Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Geology, Geochemistry, Geophysics, Archean, Subduction, and 3 moreCrust, Craton, and receiver function
Research Interests: Geology and Seismology
Passive source seismic imaging delineates fine crustal and lithospheric structures associated with the Kachchh rift zone (KRZ), Gujarat, India, which suggests a 4-7 km crustal thinning and 6-12 km asthenospheric thinning below the KRZ... more
Passive source seismic imaging delineates fine crustal and lithospheric structures associated with the Kachchh rift zone (KRZ), Gujarat, India, which suggests a 4-7 km crustal thinning and 6-12 km asthenospheric thinning below the KRZ relative to surrounding regions. The study also depicts a constant lithospheric thickness (~76-78 km) below the median high towards the west of Kachchh rift zone while a marked decrease in lithospheric thickness as well as shear velocity (Vs) is noticed across west to east and south to north of the rift zone, which perhaps suggests an increase in partial melt contents below the central KRZ in comparison to surrounding regions. Further, we notice that the seismogenic zone extends up to 34 km depth below the central KRZ. The hypocenters of the Bhuj 2001 earthquake sequence are found to be mainly concentrated in the mafic-to-ultramafic lower curst (14-34 km depth) below the central KRZ. The coincidence of common area of crustal thinning, asthenospheric upwarping and confined aftershock activity suggests that there is a possible causal relation between the occurrences of continued aftershock activity and a 6-10% drop in Vs (or presence of carbonatite melts) at lithosphere-asthenosphere boundary (LAB) below the central KRZ. This 6-10% drop in Vs can be attributed to a ~1-2% carbonatite melt currently present at the LAB. Thus, we interpret that the presence of aqueous fluids (released during the prograde metamorphic reactions of lower crustal olivine-rich rocks) and volatile CO2 [emanating from the crystallization of carbonatite melts at shallow upper mantle depths (i.e. 50-70 km)] at the hypocentral depths, might be playing a key role in generating the 2001 Bhuj earthquake sequence covering the entire lower crust.
Research Interests:
Research Interests:
The present study focuses on the delineation of the crust–mantle structure underlying the Kachchh rift zone (KRZ), by modelling P-wave receiver functions (P-RFs) and P-wave teleseismic tomography. Our RF study delineates marked crustal... more
The present study focuses on the delineation of the crust–mantle structure underlying the Kachchh rift zone (KRZ), by modelling P-wave receiver functions (P-RFs) and P-wave teleseismic tomography. Our RF study delineates marked crustal and lithospheric thinning below the central KRZ relative to the unrifted surrounding regions. This thinning model receives further support from crust-corrected normalized P-residuals, which suggest dominant negative residuals associated with the central KRZ. Teleseismic tomography using these P-residuals reveals low velocity to a depth of 170 km below the central KRZ, while there are positive residuals associated with the surrounding unrifted zones. Such a complex heterogeneous crust–mantle structure, which could be related to K/T boundary Deccan mantle plume activity and rift-related magmatism, might play a crucial role in seismogenesis of lower crustal earthquakes that have occurred in the KRZ since 2001. Inverted crust–mantle models obtained from P-RFs suggest a low shear velocity zone extending from 70–110 to 170–220 km depth beneath the central KRZ. This receives further support from the presence of low P-wave velocity down to 170 km modelled using teleseismic tomography. This lowVpandVszone in the upper mantle could be explained by the presence of trapped melts related to Deccan volcanism at 65 Ma or older rift-related magmatism.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Abstract In this paper, we outline the overview of the problem of intraplate seismicity and summarize our studies aimed at identifying potential earthquake sources in three regions located in continental environments. We study the French... more
Abstract In this paper, we outline the overview of the problem of intraplate seismicity and summarize our studies aimed at identifying potential earthquake sources in three regions located in continental environments. We study the French Massif Central situated within the West-European platform, the Gujarat area located at the northwestern edge of the Indian shield, and northeast Egypt located in the northeastern part of the African continent. These regions exhibit different levels of seismic activity. The French Massif Central reveals the lowest rate of seismicity, northeast Egypt exposes a low-to-moderate seismicity, and Gujarat reveals moderate seismicity with rare occurrence of strong events. We use a phenomenological approach for identifying possible locations of earthquakes, which is based on the pattern recognition applied to morphostructural data. The approach hypothesizes the nucleation of strong earthquakes at morphostructural nodes forming at the intersections of morphostructural lineaments, which are delineated by morphostructural zoning. Nodes are characterized by the pertinent geophysical and geological parameters, on the basis of which pattern recognition algorithm pinpoints capable nodes, i.e., the nodes where events of a certain sizes may occur. Seismic hazard assessment of continental regions is impeded because their seismic history is normally very pure. In such a situation, information on capable nodes is a necessary input for seismic hazard assessment. The example of northeast Egypt shows the exploiting capable nodes to assess seismic hazard by the Neo-Deterministic Seismic Hazard Assessment Methodology.
