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The Qilian–Haiyuan fault zone in the northeastern Tibetan Plateau has been the source of strong earthquakes in the region. In its middle segment, the Jinqianghe fault is an important active fault within the Tianzhu seismic gap; however, little is known about its slip behavior. To present a new horizontal displacement distribution along this fault, we used WorldView‐2 stereo pairs and unmanned aerial vehicle‐based photogrammetry to construct digital elevation models to obtain a detailed tectono‐geomorphic interpretation and geomorphic offsets. The offset marker measurements yielded 135 geomorphic displacements and 8 offset clusters. Radiocarbon dating was used to establish the regional age sequence of the geomorphic units in offset fluvial terraces at four study sites. The displacements and ages linked the offset clusters with the geomorphic unit sequence; the Holocene strike‐slip rate of the Jinqianghe fault was estimated to 4.8–5.6 mm/a at ∼4–12 ka and 2.9–4.7 mm/a from ∼4 ka. Three recent earthquakes (with a recurrence interval of ∼1000 years) represent an active seismic period, revealing the potential seismic hazard along this fault because it has not ruptured in the last 1500 years. [ABSTRACT FROM AUTHOR]

Atmospheric heterogeneity mainly exposes itself as tropospheric-phase delay in Satellite Interferometric Synthetic Aperture radar (InSAR) observations, which smears or even overshadows the deformation component of InSAR measurements. In this study, we estimated the performance of four Global Atmospheric Models (GAMs), i.e. European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5), ERA-Interim (ERA-I), Modern-Era Retrospective analysis for Research and Applications v2 (MERRA2) and Generic Atmospheric Correction Online Service for InSAR (GACOS), for tropospheric-phase delay reduction in InSAR applications in the Tibetan plateau, of which ERA5 is the latest GAM released by ECMWF. We demonstrated the effectiveness of Atmospheric Phase Screen (APS) correction using the four GAMs for more than 700 Sentinel-1 Terrain Observation by Progressive Scans interferograms covering two study areas in the southern (R1) and northwest margins (R2) of the Tibetan plateau. Topography-correlated signals have been widely observed in these interferograms, which are most likely due to the APS effects. We calculated the Standard Deviations (SD) and Pearson's Correlation Coefficients (r) between InSAR Line of Sight measurements and topography before and after applying APS correction. The results show that the SDs of non-deformation areas from the GAMs decrease to approximately 4 mm from around 10 mm and 12 mm originally on average for R1 and R2, respectively, and the r after the APS correction are reduced below 0.4 from around 0.8 for the selected interferometric pairs. In addition, as the newly released GAM, ERA5 has similar performance with GACOS products and outperforms other models generally. This suggests that GAMs, particularly ERA5, have great potential in the APS correction for InSAR applications in the Tibetan plateau. [ABSTRACT FROM AUTHOR]

• The Huangcheng basin has undergone three compression events since 100 Ma. • Slickenside analysis reveals north–south and east–west compression stresses. • Cretaceous sedimentary rocks in the area are sourced from the Qilian Shan-Nan Shan Block and Alashan Block. The sedimentary rocks in the Hexi Corridor, north-eastern Tibetan Plateau, contain information about crustal deformation during and after the closure of the Meso-Tethys Ocean and the growth of the Tibetan Plateau. This study examines the origin and deformation of Late Mesozoic sedimentary rocks in the Huangcheng basin where the source of Late Mesozoic sedimentary rocks and deformation styles of faults and folds remain controversial. Results from field mapping, fault kinematic analysis, and detrital zircon analysis suggest that the study region might have experienced three episodes of compression events since 100 Ma. The first episode is characterized by north–south compression, which could reflect the convergence between the Alashan and the Qilian Shan-Nan Shan. The second episode reflects the reactivation of the thrust faults related to the far-field effect resulting from the closure of the Neo-Tethys Ocean. The third episode is the regional east–west trending thrust due to the block extrusion. One set of slickensides indicates north–south compression while a second set implies nearly east–west compression, which could represent different stress orientations between the first two episodes and the third episode. Eleven detrital zircon samples from the Cretaceous to Neogene strata were collected for detrital zircon U-Pb dating and rare earth element analysis. Zircon U-Pb ages show major peaks around 265 Ma and 455 Ma with a notable lack of ages around 1.0 Ga. We infer that the source of the Neogene sedimentary rocks was the Qilian Shan while the sources of the Cretaceous sedimentary rocks were the Qilian Shan and Alashan. [ABSTRACT FROM AUTHOR]

