Tsunami heights and damage along the Myanmar coast from the December 2004 Sumatra-Andaman earthquake

The tsunami heights from the 2004 Sumatra-Andaman earthquake were between 0.4 and 2.9 m along the Myanmar coast, according to our post tsunami survey at 22 sites in Ayeyarwaddy Delta and the Taninthayi coast. Interviews to coastal residents indicate that the tsunami heights were lower than high tide level in rainy season, probably by storm surge. They also testified that the arrival times were between 2 and 5.5 hours after the earthquake but the reliability may be low because nobody felt ground shaking. Much smaller tsunami than the neighboring Thai coast, where the tsunami heights were 5 to 20 m, explains relatively slighter tsunami damage in Myanmar; the casualties were reported as 71, compared to about 8300 in Thailand. The smaller tsunami was probably due to the fact that the main tsunami source did not extend to Andaman Islands. The tsunami travel times and maximum heights computed from a 700 km long source are basically consistent with the observations. For a nearby tsunami source, the tsunami hazard would be more significant in Myanmar, because coastal houses are unprotected for tsunamis and no infrastructure exists to disseminate tsunami warning information.