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Precise knowledge of the thermal and mechanical properties of polycrystalline rocks is vital for the assessment of geothermal targets. However, although the slip behavior of rough fractures in granite under high temperatures and true triaxial stress is closely related to that corresponding to hydroshearing and induced earthquakes during geothermal recovery, it has rarely been investigated. In this study, true triaxial loading tests are conducted on intact and macrofractured granite under various high temperatures. The influences of high temperature on the thermal expansion, strength, frictional stick–slip, and failure mode are compared. The initiation and propagation of fracture slip are specifically investigated using the monitored deformation. The results indicate that the intact granite expands uniformly along σ1, σ2, and σ3. In contrast, the thermal expansion of the confined prefractured granite is anisotropic (varies in different directions), especially at higher temperatures. In addition, the peak strength of the confined intact granite tends to increase with increasing temperature above 100 °C. The fracture activation strength, residual strength, and frictional stick–slip amplitude of the prefractured granite tend to increase with increasing temperature, and the increase in peak strength becomes much more significant above 300 °C. Fracture strengthening is closely associated with a decrease in the fracture aperture and an increase in the asperity contact area between two macroscopically mated fracture surfaces at elevated temperatures. Moreover, a long quasi-static slip stage with a gradually increasing slip rate (0 – 1.6 μm/s) precedes the final seismic slip event (at a rate of 1.1 –2.6 mm/s). This study simultaneously considers the (1) irregular fracture surface, (2) true triaxial stresses, (3) high temperatures, and (4) thermal deformation and related mechanical behavior of the specimens to interpret the true triaxial loading test results and thus contributes to a better understanding of the dynamic slip process of rough fractures under thermal–mechanical coupling conditions in deep rock masses. Highlights: Prefractured granite specimens were sheared under different high temperatures using a true triaxial loading system to closely simulate the real thermal–mechanical coupling conditions of a deep rock mass. The thermal expansion of prefractured granite along the directions of σ1, σ2 and σ3 is anisotropic due to the presence of fractures, while intact granite undergoes isotropic thermal expansion. The fracture activation strength, residual strength and stick–slip amplitude tend to increase with increasing temperature, which is related to the decreasing fracture aperture and increasing asperity contact area at higher temperatures. Long preseismic slip precedes abrupt seismic slip, and the seismic slip rate is three orders of magnitude greater than the loading rate. [ABSTRACT FROM AUTHOR]

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The Wenshushan uplift is located at the western end of the Hexi Corridor，dividing the Jiuxi basin and Jiudong basin. It is one of the three major uplift zones within the Hexi Corridor. Based on high-resolution satellite image interpretation and field investigations，we found that there were multiple fault scarps on the western margin of the Wenshushan uplift，with a length of about 3 km. The scarps are relatively continuous and exhibit complex combination characteristics of alternating forward and reverse scarps. Through unmanned aerial vehicle photogrammetric technique and optically stimulated luminescence dating，a comprehensive study was conducted on the fault scarps. The fault scarps developed in different periods of alluvial fans in front of the mountain. Based on the accumulated fault scarp heights of 4.9～5.6 m and corresponding age of （37.3 ± 1.7） ka on the early alluvial fan，the vertical slip rate has been determined to be approximately 0.15 mm/a since the Late Pleistocene. The latest seismic activity occurred during the Holocene，which was a Holocene active fault with fault scarp heights of 0.5～0.7 m. According to data analysis，the formations of the fault scarps are the results of the uplift and expansion of the Wenshushan anticline.

Fault slip rates are critical for understanding the evolution of active faults, earthquake recurrence, and crustal deformation. Yet variations in slip rate along the Haiyuan Fault Zone (HYFZ), a large-scale sinistral strike-slip fault in the northeastern margin of the Tibetan Plateau, remain disputed. Here, we investigate in detail late Quaternary and present-day fault slip rates for several segments across the HYFZ based on previously published geologic and geodetic (i.e. GNSS and InSAR) estimates. Our results reveal that the strike-slip rates increase from ~1.6±0.4–1.8±0.3 mm/a on the Halahu (HLH) fault to ~5.2±1.3–6.2±0.9 mm/a on the Lenglongling (LLL) and Jinqianghe (JQH) faults, then decrease to ~3.9±0.8–4.6±0.3 mm/a on the Maomaoshan (MMS) and Laohushan (LHS) faults, subsequently remain relatively constant (i.e. ~4.6±0.8–4.8±0.7 mm/a) on the Haiyuan (HY) fault (in narrow sense), and finally decrease to ~1.3±0.1–1.5±0.3 mm/a on the Liupanshan (LPS) fault, from west to east. These results indicate that the strike-slip rates on the LLL and JQH faults are highest and decrease toward fault tips along the HYFZ, approximating an asymmetrical bell-shaped distribution. Furthermore, geodetic (short-term) and geologic (long-term) slip rates are in general agreement, indicating that the slip rates were relatively constant in the recent geologic history. Despite the shallow creep on the LHS fault, the Tianzhu Seismic Gap, Tuolaishan (TLS), LLL, and LPS faults have a large locking depth, strain accumulation, and/or long seismic quiescence period, underscoring the substantial seismic hazard in these areas. Our study contributes to characterizing the total slip rate budget across the HYFZ and provides insight into further understanding of seismic hazard and regional crustal deformation.

The Siulak and Dikit segments of the Sumatran fault system, where historical major earthquakes of Ms 7.6 in 1909, Mw 7.2 in 1995 and Mw 6.6 in 2009 occurred, are distinctive and tectonically active, yet tectonic investigation such trench-parallel motions of both segments still is challenging to be better understand and important to constrain seismic hazard. We aim to better estimate slip rates as well as locking depths using GPS velocities and determine the cumulative energy stored at the segments. We processed raw GPS data from 31 GPS stations originating from the Indonesian continuous operating reference system (Ina-CORS), the Sumatran GPS array (SuGAr), and IGS networks for 2016–2021 including UNIB stations including two UNIB stations using GAMIT/GLOBK software. The daily GPS solutions were constrained into the ITRF-2014 frame, and the GPS velocities were translated into the Sunda Block. We modeled trench-parallel GPS velocities using 1-D screw dislocation elastic model following a Bayesian approach with Metropolis MCMC sampler to estimate optimum fault parameters. Our result inferred that estimated slip rates are 20.71 [− 2.20, + 2.95] mm/yr with a locking depth of 21.62 [− 11.98, + 14.16] km in the Siulak segment and 20.21 [− 2.42, + 2.95] mm/yr with a locking depth of 21.72 [− 13.10, + 14.77] km in the Dikit segment. Our analysis demonstrates both segments having a uniform slip rate, suggesting that the segments may share similar tectonic settings. In addition, the two segments are capable of generating a magnitude six to seven or greater earthquake if a single earthquake occurs in 50 to 200 years periods. [ABSTRACT FROM AUTHOR]