Research Interests:
Research Interests:
To monitor seismicity, a 10-station broadband seismic network was deployed in the Hyderabad region by CSIR-NGRI, Hyderabad, India, during 2020-21. The analysis of radial P receiver functions using data from this network detects... more
To monitor seismicity, a 10-station broadband seismic network was deployed in the Hyderabad region by CSIR-NGRI, Hyderabad, India, during 2020-21. The analysis of radial P receiver functions using data from this network detects conversions from five major crustal and mantle discontinuities below the region. Our CCP stacking of radial PRFs also images the nature and geometry of these seismic discontinuities viz., Moho (increase in positive amplitude at 30–40 km depths), Hales discontinuity (increase in positive amplitude at 90–120 km depths), lithosphere-asthenosphere boundary (LAB) (increase in negative amplitude at 130–160 km depths), 410-km (increase in positive PRF amplitude at 410–440 km depths) and 660-km (increase in positive PRF amplitude at 620–660 km depths). Our modeling also reveals that the mean depth to the Moho, Hales discontinuity and LAB below the study region are 36, 115 and 160 km, respectively, suggesting the absence of a thick cratonic root below the EDC. We also...
Research Interests:
Utilizing broadband waveform data from 52 stations, we model the detailed crustal structure below the Uttrakhand Himalaya through the Common Conversion Point (CCP) staking of radial P- receiver functions and seismic velocity tomography.... more
Utilizing broadband waveform data from 52 stations, we model the detailed crustal structure below the Uttrakhand Himalaya through the Common Conversion Point (CCP) staking of radial P- receiver functions and seismic velocity tomography. We detect marked lateral variations in the Moho depths dipping toward the east (i.e. perpendicular to the direction of the Indian plate motion), supporting the idea that deformations in the lower crust have been decoupled from the Upper Mantle below. We also model some double Moho structures across and along the strike of the collisional front, which could be the imprints of the broken Moho boundary resulted from the huge impact of the Himalayan collision. We detect a mid-crustal low-velocity zone between 10 and 20 km depth (10–20% drop in Vp and Vs, and 10–15% increase in Vp/Vs, suggesting the presence of metamorphic/aqueous fluids) associated with the main Himalayan thrust (MHT), which was responsible for generating the 1803 Mw7.6 Uttrakhand, 1991 ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Abstract On January 26, 2020, a moderate-sized earthquake ( M L ~ 4.6) located in the Palnadu sub-basin of Cuddapah basin was felt both in the states of Telangana and Andhra Pradesh. The earthquakes prior and after the M L 4.6 are located... more
Abstract On January 26, 2020, a moderate-sized earthquake ( M L ~ 4.6) located in the Palnadu sub-basin of Cuddapah basin was felt both in the states of Telangana and Andhra Pradesh. The earthquakes prior and after the M L 4.6 are located close to the thrust and along the periphery of the backwaters of the Pulichintala Reservoir. About 965 earthquakes in the magnitude range of 0.1–4.6 M L have been located by seismological network. The epicentral parameters obtained from double difference technique illuminated a steep seismogenic structure extending up to 8 km depth using a minimum 1-D velocity model. The b -value estimate is 0.82 for a completeness magnitude of M c 1.8 and could be associated with the intraplate event having a longer recurrence time. The focal mechanism solution obtained from waveform inversion reveals a pure double-couple mechanism of a strike-slip motion with a reverse component on a N–S trending focal plane. The spatial distribution of the earthquake sequence and fault plane solution of the main event are close to a thrust which is the most likely source region of the main-shock. Highlights Relocation of the Palnadu earthquake sequence illuminated a steep seismogenic structure extending up to 8 km depth. The estimated lower b-value (0.82) could be associated with the intraplate event having a longer recurrence time. The focal mechanism solution of the main-shock ( M L 4.6) shows a strike-slip motion with a reverse component.
