TECTONIC STUDY AROUND INDORE (CENTRAL INDIA) WITH EMPHASIS ON SEISMOLOGY USING VISUAL DIGITAL IMAGE PROCESSING TECHNIQUES

摘要

In the recent past, region in and around Indore forms one of the interesting seismic zone. In August 1982 till December 1982, about 50 shocks lasting till five seconds approximately were felt. In October 1990, similar shocks were felt but their time duration and intensity of shocks was more. Geologically, Indore is part of Deccan trap basalts having different sets of joints, additionally, 60 Kms. away from Indore river Narmada flows in a rift zone flanked with faults & fractures. Geomorphological & quaternary geological studies have indicated that the area is tectonically disturbed. In the recent studies, the author has used Landsat TM and IRS LISS II data to prepare the lineament map using visual & digital image processing techniques. Statistical analysis has been carried out and the results have been interpreted emphasizing the tectonic origin of the structure lineaments. From the results obtained so far, it is difficult to conclude the exact cause for the origin and cause of the shock waves, but only inferences could be drawn presently. Looking to the tectonic set up, the author feels this may be due to normal faulting and fold axis which give rise to wedging under tension, as the area under study lies just above Narmada Tapti Rift and there is also Aravalli axis of folding which takes turn near the study area continue further to meet the Aravalli strike. The author is also of the opinion that such tremors may be due to slicken side effects in black cotton soil or the presence of vertical, angular, horizontal and columnar joints. The author also feels that such shocks can be attributed to volcanic phenomenon.