NW Himalaya Research Articles

Ground motion prediction equation for NW Himalaya and its surrounding region

An attenuation relationship, also known as a Ground Motion Prediction Equation (GMPE), has been developed for the Northwest Himalaya and its surrounding region. This GMPE utilizes strong motion data recorded by two networks: the National Center for Seismology Network and the strong motion network installed by Indian Institute of Technology Roorkee named PESMOS. For the development of this GMPE, 309 strong motion records from 86 earthquakes that occurred between 2005 and 2021 were considered. The selected earthquakes have magnitudes ranging from 3.0 to 6.9. In this study, the average of Peak Ground Acceleration (PGA) of two horizontal components was used to develop the new attenuation relationship. A multi-regression model was chosen for the analysis. The proposed attenuation relationship is.Log10 PGA = 1.889 + 0.3996 × M - 0.95736 log10 (HD + exp (0.4114 × M)) ± 0.3646Where, PGA is peak horizontal acceleration in gal of strong ground motion, M is the magnitude, and HD is the hypocentral distance from the source. The standard error of the proposed relationship is 0.3646. This newly developed attenuation relationship holds significance for various applications, including site-specific studies, seismic hazard estimation, ground motion simulation, earthquake early warning (EEW), and engineering applications. It provides valuable insights into the behavior of ground motion in the Northwest Himalayan region, allowing for better preparedness and mitigation strategies against seismic hazards in the area.

The origin of the ultrahigh-pressure Tso Morari complex, NW Himalaya: implication for early Paleozoic rifting

AbstractThe origins and age distribution of the Himalayan high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks are critical for understanding the pre-Himalayan history. Although the protoliths to the UHP Tso Morari eclogites in Ladakh, NW Himalaya are believed to be the Permian Panjal volcanics, the geochronological evidence is absent. Here, we demonstrate that the protoliths of the UHP Tso Morari Complex formed in a continental rift setting at the Indian margin associated with the northern East Gondwana during the Early Paleozoic. Zircon U–Pb dates from eight gneisses and one garnet amphibolite indicate the Early Paleozoic bimodal magmatism of 493–476 Ma, which could be associated with the separation of South China from North India. Except for arc-related eclogites found in the Nidar ophiolite, the eclogites and amphibolites are rift-related, exhibiting enriched light rare earth elements and high concentrations of incompatible elements, along with evidence for crustal contamination. Our findings support the previously reported diversity in the sources and ages of the protoliths of the Himalayan HP–UHP metamorphic rocks along the orogen.

Surin-Mastgarh Anticline in NW Himalaya from 2D seismic data, and its implication on geotectonics and hydrocarbon exploration

Surin-Mastgarh Anticline in NW Himalaya from 2D seismic data, and its implication on geotectonics and hydrocarbon exploration

3D Crustal Structure of the Jammu and Kashmir Himalaya: Signatures of Mid‐Crustal Ramp and Lesser Himalayan Duplex

AbstractThe NW Himalayan “seismic gap” lies between the 1905 and 2005 earthquake rupture zones and straddles the meisoseismal zone of the 1555‐Kashmir earthquake. Sufficient elastic strain has now accumulated across this region to drive a mega‐thrust earthquake. We model the crustal structure and geometry of the Main Himalayan Thrust (MHT) using Jammu and Kashmir Seismological NETwork data. P‐wave receiver‐function spatial and common‐conversion‐point (CCP) stacks, and joint inversion with Rayleigh‐wave group‐velocities are used to construct 3D Vs model of the region. This model reveals increasing crustal thickness from foreland‐to‐hinterland, and an under‐thrust Indian crust beneath NW Himalaya. The Moho is at ∼45 km depth beneath Sub‐Himalaya deepening to ∼70 km beneath Higher‐to‐Tethyan Himalaya with a gentle NE dip. The MHT forms a low‐velocity layer and has a flat–ramp geometry. The flat segment is beneath Sub‐to‐Lesser Himalaya at 6–10 km depth, and dips ∼4°. The mid‐crustal (frontal) ramp is beneath Kishtwar Higher‐Himalaya and Zanskar Range at 10–16 km depth, and dips ∼13–17°. Crustal structure varies along‐arc between east (Kishtwar) and west (Kashmir Valley) segments. A Lesser Himalayan duplex (LHD) lies beneath the Kishtwar Window and is bound by MHT and Main Central Thrust. The LHD high‐angle imbricate structures are illuminated by moderate seismicity. Beneath Kashmir Valley, the underthrust crust is ∼10 km thicker, has higher crustal Vs, and a shallower MHT at ∼10 km depth. The westward shallowing of MHT occurs through a lateral ramp. Aftershocks of the 2013‐Kishtwar earthquake concentrate on the frontal–lateral ramp intersection and mark the MHT down‐dip locked‐to‐creep transition.