Research Interests:
Research Interests:
Abstract Changes in the dominant tectonic regimes and the modes of formation and maturation of the continental crust during the Precambrian are a subject of active debate. Here, we discuss these issues in terms of new information on the... more
Abstract Changes in the dominant tectonic regimes and the modes of formation and maturation of the continental crust during the Precambrian are a subject of active debate. Here, we discuss these issues in terms of new information on the crustal and lithospheric architecture of the different terranes in the Eastern part of the Indian Shield (EIS). We present well-constrained estimates of the crustal and lithospheric thickness characterizing different terranes of the EIS through the joint inversion of P-receiver functions (PRF) and fundamental mode group velocity dispersion data of Rayleigh waves (10–100 s). The lithospheric thicknesses are also computed independently using the S-receiver function (SRF) modeling. The study involved 2167 PRFs and 100 SRFs from 15 broadband stations. Our modeling detects a marked crustal (~4–8 km) and lithospheric (~15–20 km) thinning beneath the Singhbhum-Odisha-Craton (SOC), spatially correlating with the central part of the craton comprising the gneissic terrain contrasted by a crustal thickening (~2–6 km) beneath the horseshoe-shaped Iron Ore Group. We propose that such a crustal configuration beneath the Paleoarchean craton may suggest the dominance of vertical tectonic processes such as thickening of an oceanic mafic plateau and recurrent melting producing the TTGs and the Singbhum Granite suite. Infra-crustal reworking involving Rayleigh-Taylor instabilities and gravitational processes could explain the crustal architecture of the SOC much similar to a few other Paleoarchean cratons such as Pilbara (Australia), Barberton and Kappvaal (South Africa). Our modeling has also revealed a relatively smaller degree of crustal (2–4 km) and lithospheric thinning (4–10 km) beneath the Eastern Ghat Mobile Belt, south of the SOC. We observe a relatively thicker crust (~42 km) characterized by a flat Moho over a large area (~40,000 sq. km) encompassing the Chota Nagpur Granite Gneiss Terrane (CGGT). Such thickening is consistent with the convergence and collision tectonics involving the SOC and CGGT. However, we note a 15–20 km lithospheric thinning associated with the CGGT. Such thinning may mainly relate to Phanerozoic rifting along the Damodar graben and Rajmahal magmatism. Broadly, our model of the crustal and lithospheric architecture of the EIS reflects the imprints of northward subduction of SOC beneath the CGGT.
Research Interests: Earth Sciences, Geology, Archean, Precambrian, Crust, and 3 moreCraton, Lithosphere, and receiver function
Research Interests:
The loss of human lives, properties and damages due to the occurrences of moderate to large size earthquakes have been a major concern for the economic development of many countries in the world. Earthquakes would continue to occur in a... more
The loss of human lives, properties and damages due to the occurrences of moderate to large size earthquakes have been a major concern for the economic development of many countries in the world. Earthquakes would continue to occur in a region and would remain among the most devastating natural hazards. Seismically active countries viz., China, India, Japan, USA, Mexico and a few other countries are classified as high earthquake hazard regions while continents/countries with low rate of earthquake occurrence include Africa, Australia, Canada etc. On many occasions in the past, high earthquake hazard countries have experienced major economic setbacks due to the occurrences of major earthquakes. In the present paper, the causative mechanisms of major devastating earthquakes of Mw≥7.5 in the Asian countries (including high hazard countries like China, Japan, India, Taiwan and Nepal) during the past 25 years and major damages rendered by these earthquakes is discussed.
Research Interests:
Since the initial collision at 55 Ma, rocks of the Indian crust below the Himalayas have undergone modification chemically and compositionally due to the ongoing India–Asia convergence. The local earthquake tomography images a shallow... more
Since the initial collision at 55 Ma, rocks of the Indian crust below the Himalayas have undergone modification chemically and compositionally due to the ongoing India–Asia convergence. The local earthquake tomography images a shallow (~ 1–2°) north-easterly dipping low-velocity layer (10–20% drop in Vp and Vs, 10–15% increase in Vp/Vs) beneath the region between 10 and 20 km depth, which is inferred as the main Himalayan thrust (MHT). The presence of this low-velocity layer may be attributed to the presence of aqueous/metamorphic fluids or high fluid pressure, which may trigger crustal earthquakes by lowering the frictional coefficient (~ 0.01–0.08) on the MHT. The 1803 M w 8.2 Garhwal, 1991 M w 6.8 Uttarkashi and 1999 M w 6.4 Chamoli earthquakes have also been modelled to be triggered on the MHT, by the presence of aqueous/metamorphic fluids or high pore-fluid pressure. Besides, our modelling predicts three un-ruptured similar low-velocity zones on the MHT for generating future moderate to large fluid-triggered earthquakes in the region. The mapped low-velocity anomalies at 25–35 km depths further support the idea of the presence of a relatively higher temperature due to the hotter mantle below, which induces ductile rheology that prevents the lower crustal seismicity.
