Small tsunami waves hit Japan’s northern-most island late on Wednesday 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 40cm came ashore near Nemuro on the Pacific Coast of Hokkaido Island just before 10pm local time (1pm GMT), nearly two hours after the estimated 8,1-magnitude quake. Other waves of 10cm to 20cm were also recorded.
There were no immediate reports of more significant waves either in Japan or in the Kuriles. Hokkaido officials had urged hundreds of households to move to higher ground after initial predictions of a tsunami 1m to 2m high. Others said higher waves could still arrive.
Authorities on the Russian island of Sakhalin said the quake struck near uninhabited islands at the centre of the Kurile chain, which stretches north-east from Hokkaido to the Kamchatka peninsula.
The site of the quake was roughly 1 700km north-east of Tokyo. Russian authorities said the earthquake struck 130km east of Simushir Island.
A lesser warning was issued for a wide swathe of the eastern coast of northern and central Honshu, Japan’s main island, but most waves in these areas were predicted to only hit 50cm at the highest.
”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 1.30pm GMT.
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 spokesperson Ivan Chernyakhovskiy in Moscow.
”All our facilities are designed to standards that take into account all geological hazards and are built to withstand tsunamis.”
Little to no shaking
Television footage of deserted harbours along Hokkaido’s eastern coast showed boats patrolling the water but otherwise the areas appeared calm.
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 United States Geological Survey said the quake, which it initially estimated at magnitude 7,8, occurred at 8.14pm local time with the focus 27,7km below the seabed.
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 II. 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 south-western coast. — Reuters