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TOKYO - Small tsunami waves hit Japan's northernmost island this morning after a major quake in the north Pacific triggered a full-scale tsunami warning for areas of northern Japan and Russia's sparsely populated Kurile islands.
An initial tsunami of 40 cm came ashore near Nemuro on the Pacific coast of Hokkaido island, just before 10pm (2.00am NZT), nearly two hours after the estimated 8.1 magnitude quake. Other waves of 10 to 20 cm were also recorded.
There were no immediate reports of more significant waves either in Japan or in the Kuriles, and Japan's meteorological agency said tsunami warnings were lifted at 3.32pm GMT (4.32am NZT). Initially, Hokkaido officials had issued predictions of a tsunami 1 to 2 metres high.
Japanese officials had urged thousands of people to move to higher ground, with emergency authorities taking to the streets to spread the warning.
Authorities on the Russian island of Sakhalin said the quake struck near uninhabited islands at the centre of the Kurile chain, which stretches northeast from Hokkaido to the Kamchatka peninsula.
The site of the quake was roughly 1,700 km northeast of Tokyo. Russian authorities said the tremor struck 130 km east of Simushir island.
"We have been repeatedly urging people to evacuate. We did not feel an earthquake," Yasukatsu Imai, a Nemuro official, told NHK public television.
Russian emergency services went on high alert and evacuated a small settlement after the quake, but no tsunami had been reported by 2.30pm GMT (3.30am NZT).
Sakhalin Energy, operator of the Shell-led Sahkalin-2 oil and gas exploration project, said the venture was unaffected.
"Right now there is no impact on our activities," said Sakhalin Energy spokesman Ivan Chernyakhovskiy in Moscow.
"All our facilities are designed to standards that take into account all geological hazards and are build to withstand tsunamis."
Television footage of deserted harbours along Hokkaido's eastern coast showed boats patrolling the water but otherwise the areas appeared calm. Firemen monitored water levels from bridges in some cities.
Hokkaido residents reported feeling little to no shaking from the earthquake, but authorities stopped trains in the eastern part of Hokkaido.
"Residents are evacuating. Some don't have cars so we have mobilised buses to help them evacuate to high places," an official in the town of Yubetsu told NHK.
The US Geological Survey said the "great" quake, which it initially estimated at magnitude 7.8 and later raised to 8.3, occurred at 8.14pm (1.14am NZT) with the focus 27.7 km below the seabed.
It later reported two strong aftershocks, one of magnitude 6.5 and another of 6.3.
Japanese know the Kuriles as the Chishima islands. Japan claims the four Russian-controlled islands closest to Hokkaido, calling them the Northern Territories.
The Soviet Union seized the islands, which it calls the Southern Kuriles, at the end of World War Two. Tokyo and Moscow continue to wrangle over their future, and the dispute has prevented the two countries from signing a peace treaty.
A tsunami, Japanese for "harbour wave", travels at dizzying speed in the open ocean and, when it approaches shallow water along a coast, it slows and swells. In an inlet, it can rise to a towering height very quickly.
In 1993, a tsunami caused by a 7.8 magnitude quake killed about 200 people on the island of Okushiri, off Hokkaido's southwestern coast.
Nearly two years ago, up to 232,000 people were killed or left missing by a tsunami off Aceh in Indonesia.
- REUTERS