Clay minerals as paleo-climate proxy in Quaternary Dun sediments, NW Himalaya, India

Clay minerals as paleo-climate proxy in Quaternary Dun sediments, NW Himalaya, India

Magmatic records from the Karakoram terrane: U–Pb zircon ages from granites and modern sediments in the Nubra Valley, NW Himalaya

The Karakoram terrane is a sliver of peri-Gondwana continental crust preserved within the Karakoram and Saltoro ranges in Ladakh, India. It became a part of Eurasia during the Jurassic, and until Late Cretaceous its southern margin was an active continental margin represented by the Karakoram (Arc) Batholith. Its magmatism is thought to be extinguished during Late Cretaceous by collision with the Shyok ophiolite, however, geochronological data are limited. The Karakoram terrane is a key element in the geodynamics of Himalaya and more studies are needed to improve geological understanding and tectonic evolution of the southern margin of Eurasia pre- and post- final continental collision with the Indian continent. We present petrographic, geochemical, and geochronological observations for anatectic magmatism which formed granitic intrusions within the terrane at c. 14 Ma and 12 Ma. Results from detrital zircon dating of modern sediments from the Karakoram terrane reveal three distinct age populations at c. 108, 82, and 13 Ma which correspond to known geological events. Current geochronological data for the Karakoram terrane indicate presence of two major magmatic episodes, the first occurred during Jurassic–Cretaceous and was related to subduction processes, and second, occurred during the Miocene and was related to the anatexis of the Karakoram lithosphere upon the terminal continental collision. The intervening magmatic events are still uncharacterised.

Comments on Malik et al., 2023. Geological evidence of paleo-earthquakes on transverse rightlateral strike slip fault along the NW Himalayan front: Implications towards fault segmentation and strain Partitioning. Journal of Asian Earth Sciences 244, 105518. https://doi.org/10.1016/j.jseaes.2022.105518

Comments on Malik et al., 2023. Geological evidence of paleo-earthquakes on transverse rightlateral strike slip fault along the NW Himalayan front: Implications towards fault segmentation and strain Partitioning. Journal of Asian Earth Sciences 244, 105518. https://doi.org/10.1016/j.jseaes.2022.105518

Replies to comments raised by Singh T., and Rajendran C.P. On paper “Geological evidence of paleo-earthquakes on a transverse right-lateral strike-slip fault along the NW Himalayan front: Implications towards fault segmentation and strain partitioning” by Malik et al. (2023), [JAES, 244, 105518

Replies to comments raised by Singh T., and Rajendran C.P. On paper “Geological evidence of paleo-earthquakes on a transverse right-lateral strike-slip fault along the NW Himalayan front: Implications towards fault segmentation and strain partitioning” by Malik et al. (2023), [JAES, 244, 105518

Creeping slopes in NW Himalaya and Joshimath slide: constraints from GPS measurements

