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Understanding the active tectonic processes in the Nandakini Watershed is imperative for evaluating geological hazards and seismic risks, as well as for informing land-use planning and natural resource management strategies in the region. Tectonic geomorphology serves as a vital tool for characterizing recent tectonic movements. This research employs GIS techniques to elucidate tectonic activity and its influence on drainage patterns in the Nandakini Watershed, utilizing morphometric parameters derived from SRTM DEM data. Morphometric indices are employed to assess the tectonic movement within drainage basins, capturing both areal and linear factors such as drainage density, texture, circulatory and bifurcation ratios, and stream length ratios. The linear and areal morphometric indices are categorized into three classes representing varying degrees of active tectonic activity. These classifications are then utilized to compute the relative active tectonic index (IRAT). In addition, geomorphic parameters include hypsometric integral, stream length-gradient index, normalized steepness index, chi gradient index, and swath profiles. The majority of the studied region is in an extremely high to moderately active tectonic zone. Large-scale faults and thrusts within the basins are closely correlated with these zones that have been identified. The integrated methodology of GIS-based morphometric analysis and geomorphic study enables the identification of deformed landforms associated with ongoing tectonic activity. Furthermore, these results offer valuable insights for informing watershed management strategies and promoting sustainable land use planning initiatives.

Failed rifts are widely assumed to enter post‐rift tectonic quiescence after termination of intracontinental rifting, but a comprehensive understanding of their regional morphotectonics is lacking. Our quantitative, rift‐scale geomorphic analyses in the Suez Rift, an archetypal failed rift in Egypt, reveals widespread rifting after presumed rift “failure.” Stacked topographic swaths document normal fault offsets in Plio‐Quaternary rocks and fluvial metrics show steep gradients consistent with active faulting along the entire rift length. Quaternary shorelines uplifted along both margins constrain footwall uplift rates of up to 0.13 ± 0.04 mm/yr on normal faults with down‐dip heights of 10–15 km that were active by 3.12 ± 0.23 and 4.44 ± 0.2 Ma or earlier times. Pleistocene‐Recent extension rates of 0.26–0.55 mm/yr are lower than rates characterising preceding rift phases, albeit compatible with those of modestly active intracontinental rifts (e.g., Basin and Range). Our evidence of active extension after rift “abandonment” supports continued but decelerated rifting, not failure, in the Suez Rift.

The geomorphological expression of tectonic activity in the Karoun River Basin, a tectonically active region within the Zagros Mountains of Iran, was investigated. The basin’s complex geological setting, influenced by the collision of the Arabian and Eurasian plates, provides an optimal environment for analyzing tectonic-geomorphic interactions. A combination of geomorphic indices, including the Stream-Gradient Index (SL), Asymmetric Factor (Af), Hypsometric Integral (Hi), and Valley Floor Width to Valley Height Ratio (Vf), was employed to assess tectonic influences on landscape development. Elevated SL values were interpreted to suggest active uplift, while asymmetric drainage patterns (Af) and narrow valley profiles (Vf) were found to further support tectonic dominance. Hypsometric analysis (Hi) indicated youthful landforms undergoing continuous tectonic modification. To augment conventional geomorphic assessments, advanced machine learning techniques, specifically Random Forest (RF) and Convolutional Neural Networks (CNNs), were utilized to model the spatial distribution of geomorphic indices. Interpretability methods such as SHAP (SHapley Additive exPlanations) were applied to elucidate the relationships between tectonic processes and geomorphic features, enhancing model accuracy and mechanistic interpretation. The Index of Active Tectonics (Iat), derived through GIS-based analysis, was used to categorize the basin into three tectonic activity classes: Class 1 (very high activity, 24% of the area), Class 2 (high activity, 63%), and Class 3 (moderate activity, 10%). The findings highlight the significance of tectonic geomorphology in natural hazard evaluation, particularly landslide susceptibility in steep, tectonically uplifted terrains. Additionally, the examination of river terraces contributes to understanding historical landscape responses to tectonic and climatic forcing, advancing knowledge of long-term geomorphic evolution. The integration of traditional geomorphic indices with machine learning establishes a robust analytical framework for future research in tectonically active regions, with implications for geological hazard assessment and environmental planning.

