Inundation, run-up heights, cross-section profiles and littoral environment along the Tamil Nadu coast after 26 th December 2004 Tsunami

Abstract

On 26 December 2004 the coastal areas of different countries around the Indian Ocean including India were hit by a Tsunami that caused extensive fatalitites and damage to coastal property. On the initiative of Director, National Institute of Oceanography (NIO) and under the leadership of Dr. G. C. Battacharya, Scientist F, NIO,) surveys were carried out along several coastal areas of India for eliciting information about the inundation and several related aspects of the Tsunami. Different locations were surveyed were between Vedaranyam in the south to Pulicat lake on the north of Tamil Nadu and at Krishnapatnam in Andhra Pradesh. The survey was planned to carry out survey as per IOC manuals and Guideline report No. 37 dealing with the Post-Tsunami field surveys. This report pertains to surveys carried out mainly along the Tamil Nadu coast and presents basic data and preliminary information on Tsunami inundation limit, run-up height, cross sectional profiles at different locations and littoral environmental observations in the surf zone. More than 25 locations were surveyed to assess the inundation limits as well as runup heights. Cross-sectional profiles from the shoreline till the inundation limit were measured using automatic leveling equipment and a graduated staff with reference to local water level at the time of survey. These profiles were reduced to the Chart Datum (CD) approximately arrived from the time of observation of the water line and the corresponding tide predicted for the location. The lateral inundation limit varied between 31 m at Kottaikadu Kuppam village and 862 m at Nagore. The run-up height with respect to CD varied between 1.987 m at Arkattuthurai and 6.54 m at Periyakalapet. Primarily this report presents preliminary findings on Tsunami inundation and detailed data on cross section profiles based on which the Tsunami run-up heights were estimated.