Origin and Significance of Hemavathi-Tirthahalli Mega-Lineament

LANDSAT MSS False Colour Composite on 1 : 537,000 scale has been interpreted to study the lineaments in the study area (Frame 145-051 covering Hassan, Chikmagalur, Kodagu, Shimoga, Mysore, Dakshina Kannada, Tumkur, Chitradurga Districts of Karnataka and Kasaragod District of Kerala). The most prominent lineament is about 190 km long and is named Hernavathi-Tirthahalli mega-lineament. The direction of this mega-lineament is almost parallel to the west coast. This mega-lineament with considerable length and almost parallel orientation to the west coast indicates that it developed at the time of the West Coast Fault. Major lineaments like Yagachi, Tunga and a good number of other lineaments are also parallel to the west coast. As most of the earthquakes (between 1967 and 1977) in Southern Peninsula occurred in the vicinity of NNW-SSE to NW-SE trending mega lineaments, the Hemavathi-Tirthahalli mega-lineament should be studied to understand its seismic status.