Geophysical and geological data from the North Mozambique Channel acquired during the 2020–2021 SISMAORE oceanographic cruise reveal a corridor of recent volcanic and tectonic features 200 km wide and 600 km long within and north of Comoros Archipelago. Here we identify and describe two major submarine tectono-volcanic fields: the N’Droundé province oriented N160°E north of Grande-Comore Island, and the Mwezi province oriented N130°E north of Anjouan and Mayotte Islands. The presence of popping basaltic rocks sampled in the Mwezi province suggests post-Pleistocene volcanic activity. The geometry and distribution of recent structures observed on the seafloor are consistent with a current regional dextral transtensional context. Their orientations change progressively from west to east ( ∼ N160°E, ∼ N130°E, ∼ EW). The volcanism in the western part appears to be influenced by the pre-existing structural fabric of the Mesozoic crust. The 200 km-wide and 600 km-long tectono-volcanic corridor underlines the incipient Somalia–Lwandle dextral lithospheric plate boundary between the East-African Rift System and Madagascar.

Graphical Abstract

Present‐day convergence between Caribbean and North American plates is accommodated by subduction zones, major active thrusts and strike‐slip faults, which are probably the source of the historical large earthquakes on Hispaniola. However, little is known of their geometric and kinematic characteristics, slip rates and seismic activity over time. This information is important to understand the active tectonics in Hispaniola, but it is also crucial to estimate the seismic hazard in the region. Here we show that a relatively constant NE‐directed shortening controlled the geometry and kinematics of main active faults in southern central Hispaniola, as well as the evolution of the Quaternary stress regime. This evolution included a pre‐Early Pleistocene D1 event of NE‐trending compression, which gave rise to the large‐scale fold and thrust structure in the Cordillera Central, Peralta Belt, Sierra Martín García and San Juan‐Azua basin. This was followed by a near pure strike‐slip D2 stress regime, partitioned into the N‐S to NE‐SW transverse Ocoa‐Bonao‐La Guácara and Beata Ridge fault zones, as well as subordinate structures in related sub‐parallel deformation corridors. Shift to D2 strike‐slip deformation was related to indentation of the Beata Ridge in southern Hispaniola from the Early to Middle Pleistocene and continues today. D2 was locally coeval by a more heterogeneous and geographically localized D3 extensional deformation. Defined seismotectonic fault zones divide the region into a set of simplified seismogenic zones as starting point for a seismic hazard modeling. Highest peak ground acceleration values computed in the Ocoa Bay establish a very high seismic hazard. Key Points Active faults in central southern Hispaniola are controlled by NE‐directed shortening Quaternary stress regime evolution includes a compressional D1 followed by a strike‐slip D2, locally coeval with an extensional D3 Modeling establishes a very high seismic hazard zone centered in the Ocoa Bay

Khonde, N.; Katange, K.; Singh, G.; Kumar, A.; Maurya, D.M.; Giosan, L., and Ghosh, T., 2024. Recent sedimentation across Kori Creek in the western Great Rann of Kachchh Basin: Insights from tidal network changes, sedimentological, clay mineralogical, and rare earth element studies. Journal of Coastal Research, 40(2), 289–302. Charlotte (North Carolina), ISSN 0749-0208. Kori Creek is one of the most important creeks along the coastline of the Kachchh basin and forms a connecting passage between the Arabian Sea and the Great Rann of Kachchh (GRK) basin. Historically, this region has supported maritime activities between the Kachchh region and Sindh (now part of Pakistan) and witnessed significant landscape changes in the past few centuries. This study demonstrates tidal network changes that occurred over the past four decades (from 1984 to 2020) using satellite data in the Kori Creek region and western GRK basin. The results show that Kori Creek extended more than 30 km landward during the past four decades on account of ongoing tectonic adjustment and headward erosion of tidal channels in the GRK. Short sediment cores collected across the Kori creek in a transect provided evidence of the establishment, extension of tidal channels, and changing dominance of tidal flooding and channel influences on the sediment distribution. The clay mineralogical composition of the Kori Creek region shows the dominance of illite and chlorite over smectite and kaolinite minerals in general. However, from north to south (KC-1 to KC-5), clay compositions show a relative increase in smectite, indicating an increasing contribution due to sediment redistribution from the Indus delta, probably through coastal currents in modern time. The Rare Earth Element composition of the Kori Creek sediments is consistent and shows homogenised sediments that were dominantly sourced from the felsic rocks in the hinterland. Presently, the Kori Creek sediments do not receive significant sediments from rivers in the terrestrial part, the mineralogical composition, and chemical signatures suggest the Indus and the GRK as secondary sources for the Kori Creek modern sediments.