Quantitative analysis of the slip rate of active faults and their seismic parameters is important for seismic hazard analysis. In this study, we first construct an elastic block model to obtain the slip rate of boundary faults based on the distribution characteristics of active faults, seismicity, and global navigation satellite system (GNSS) observations in Sichuan–Yunnan, China. Then, the long-term seismic risks of the boundary faults are quantitatively evaluated based on the principle of seismic moment balance. The Sichuan–Yunnan region can be divided into 17 relatively independent and stable subblocks. There is clear zoning in the distribution and mechanisms of boundary fault movement and deformation. The boundary faults exhibit an alternating dextral–sinistral–dextral–sinistral strike-slip pattern from northeast to southwest. Among these boundary faults, the Xianshuihe–Xiaojiang fault zone has a high sinistral strike-slip rate, and the Jinshajiang fault plays an important role in accommodating the movement and deformation of the subblocks in the Chuandian block. The dextral strike-slip rate is approximately 10 mm/yr, which is diffusely transferred to the secondary boundary faults in the Chuandian block. Comparison of the rates of moment accumulation and release reveals that the southern segment of the Xiaojiang fault, the Longriba fault, the Daliangshan fault, and the Yuanmou fault exhibit significant moment deficits, with corresponding moment magnitudes exceeding Mw 7.5. More attention should be given to the strong earthquake risks of these faults. The Xianshuihe–Xiaojiang, Jiali–Lancangjiang, and Red River faults, which are arc shaped, dominate the regional deformation and determine the motion and deformation model of the subblocks and secondary boundary faults within the Chuandian block and the area southwest of the Red River fault. [ABSTRACT FROM AUTHOR]

In Iceland, the most seismically active region in Northern Europe, large earthquakes up to ~ M w 7 repeatedly take place in the two transform zones of the country. Of the two, only the South Iceland Seismic Zone (SISZ) in southwest Iceland is on land and with a large part of the country's population either collocated or in close proximity to it. Strong earthquake occurrence in the SISZ takes place on a bookshelf fault system, an array of short, vertical, and dextral strike-slip faults oriented perpendicular to the overall transform motion. Importantly, this system has recently been shown to be continuous further towards the west along the entire Reykjanes Peninsula Oblique Rift (RPOR), making the bookshelf fault system approximately twice as long as previously thought. Moreover, a systematic spatial variation of maximum earthquake magnitudes characterizes the SISZ-RPOR system, from ~ M w 7 down to ~ M w 5.5 from eastern SISZ to western RPOR, respectively, indicates a subzonation of the seismic region. The above has not been taken into account in past probabilistic seismic hazard assessments (PSHA) and poses a challenge as the historical earthquake catalogue precludes reliable estimates of seismicity parameters for individual subzones of the SISZ-RPOR system. In this study, we address this issue using a recently developed physics-based finite-fault model of the SISZ-RPOR bookshelf fault system, and quantitatively estimate the time-independent magnitude-frequency distributions (MFDs, of the Gutenberg-Richter type) for each subzone. We establish zone-specific distributions representative of long-term fault slip rates and derive the seismicity parameter estimates corresponding to the 2.5, 50, and 97.5 percentiles of fault slip rates along the SISZ-RPOR as predicted by the physics-based model. We present new and quantitative estimates of subzone MFDs and show that the model effectively explains the historical earthquake catalogues. The results of this study not only enable the efficient yet physically realistic and consistent revision of conventional time-independent PSHA for southwest Iceland using e.g., empirical ground motion models, but also a more comprehensive physics-based PSHA from finite-fault rupture modeling and advanced seismic ground motion simulation techniques. [ABSTRACT FROM AUTHOR]

The accommodation of the substantial eastward crustal motion of the Bayan Har block characterizes the dynamics of faults located at the eastern Tibetan Plateau. However, uncertainties persist concerning the manner and amount of deformation distributed on these faults, with slip senses and rates constituting critical factors. In the northeastern segment of the Longmenshan thrust zone, the contentious activity and the unknown geologic slip rate present challenges. This study, focusing on the Qingchuan fault, the predominant fault within the northeastern Longmenshan, employed satellite imagery interpretation, displaced fluvial terraces surveying, displacement measurements, and chronological analysis to comprehensively characterize its fault activity. Our investigation robustly demonstrates the Qingchuan fault has been active since the late Quaternary, and is primarily marked with a pronounced dextral slip at a rate of 0.6–1.0 mm/year. By quantitatively assessing the deformation rates of the faults at the eastern Tibetan Plateau, we propose that they sufficiently accommodate the entire eastward crustal movement of the Bayan Har block; thereby no additional deformation propagates beyond the Qingchuan fault. Furthermore, we introduce a subblock model to elucidate the regional crustal deformation pattern, wherein the eastward movement of the Bayan Har block transfers to the northeastward movement of the Bikou subblock. This movement results in reverse slip patterns for the Minjiang and Huya faults, while the Beichuan and Qingchuan faults predominantly experience dextral displacements. The complex strain partitioning within the northern Longmenshan range underscores the observed variations in slip patterns across different segments of the Longmenshan thrust zone, advancing our understanding of fault behavior and the orchestration of crustal deformation in this intricate tectonic framework. Key Points: We first obtain a geologic slip rate of 0.6–1.0 mm/year for the Qingchuan fault in the northeastern segment of the Longmenshan thrust zoneThe Qingchuan fault absorbs a small amount of crustal deformation but acts as the termination structure at the eastern Tibet PlateauThe strain partitioning in the northern Longmenshan range leads to the dominantly dextral rather than reverse slip of the Qingchuan fault [ABSTRACT FROM AUTHOR]

The NW-SE-trending dextral strike-slip faults on the north side of the Tian Shan, e.g., the Karatau fault, Talas–Fergana fault, Dzhalair–Naiman fault, Aktas fault, Dzhungarian fault, and Chingiz fault, play an important role in accommodating crustal shortening. The classic viewpoint is that these strike-slip faults are an adjustment product caused by the difference in the crustal shortening from west to east. Another viewpoint attributes the dextral strike-slip fault to large-scale sinistral shearing. The Alakol Lake fault is a typical dextral strike-slip fault in the north Tian Shan that has not been reported. It is situated along the northern margin of the Dzhungarian gate, stretching for roughly 150 km from Lake Ebinur to Lake Alakol. Our team utilized aerial photographs, satellite stereoimagery, and field observations to map the spatial distribution of the Alakol Lake fault. Our findings provided evidence supporting the assertion that the fault is a dextral strike-slip fault. In reference to its spatial distribution, the Lake Alakol is situated in a pull-apart basin that lies between two major dextral strike-slip fault faults: the Chingiz and Dzhungarian faults. The Alakol Lake fault serves as a connecting structure for these two faults, resulting in the formation of a mega NW-SE dextral strike-slip fault zone. According to our analysis of the dating samples taken from the alluvial fan, as well as our measurement of the displacement of the riser and gully, it appears that the Alakol Lake fault has a dextral strike-slip rate of 0.8–1.2 mm/a (closer to 1.2 mm/a). The strike-slip rate of the Alakol Lake fault is comparatively higher than that of the Chingiz fault in the northern region (~0.7 mm/a) but slower than that of the Dzhungarian fault in the southern region (3.2–5 mm/a). The Chingiz–Alakol–Dzhungarian fault zone shows a gradual decrease in deformation towards the interior of the Kazakhstan platform. [ABSTRACT FROM AUTHOR]

