finally, and most importantly, we summarized the coupling mechanism between deep geodynamics and horizontal deformation as observed by modern geodetic techniques. In the upper mantle, the leading edge of the subducting Indian plate reached the SW boundary of Tarim basin and forms a closed structure in western Himalaya. Then, the Tibetan Plateau underwent a tectonic escape towards the east under the continuous compression between the Indian and Eurasian plates. During the process of tectonic escape, the role of the N–S direction normal faults in the Himalayan tectonic zone is limited. [ABSTRACT FROM AUTHOR]

The Kurai Fault Zone (KFZ) is one of the most hazardous seismogenic structures in the Gorny Altai (Russia), which bounds the largest Kurai and Chuya intermontane basins from the north. Trenching studies, radiocarbon dating of colluvial wedge deposits, and 230Th-U dating of seismogenic travertine of the Meshtuyaryk field showed that the fault scarp in the northwestern part of the Chuya Depression was formed by earthquakes that occurred ca. 9.5, 7.7, 5.8, and 4.8–3.4 ka BP. The last two palaeoearthquakes are younger than 3.2 ka BP. The parameters of seismogenic ruptures, as well as the distances between coeval seismogenic travertines along the KFZ, yielded estimates of the Mw of the four oldest palaeoearthquakes as 6.8–7.6 and ESI 2007 shaking intensities of VIII–XI. The results of 230Th-U dating suggest that deposition of the Meshtuyaryk travertines was triggered by three strong palaeoearthquakes at ca. 9.5, 7.7, and 4.8–3.4 ka BP, which activated faults and caused a rapid rise along them of ambient-temperature bicarbonate groundwaters previously sealed in deep-seated limestone aquifers. [ABSTRACT FROM AUTHOR]