Experts Assess Java Tsunami

As happens after any major disaster, the experts come out of the woodwork, voice their opinion and pass the buck. It happens everywhere in the world. At least this time in Indonesia they freely admitted to a few wrongs.

It seems that scientists admitted they were wrong all along in stating Java's southern coast was a tsunami-free region and pledged to do more to identify disaster prone areas and believe that there are no tsunami-free areas along the southern coast of Java, Bali and Nusa Tenggara, which directly face the plates' subduction zone.

A senior official of the Meteorology and Geophysics Agency's Center of Volcanology flew in the face of scientists' predictions that tsunamis were unlikely in southern Java. The assertions continued in the immediate aftermath of a temblor with its epicenter off the coast that measured 6.8 on the Richter scale.

He referred to what is known as the Ring of Fire where the Eurasia and Indo-Australia sea plates slip past each another creating motions that could generate earthquakes along the plate boundaries.

He added that the agency's assessment was based on the fact that there was no record of a tsunami in the area dating back to the 19th century and that there is no historical data that such a geological disaster had occurred in the region.

Hamzah Latief an expert on tsunamis from the Bandung Institute of Technology countered that the southern coast of Java had a long history of tectonic movement as well as tsunamis. From his own records he said there were at least three quake-triggered giant waves measuring up to four meters in height along the coast in 1859, 1904 and as recently as 1957.

He said all coastal areas stretching from the Andaman Sea in Thailand to Timor Leste were prone to tectonic movements but tsunamis could only occur if a quake measured over 6 on the Richter scale.

Oceanographers believe that powerful quakes are usually the result of a sudden rise or fall of a section of the earth's crust under or near the ocean could cause a seismic disturbance that can displace the sea's water column. This would cause a rise or fall in the level of the ocean above which would be initial formation of giant waves.

Heri Harjono of the Indonesian Institute of Sciences' Center of Geotechnology Study urged scientists to organize paleo-tsunami research to identify sediment or materials that came from giant waves in previous eras.