Tsunami Report(Page 21-40)

The Tide gauge data from major ports of India maintained by Survey of India hasbeen processed by National Institute of Oceanography which showed that thetsunami hit Chennai at 09:06 hrs, Machillipatanam, Visakhapatnam and Paradip, at09:05 hrs, Tuticorin at 09:57 hrs, along the east coast and on the west coast it hitKochi at 11:10 hrs and Mormugao at 12:25 hrs (Fig.17). The non-tidal oscillationscontinued at Visakhapatnam, Tuticorin, Kochi and Mormugao well after the mainevent took place. NIOT’s ATG at Kochi has also recorded first hit of tsunami at11:12 hrs coincided with that of Survey of India tide gauge.There were no reports of inundation of coastal areas due to tsunami in the northernAndhra Pradesh and Orissa as the water level rose by less than 0.5 m. However, theinland areas like Ports and Harbours, for example, Visakhapatnam Fishing Harbourand Port experienced amplification of tide due to coning effect from outer harbour toentrance channel and unusual current speed in the order of 5 to 10 m/s (Fig.18).These strong flood and ebb currents have forcefully pulled 15-20 fishing boats out ofharbour (Fig.19); during the course few boats encountered minor damage.Although Tuticorin is situated south of Rameswaram, Tamilnadu, it witnessedtsunami at 09:57 hrs, almost an hour later it hit Chennai coast. It is to notice thatwhen high energy tsunami waves traverse horizontally across Indian Ocean, the eastcoast of Sri Lanka has absorbed the devastating tsunami energy and the refractedwaves with low energy only reached its west coast and southern east coast ofTamilnadu, which is confirmed by the wave modelling studies (Figs. 13 & 14). Thusmost of the southern coastal belt of Tamilnadu, shadowed by Sri Lanka, were lessaffected. It is for this reason, the refracted tsunami waves took more time to reachTuticorin.27