New calculations by a Japanese government panel showed a seaside town in Japan's southwestern island of Shikoku could be at risk of a tsunami wave topping more than 34 meters, about two times higher than the previous estimation, urging the locals to rethink their counter-tsunami measures.

The report was released in the end of last month by a government expert panel studying the estimated impact caused by a massive earthquake in "Nankai Trough" off Japan's Pacific coast, which stretches east of the country's main island of Honshu to the southern island of Kyushu.

The new report was calculated by the latest scientific data on 16 possible cases caused in the Nankai Trough of 9.1-magnitude tremor, following last March's 9.0-magnitude earthquake and tsunami which hit the country's northeast and left about 19,000 people dead or missing.

The new calculations pointed out a total of 23 sea side municipalities along the country's Pacific coast, in six prefectures including Kochi and Tokushima in the island of Shikoku, would be at risk of a tsunami with the highest wave of more than 20 meters if a powerful earthquake strikes at high-tide. Among them, Kuroshio Town in the Kochi prefecture, located in the southwestern area of the island, could be worst hit by the resulting wave at 34.4 meters high, the revised estimates said.

An earlier forecast released in 2003 had said that the potential maximum height of such a tsunami wave was 17 meters.

The revised report also warned 90 municipalities in 11 prefectures could expect waves of 10 meters or more. Kochi City in the island of Shikoku, for example, could expect waves up to 14.7 meters high while the tsunami wave could top 7.7 meters in Wakayama City in the Kansai region. The old report counted only 10 cities and towns in two prefectures for the model.

Meanwhile, the panel also pointed out that a strong earthquake could shake 396 municipalities in 21 prefectures at the seismic intensity of 6 upper and the maximum 7 on the Japanese scale, forecasting that it is more than five times larger than that assumed in the previous calculations.

In Japan, local governments in the coastal areas have constructed sea walls and evacuation towers, or have arranged evacuation roads and sites in higher ground to prepare for the worst scenario based on historical data.

The fishing town of Kuroshio with a population of 13,000 people, for instance, constructed two year ago an evacuation tower with a height of 12 meters above sea level, which is situated neat the tall, about 700 meters inwards from the beach line. But Masafumi Kadota, spokesperson of Kuroshio Town told Xinhua that although the latest calculations are not predictions, people living in the town were surprised at the announcement especially after the time they completed the new evacuation tower construction project, already spending 30 million yen (about 361, 445 U.S. dollars).

"Even if the new estimates are based on hypothetical scenarios, we understand that they will force local governments like us to rethink the whole layout of residential areas."

"Our future option may include such a policy requiring many, or all have to move to higher places in the middle of hills situated inner part of the town, and to resettle in," he said.

The Japanese government panel said it would further release flood projections based on the calculating tsunami heights while the Cabinet Office's Central Disaster Prevention Council is planning by this summer to show the estimated major risks led by tsunami waves, including the number of dead as well as buildings or houses damaged.

The Fukushima No. 1 nuclear power station was instantly demolished by the actual 15-meter surge in last year's March 11 disaster, although it was designed to withstand a 6-meter tsunami. While raising criticism over the central government's failures to take into account potential threats, the lessons learned from last year's earthquake and tsunami are now prompting municipal governments to more widely discuss on the latest calculations and on potential risks which are brought about by the scenario.