Research Interests:
The earthquake hazard associated with the Main Himalayan Thrust (MHT) is a critical issue for India and its neighbouring countries in the north. We used data from a dense seismic network in Uttarakhand, India, to model the lateral... more
The earthquake hazard associated with the Main Himalayan Thrust (MHT) is a critical issue for India and its neighbouring countries in the north. We used data from a dense seismic network in Uttarakhand, India, to model the lateral variations in the depths of MHT (2–6% drop in Vs at 12–21 km depths), Moho (a sharp increase in Vs (by ~ 0.5–0.7 km/s) at 39–50 km depths) and lithosphere (a marked decrease in Vs(~ 1–3%) at 136–178 km depths), across the Himalayan collisional front. Our joint inversion of radial PRFs and group velocity dispersion data of Rayleigh waves detects three NNE trending transverse lithospheric blocks segmenting the lithosphere in Uttarakhand Himalaya, which spatially correlate well with the northward extension of the Delhi -Haridwar Indian basement ridge, an inferred tectonic boundary and great boundary fault, respectively. Our radial receiver function imaging detects highly deformed and segmented crustal and lithospheric structures associated with three mapped t...
Research Interests:
Understanding the dominant crustal accretion model in any Archean craton is the key to understanding the dominant geodynamic process responsible for early crust formation during the Hadean (> 4.0 Ga) and Archaean (4.0–2.5 Ga). The... more
Understanding the dominant crustal accretion model in any Archean craton is the key to understanding the dominant geodynamic process responsible for early crust formation during the Hadean (> 4.0 Ga) and Archaean (4.0–2.5 Ga). The continental crust has been proposed to have formed through either horizontal/vertical accretion related to subduction or mantle plume tectonic processes. Here, the Moho depths and average crustal Vp/Vs ratios are modelled at 16 broadband stations in the Eastern Indian Shield (EIS) through HK stacking of radial P-receiver functions (PRFs). These modelled parameters are used to test both plume and subduction models, which might have played a key role in the crustal accretion of the EIS throughout the Archean. We observe a correlation between crustal age and composition within the ellipsoidal Paleoarchean cratonic domain in the Singhbhum-Odisha-Craton (SOC), which reveals an increase in age from the younger granitoid core of the SOC (with thinning of felsi...
Research Interests: Geology, Geochemistry, Proterozoic, Archean, Subduction, and 4 moreCrust, Continental Crust, Craton, and felsic
Research Interests:
Research Interests:
The uncertainty in the empirical ground motion prediction models (GMMs) for any region depends on several parameters. In the present work, we apply an artificial neural network (ANN) to design a GMM of peak ground acceleration (PGA) for... more
The uncertainty in the empirical ground motion prediction models (GMMs) for any region depends on several parameters. In the present work, we apply an artificial neural network (ANN) to design a GMM of peak ground acceleration (PGA) for Kachchh, Gujarat, India, utilizing independent input parameters viz., moment magnitudes, hypocentral distances, focal depths and site proxy (in terms of average seismic shear-wave velocity from the surface to a depth of 30m (Vs30)). The study has been performed using a PGA dataset consisting of eight engineering seismoscope (SRR) records of the 2001 Mw7.7 Bhuj earthquake and 237 strong-motion records of 32 significant Bhuj aftershocks of Mw3.3-5.6 (during 2002-2008) with epicentral distances ranging from 1.0 to 288 km.We apply a feed-forward back propagation ANN method with 8 hidden nodes, which is found to be optimal for the selected PGA database and input-output mapping. The standard deviation of the error has been utilized to examine the performan...