• The Riganpei Co fault is divided into four segments based on the distribution of displacements. • The COPD within 0–30 m for each segment reveals that at least four large earthquakes ruptured this fault. • Reconstructed slip distribution shows a complex pattern of strong earthquake activities on different segments of the fault. High-resolution topographic datasets are useful for revealing offset features of fault geomorphology and are thus important for reconstructing the evolution history of faults. The Riganpei Co fault, located in the central Tibetan Plateau, is an important active fault on the northern boundary of the Bangong-Nujiang suture zone. In this study, WorldView-2 stereo images were used to generate high-resolution topographic data in a 1 km range on both flanks of the middle section of the Riganpei Co fault. We interpreted the tectonic geomorphology along the fault, classified it into distinct units, and measured the horizontal displacement of each unit. Within approximately 70 km along the fault, we obtained 396 displacement measurements ranging from 0 to 60 m. Given the evident uneven distribution of displacement, the fault was divided into four segments. In each fault segment, the reconstructed slip distributions revealed a tendency of larger displacements in the center and smaller displacements toward the ends. The cumulative offset probability distribution (COPD) of displacements displays 4–5 offset clusters in the range of 0–30 m for each segment, suggesting that at least four large earthquakes ruptured this fault. The binned COPD demonstrated that there are differences in the displacement accumulation modes among these fault segments, where the middle segment follows a characteristic slip accumulation mode. Reconstructed cumulative slip profiles revealed a complex pattern of strong earthquake activities along the Riganpei Co fault. [ABSTRACT FROM AUTHOR]

The Qilian Shan, located in the northeastern Tibet, is under strong tectonic activity and earthquake motion due to the propagation of the plateau. At the mountain front of the eastern Qilian Shan, the Tongziba River, in the southern Zhangye Basin, flows northward and successively cuts the Minle‐Damaying Fault and the Yonggu Anticline, two parallel structures within the Frontal Thrust system of the Qilian Shan. Here we present a detailed record of seven strath terraces of this river that documents the history of active deformation of the two structures. Based on the estimated crustal shortening distance from the deformed terraces and the terrace formation age constrained by AMS 14C and optically stimulated luminescence (OSL) dating, a horizontal slip rate of 1.4 ± 0.5 mm/year of the Minle‐Damaying Fault is constrained since 16.7 ± 1.8 kyr, and a shortening rate of 1.3 ± 0.4 mm/year across the Yonggu Anticline has been estimated in a similar time frame, respectively. In total, the shortening rate across the mountain front is estimated to be 2.7 ± 0.6 mm/year. GPS data show a similar modern shortening rate in this area, which indicates the rate of crustal shortening may be comparable in the modern and 104‐year scales. Our study supports a higher crustal shortening rate along the mountain front of the eastern Qilian Shan than that of the western Qilian Shan since the Late Quaternary. Key Points: The Minle‐Damaying Fault and the Yonggu Anticline have been active since at least 16.7 ± 1.8 kyrEstimated Late Quaternary shortening rate across the eastern Qilian Shan foreland is 2.7 ± 0.6 mm/year from terraces analysisCrustal shortening rate along the mountain front of the eastern Qilian Shan is probably higher than that of the western Qilian Shan [ABSTRACT FROM AUTHOR]

Erosion at the Earth's surface is a major factor controlling the landscape evolution. Cosmogenic nuclides provide a valuable tool for the quantitative study of surface erosion. We employ cosmogenic nuclide 21 Ne analysis to quantify the average erosion rate in the Shapotou area, at the northeastern margin of the Tibetan Plateau, based on the steady-state erosion model. A series of erosional surfaces on the river terraces generated by the Yellow River incision offer us a new approach to determine whether the cosmogenic 21 Ne nuclide inventory has reached equilibrium between nuclide production and loss by surface erosion. Using the steady-state 21 Ne concentration, the average erosion rate in this area is determined to lie between 0.54 ± 0.11 cm ka −1 and 0.72 ± 0.21 cm ka −1 . A depth profile of the subsurface cosmogenic 21 Ne concentrations provides additional evidence for the validity of our steady-state erosion model. Our results reveal that the erosion rate in this area lags significantly behind the incision rate of the Yellow River, which increased the local relief in the Shapotou area. [ABSTRACT FROM AUTHOR]

Active fault zones are areas impacted by intense tectonic activity, where geohazards such as landslides occur and their distribution characteristics vary across segments. Using the Litang fault zone in the eastern Tibetan Plateau as an example, this study cataloged landslides within a 10 km range on both sides of the fault zone. The Litang fault zone was divided into four sections based on landform characteristics and the spatial distribution of active faults. A comprehensive analysis was conducted on the relationship between landslide distribution and topography, lithology, and active faults in different sections. Additionally, the study employed a random forest model to compare landslide susceptibility between the whole-region and its sub-regions. The results show that lithology and topography significantly influence the distribution of landslide types. The Upper Triassic sandstone, Slate exhibit more debris flows in areas with slopes ranging from 5° to 35°, while slopes >35° in the Upper Triassic sandstone, Slate are prone to unstable slopes. Rock avalanche occur in Upper Triassic sandstone, Slate, and Quaternary sand and gravel. Active faults play a key role in control ling landslides distribution through distance, hanging wall, locked segment, and direction effects. The number of landslides is positively correlated with the activity of faults. Additionally, the dip angle and motion characteristics of faults have significant influence on the distribution of landslides. The results of landslide susceptibility evaluation show that sub-region models have higher accuracy than the whole-region model. This study provides a new method for exploring the spatial distribution of landslides and can provide scientific reference for reducing landslide disasters in active fault zones. • Landslides is significantly influenced by distance, hanging wall, locked section, and directionality of the active fault • Fault activity is positively correlated with landslide numbers, while the dip angle and motion affect distribution pattern • Sub-regional model can effectively reveal the spatial differences in landslide susceptibility along the active fault zone [ABSTRACT FROM AUTHOR]