The convergence zone of the Eurasian (EURA) and North Africa plate (NUBIA) is primarily marked by the activity between the Betics in south of Spain and the Rif and Atlas in Morocco. This area, where the diffuse tectonics between these plates are currently converging in a NW-SE direction, presents several continuous fault zones, such as the Betic–Alboran–Rif shear zone. The Royal Institute and Observatory of the Spanish Navy (ROA) currently operates geodetic stations in various parts of North Africa, some in particularly interesting locations, such as the Alhucemas (ALHU) rock, and also in more stable areas within the Nubian plate, such as Tiouine (TIOU). For the first time, the displacement velocities of the ROA CGNSS stations have been estimated to provide additional geodynamic information in an area with few stations. The obtained velocities have been compared with other recent studies in this field that included data older than 10 years or episodic campaigns without continuous stations. PRIDE (3.1.2) and SARI (February, 2025) software were used for processing, and the velocities were obtained by the ROA for international stations (RABT, SFER, MALA, HUEL, LAGO, TARI, and ALME). These initial results confirm the convergence trend between Eurasia and Nubia of approximately 4 mm/year in the NW-SE direction. It is also evident that there is independent behavior among the Atlas stations and those in the Moroccan Meseta compared to those located in the Rif mountain range, which could indicate the separation of smaller tectonic domains within the continental plate convergence zone. Along the Rif coast in Al Hoceima Bay, the faults are being approached; additionally, there is a slight clockwise displacement towards Melilla, which has also been demonstrated by stations in the Middle Atlas, such as TAZA. As for the stations in the Strait of Gibraltar, they exhibit a similar behavior until reaching the diffuse zone of the Guadalquivir basin where the diffuse convergence zone may exist. This may explain why stations to the north of the basin, such as LIJA or HUEL, change their behavior compared to nearby ones like SFER in the south. Furthermore, Alboran seems to follow the same displacement in direction and velocity as the other stations in North Africa and southern Spain.

China’s first optical stereo mapping satellite with a sub-meter resolution, GaoFen-7 (GF-7), launched in November 2019, shows significant potential for providing high-resolution topographic and geomorphic data for quantitative research on active tectonics. However, no studies have evaluated the capability of the GF-7-generated digital elevation model (DEM) for quantitatively studying active tectonics. This study aimed to validate the accuracy of the DEMs extracted from GF-7 stereo imagery, with or without ground control points (GCPs), and evaluated the potential of applying GF-7 DEMs to active tectonics. First, GF-7 stereo images were processed to obtain DEMs with a spatial resolution of 2 m, utilizing three different methods, including block adjustment without GCPs, block adjustment with the aid of Google Earth images and SRTM DEM, and block adjustment with GCPs derived from the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) data. These three generated DEMs were called GF-7 DEMMethod1, GF-7 DEMMethod2, and GF-7 DEMMethod3, respectively, and were verified by the airborne LiDAR data in the Hasishan section of the Haiyuan fault. Second, the capability of the GF-7 DEMs for identifying active faults, fault scarps, and horizontal offsets was evaluated. Finally, 8 vertical and 13 horizontal offsets were measured based on three different GF-7 DEMs, and airborne LiDAR data were used to verify the measurements’ accuracies. The results indicated that the accuracy of GF-7 DEMMethod1 was the worst and that of GF-7 DEMMethod3 was superior to that of GF-7 DEMMethod2. The GF-7 DEMs could effectively identify the apparent fault scarps and horizontal offsets. The RMSE values of the vertical offsets measured based on GF-7 DEMMethod1, GF-7 DEMMethod2, and GF-7 DEMMethod3 were 0.55 m, 0.55 m, and 0.41 m, respectively. The horizontal offsets yielded RMSE values of 3.98 m, 2.52 m, and 1.37 m, respectively. These findings demonstrated that vertical and horizontal offsets could be accurately measured using the DEMs generated from GF-7 stereo images. Meanwhile, our study indicated that the GCPs derived from ICESat-2 data could be utilized to improve the accuracies of the GF-7 DEM, and the measurements of vertical and horizontal offsets.

We present a user‐friendly and versatile Monte Carlo simulator for modeling profiles of in situ terrestrial cosmogenic nuclides (TCNs). Our program (available online at http://geochronology.earthsciences.dal.ca/downloads‐models.html) permits the incorporation of site‐specific geologic knowledge to calculate most probable values for exposure age, erosion rate, and inherited nuclide concentration while providing a rigorous treatment of their uncertainties. The simulator is demonstrated with 10Be data from a fluvial terrace at Lees Ferry, Arizona. Interpreted constraints on erosion, based on local soil properties and terrace morphology, yield a most probable exposure age and inheritance of 83.9−14.1+19.1 ka, and 9.49−2.52+1.21 × 104 atoms g−1, respectively (2σ). Without the ability to apply some constraint to either erosion rate or age, shallow depth profiles of any cosmogenic nuclide (except for nuclides produced via thermal and epithermal neutron capture, e.g., 36Cl) cannot be optimized to resolve either parameter. Contrasting simulations of 10Be data from both sand‐ and pebble‐sized clasts within the same deposit indicate grain size can significantly affect the ability to model ages with TCN depth profiles and, when possible, sand—not pebbles—should be used for depth profile exposure dating.