The slip rate of strike-slip active faults is crucial for fault rupture behavior analysis and seismic hazard assessment. Although many segments of the Yilan-Yitong Fault Zone (YYFZ) in NE China have been strongly deformed since the late Quaternary, little progress has been made on its slip rate. With the help of highresolution satellite images, detailed field investigations, seismic reflections, and Quaternary chronological dating, we mainly studied the late Quaternary rightslip rate of the YYFZ. Field investigations revealed an ~15 km long by ~1-2 m high-surface scarp belt extending along the Tangyuan graben interior, with a series of sag ponds and small parallel bulges. Research has revealed that the most recent paleoearthquake (~M 7.0) occurred between 2,800± 600 a BP and 1,700 ± 200 a BP, with evidence of coseismic surface rupture. The T2 terrace abandonment age of the Heijin River is approximately 55.13 ± 1.78 ka (OSL), and the maximum cumulative right-lateral offset may reach 110 ±5 m. Thus, the maximum right-slip rate of the Tangyuan segment of the YYFZ since the late Quaternary is constrained to 1-2 mm/a according to the upper terrace model. This study suggests that the presence of a new fault in the basin interior merits more attention when assessing the influential surface range and earthquake potential along the YYFZ, and the features of "low tectonic loading rate, activity migration in space, and clustering in time separated by ten thousand years of seismic quiescence" observed along the YYFZ are highly important for earthquake model construction and tectonic deformation studies in stable continental regions (SCRs). [ABSTRACT FROM AUTHOR]

The slip rate of strike-slip active faults is crucial for fault rupture behavior analysis and seismic hazard assessment. Although many segments of the Yilan-Yitong Fault Zone (YYFZ) in NE China have been strongly deformed since the late Quaternary, little progress has been made on its slip rate. With the help of highresolution satellite images, detailed field investigations, seismic reflections, and Quaternary chronological dating, we mainly studied the late Quaternary rightslip rate of the YYFZ. Field investigations revealed an ~15 km long by ~1-2 m high-surface scarp belt extending along the Tangyuan graben interior, with a series of sag ponds and small parallel bulges. Research has revealed that the most recent paleoearthquake (~M 7.0) occurred between 2,800± 600 a BP and 1,700 ± 200 a BP, with evidence of coseismic surface rupture. The T2 terrace abandonment age of the Heijin River is approximately 55.13 ± 1.78 ka (OSL), and the maximum cumulative right-lateral offset may reach 110 ± 5 m. Thus, the maximum right-slip rate of the Tangyuan segment of the YYFZ since the late Quaternary is constrained to 1-2 mm/a according to the upper terrace model. This study suggests that the presence of a new fault in the basin interior merits more attention when assessing the influential surface range and earthquake potential along the YYFZ, and the features of "low tectonic loading rate, activity migration in space, and clustering in time separated by ten thousand years of seismic quiescence" observed along the YYFZ are highly important for earthquake model construction and tectonic deformation studies in stable continental regions (SCRs). [ABSTRACT FROM AUTHOR]

Located on the southeastern periphery of the Tibetan Plateau, the Xianshuihe fault (XSHF) is an active left-lateral strike-slip fault renowned for its frequent and intensive seismic activities. This highlights the necessity of employing advanced geodetic methodologies to precisely evaluate the fault kinematics and seismic hazard potential along this fault. Among these techniques, interferometric synthetic aperture radar (InSAR) stands out for its high spatial resolution and regular revisit intervals, enabling accurate mapping of interseismic deformation associated with fault motion. However, the precision of InSAR in measuring deformation encounters several challenges, particularly artifacts stemming from phase unwrapping errors and atmospheric phase delays. In this study, we utilize ascending and descending Sentinel-1 InSAR images spanning from January 2017 to January 2023 to drive the line-of-sight (LOS) mean crustal velocities associated with the XSHF with emphasis on phase unwrapping errors and atmospheric delay corrections. Then, the reliability of the derived LOS velocities is assessed using independent observations from the Global Navigation Satellite System (GNSS). The inferred fault slip rate along the XSHF shows significant along-strike variations, gradually decreasing from ~11.1 mm/yr at the Luhuo section to ~6.6 mm/yr at the Kangding section and then sharply increasing to ~13.0 mm/yr towards its eastern terminus at the Moxi section. The fault locking depth shows similar along-strike variations, decreasing from ~19.5 km in the northwestern part to ~4.8 km at the Kangding section, before increasing to 19.6 km at the Moxi segment. Notably, apparent surface fault creeping, characterized by a slip rate of ~2.7 mm/yr, is observed at the Kangding segment, likely resulting from postseismic slip following the 2014 Mw 6.3 Kangding earthquake. [ABSTRACT FROM AUTHOR]

The New Zealand Community Fault Model (NZ CFM) is a publicly available representation of New Zealand fault zones that have the potential to produce damaging earthquakes. Compiled through collaborative engagement between New Zealand earthquake-science experts, this first edition (version 1.0) of the NZ CFM builds upon previous compilations of earthquake-source active fault models with the addition of new and modified information. Developed primarily to support an update of the New Zealand National Seismic Hazard Model, the NZ CFM comprises two principal components. The first dataset is a two-dimensional map representation of the surface traces of 880 generalised fault zones. Each fault zone is assigned specific geometric and kinematic attributes, including uncertainties, supplemented with a subjective quality ranking focused primarily on the confidence in assigned slip rates. The second component is a three-dimensional representation of the fault zones as triangulated mesh surfaces that are projected down-dip from the two-dimensional mapped traces to a geophysically-defined maximum fault rupture depth. This article summarises the compilation and parameterisation of the NZ CFM, along with background on its relation to predecessor datasets, and forward applications to probabilistic seismic hazard assessment and physics-based earthquake models currently being developed for Aotearoa New Zealand. [ABSTRACT FROM AUTHOR]

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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.