Slow slope movement is very common in the Himalayan region. In most cases, the topsoil, weathered rock mass, debris of paleo-landslide or of glacial origin, etc. slowly slides until it stabilizes or fails. In some cases, even the bedrock may be involved in sliding. Here we report four such sliding slopes on which GPS were actually installed for tectonic deformation monitoring in the Himalayan region after a careful investigation but they recorded slow slope sliding. The slow sliding motion on these slopes varied from 10-15 mm/year to 5-6 m/year. The slow slides did not show any anomalous seasonal variation due to hydrological loading. Amongst the four, the Joshimath slide exhibited a large variation in sliding motion which varied from less than a mm/day to 15 mm/day during 2022-2023, causing cracks on the ground and buildings and panic amongst the residents. Even the highly non-linear motion with a sudden change in sliding motion at Joshimath appears to be of viscous creep type. The exact time of initiation of this episode of slide is not known but the available InSAR analyses imply that it is moving at least since 2018. Its motion does not seem to be affected by the February 7, 2021 floods, however, whether the anthropogenic activities around the sliding zone influenced its motion and initiation, remains to be debated.

Response of NPK Fertilization and Irrigation in Nutrient and Soil Moisture Distribution Under High-Density Apple Plantation in the NW Himalayan Region

ABSTRACT Drip fertigation provides enormous opportunities for the effective utilization and distribution of water and nutrients in sustainable management of orchard. Under various drip irrigation and fertigation schedules, the analysis of NO3 −-N and NH4 +-N distribution within the soil has been found to be efficacious to enhance the crop growth. Over the 2-year period of study (2019 and 2020), the response of NPK fertilization and irrigation in nutrient and soil moisture distribution under high-density apple plantation in the NW Himalayan region was investigated. In the present study, under drip irrigation, the wetting front extended up to 45 cm horizontally from the emitter; however, the maximum increase in soil moisture content remained confined near the emitting point. The soil moisture content decreased consistently with the increasing horizontal distance from the emitter. Drip irrigation recorded a higher soil moisture content at the surface soil depth of 0–15 cm compared to conventional surface irrigation, where the sub-surface soil depths of 15–30 cm registered a higher moisture content. The distribution of NO3 −-N and NH4 +-N content under drip fertigation nearly followed the soil moisture distribution pattern. The NO3 −-N and NH4 +-N content was maximum below the emitter and decreased thereafter with the increasing lateral distance from the emitter as nutrient mobility in soil is primarily governed by water movement. The decreasing trend of NO3 −-N and NH4 +-N with the increasing lateral distances is in accordance with the water distribution pattern under drip irrigation. The nutrient mobility is proved to be well pronounced under the drip fertigation system, and nutrients carried along with the water movement get concentrated near the outer periphery of the wetting zone.

Mass multiplication of Trichoderma asperellum on conifer needles and weed foliage

The impact of hazard by chemical fungicides has necessitated the development of safe and eco-friendly bio-fungicides. Trichoderma asperellum is one of the potent biocontrol agents and for its cost-effectiveness large scale production on several agricultural and industrial wastes has been tested so far. Forest fire due to highly inflammable pine needles and invasion of weeds are considered as a major cause of biodiversity loss in forests of NW Himalaya. Therefore, in the present work, the potential of forest wastes like needles of five conifer species and foliage of three noxious weeds along with some commonly used substrates were evaluated for the mass production of T. asperellum. Amongst all the screened substrates, the highest spore count was recorded on Pinus roxburghii needle powder supplemented with yeast extract and potato dextrose broth. Therefore, authors recommend the use of P. roxburghii needles for the mass multiplication of Trichoderma species as a replacement for useful agro-wastes.

