Japan: Major earthquake occurs in northern Honshu March 20; tsunami warning issued

Event

A magnitude-7.0 earthquake occurred in northern Honshu at 18:09 March 20. The epicenter was about 58 km (36 miles) northeast of Sendai. The tremor occurred at a depth of about 80 km (50 miles), and strong shaking was probably felt throughout the impacted area. There have been no initial reports of damage or casualties as a result of the earthquake; however, significant damage is possible near the epicenter. It could take several hours until authorities can conduct comprehensive damage assessments, especially in remote areas. Aftershocks are likely over the coming hours. The Japan Meteorological Agency (JMA) has issued a Tsunami Advisory for coastal areas of Miyagi Prefecture and a Tsunami Forecast (slight sea-level changes) for eastern coastal areas extending between coastal central Honshu and Hokkaido.

Officials may temporarily shut down transportation infrastructure in the tremor zone to check for damage. Minor disruptions could occur during shutdowns, but service will likely resume quickly if no damage is found. Utility outages are possible, particularly near the earthquake's epicenter.

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.