Relative active tectonics evaluation using geomorphic and drainage indices, in Dadra and Nagar Haveli, western India

The present study area,Dadra and Nagar Haveli,contains several lineaments and traces of active faults.The various aspect of the geomo rphic analysis,i.e.,stream length(SL) gradient,hypsometric integral(HI),basin shape(BS),valley floor(VF),have been applied to evaluate the relative index of active tectonics(RIAT) of the Damanganga watershed.The high and low zones of tectonic activity have been identified based on the geomorphic analysis of the watershed.After evaluation of all indices,three classes,class IIhigh(1.3 ≤RIAT <1.5),class Ⅲ-moderate(1.5 ≤RIAT <1.8),and class Ⅳ-low(1.8 ≤RIAT),have been obtained to outline the degree/gradation of comparative tectonic activities in the study area.The appraised outcome of the RIAT dispersal is also well reinforced by the geomorphic evidence in the field.The collective outcomes of geomorphic evidence,such as stream deflection and analysis of lineament,deflection of streams,and geomorphic indices,conceal that the Damanganga watershed is affected by tectonic activity.

Crustal Deformation Revealed by GPS in Kumaun Himalaya,India

The foremost Global Positioning System(GPS) derived measurements in the Kumaun Himalaya indicate that most of the crustal motion of the Indian plate is accommodating towards the base as well as on the hanging wall of Main Central Thrust(MCT).Deformation pattern within the Kumaun Himalaya varies from south to north and indicates maximum deformation rate near MCT.Our study,based on the campaign mode GPS survey during 2003- 2006,reveals that the area between north of North Almora Thrust(NAT) and at the base of Great Himalaya registers maximum strain rate,which is lowered towards the Trans Himadri Fault(THF).The GAMIT-GLOBK processed campaign data of the area show that currently,the Himalayan Frontal Fault(HFF) and Main Boundary Thrust(MBT) are locked with the Indian plate,and a 6.7 ± 2.5 mm/yr of horizontal shortening is taking place between the Lesser Himalaya and Peninsular India.

Geodetic characterization of active Katrol Hill Fault(KHF)of Central Mainland Kachchh,western India

After the M7.7 earthquake in 2001,the Kachchh rift basin became the focus of various geological and geophysical researches on the western Indian plate.As an essential technology,the Global Navigation Satellite System(GNSS)has been utilized to study the deformation pattern in the central mainland Kachchh.We select the east-west striking Katrol Hill Fault(KHF)as the study area and analyze the crustal deformation pattern using the datasets from 2014 to 2019.The geodetic results along the KHF reveal a mean deformation of about 2.1 mm per year,which is higher in the eastern part and lower in the central and western parts.The investigation of deformation and derived strain reveals the segmented behavior of KHF,while the dominance of compressive strain(maximum 22 nanostrain/yr)in the eastern segment makes it the most active segment of the KHF.A higher deformation rate along the eastern KHF can be considered significant in terms of seismic hazard for this part of the Indian plate.

Crustal deformation measurements by global positioning system(GPS)along NSL,western India

The Narmada Son Lineament(NSL)is a major palaeo-rift system and seismically active intra-plate region.In this paper,we processed and analyzed the GPS data from 2009 to 2016 to study the geodynamic characteristics of NSL.The velocities derived from GPS were used to calculate the associated deformation and crustal strain,while the slip deficit was estimated using the horizontal motion of GPS sites.The investigation reveals that the maximum deformation of western NSL is 1.6 mm per year,and the upper bound of the seismic moment(M;)is 2.0×10;dyn/cm,corresponding to an earthquake of about 6.0 magnitude.The study highlights the significance of Aravalli and Satpura mobile belts.The estimated strain of 0.03μstrain/yr is low but comparable to the stable continental region,and a close association of factors(the fragility,crustal conductors,and compressive tectonics)is considered responsible for seismogenic activities in western NSL.