Research Interests:
A seismic network of ten three-component broadband seismographs was deployed in and around Hyderabad city during September–October 2020, which enabled us to record a rare lower-crustal cratonic earthquake of Mw 3.9 that occurred on 25... more
A seismic network of ten three-component broadband seismographs was deployed in and around Hyderabad city during September–October 2020, which enabled us to record a rare lower-crustal cratonic earthquake of Mw 3.9 that occurred on 25 July 2021 (23:31:01.1) at 35 km depth below the region about 140 km south of Hyderabad city. Utilizing broadband waveforms from this network, we model source parameters and moment tensor solution of this rare event using simultaneous inversion of S-wave spectra and ISOLA software, respectively. The average corner frequency, seismic moment, moment magnitude, stress drop, and source radius are 3.87 Hz, 7.14E + 14 N-m, 3.8, 3.92 MPa, and 229 m, respectively. The modelled mean crustal Q varies from 506 (at VKB) to 4136 (at NLG), with an average of 2182 ± 1178, suggesting lower crustal attenuation below the Hyderabad region. We perform a deviatoric moment tensor inversion of multiple point sources on the band-passed (0.04–0.1 Hz) displacement traces of the Hyderabad event. The best fit is obtained at 35 km centroid depth, with a moment magnitude of 3.9, and a normal dip-slip mechanism with a minor strike-slip component with strike of 169°, dip of 65°, and rake of −113°. The P-axis orients N42°E, which is parallel to the direction of the absolute plate motion direction of the Indian Plate, while the T-axis orients E–W. The occurrence of this earthquake could be attributed to the sudden movement on the almost-vertical plane in the viscous lower crust due to high fluid pore pressure resulting from the presence of CO2-rich mantle fluids.
Research Interests:
The present work focuses on the three-dimensional mapping of fractal correlation dimensions and b-values of the Palghar (Maharashtra) and Pulichintala (Andhra Pradesh) regions of the Indian shield. The study is done using catalogues of... more
The present work focuses on the three-dimensional mapping of fractal correlation dimensions and b-values of the Palghar (Maharashtra) and Pulichintala (Andhra Pradesh) regions of the Indian shield. The study is done using catalogues of 8766 Palghar earthquakes of ML0.4–4.7 and 965 Puclichintala earthquakes of ML ranging from −0.4 to 4.6. The b-values are estimated using the maximum likelihood approach, while fractal dimensions are modelled using the correlation dimension approach. The b-value is modelled to be 0.88 ± 0.02 for the Palghar sequence and 0.75 ± 0.04 for the Pulichintala sequence. The modelled b- and D2-values vary from 0.1 to 2.5 and 0.39 to 2.62, respectively, for the Palghar sequence, while they vary from 0.2 to 1.68, and 0.68 to 3.0, respectively, for the Pulichintala sequence. The modelled large b-value (~ 2.5) for the Palghar sequence in particular signifies the typical characteristic of swarm earthquakes. We examine the b-D2 correlations for both the swarm activity sequences and found a positive correlation (i.e. D2 = 1.085 + 0.0015b) for the Palghar sequence while a negative correlation (i.e. D2 = 0.99–0.0414b) for the Pulichintala sequence. The spatial distribution of D2 and b-values suggests that the seismicity in the Palghar region is occurring in the areas with lower to moderate b-values and moderate correlation dimensions, while the seismicity in the Pulichintala region is occurring in areas with moderate b-values and higher D2 values. Based on our results, we interpret the Palghar region as a high tectonic stress region, which can generate moderate earthquakes in future, while the Pulichintala region is a low stress region that can accumulate low levels of tectonic stress posing relatively less earthquake hazard.
Research Interests:
To comprehend the seismo-tectonic process of the aftershock zone of the 26 January 2001 Mw 7.7 Bhuj earthquake sequence of Mw 7.7, we relocated 999 aftershocks (M w 2.0-5.3) using HYPODD relocation technique and the data from a close... more
To comprehend the seismo-tectonic process of the aftershock zone of the 26 January 2001 Mw 7.7 Bhuj earthquake sequence of Mw 7.7, we relocated 999 aftershocks (M w 2.0-5.3) using HYPODD relocation technique and the data from a close combined network (NGRI, India and CERI, USA) of 8-18 digital seismographs during 12-28 February 2001. These precisely relocated aftershocks (ERH < 30 meter, ERZ < 50 meter) delineate an east-west trending blind thrust dipping (~ 45 The tomographic inversion technique is used to invert 5516 P-travel times and 4061 S-P travel time differences from 600 aftershocks recorded at 8 to 18 stations. Tomographic results suggest a regional high velocity body (characterized by high Vp (7-8.5 km/s), high Vs (4-4.8 km/s) and small σ (0.24-0.55)) with a head extending 60 km in N-S and 40 km in E-W at 10-40 km depths. This high velocity anomaly is inferred to be a mafic pluton/rift pillow, which might have intruded during the rifting time (~135 Ma). Another impor...
