S Y Waghmare
Articles written in Journal of Earth System Science
Volume 93 Issue 4 November 1984 pp 353-362
The method of rectangular harmonic analysis is applied to the geomagnetic field data from central India to isolate long wavelength magnetic anomalies associated with largescale crustal structures. The long-wavelength anomalies have accounted for approximately 20 % of the spatial variability of the residual magnetic field over the International Geomagnetic Reference Field. On the magnetic anomaly map, reflecting the surface expression of longwavelength anomalies, the Tapi-Narmada-Son zone is characterized by a feeble positive anomaly bounded by a strong negative anomaly. The anomaly pattern is believed to be caused by the large-scale undulation in Moho and related variations in the thickness of the lower (basaltic) crust. The other two prominent anomalies, the magnetic low striking northwest and the magnetic high trending east-northeast, appear to be related to the deep structural feature of the Godavari graben and the eastern Rajasthan lineament respectively.
Volume 98 Issue 4 December 1989 pp 319-326
This paper presents the results of a magnetometer array study covering Kangra region to supplement information already available on the nature of geoelectrical structure at the foothills of Himachal Pradesh-Kumaun-Himalaya. The observed induction pattern across the Himalayan frontal fault is found to be the expression of a psuedo-geomagnetic coast effect associated with the edge of sheet current flowing in the sediments of the IndoGangetic Plains. An additional conductive sheet that is required beneath the frontal folded belt may represent increased hydration of certain sedimentary layers.
Volume 118 Issue 3 June 2009 pp 261-272
Repeated measurements of the total geomagnetic ﬁeld on the ﬁve proﬁles have revealed a picture of stress-induced tectonomagnetic effect in the form of secular variation of the total geomagnetic ﬁeld in the tectonically and seismically active area of Jabalpur and adjoining areas of the Narmada-Son lineament (NSL),central India.For this experiment,a reference base station was established within the study area at Jabalpur.Using proton precession magnetometers with a sensitivity of 0.1 nT, simultaneous measurements of total geomagnetic ﬁeld were made annually at the base and all ﬁeld stations.Five cycles of repeated observations have been performed between 2003 and 2007.For data analysis,a difference method has been applied and the residuals have been calculated as secular variations of the total geomagnetic ﬁeld with values ranging from ± 0.1nT to about > ± 14.6$nT/yr$ over the different stations.The anomalies in secular variation of the total geomagnetic ﬁeld may be related to anomalous accumulation of tectonic stresses and tensions on the deep fault zones and crustal blocks due to recent geodynamic processes and active geological inhomogeneities in the NSL.
Volume 128 | Issue 8
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