P V VIJAYA KUMAR
Articles written in Journal of Earth System Science
Volume 126 Issue 7 October 2017 Article ID 0101
Frequency characteristics of geomagnetic induction anomalies in Saurashtra region
P V Vijaya Kumar P B V Subba Rao C K Rao A K Singh P Rama Rao
Magnetovariational studies were carried out along four different EW profiles in Saurashtra region in different phases, during January 2007–March 2012. Transient geomagnetic field variations (X, Y horizontal field and Z vertical field components) recorded along these profiles are analyzed to infer the electrical conductivity distribution of the region. The vertical field transfer functions which depict the characteristics of electrical conductivity distribution are presented in the form of induction arrows. From the spatial distribution of these arrows, it is inferred that the sediments filling the offshore basins have more conductivity than those basins in Saurashtra region.
Volume 130 All articles Published: 24 May 2021 Article ID 0102 Research Article
P V VIJAYA KUMAR P B V SUBBA RAO A K SINGH AMIT KUMAR P RAMA RAO
Magnetotelluric (MT) data has been collected along 32 stations along E–W profile in northern part and eight LMT (long period MT) stations in north-central part of Saurashtra region. Dimensionality analysis is carried out prior to MT modelling for obtaining the subsurface dimension as well as the direction of the underlying substructures. To estimate the subsurface dimensionality from MT data, different techniques Swift skew, Bhar’s skew, normalized weights, phase tensor (PT) analysis and Wall’s rotational invariant approach have been applied. These results suggest 1D structure for lower periods (0.01–1 s) and 3D structure for higher periods (1–10000 s) along two different profiles indicating that the study area is highly heterogeneous. Regional strike has been estimated through phase tensor (PT) and Groom–Bailey (GB) techniques suggests N40$^{\circ}$ E regional strike direction that correlates well with the Delhi–Aravalli tectonic trend. 2D modelling of MT/LMT data sets brings out different resistivity and conductivity blocks. Basaltic magmatic intrusion and its recrystallization have resulted in resistivity blocks with conductivity anomalies (trapped fluids) in between them. It has been reflected as 3D structures at higher periods. Different sedimentary basins at shallow depth are observed as 1D structure in dimensionality analysis.
$\bf{Highlights}$
$\bullet$ Magnetotelluric (MT)/long period Magnetotelluric (LMT) survey is carried out in northern part of Saurashtra. Different dimensionality techniques were used to assess the structural dimensionality of the electrical conductivity of the earth and were compared.
$\bullet$ Analysis of MT sites by using various methods indicates the electrical conductivity structure is less complex at the shallowest depths with mixed 1D and 2D cases that are affected by galvanic distortion. Both MT/LMT denote complex 3D nature from middle and lower depths.2D inversion of MT/LMT data brings out large-scale heterogeneities in the crust. This is attributed to different resistive and conductive blocks present at mid-crustal depths and extending up to lower crustal depths and correlates with dimensionality analysis.
Volume 131 All articles Published: 28 March 2022 Article ID 0088 Research article
P B V SUBBA RAO VASU DESHMUKH P V VIJAYA KUMAR A K SINGH
Both audio-magnetotelluric and magnetotelluric data were acquired across Aravalli and Tural hot springs (in Konkan region of Deccan volcanic province). The objective is to bring out the geoelectrical crustal structure beneath these geothermal zones. Two-dimensional inversion of data brings out different conductivity anomalies (i) shallow conductivity anomaly related to upward propagation of meteoric water through faults/fracture zones, (ii) major fracture/fault zones extending up to midcrustal depths through which Deccan volcanism may have erupted and (iii) the presence of mid-crustal conductivity anomalies are related to trapped carbonate Cuids that are linked to thermal effects of Deccan volcanism.
Volume 132, 2023
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