The Indo-Burman arc is the boundary between the India and Burma plates, north of the Sumatra–Andaman subduction zone. The existence of active subduction in the Indo-Burman arc is a debatable issue because the Indian plate converges very... more
The Indo-Burman arc is the boundary between the India and Burma plates, north of the Sumatra–Andaman subduction zone. The existence of active subduction in the Indo-Burman arc is a debatable issue because the Indian plate converges very obliquely beneath the Burma plate. Recent GPS measurements in Bangladesh, Myanmar, and northeast India indicate 13–17 mm/y of plate convergence along a shallow dipping megathrust while most of the strike-slip motion occurs on several steep faults, consistent with patterns of strain partitioning at subduction zones. A short period of instrumentally recorded seismicity and sparse historical records are insufficient to assess the possibility of great earthquakes at the Indo-Burman megathrust. Using the advantage of the Block-and-Fault Dynamics model allowing simultaneous simulation of slow tectonic motions and earthquakes, we test the hypothesis whether the India-Burma detachment is locked and able to produce great earthquakes, or it slips aseismically?...
Research Interests:
Research Interests:
Abstract The shear-wave splitting parameters (i.e. fast axes orientation (ψ) and delay time (δt)) are measured at four broadband stations in Rajasthan, using SKS/SKKS core phases from three-component broadband waveforms of 30 events... more
Abstract The shear-wave splitting parameters (i.e. fast axes orientation (ψ) and delay time (δt)) are measured at four broadband stations in Rajasthan, using SKS/SKKS core phases from three-component broadband waveforms of 30 events recorded during 2014–16. The thicknesses of lithosphere at these four stations are also inferred from the estimated delays. The average splitting parameters (ψ, δt) at the northern-most (JAI) and southern-most (BAN) stations are modeled to be 36.44° ± 08.36° and 1.48 ± 0.32 s, and 35.72° ± 10.47° and 1.86 ± 0.34 s, respectively. While these parameters at UDI and BUN stations are found to be 41.08° ± 08.54° and 1.61 ± 0.26 s, and 43.86° ± 08.96° and 1.68 ± 0.27 s, respectively. Thus, our modeling reveals a mean fast axes orientation of (39° ± 9°) with a mean delay of 1.7 ± 0.3 s, for Rajasthan, which could be attributed to the frozen lithospheric anisotropy in the direction of current absolute plate motion of the Indian plate. A slight regional variation of observed orientation of fast axes ranging from 35.7°(at BAN) to 43.9° (at BUN)could be attributed to the tectonic control rather than current plate motion. In addition, the mean orientations of fast axes are measured to be 36.4o at UDI and 41.1o at JAI, respectively. Thus, this observed coherent variation of fast axes orientation across the Rajasthan suggests a significant contribution from the asthenospheric flow. Further, estimated mean delay time (1.7 ± 0.3 s) does also suggest a contribution from the anisotropy associated with asthenospheric flows. The maximum delay (∼1.86 s) is estimated at southernmost BAN station, suggesting a thick anisotropic layer of ∼214 km, while minimum delay (∼1.48 s) is modeled at northernmost JAI station, suggesting a 170-km thick anisotropic layer. While asthenospheric layer thicknesses at UDI and BUN are found to be 185 and 193 km, respectively. This observation suggests a relatively more anisotropic and thick lithosphere in the south in comparison to that in the north. The measured deviation of fast axis orientation from the absolute Indian plate motion varies from 1 to 4.3°, which could be related to the changes in asthenosphric flow pattern due to the presence of topography at the base of lithosphere.
Research Interests:
Research Interests:
MIB Raposo, AO Chaves, P. Lojkasek-Lima, MS D’Agrella-Filho and W. Teixeira................... 43 Development of fluid conduits in the auriferous shear zones of the Hutti Gold Mine, India: evidence for spatially and temporally heterogeneous fluid flow J. Kolb, A. Rogers, FM Meyer and TW Vennemann...more