Japan: Disruptions, evacuations ongoing after 7.3-magnitude earthquake strikes east of Honshu Island March 16 /update 1

Event

As of early March 17, Japanese authorities are continuing their response to a strong magnitude-7.3 earthquake that struck off the east coast of Honshu late the previous day. Over two million households are without power and several public transport networks have temporarily suspended service following the temblor. The Japanese Meteorological Agency (JMA) is maintaining low-level tsunami advisories for much of the east coast of Honshu and Hokkaido.

The earthquake occurred east of Honshu Island at around 23:36 March 16. The epicenter was about 57 km (35 miles) east-northeast of Namie. Violent shaking was reportedly felt in large parts of eastern Japan, including Tokyo. As of early March 17, the JMA is maintaining a Tsunami Advisory (the second-lowest level on a four-tier scale) for coastal areas of Miyagi and Fukushima prefectures, indicating possible tsunami waves of 1 meter (3 feet) or less for these areas. The expected time of wave arrival has now passed and initial reports of observed tsunami waves at Ishinomaki Port in Miyagi prefecture suggest the waves may be smaller than first feared; however, details remain unclear and the warnings are likely being maintained in the short term as a precautionary measure until it is certain the threat has passed. The JMA has also issued a Tsunami Forecast (the lowest level) for the east coast of Honshu and southern and eastern coastal areas of Hokkaido, advising of minor sea level fluctuations in those areas. The Pacific Tsunami Warning Center (PTWC), on the other hand, has stated that based on the available data the tsunami threat from the earthquake appears to have passed.

The initial tsunami threat had prompted authorities to issue evacuation orders in parts of the coastal towns and cities of Watari, Iwanuma, Shiogama, Yamamoto, Higashi-Matsushima, Matsushima, Shichigahama, Tagajo, Sendai, and Natori in Miyagi Prefecture, as well as Futaba in Fukushima Prefecture, with further evacuations being continually announced, Several shelters have also been opened across Fukushima and Miyagi prefectures. For further details on the evacuation areas and shelter locations, click here.

As of 00:01 March 17, the Tokyo Electric Power Company (TEPCO) has reported that over 2 million households across eight prefectures within its jurisdiction are without power following the earthquake, including more than 700,000 in Tokyo. Tohoku Electric Power has reported around 150,000 outages across Miyagi, Fukushima, Aomori, Iwate, and Niigata prefectures.

Numerous railways, metros, airports, and bus lines across eastern Honshu have temporarily suspended service for damage assessments. Although many are now resuming operations once receiving the all-clear, residual disruptions are likely across most services in the coming hours. Nuclear power plants in the region are also conducting safety checks following the earthquake.

It may take some time for damage assessments to be complete and the true extent of the impact of the earthquake is likely to emerge in the coming hours and days. Additionally, aftershocks are likely in the short term, which may hamper recovery and response efforts. A magnitude-5.5 aftershock has already been recorded at around 00:52 March 17.

Advice

Move away from the immediate coastline; tsunamis can be long-duration events, and the threat may persist for hours. Vacate multistoried buildings or unreinforced structures in areas where strong shaking occurred; aftershocks could cause additional damage. Cellular networks may be overwhelmed; use text messaging if services are available. Due to the threat of landslides, seek updated information on road conditions before driving in hilly areas in the affected area.