The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang Plateau. In previous studies, its movement characteristics are mainly investigated with geological and seismic observations, and the tectonic transformation role of the fault on its east is not yet clear. This study uses data fusion to obtain denser GPS observations near the Qinghai Nanshan fault. Based on tectonic characteristics, we establish a block model to investigate the fault slip rate, locking degree, and slip deficit. The results show that the Qinghai Nanshan fault slip rate is characterized by sinistral and convergent movement. Both the sinistral and convergent rates display a decreasing trend from west to east. The locking degree and slip deficit are higher in the western segment (with an average of about 0.74 and 1.1 mm/a) and lower in the eastern segment. Then, we construct a strain rate field using GPS observations to analyze the regional strain characteristics. The results indicate that along the fault, the western segment shows a larger shear strain rate and negative dilation rate. Regional earthquake records show that the frequency of earthquakes is lower near the fault. The joint results suggest that the western segment may have a higher earthquake risk. In addition, the insignificant fault slip rate in the eastern segment may indicate that it does not participate in the tectonic transformation among the Riyueshan, Lajishan, and West Qinling faults.

Slip rate is a key parameter that represents the interfacial contact state between the tool and the workpiece, and it determines the heat generated during friction stir welding (FSW). However, it is difficult to experimentally measure this interfacial field, and the actual contact state is quite unclear. Therefore, an advanced slip rate model is needed to determine the contact state and to accurately elucidate the heat generation mechanism in FSW. In this paper, a novel model is proposed to directly calculate the slip rate based on welding parameters; this model is established by conducting parametric inversion on the slip rate through finite element analysis. The results show that the slip rate increases with increasing welding speed and decreases with increasing rotational speed. Furthermore, the slip rate model reveals the impacts of the welding parameters on the interfacial contact state. When n/v is greater than 4.6, the dominant mode of heat generation is sticking friction in FSW. Conversely, the major mode of heat generation is sliding friction. A finite element model is used to investigate the thermal process and the distribution characteristics of the temperature field during FSW of 2219 aluminum alloy. The temperature field in the weld zone presents a ''bowl-shaped'' distribution, with the temperature at the top being higher than that at the bottom. Moreover, the temperature peak occurs at half the radius of the shoulder. The above results provide an important reference for understanding the heat generation mechanism and temperature history during FSW of aluminum alloys.

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]

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Utilizing an updated dataset of 145 GNSS surface velocities, this study examines the fault slip rate and fault geometry along the Main Himalayan Thrust (MHT) in the central Himalaya. Employing a Bayesian inversion model, the present analysis reveals that the upper portion of the MHT ramp exhibits full locking, while the lower flat displays creeping motion. The estimated locking depth and fault depth of MFT range from 4.3 ± 2.6 km to 9.7 ± 2.2 km and 13.5 ± 3.1 km to 15.8 ± 1.9 km, respectively, along the central Himalaya. Further, the slip rate along the transition zone lies in the range of 1.4 ± 0.8 mm/yr to 2.7 ± 0.5 mm/yr. Considering the amount of uncertainties as ~1–2 mm/yr in GNSS velocities, the study suggests that the transition zone along the middle flat of the MHT also exhibits locking behavior. Thus, the estimated locking depth extends to ~15.0 km down-dip and covers a horizontal distance of ~90 km (locking line) on the surface, reaching the foothills of the Higher Himalaya. Furthermore, along the deeper flat of the MHT, the slip rate ranges from 19.4 ± 2.5 mm/yr in the west to 12.8 ± 1.6 mm/yr in the east along Nepal Himalaya. The analysis also calculates the slip deficit rate along the MHT fault plane, revealing values of ~15.1 mm/yr in western Nepal, ~12.7 mm/yr in central Nepal, and ~10.6 mm/yr in eastern Nepal. These slip deficit rates across different segments of central Nepal indicate the potential for large earthquakes in the region. The results are further supported by a resolution test using a checkerboard synthetic model, demonstrating the capability of the GNSS network to capture the slip rate along the MHT. These findings inevitably contribute to a comprehensive assessment of the seismic hazard potential in the central Himalayan region. [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.)

The potential for future earthquakes on faults is often inferred from inversions of geodetically derived surface velocities for locking on faults using kinematic models such as block models. This can be challenging in complex deforming zones with many closely spaced faults or where deformation is not readily described with block motions. Furthermore, surface strain rates are more directly related to coupling on faults than surface velocities. We present a methodology for estimating slip deficit rate directly from strain rate and apply it to New Zealand for the purpose of incorporating geodetic data in the 2022 revision of the New Zealand National Seismic Hazard Model. The strain rate inversions imply slightly higher slip deficit rates than the preferred geologic slip rates on sections of the major strike‐slip systems including the Alpine Fault, the Marlborough Fault System and the northern part of the North Island Fault System. Slip deficit rates are significantly lower than even the lowest geologic estimates on some strike‐slip faults in the southern North Island Fault System near Wellington. Over the entire plate boundary, geodetic slip deficit rates are systematically higher than geologic slip rates for faults slipping less than one mm/yr but lower on average for faults with slip rates between about 5 and 25 mm/yr. We show that 70%–80% of the total strain rate field can be attributed to elastic strain due to fault coupling. The remaining 20%–30% shows systematic spatial patterns of strain rate style that is often consistent with local geologic style of faulting. Plain Language Summary: The potential for future earthquakes on faults is often inferred from velocities of the ground surface derived from satellite geodesy, but this approach can be challenging in complex deforming zones with many closely spaced faults. We present a new methodology for estimating the rate at which energy is accumulating on faults using measurements of surface strain rates. The method is applied to New Zealand for the purpose of incorporating geodetic data in the 2022 revision of the New Zealand National Seismic Hazard Model. We show that 70%–80% of the total deformation field can be attributed to energy accumulation on known active faults while the source of the remaining 20%–30% remains unknown. Along some of the major faults in New Zealand we find some important differences in rates of energy accumulation from what is expected from geologic data. Estimated rates are significantly lower than even the lowest geologic estimates on some faults in the fault system near highly‐populated Wellington. Key Points: We develop a method to invert geodetically derived strain rates for slip deficit rates on faultsWe find small but systematic differences between slip deficit rates and geologic slip ratesAbout 70%–80% of the surface strain can be attributed to elastic strain due to coupling on faults [ABSTRACT FROM AUTHOR]

