An electrical resistivity tomography survey was conducted to assess the subsurface conditions associated with the coseismic liquefaction phenomenon in the epicentral region following the M w 5.8 Mirpur earthquake (Pakistan) on 24 September 2019. The Mirpur earthquake produced extensive coseismic liquefaction-induced surface deformations, including: sand blows, ground failure and lateral spreading along the Upper Jhelum Canal and in the nearby villages. Electrical resistivity data were acquired along three profiles and calibrated with available borehole data. The inverted electrical resistivity tomography profiles reveal three regional geoelectric layers, which consist of an upper 2--5-m-thick discontinuous zones of medium resistivity values ranging from 25 m to 60 m, underlain by a 7-8-m-thick zone of low resistivity (<10 m) and a basal layer of high resistivity (> 100 m). Based on geological and geophysical data, we infer that. (1) disrupted geoelectric layers in the shallow subsurface and spatially extended low electrical resistivity (<8 m) layers document the elevated groundwater table due to sudden increase in pore-water pressure triggered by the Mirpur earthquake. These lenses of high conductivity may represent potential hazards in the case of future earthquakes in the study area. (2) Fracture azimuths vary between 120°± 15°and 335°-45°(subparallel and orthogonal to the strike of the Himalayan Frontal Thrust. (3) Common coseismic deformational features (e.g., sand blow and ground fracture) are located within the zone of maximum-recorded ground shaking (intensity of VI) and underlain by Quaternary alluvial sediments. (4) Mega fractures (1.60 m wide and up to 187 m long) oriented parallel to the canal resulted from lateral spreading. We conclude that high resistivity structures extending from depth to the shallow subsurface resulted from either intrusion of air or eruption of sands from layer three. We suggest that high-resolution geoelectrical imaging

Feedbacks between climatic and geological processes are highly controversial and testing them is a key challenge in Earth sciences. The Great Escarpment of the Arabian Red Sea margin has several features that make it a useful natural laboratory for studying the effect of surface processes on deep Earth. These include strong orographic rainfall, convex channel profiles versus concave swath profiles on the west side of the divide, morphological disequilibrium in fluvial channels, and systematic morphological changes from north to south that relate to depth changes of the central Red Sea. Here we show that these features are well interpreted with a cycle that initiated with the onset of spreading in the Red Sea and involves feedbacks between orographic precipitation, tectonic deformation, mid-ocean spreading and coastal magmatism. It appears that the feedback is enhanced by the moist easterly trade winds that initiated largely contemporaneously with sea floor spreading in the Red Sea.

Given active tectonism, rough terrain, and climate, the mountainous ranges in northern Pakistan are prone to geohazards, including earthquakes, unstable slopes, and landslides. The frequent landsliding in the region poses a risk to communities, economic activities, and transportation networks. In this context, the unstable slope above Mayun village calls for a multi-method approach for better assessment of the slope for planning interventions aimed at hazard mitigation. We conducted an integrated study including uncrewed aerial vehicle (UAV) and ground-penetrating radar (GPR) in coordination with geomorphic field observations to image the possible slip surfaces for a comprehensive understanding of a potential future rockslide with significant socioeconomic consequences. UAV-derived results helped delineate the overall extent of the unstable slope and its downslope area in a quick, remote, and safe way. GPR profiles have enabled the reconstruction of the bedrock’s morphology and its internal structure and the depth distribution of cracks running through the overburden and bedrock. The results provided insight into the stable and unstable compartments of the slope due to the thin cover of surficial deposits, high impedance contrast at the overburden-bedrock interface, lateral heterogeneities, and presence of open cracks, and almost detached blocks, respectively. These data on the dynamic properties of a landslide-prone slope could be used for the correct planning of civil infrastructure to minimize the potential risk of building damage in the seismically active Hunza valley.

Reconstructing the geometry of exhumation in the western Himalayan syntaxis region around Nanga Parbat is of critical importance to understanding how tectonics and surface processes interact during orogenesis. In order to determine the role played by the main Himalayan thrusts, we combine apatite U-Pb dating with apatite and zircon (U-Th-[Sm])/He analyses as well as apatite fission track dating from the Neelum valley region of Azad Jammu and Kashmir, Pakistan. Apatite U-Pb ages range from Proterozoic to mid-Miocene and can be separated into three age groups depending on the degree to which they have been affected by Himalayan tectonothermal events. Pooled fission track ages range from 7.0 ± 0.4 to 2.2 ± 0.4 Ma (1σ), apatite He ages range from 8.7 ± 0.2 to 2.0 ± 0.2 Ma, and zircon He ages range from 20.0 ± 0.4 to 6.1 ± 0.1 Ma. The data support rapid regional cooling at 10-8 Ma caused by the removal of 5-6 km of crust. This is synchronous with the initiation of movement along the Main Boundary thrust. Stream power analysis of the Neelum River catchment indicates a high normalized steepness index (k sn) of >500 m 0.9 along the major river and lower k sn in the headwaters. The boundary between the different apatite U-Pb age groups and the transition from high k sn to lower k sn values coincide with the mapped trace of the Main Central thrust, corroborating the presence of the thrust in the southwestern part of the region. Compiling all apatite fission track cooling ages from the Nanga Parbat syntaxis region shows that cooling age contours are parallel to the major thrusts. Collectively these data provide convincing support for the contention that the well-established pattern of exhumation known from much of the Himalayan front continues around to the western syntaxis of the Himalayas.