Sedimentological Attributes of the Middle Jurassic Samana Suk Formation Exposed in Village Rani-Wah Haripur, Southern Hazara Basin (NW Himalayan Fold and Thrust Belt, Pakistan)

Sedimentological Attributes of the Middle Jurassic Samana Suk Formation Exposed in Village Rani-Wah Haripur, Southern Hazara Basin (NW Himalayan Fold and Thrust Belt, Pakistan)

Longitudinal Profiles and Geomorphic Indices Analysis on Tectonic Evidence of Fluvial Form, Process and Landform Deformation of Doodhganga, SW Kashmir Valley, NW Himalayas

Longitudinal Profiles and Geomorphic Indices Analysis on Tectonic Evidence of Fluvial Form, Process and Landform Deformation of Doodhganga, SW Kashmir Valley, NW Himalayas

Ascertaining Potential Causes of Hillslope Failure Associated to Human Settlement: A Case Study from Alaknanda Valley, Uttarakhand, NW Himalaya, India

Abstract Growing human population along the river valleys in hilly terrain particularly on the fluvial sediments poses increasing risk of terrace instability and subsequent failure. Such instability and failure result in frequent loss of settlement, agricultural lands, and often lives. Alaknanda River valley in Uttarakhand comprises many fluvial terrace slopes that accommodate human settlement and hence one such fluvial terrace slope was taken as a case study area. On Feb. 28, 2022, Saari (or Sari) village, situated on the fluvial sequence, witnessed a slope failure collapsing 3 houses but no casualties. The hillslope with a total disturbed area of ~3889±5.0 m2 and failed material volume of ~16858±4.3 m3 partially dammed a tributary of Alaknanda River, which passes through the toe of the failed slope. The present study is an attempt to understand the instability that led to such failure because there was no extreme rainfall or earthquake prior to this failure. Preand post-failure topography of slope was used to demarcate the detachment and deposition zones. Pre-failure topography was used to perform the Finite Element Method (FEM) based slope stability simulation. In order to evaluate the possible contribution of exposed rockmass in failure, kinematic analysis was also performed. Results revealed the development of displacement pattern, particularly due to anthropogenic loads that must have initiated this failure. Such studies are primary requisites for an effective disaster mitigation in the NW Himalaya where growing human population on fragile hillslopes are at risk.

Paleoseismological investigation along the back thrust bounding the northern limb of Janauri Anticline, NW Himalaya, India

Regardless of numerous paleoseismological studies along the active front of the Himalayas, it still lacks precision with respect to earthquake recurrence, rupture, slip mechanism, etc. which hinders understanding of the region's seismic hazards. Considering the seismic hazard posed by the previous Himalayan earthquakes, for instance, from Kashmir, Chamba, Kumaun-Garhwal, Nepal, etc., it becomes vital to identify the seismogenic structures and length of rupture that might be affected in the near future. In the present study, the paleoseismological investigation is carried out along the ∼150 km long Back Thrust (BT) of Himalayan Frontal Thrust bounding the northern limb of Janauri Anticline (JA) in northwest frontal Himalaya. By taking advantage of the optically stimulated luminescence (OSL) dating technique, the present study reports three newly identified seismic events along the BT i.e. 535-1269 AD Event I, 1447–1636 AD Event II, and 1660–1929 AD Event III. Our findings at Palahta locality of Punjab state complement, i.e., 1447–1636 AD (Event II), the effectiveness of previously identified more recent earthquake (MRE) at Hajipur, which further suggest the rupture length of ∼97 km along BT. The other results on the timing of seismic events (Event I and Event III) are well thought out and considered here as independent. Such independent events tend to fill an important gap in the database and provide us an opportunity to explore the paleoseismic events in more detail along the seismogenic structures of the Himalayas. Such a well-established database would assist in better seismic hazard estimation and will directly influence the long-term planning for infrastructure development in the regions like the Himalayas.