Abstract The Osaka Bay is situated at a seismically active region north of the Median Tectonic Line and east of Awaji Island in western Japan, known as part of the Kinki Triangle and the Niigata–Kobe Tectonic Zone. Dense distribution of active faults and high geodetic strain rates characterize the region, posing a major seismic hazard potential to the coastal and metropolitan areas of the Kansai region. To investigate the shallow structure and recent deformation history of active faults in the Osaka Bay, we acquired 15 high-resolution seismic profiles using a Mini-GI airgun and a Boomer as active sources, together with multi-beam bathymetry data across the Osaka Bay Fault. Our seismic sections image a ~ 0.1 to 3.7 km-wide asymmetric anticline forelimb above the Osaka Bay Fault at shallow depths, coupled with a ~ 2.6 km-wide syncline to the west, and a broad, ~ 11 km-wide syncline in the footwall to the east. The synclinal axial surface at shallow depths measured in this study ranges 75°–89°. We observe the vertical displacement of the Osaka Bay Fault increasing northwards along strike. The sediment thickness on the hanging wall, however, is variable, modified by non-tectonic processes such as by tidal currents, affecting the geometry of growth strata. The most recent deformation by the Osaka Bay Fault reaches to near the seafloor by active folding, with large vertical offsets of 8–14 m over the last ~ 11 ka, and 5–11 m over the last ~ 5 ka. By combining with previously reported borehole age data, the average uplift rate on the Osaka Bay Fault is estimated to be ~ 1.0 to 1.7 m/ka during the Latest Pleistocene to Holocene. The inferred slip of the Osaka Bay Fault during the Holocene is likely to account for > 5% of the regional geodetic strain accumulation within the Kinki Triangle. Further studies to evaluate the Holocene slip rates of regional faults are necessary to assess the seismic hazards and the internal strain budgets within the Kinki Triangle and the Niigata–Kobe Tectonic Zone. Graphical abstract

Abstract The Jiali-Chayu fault, situated on the eastern side of the eastern Himalayan syntaxis, is the southeastern margin of the large strike-slip fault zone of the Jiali Fault. The study of the distribution and activity within this fault zone is imperative for a comprehensive understanding of the tectonic movement patterns in the southeastern Tibetan Plateau. Previous studies have established that the kinematic characteristic of the Jiali-Chayu fault diverges significantly from that of other segments within the Jiali fault. Nonetheless, the current tectonic characteristics, including the slip sense, slip rate, and geometric deformation of this fault, are still not well resolved, leading to divergent interpretations regarding its contemporary activity intensity. This paper introduced an optimized time-series InSAR method with phase compensation designed for regions characterized by low coherence and exhibiting slow deformation. Using Sentinel-1 SAR data from both ascending and descending orbits spanning the period between 2017 and 2022, we successfully derived deformation rates for the middle part of the Jiali-Chayu fault at a spatial resolution of 150 m. The slip and dip rates of active faults are determined by considering the fault movement rates from two different observation angles, in conjunction with strike angle and the assumed dip angle of the fault. The results show that the deformation rates of the three branches are very different, with F2-1 and F2-2 exhibiting notable activity, while other areas exhibit relatively weaker activity. The strike-slip rates for F2-1 and F2-2 faults range between 3.6 and 5.3 mm/a and 3.05 to 5.13 mm/a, respectively, while their respective dip-slip rates fall within the range of 1.1–2.7 mm/a and 2.99–5.02 mm/a. In accordance with the fault slip directions, we classify the F2-1 fault as a sinistral (left-lateral) strike-slip fault and the F2-2 fault as a dextral (right-lateral) strike-slip fault. This study addresses a gap in remote sensing methods for detecting active fault activity in this region, providing a systematic foundation for identifying weak activity characteristics within the fault zone. Graphical Abstract

The Osaka Bay is situated at a seismically active region north of the Median Tectonic Line and east of Awaji Island in western Japan, known as part of the Kinki Triangle and the Niigata–Kobe Tectonic Zone. Dense distribution of active faults and high geodetic strain rates characterize the region, posing a major seismic hazard potential to the coastal and metropolitan areas of the Kansai region. To investigate the shallow structure and recent deformation history of active faults in the Osaka Bay, we acquired 15 high-resolution seismic profiles using a Mini-GI airgun and a Boomer as active sources, together with multi-beam bathymetry data across the Osaka Bay Fault. Our seismic sections image a ~ 0.1 to 3.7 km-wide asymmetric anticline forelimb above the Osaka Bay Fault at shallow depths, coupled with a ~ 2.6 km-wide syncline to the west, and a broad, ~ 11 km-wide syncline in the footwall to the east. The synclinal axial surface at shallow depths measured in this study ranges 75°–89°. We observe the vertical displacement of the Osaka Bay Fault increasing northwards along strike. The sediment thickness on the hanging wall, however, is variable, modified by non-tectonic processes such as by tidal currents, affecting the geometry of growth strata. The most recent deformation by the Osaka Bay Fault reaches to near the seafloor by active folding, with large vertical offsets of 8–14 m over the last ~ 11 ka, and 5–11 m over the last ~ 5 ka. By combining with previously reported borehole age data, the average uplift rate on the Osaka Bay Fault is estimated to be ~ 1.0 to 1.7 m/ka during the Latest Pleistocene to Holocene. The inferred slip of the Osaka Bay Fault during the Holocene is likely to account for > 5% of the regional geodetic strain accumulation within the Kinki Triangle. Further studies to evaluate the Holocene slip rates of regional faults are necessary to assess the seismic hazards and the internal strain budgets within the Kinki Triangle and the Niigata–Kobe Tectonic Zone. [ABSTRACT FROM AUTHOR]

A planetary exploration rover has been employed for scientific endeavors or as a precursor for upcoming manned missions. Predicting rover traversability from its wheel slip ensures safe and efficient autonomous operations of rovers on deformable planetary surfaces; path planning algorithms that reduce slips by considering wheel-soil interaction or terrain data can minimize the risk of the rover becoming immobilized. Understanding wheel-soil interaction in transient states is vital for developing a more precise slip ratio prediction model, while path planning in the past assumes that slips generated at the path is a series of slip ratio in steady state. In this paper, we focus on the transient slip, or slip rate the time derivative of slip ratio, to explicitly address it into the cost function of path planning algorithm. We elaborated a regression model that takes slip rate and traction force as inputs and outputs slip ratio, which is employed in the cost function to minimize the rover slip in path planning phase. Experiments using a single wheel testbed revealed that even with the same wheel traction force, the slip ratio varies with different slip rates; we confirmed that the smaller the absolute value of the slip rate, the larger the slip ratio for the same traction force. The statistical analysis of the regression model confirms that the model can estimate the slip ratio within an accuracy of 85% in average. The path planning simulation with the regression model confirmed a reduction of 58% slip experienced by the rover when driving through rough terrain environments. The dynamics simulation results insisted that the proposed method can reduce the slip rate in rough terrain environments. [ABSTRACT FROM AUTHOR]

