Japan Downgrades Tsunami Warning After Powerful Quake Rocks Taiwan

Japan downgraded a tsunami warning Wednesday morning after waves reached islands in Okinawa Prefecture following a powerful earthquake that struck off Taiwan. The magnitude 7.7 quake had initially prompted a forecast of waves of up to 3 meters for some parts of Okinawa, with residents strongly urged to evacuate coastal areas. The warning was later downgraded to a tsunami advisory at 10:40 a.m., with the expected height of waves reduced to 1 meter.

There were no immediate reports of damage or casualties, the government said, but people were still urged to stay away from the coast.

The massive quake — the largest to hit Taiwan in 25 years — also prompted tsunami warnings for the island. The quake also knocked out power in some areas of the island’s east, with television footage showing collapsed buildings. Media reports said some people had been trapped in the rubble, but there were no immediate reports of deaths or injuries.

Tsunami warnings were also issued in the coastal areas of several provinces of the Philippines.

This was the first time a tsunami had been detected in Japan since a powerful earthquake hit the Noto Peninsula area in Ishikawa Prefecture on New Year’s Day, with NHK earlier warning viewers via a large banner to “Evacuate! Run!”

According to Japan’s Meteorological Agency, Wednesday’s quake was as big as — if not bigger — than the Noto temblor, registering a magnitude 7.7. The quake had also been recorded as high as a 4 on the 7-point Japanese shindo seismic intensity scale in Yonaguni, which sits just 110 kilometers (70 miles) from Taiwan.

The United States Geological Survey (USGS) said the quake, which struck at 8:58 a.m., had registered a magnitude 7.4, originating 18 km south southwest of Hualien, Taiwan, at a depth of 34.8 km, while the JMA said it occurred at a depth of 23 km.

The first tsunami waves of at least 30 centimeters high arrived at Yonaguni Island at 9:18 a.m., while waves as high as 20 cm also reached Ishigaki Island as of 9:32 a.m. and Miyako Island as of 10:03 a.m. Tsunami waves had been forecast to reach the main island of Okinawa around 10 a.m. and Naha Harbor, Kumejima and Nanjo at 10:10 a.m., and Nakagusuku Bay Port by 10:20 a.m., according to NHK.

Although the tsunami warning was downgraded to an advisory, people were still urged to continue to stay away from the coast, with the continued likelihood of waves rushing the shore multiple times and the height increasing suddenly, a Meteorological Agency official told a news conference.

People were urged to maintain a sense of vigilance given that the tsunami that resulted from the March 2011 Tohoku earthquake also began with waves that were just a couple of centimeters high.

Since the earthquake occurred some distance from the Okinawan islands, some residents may not have noticed the temblor, though residents have also been urged to evacuate nonetheless, since the tsunami could still reach those areas.

Given that Okinawa is a tourism hub, and many visitors — both foreign and domestic alike — are unfamiliar with the area and tsunami protocol, Okinawa residents are being asked to help them evacuate, if necessary.

People have been warned to evacuate without vehicles to avoid causing traffic jams that could slow the process. Those in vehicles have been asked to park their cars on the left side of the street and leave them behind.

At Naha Airport, takeoffs and landings were suspended for commercial planes as of 9:25 a.m., according to multiple media reports citing the transport ministry. Use of aircraft by the Japan Coast Guard and Self-Defense Forces continued, the Mainichi daily reported.

The JMA also warned that aftershocks — possibly as strong as the initial quake — could continue over several days. JMA officials noted that there had been a 10% to 20% possibility that a tremor of the same scale could occur within the week, citing past major earthquakes. They said the chances were “especially high” over the first two to three days, and urged residents to stay alert.

Meanwhile, a quake registering a shindo 3 also hit the Noto area Wednesday morning, the latest in a series of tremors that have continued to strike the region since the New Year’s Day earthquake._Japan Times