Intense compression following the India-Asia collision is responsible for basin sedimentation and deformation in the northeastern Tibetan Plateau. Despite significant advances in elucidating basin development and associated deformation, debate continues regarding the onset of basin sedimentation along the plateau margin. One of the debated issues is whether the Cenozoic basin sedimentation was a response to deformation soon after plate collision at approximately 50 Ma, or if it was related to a former stress field overprinted by an expanded plateau 20–30 Ma later. To address this issue, a complete spatiotemporal pattern of deformation is central to understanding the basin development linked to plateau growth. Here, we report new deformation constraints in the Baima Basin, a depocenter located on the northern margin of the Arcuate Ranges area (AR), northeastern Tibetan Plateau. A combination of high-resolution magnetostratigraphic results, 10Be/26Al cosmogenic nuclide burial ages and previous chronological constraints provides a prolonged sedimentary history, containing the onset of a N–S-trending normal-faulting basin in the late Eocene, basin subsidence for predominant deposition at 13.6–6.0 Ma and dextral transpression since 6.0 Ma. In the predominant deposition stage, the basin accumulated upward fining sediments under a relatively stable climate context. Dextral transpression along the N–S-striking fault disrupted the once prevailing subsidence at ca. 6.0 Ma, resulting in growth strata, an increase in coarse-grained deposits and lower accumulation rates in the Baima Basin. Dextral strike-slip was probably caused by stepwise forward propagation beginning approximately 8 Ma in the AR, which may be related to late Miocene plateau-scale strike-slip motion. These new data imply that predominant sedimentation and basin deformation in response to plateau expansion could have occurred much later than the onset of the basin. • Predominant basin sedimentation by normal faulting prevailed around ca. 13–8 Ma. • Stepwise forward compression overprinted the normal-faulting basins since ca. 8 Ma. • Growth strata indicate northward compression since ca. 6 Ma in the Baima Basin. [ABSTRACT FROM AUTHOR]

The development of high topography associated with the Indo-Asian collision plays a central role in ongoing debates over the linkages between development of the Tibetan Plateau and climate. In northeastern Tibet, the widespread appearance of coarse terrestrial sediment during the Oligocene is commonly interpreted to herald the development of a foreland basin in response to crustal thickening along the present-day margin of the plateau. However, a lack of direct observations relating sediment accumulation to fault activity leaves this interpretation uncertain. Here, we present new stratigraphic observations along the northern margin of the Longzhong basin that provide insight into the tectonic setting of basin development. A combination of field and subsurface observations, including the geometry of basin-bounding faults, sedimentary provenance, paleoflow direction, isopach and sedimentary facies distribution patterns, constrains basin evolution from the Middle Tertiary through Quaternary time. Our results suggest that NE-SW extension across normal faults controlled development of accommodation space in the northern Longzhong basin during the Oligocene to early Miocene. Continued sediment accumulation from the mid-Miocene through Pliocene occurred in a broad, shallow basin, consistent with thermal subsidence following extension. Basin inversion initiated between 10 Ma and 6 Ma, associated with the development of the modern Haiyuan fault system. Our results imply that the onset of Tertiary sedimentation in the Longzhong basin does not represent a developing fore-deep associated with a nascent Tibetan Plateau, but rather reflects transtensional deformation inboard of extensional basins along the East Asian margin. [ABSTRACT FROM AUTHOR]

Available data from the Qilian Shan in north-east Tibet suggested that decadal-scale erosion rates were closely correlated with local topographic gradient, but not with climatic factors. However, a climatic change to more arid condition was proposed to explain the discrepancy between short-term and long-term erosion rates. In order to re-evaluate the topographic, tectonic and climatic influences on erosion, we adopted five parameters (slope, mean local relief, historical cumulative seismic moment, runoff coefficient of variation and fault density) to study 11 drainage basins in north-east Tibet. Our results showed that terrain gradient, rock fracture density and rainstorm intensity had strong influence on erosion rates while 60-year cumulative seismic moments of historical earthquakes showed weaker correlations. There was a spatial variation in the erosional mechanisms across the basin, with detachment-limited dominance around the ridges (slope > 20°) and deposition dominant in the flat areas. The variation may lead to the discrepancy between short-term and long-term erosion rates. In general, our study supports the 'bath-tub' model for low relief intermountain basins, hence providing new insights into the landscape evolution of the Qilian Shan in northeastern Tibetan Plateau. [ABSTRACT FROM AUTHOR]