In this study, we provide the first field-based assessment of the seismic potential of the Te Puninga Fault, Hauraki Plains, Waikato region. Initially considered to be part of the nearby Kerepehi Fault, our new mapping and field data suggest the Te Puninga Fault is independent. A new net slip rate value of 0.25 mm/yr, based on geomorphic data and evaluations from two paleoseismic trenches, is slightly higher than previously considered. Comparisons of geomorphic expression between the two faults suggest that the slip rate currently assigned to the Kerepehi Fault could be underestimated. The earthquake magnitude estimated here for the Te Puninga Fault (Mw 6.9 ± 0.35) is based on a characteristic earthquake model. New PGA and MMI estimates here are only slightly larger than those published prior to this study. Although ruptures of the Te Puninga Fault are infrequent (derived recurrence range of 3000–11,500 years), and thus its hazard is low, with this paper we wish to enhance the community awareness to prepare for the rare large earthquake in the region. We also recommend that this new information is added to fault databases used for seismic assessment. [ABSTRACT FROM AUTHOR]

In this study, alternatively to the megathrust, we identify upper plate normal faults orthogonal to the trench as a possible tsunami source along the Lesser Antilles subduction zone. We study the Morne Piton Fault system, a trench-perpendicular upper crustal fault affecting the Lesser Antilles forearc at the latitude of Guadeloupe. By the means of seismic reflection, high resolution bathymetry, Remotely Operated Vehicle images and dating, we reassess the slip rate of the Morne Piton Fault at 0.2 mm.yr-1 since fault inception (i.e. 7 Ma), dividing by five previous estimations and thus increasing the earthquake time recurrence and lowering the associated hazard. We evidence a metric scarp with striae at the toe of the Morne Piton Fault system suggesting a recent fault rupture. We estimate a fault rupture area of ~ 450-675 km2 and then a magnitude range for the seismic event around Mw 6.5 ± 0.5. We present results from a multi-segment tsunami model representative for the worst-case scenario which gives an overview of what could happen in terms of tsunami generation if the whole identified Morne Piton Fault segments ruptured together. Our model illustrates the potential impact of local tsunamis on the surrounding coastal area as well as local bathymetric controls on tsunami propagation as (i) shallow water plateaus act as secondary sources and are responsible for a wrapping of the tsunami waves around the island of Marie-Galante, (ii) canyons are focusing and enhancing the wave height in front of the most touristic and populated town of the island, (iii) a resonance phenomenon is observed within Les Saintes archipelago showing that the waves' frequency content is able to perturbate the sea-level during many hours after the seismic rupture. [ABSTRACT FROM AUTHOR]

Copyright of Earthquake (1000-3274) is the property of Editorial Office of Earthquake Journal 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.)

In the context of automatic driving, the analysis of the steering motion characteristics is critical for enhancing the efficiency of crawler harvesters. To address issues such as the low transmission efficiency and the large steering radius encountered by traditional crawler harvesters featuring hydrostatic drives, a driven steering crawler harvester chassis was designed. This involved analysis of the chassis transmission system structure and its steering characteristics under several conditions, including differential steering, differential direction reversal, and unilateral braking steering. The steering parameters were determined based on real-time kinematic positioning–global navigation satellite system (RTK-GNSS) measurements, and they were compared with theoretical predictions based on the crawler harvester steering kinematics. The slip rates and modified models of the crawler chassis for various steering modes were then obtained. The results indicated that the increase in the ratio between the running input and steering input speeds led to larger track steering radii and smaller average rotational angular velocities. Remarkably, the slopes of the linear fits of the tracked chassis steering parameters varied significantly under differential direction reversal and differential steering modes. Compared with the actual results, the correlation coefficient of the tracked chassis steering parameters fitting model is close to 1. The steering parameter model was deemed suitable for actual operational requirements. The results provide a valuable reference for designing navigation and steering models of crawler harvesters operating on different road surfaces. [ABSTRACT FROM AUTHOR]

The NW-SE-trending dextral strike-slip faults on the north side of the Tian Shan, e.g., the Karatau fault, Talas–Fergana fault, Dzhalair–Naiman fault, Aktas fault, Dzhungarian fault, and Chingiz fault, play an important role in accommodating crustal shortening. The classic viewpoint is that these strike-slip faults are an adjustment product caused by the difference in the crustal shortening from west to east. Another viewpoint attributes the dextral strike-slip fault to large-scale sinistral shearing. The Alakol Lake fault is a typical dextral strike-slip fault in the north Tian Shan that has not been reported. It is situated along the northern margin of the Dzhungarian gate, stretching for roughly 150 km from Lake Ebinur to Lake Alakol. Our team utilized aerial photographs, satellite stereoimagery, and field observations to map the spatial distribution of the Alakol Lake fault. Our findings provided evidence supporting the assertion that the fault is a dextral strike-slip fault. In reference to its spatial distribution, the Lake Alakol is situated in a pull-apart basin that lies between two major dextral strike-slip fault faults: the Chingiz and Dzhungarian faults. The Alakol Lake fault serves as a connecting structure for these two faults, resulting in the formation of a mega NW-SE dextral strike-slip fault zone. According to our analysis of the dating samples taken from the alluvial fan, as well as our measurement of the displacement of the riser and gully, it appears that the Alakol Lake fault has a dextral strike-slip rate of 0.8–1.2 mm/a (closer to 1.2 mm/a). The strike-slip rate of the Alakol Lake fault is comparatively higher than that of the Chingiz fault in the northern region (~0.7 mm/a) but slower than that of the Dzhungarian fault in the southern region (3.2–5 mm/a). The Chingiz–Alakol–Dzhungarian fault zone shows a gradual decrease in deformation towards the interior of the Kazakhstan platform.

Comparison of geodetic slip-deficit rates with geologic fault slip rates on major strike-slip faults reveals marked differences in patterns of elastic strain accumulation on tectonically isolated faults relative to faults that are embedded within more complex plate-boundary fault systems. Specifically, we show that faults that extend through tectonically complex systems characterized by multiple, mechanically complementary faults (that is, different faults that are all accommodating the same deformation field), which we refer to as high-Coefficient of Complexity (or high-CoCo) faults, exhibit ratios between geodetic and geologic rates that vary and that depend on the displacement scales over which the geologic slip rates are averaged. This indicates that elastic strain accumulation rates on these faults change significantly through time, which in turn suggests that the rates of ductile shear beneath the seismogenic portion of faults also vary through time. This is consistent with models in which mechanically complementary faults trade off slip in time and space in response to varying mechanical and stress conditions on the different component faults. In marked contrast, structurally isolated (or low-CoCo) faults exhibit geologic slip rates that are similar to geodetic slip-deficit rates, regardless of the displacement and time scales over which the slip rates are averaged. Such faults experience relatively constant geologic fault slip rates as well as constant strain accumulation rate (aside from brief, rapid post-seismic intervals). This suggests that low-CoCo faultsd "keep up" with the rate imposed by the relative plate-boundary condition, since they are the only structures in their respective plate-boundary zone that can effectively accommodate the imposed steady plate motion. We hypothesize that the discrepancies between the small-displacement average geologic slip rates and geodetic slip-deficit rates may provide a means of assessing a switch of modes for some high-CoCo faults, transitioning from a slow mode to a faster mode, or vice versa. If so, the differences between geologic slip rates and geodetic slip-deficit rates on high-CoCo faults may indicate changes in a fault's behavior that could be used to refine next-generation probabilistic seismic hazard assessments.

