Astronomical Tide Levels along the Coasts

of the Indian Ocean

by
Yoshinobu TSUJI, Yuichi NAMEGAYA, and Junichi ITO
(Earthquake Research Institute, the University of Tokyo)


1)  We calculated the astronomical tide levels at 100 points on the coasts of the Indian Ocean, including the coast of Indonesia, Thailand, Sri Lanka, and India from the beginning of December 2004 through the end of December 2005 by using 5-39 harmonic constants of the tidal components M2, S2, O1, K1, etc. given by the Hydrographic and Oceanographic Department, the Japan Coast Guard, Tsukiji, Tokyo.

We expect that those data will be useful in compensation of the astronomical tide component for the data obtained as the results of field surveys.

We checked the calculated results at Colombo and another several points by comparing with those of the standard ports in gTide Table 2005 vol. 2h published by the Japan Coast Guard gAdmiralty Tide Tables 2005h, published by Hydrographic Office, UK..  The maximum differences of our calculated results with thosee Tide Tables are generally within 15 minutes in ebb/flood times, and 10cm in level at ebb/flood time.

2)  Numerals in each line denote as follows:

Year, Month, Day, Time [hour], Sea Level [cm].

The time is given in the local time for each station, and is not the universal time.

3) The calculated tide levels are height above the lowest low level at each ports, which is generally situated at Zo, the sum of the amplitude values of four principal tide components (M2, S2, K1, and O1) below the mean sea level.


Maldives (GMT: +5.0h)
Sri Lanka (GMT: +6.0h)
India (GMT: +5.5h)
Bangladesh (GMT: +6.0h)
Myanmar (GMT: +6.5h)
Thailand (GMT: +7.0h)
Malaysia (GMT: +8.0)
Sumatera Island (GMT: +7.0)
Somalia (GMT: +3.0)