Joint Regression Analysis of Variance for Seed Yield and its Attributing Traits by Eberhart and Russell (1966) Model in Black Gram (Vigna mungo L.) Under Rainfed Conditions of NW Himalaya’s

Joint Regression Analysis of Variance for Seed Yield and its Attributing Traits by Eberhart and Russell (1966) Model in Black Gram (Vigna mungo L.) Under Rainfed Conditions of NW Himalaya’s

Evidence of Strain Accumulation and Coupling Variation in the Himachal Region of NW Himalaya From Short Term Geodetic Measurements

AbstractHimachal region of Northwest Himalaya exhibits the widest structural re‐entrant in Kangra region and significant strain partitioning along the frontal and hinterland out‐of‐sequence faults. We report results of continuous GPS measurements from 10 new sites in the region and analyze them along with the previously published results to constrain the ongoing arc‐normal and arc‐parallel convergence rates at 16.5 ± 1.1 and 4–5 mm/yr respectively. Thus, the ongoing convergence is oblique by 15°–20°. The Main Himalayan Thrust (MHT) is strongly coupled up to ∼100 km from the Main Frontal Thrust but displays significant variation in coupling in the transition zone across the Kangra re‐entrant and the adjoining western salient. Joint analysis of the coupling variation, the geologically inferred MHT geometry variations and the local topographic anomaly pattern strongly suggest the possibility of a potentially active, strain accumulating segment of MBT along the southern margin of Dhauladhar ranges in Western Himachal region, which is also proposed to be influencing the long‐term topographic growth in the region. Although a general agreement is observed between the long‐term shortening rates along the active faults and the estimated geodetic convergence in this region, the ensuing discussion highlights their complex relationship in terms of temporal and spatial variability in the fault activity and elastic‐inelastic deformation. We use the fault orientation and the estimated convergence rate to geometrically constrain a mean dextral slip‐rate of 4.4–5.7 mm/yr along a recently discovered Khetpurali‐Taksal fault, which is proposed to partition the majority of ongoing arc‐parallel deformation along it.

Deciphering Hydrochemistry and Fluid-Mineral Equilibria from Characteristic Low-Enthalpy Geothermal Waters of Himalaya and Eastern India

Geothermal energy, with associated low-carbon emissions compared to conventional fossil fuels, is presently one of the potential renewable energy sources. The decryption of the chemistry of thermal manifestations of geothermal systems, in terms of relative abundances of various chemical facies, is mandatory before launching systematic geothermal exploration in a given area as it provides valuable information on the basic characteristics of the geothermal reservoir. For the present study, three clusters of hot springs have been selected -1) Shyok-Nubra valleys geothermal prospect in NW Himalaya, 2) Subansiri valley geothermal areas in NE Himalaya and 3) the hot spring system occurring along Munger-Saharsa Ridge Fault Zone (MSRF) in the Eastern part of India. The study of these geothermal systems with low to moderately high temperatures of 35−75°C, has been carried out with two main objectives. The first objective is to estimate reservoir temperature and other characteristics in the three above-mentioned hot spring groups using conventional chemical geothermometry techniques for the first-hand assessment of the quality of the geothermal resource and postulating its possible application. The second objective of the study is to understand the distribution of stable isotopes (δ2H and δ18O) in the studied geothermal systems to reveal reservoir-related hydrological aspects of the geothermal system. The three groups of hot springs show large variations in total dissolved solids (TDS) from <150 to about 1800 mg/L. Enigmatic and inexplicably low TDS values of 126 to 150 mg/Lare reported from the three Bhimband hot springs along MSRF Zone. These springs discharge Ca−Mg−HCO3 type water. The dearth of dissolved ionic species in these springs indicates lack of water-rock interaction in Bhimband area. Silica is the most abundant solute species and corresponds to a reservoir temperature of about 75°C. It may be inferred that relatively inert lithology in the reservoir and very high water-to-rock ratio might have rendered the observed chemical signatures to Bhimband hot springs. Shyok-Nubra springs at Changlung and Panamik are predominantly Na-HCO3 type with TDS values of about 1700 and 550 mg/L, respectively. These hot springs give an indication of water-rock interaction in different types of lithology at temperatures of 120 to >150°C resulting in the observed chemical differences between the two. Thermal water at Taksing in NE Himalaya is also Na−HCO3 type. Chetu hot spring with TDS of >1100 mg/Lis anomalous in two ways. First, it has a very high SO4 content of 358 mg/Land second, it has the lowest silica value. There is a possibility that the Chetu hot spring has its chemistry influenced by the dissolution of sulfates of Ca and Na. Preliminary stable isotope study indicates that the geothermal fluid is derived from meteoric sources. The lack of any indication for positive δ18O-shift suggests that reservoir temperatures of the springs are generally low. Keywords: Thermal Waters, Hydrogeochemistry, Reservoir Temperature, Stable Isotopes, Himalayas, Bihar