A planetary exploration rover has been employed for scientific endeavors or as a precursor for upcoming manned missions. Predicting rover traversability from its wheel slip ensures safe and efficient autonomous operations of rovers on deformable planetary surfaces; path planning algorithms that reduce slips by considering wheel-soil interaction or terrain data can minimize the risk of the rover becoming immobilized. Understanding wheel-soil interaction in transient states is vital for developing a more precise slip ratio prediction model, while path planning in the past assumes that slips generated at the path is a series of slip ratio in steady state. In this paper, we focus on the transient slip, or slip rate the time derivative of slip ratio, to explicitly address it into the cost function of path planning algorithm. We elaborated a regression model that takes slip rate and traction force as inputs and outputs slip ratio, which is employed in the cost function to minimize the rover slip in path planning phase. Experiments using a single wheel testbed revealed that even with the same wheel traction force, the slip ratio varies with different slip rates; we confirmed that the smaller the absolute value of the slip rate, the larger the slip ratio for the same traction force. The statistical analysis of the regression model confirms that the model can estimate the slip ratio within an accuracy of 85% in average. The path planning simulation with the regression model confirmed a reduction of 58% slip experienced by the rover when driving through rough terrain environments. The dynamics simulation results insisted that the proposed method can reduce the slip rate in rough terrain environments.

Physics‐based earthquake simulators have been developed to overcome the relatively short duration and incompleteness of historical earthquake and paleoseismic records, respectively. These simulators have the potential to be a useful addition to seismic hazard assessment as they produce millions of synthetic earthquakes over thousands to millions of years using predefined fault geometries and slip rates. Due to the sparsity of fault data and the computational expense of the modeling, it is common to simplify earthquake simulator input parameters. Fault surfaces are typically characterized by simplified mapped traces and constant dip with depth, with slip rates that are often assumed to be uniform over the fault plane. This study uses the well‐defined 3D geometry of an active normal fault in offshore Aotearoa New Zealand, the Cape Egmont Fault, to demonstrate the impact of using nonuniform slip rates and nonplanar fault geometries on the resulting synthetic earthquakes from the earthquake simulator RSQSim. Adopting variable slip rates that decrease to zero along the fault tipline (rather than uniform slip rates) reduces unrealistically high nucleation rates of seismicity along fault edges. Introduction of complex 3D fault geometries, including fault segmentation and bends on kilometer scales, and variable slip rates produces less characteristic earthquake populations, increasing the number of M6‐7 moderate‐large magnitude events. Incorporation of variable fault geometries and slip rates in physics‐based simulators may modify the seismic hazards estimated from synthetic earthquake catalogs. Plain Language Summary: Earthquake simulators are used to study and anticipate earthquakes. These simulators produce millions of synthetic earthquakes over thousands to millions of years using predefined fault properties. We use a well‐defined active normal fault in offshore Aotearoa New Zealand, to examine the impact of nonuniformly distributed fault slip rates and nonplanar fault geometries on the resulting synthetic earthquake catalogs. We show that adopting variable fault slip rates, with a gradual decrease in slip rate toward fault‐surface edges, reduces the unrealistic occurrence of high concentrations of earthquakes along the fault tip line. The study also shows that utilization of complex 3D fault geometries together with variable slip rates produces populations of earthquakes in a less predictable manner, increasing the number of moderate to large magnitude events. Therefore, details of the input fault geometries and slip rate distributions can significantly affect the resulting synthetic earthquake catalogs from physics‐based earthquake simulators with significant implications for seismic hazard applications. Key Points: Variable, rather than constant, slip rates reduce high seismicity rates along the fault edges and can improve the depth distributions of eventsIntroduction of complex 3D fault geometries produces less characteristic earthquake populationsVariable fault geometries and slip rates in physics‐based simulators can improve the synthetic earthquake catalogs [ABSTRACT FROM AUTHOR]

During the friction stir welding process, the motion of the stirring tool is divided into two parts: the rotational motion and the lateral feed, both of which influence the temperature distribution, material flow, and slip rate. The effect of the rotational motion in numerical simulations is usually the focus of research, but the changes in material flow, slip, and heat generation due to welding speed are usually neglected. In this study, the numerical model of stationary shoulder friction stir welding (SSFSW) was developed to optimize the effect of welding speed on heat generation and material flow based on the instantaneous velocity center (IVC), and the relationship between n/v and IVC were discussed. The instantaneous velocity center distance was inversely proportional to n/v, and its magnitude affected the difference in temperature between the AS and RS. [ABSTRACT FROM AUTHOR]

The East Kunlun fault zone (EKFZ), located northeast of the Qinghai–Tibet Plateau, has experienced several strong earthquakes of magnitude seven or above since 1900. It is one of the most active fault systems and is characterized by left-lateral strike-slip. However, the Xidatan–Dongdatan segment (XDS) of the East Kunlun fault zone (EKFZ) has had no earthquakes for many years, and the Kunlun Mountains MS 8.1 earthquake has a stress loading effect on this segment, so it is widely regarded as a high-risk earthquake gap. To this end, we collected the Sentinel-1 data of the XDS of the EKFZ from July 2014 to July 2019 and obtained the high-precision interseismic deformation field by the Interferometric Synthetic Aperture Radar (InSAR) technique to obtain the slip rate and locking depth of the XDS of the EKFZ, and the seismic potential of the segment was analyzed. The results are as follows: (1) The LOS deformation field of the XDS of the EKFZ was obtained using Sentinel-1 data of ascending and descending orbits, which indicated that the XDS of the EKFZ is dominated by horizontal motion. Combined with the interference results, it is shown that the strike-slip rate dominates the deformation information of the XDS of the EKFZ. The deep strike-slip rate of the fault is about 6 mm/yr, the deep dip-slip rate is about 2 mm/yr, and the slip-deficit rate on the fault surface is about 6 mm/yr; (2) Combined with the spiral dislocation theory model, the slip rate of the XDS to Xiugou Basin of the EKFZ has a gradually increasing trend, with an average slip rate of 9.6 ± 2.3 mm/yr and a locking depth of 29 ± 5 m; (3) The stress accumulation is about 483 ± 92 years in the XDS of the EKFZ, indicating that the cumulative elastic strain energy of the XDS can produce an MW 7.29 ± 0.1 earthquake in the future. [ABSTRACT FROM AUTHOR]

Copyright of Earthquake (1000-3274) is the property of Editorial Office of Earthquake Journal 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.)

