Tsunami waves have begun reaching the northeastern coast of Japan following a powerful magnitude 7.5 earthquake that struck off the Sanriku coast on Monday afternoon, April 20, 2026. The Japan Meteorological Agency (JMA) confirmed that waves were observed at several key ports, while thousands of residents remain under urgent evacuation orders as authorities warn of potentially larger surges to follow.

First Waves Observed at Kuji and Miyako Ports

The JMA reported that a tsunami wave of 80 centimetres (approximately 31 inches) reached Kuji Port in Iwate Prefecture at 5:34 PM local time. Earlier, at 5:22 PM, a 40-centimetre wave was recorded at Miyako Port, also in Iwate. While the initial waves were under one meter, broadcasters, including NHK, have cautioned that tsunami activity can last for several hours and that waves often grow in height with subsequent surges. Residents are being told to remain on high ground and not return to coastal areas until all warnings are officially lifted.

Tsunami Waves Hit Kuji Port

Tsunami Observation in Japan So Far

Full List of Tsunami Warnings and Advisories

As of Monday evening, the JMA has categorised the coastal threat across several regions. Residents in "Warning" zones are urged to evacuate immediately to high ground or a tsunami evacuation building.

Tsunami Warning (Estimated height up to 3 meters):

  • Iwate Prefecture

  • Aomori Prefecture (Pacific Coast)

  • Hokkaido (Pacific Coast East and Central)

Tsunami Advisory (Estimated height up to 1 meter):

  • Miyagi Prefecture

  • Hokkaido (Pacific Coast West)

Tsunami Waves Observed in Various Locations in Japan

Impact and Infrastructure Status

The earthquake, which struck at a shallow depth of 10 kilometers at 4:53 PM, registered a "5-upper" on the Japanese seismic intensity scale in parts of Aomori. This level of shaking is strong enough to make walking difficult and can cause unsecured furniture to topple.

  • Nuclear Facilities: Plant operators, including Tokyo Electric Power Company (TEPCO), reported no abnormalities at the Fukushima Daiichi or Daini plants. No issues were detected at the Onagawa or Higashidori nuclear stations.

  • Transport: JR East has suspended the Tohoku Shinkansen bullet train services between Tokyo and Shin-Aomori for safety track checks. Akita Shinkansen services are also currently halted.

  • Casualties: There have been no immediate reports of deaths or major structural collapses, though damage assessments in remote coastal villages are ongoing.

Prime Minister Sanae Takaichi addressed the nation from the emergency task force center. She urged residents to evacuate to safer and higher ground. The Maritime Self-Defense Force has deployed helicopters to survey the coastline for signs of damage or trapped residents.

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TruLY Score 3 – Believable; Needs Further Research | On a Trust Scale of 0-5 this article has scored 3 on LatestLY, this article appears believable but may need additional verification. It is based on reporting from news websites or verified journalists (Official X Account of NHK News), but lacks supporting official confirmation. Readers are advised to treat the information as credible but continue to follow up for updates or confirmations

(The above story first appeared on LatestLY on Apr 20, 2026 03:27 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).