Depth-dependent seismic anomalies and potential asperity linked to fluid-driven crustal structure in Garhwal region, NW Himalaya

Characterizing the stress heterogeneity and crustal complexities are essential to understand the important aspects of rupture development and its propagation in a tectonically active region. We analyze a continuous seismic data (1999–2020) to estimate stress drops, b-value, fractal dimension (Dc) and focal mechanisms using a local network of 14 broadband stations. Seismic periodicity on a Himalayan major thrust above locked zone, involves long period of stress accumulation and interseismic strain. There exist a good spatio-temporal-depth correlation between the estimated results which indicates the positive anomaly at 12–14 km (stress transition) beneath the Chamoli region. Interestingly, this region shows maximum geodetic strain rate with comparatively high-stress drop, low coefficient friction value and very low b- (0.583 ± 0.02) and Dc- (1.20 ± 0.01) values. Majority of moderate to strong earthquakes and swarms activity have occurred in this region with maximum crustal accommodation. It is also observed that the significant temporal decrease in b-value always followed by moderate earthquakes. Here shallow crustal potential seismogenic asperity controls the earthquake's stress drop and rupture propagation. The observed correlations strongly support the evidence of entrapped fluid-faults interaction which alters pore pressure and generates numerous ruptures. Also, the role of pressurized entrapped fluids and roughness of fault-plane responsible for low friction zone and microseismicity. Continuous stress accumulation along the fault-plane within the asperity could release significant amount of energy in future.

Comparative Assessment of Nutrient Management Technologies for Yield, Quality, Nutrient Use Efficiencies and Economics of Cauliflower-Tomato Production System Under Subtropical Conditions in NW Himalayas

ABSTRACT Cauliflower and tomato are two most important cash crops of the North-Western part of Himalayas often grown in sequence and bring remunerative returns to the farmers of mid-hill region. The study was undertaken in order to evaluate the effect of application of various nutrient combinations through organic and inorganic inputs on the post harvest soil fertility status, crop quality parameters, nutrient use efficiencies, nutrient harvest indices, and economics of the cauliflower–tomato production system. The total of 11 treatment combinations, comprising sole organics, graded doses of inorganics and substitution of inorganics with organic inputs were studied. The study concluded that the application of 75% NPK + 100% FYM + 25% recommended N through FYM and VC on 50:50 N-equivalence basis significantly improved most of the quality and yield parameters in both the crops simultaneously giving highest N (197.8 kg ha−1) and K (167.4 kg ha−1) uptake, NUE (46.3%), AE (57.0 kg kg−1), P harvest index (50.7%) and net returns (5476 US$ ha−1) in cauliflower. This treatment was also accorded with significantly highest N (141.9 kg ha−1), P (30.6 kg ha−1), and K (185.0 kg ha−1) uptake, NUE (33.6%), AE (115.4 kg kg−1), and net returns (7858 US$ ha−1) in tomato. Hence, it is concluded that 75% NPK + 100% FYM + 25% recommended N through FYM and VC on 50:50 N-equivalence basis may be adopted as cost-effective nutrient module for farmers following cauliflower–tomato cropping sequence to achieve higher crop production on sustainable basis.