Aiming at the problem that the current ABS control algorithm cann't make full use of the ground braking force to complete the braking when the complex road surface is in emergency braking, the ABS sliding mode variable structure control method based on road surface identification is proposed. Combined with the in-wheel motor of in-wheel motor electric vehicle, a coordinated control method of motor hydraulic composite is designed. Based on the fuzzy logic control method, the road adhesion coefficient is estimated to realize the identification of typical roads and dynamically obtain the optimal slip rate of different roads. The ABS sliding mode variable structure controller is designed with the optimal slip ratio and the actual slip ratio as input, and the saturation function is used to replace the sign function in the traditional sliding mode variable structure control to weaken the ' chattering ' phenomenon in the sliding mode variable structure control, and then the ABS controller is designed. Taking the experimental prototype vehicle driven by four-wheel hub motor as the research object, an eight-degree-of-freedom dynamic simulation model of the whole vehicle is established. Compared with the traditional PID controller, the braking time is shortened by 0.2 s and the braking distance is shortened by 2.3 m, which shows the feasibility of the designed controller. Through the simulation braking experiment of the docking road, the adaptability and real-time performance of the ABS sliding mode controller are verified, and the importance of the road adhesion coefficient identification to the ABS controller is verified. [ABSTRACT FROM AUTHOR]

Frictional pairs consisting of plasma powder frictional coatings and a steel counterbody operating in the presence of oil are developed for disk and conical frictional devices. The dynamic frictional coefficient is determined as a function of the slip velocity and the distributed load for the given frictional devices. [ABSTRACT FROM AUTHOR]

Located on the southeastern periphery of the Tibetan Plateau, the Xianshuihe fault (XSHF) is an active left-lateral strike-slip fault renowned for its frequent and intensive seismic activities. This highlights the necessity of employing advanced geodetic methodologies to precisely evaluate the fault kinematics and seismic hazard potential along this fault. Among these techniques, interferometric synthetic aperture radar (InSAR) stands out for its high spatial resolution and regular revisit intervals, enabling accurate mapping of interseismic deformation associated with fault motion. However, the precision of InSAR in measuring deformation encounters several challenges, particularly artifacts stemming from phase unwrapping errors and atmospheric phase delays. In this study, we utilize ascending and descending Sentinel-1 InSAR images spanning from January 2017 to January 2023 to drive the line-of-sight (LOS) mean crustal velocities associated with the XSHF with emphasis on phase unwrapping errors and atmospheric delay corrections. Then, the reliability of the derived LOS velocities is assessed using independent observations from the Global Navigation Satellite System (GNSS). The inferred fault slip rate along the XSHF shows significant along-strike variations, gradually decreasing from ~11.1 mm/yr at the Luhuo section to ~6.6 mm/yr at the Kangding section and then sharply increasing to ~13.0 mm/yr towards its eastern terminus at the Moxi section. The fault locking depth shows similar along-strike variations, decreasing from ~19.5 km in the northwestern part to ~4.8 km at the Kangding section, before increasing to 19.6 km at the Moxi segment. Notably, apparent surface fault creeping, characterized by a slip rate of ~2.7 mm/yr, is observed at the Kangding segment, likely resulting from postseismic slip following the 2014 Mw 6.3 Kangding earthquake.

This study delves into slip distribution on the North Tabriz Fault (NTF), a critical aspect of seismic hazard analysis due to its proximity to the Tabriz metropolis. The study operates within a uniform elastic half-space, maintaining constant values for fault geometry and regional rheological parameters throughout the research. To calculate strain boundary conditions, permanent and periodic global positioning system (GPS) data from the northwest region were utilized. The fault was constrained perpendicularly while allowing tangential movement, facilitating the determination of its annual slip rate using the boundary element method, with the Okada analytical model serving as the fundamental solution. The findings underscore the intricate relationship between the fault’s slip rate and boundary conditions, revealing a predominant right-lateral strike-slip motion. The study offers two slip rate assessments, obtained through earthquake focal mechanisms and GPS velocity data, yielding values of 5 and 5.5 mm/year{\rm{mm}}/{\rm{year}}, respectively. Importantly, the alignment of these calculated slip rates with paleo-seismological data underscores the credibility of the results generated via the boundary element method, distinguishing it as a reliable approach when compared to other numerical and analytical techniques. This research provides valuable insights into the behavior and slip dynamics of the NTF, which is pivotal for assessing seismic risks.

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.)

We investigate the present‐day strike‐slip faulting and intracontinental deformation of North China using horizontal GPS velocities and a block modeling strategy. The data demonstrate that the fault slip rates and block rotations in North China can be better constrained using GPS velocities where the influence of groundwater extraction has been reduced by applying median spatial filtering of the velocity field. The modeled senses of motion and slip rates on active faults are generally in good agreement with the geological estimates. The left‐lateral slip rate along the boundary fault of Weihe Graben is apparently lower than the differential motion between the South China Block and Ordos Block. The missing left‐lateral slip is accommodated by the counterclockwise rotation of the Ordos Block. The sinistral slip rate along the eastern segment of the Altyn Tagh‐Haiyuan‐Qinling fault system decreases eastward from ∼1.0 to ∼0 mm/yr, much slower than that expected in the fast eastward extrusion hypothesis. We interpret the systematic counterclockwise rotation of blocks and left/right‐lateral faulting in North China to be driven both by the left‐lateral shear between the South China Block to the south and Yinshan‐Yanshan Block to the north and a push from the Tibetan Plateau on the southwestern margin of the Ordos Block. Plain Language Summary: North China is in a complex tectonic regime with all types of faults (strike‐slip, normal, and thrust faults) around its margins and internal blocks rotating counterclockwise. Why and how such a complex deformation occurs in North China is a crucial scientific question but unsolved. Based on the newly improved GPS data, we quantitatively determined the present‐day fault slip rates and block rotations in and around North China. Our research indicates a low left‐lateral slip rate (0–1.0 mm/yr) along faults between North China and South China, in contrast to much faster values (8 to >10 mm/yr) given in previous studies and expected by the continental escape hypothesis. Therefore, we propose that the complex tectonic deformation in North China is mainly driven by both left‐lateral shear between South China and Yinshan‐Yanshan Block and an eastward push from the Tibetan Plateau at the southwestern margin of the Ordos Block in western North China. Key Points: Geodetic data are used to obtain fault slip rates on North China using a carefully regularized block model and noise‐reduced GPS velocitiesLeft‐lateral slip rate at the eastern termination of the South China Block extrusion boundary decreases eastward from ∼1.0 to ∼0 mm/yrRight‐later shear in the Shanxi Graben results from a combination of block rotations and relative motions [ABSTRACT FROM AUTHOR]