REFRACTION OF TSUNAMI WAVES OF 26 DECEMBER 2004, ALONG SOUTHWEST COAST OF INDIA

In this paper the refraction of the tsunami of 26 December 2004, which caused severe damage along the south west coast of India has been studied. Wave refraction diagrams for the possible wave directions indicate convergence around the places like Kolachel, around Kollam and Alappuzha, where greater destructions occurred due to this tsunami and divergence at the places spared by the tsunami. Broad areas vulnerable to tsunamis have been identified. Possible causes for increased destruction in Kolachel at the southern tip of Indian peninsula are discussed. Bottom topography is one of the factors that determine the intensity of the tsunami waves. Bottom steering is caused by the wave refraction. Comparatively gentler sloping topography in a zone north of Kollam at depths beyond 200m and the topographic dome off Kollam appear to have influence on determining the impact of tsunamis.