Government mobilizes infrastructure response as rail services suspended across Iwate
Government emergency task force mobilized; rail suspended; evacuation advisories issued to 11 towns.
Event / Disaster
Japan Iwate Earthquake Tsunami
A 7.4 magnitude earthquake struck off northern Iwate Prefecture in the Pacific Ocean on April 20, 2026, triggering a tsunami alert with waves up to three meters. The Japan Meteorological Agency issued evacuation orders for coastal residents as initial waves of 70-80 centimeters were observed within an hour.
10 reported locations
Daily activity
0 articles0 articles
2026-08-18 to 2026-11-15 · UTC publication dates
Coverage begins 20 Apr, 11:07 UTC
Follow the documented timeline or explore the related reporting.
What happened
Tsunami alert issued for Iwate, Aomori, and Hokkaido following earthquake
The Japan Meteorological Agency issued a tsunami alert for the coasts of Iwate, Aomori to the north, and southeastern Hokkaido following the 7.5-magnitude earthquake. The agency warned that a tsunami of up to 3 meters (10 feet) could hit the affected areas and issued milder tsunami advisories for Miyagi and Fukushima to the south of the epicenter.
Iwate Prefecture issues evacuation advisories to 11 towns
The Iwate Prefecture issued non-binding evacuation advisories to residents in 11 towns in response to the earthquake and tsunami threat. The Japan Meteorological Agency urged residents in the region to immediately stay away from the coast or along rivers and take shelter on higher ground.
Tsunami waves detected at Kuji Port and other locations in Iwate Prefecture
A tsunami of approximately 80 centimeters (2.6 feet) was detected at Kuji port in Iwate Prefecture, and a smaller tsunami of approximately 40 centimeters (1.3 feet) was recorded at another port in the prefecture following the earthquake.
7.5-magnitude earthquake strikes off Sanriku coast in northern Japan
A powerful earthquake with a preliminary magnitude of 7.5 struck off the coast of Sanriku in northern Japan at approximately 4:53 p.m. local time (0753 GMT). The earthquake occurred at a depth of approximately 10 kilometers (6 miles) below the sea surface.
Shinkansen high-speed rail services suspended in Iwate Prefecture
Shinkansen high-speed rail services in Iwate Prefecture were suspended as a result of the earthquake. The earthquake was strong enough to rattle towers as far away as Tokyo.
Prime Minister Sanae Takaichi mobilizes emergency task force in response to earthquake
Prime Minister Sanae Takaichi announced that the government had mobilized an emergency task force following the earthquake. She instructed citizens in affected areas to evacuate and stated that possible damage and casualties were being investigated.
No issues reported at Fukushima Daiichi and Fukushima Daini nuclear plants
Tokyo Electric Power Company reported that no issues were detected at the Fukushima Daiichi and Fukushima Daini nuclear power plants following the earthquake.
Japan Meteorological Agency warns of possible aftershocks over coming week
The Japan Meteorological Agency warned that aftershocks are possible over the next week and could be similar in magnitude to the 7.5-magnitude earthquake that struck earlier in the day.
Nankai Trough poses risk of catastrophic megaquake with 298,000 potential deaths
The 800-kilometer Nankai Trough, where the Philippine oceanic plate gradually subducts beneath Japan's continental plate, is identified as the location of a potential megaquake. The Japanese government estimates such an event could kill up to 298,000 people and cause up to 2 trillion dollars in damages.
January 2024 Noto Peninsula earthquake killed nearly 470 people
On January 1, 2024, a magnitude 7.5 earthquake struck the Noto Peninsula in central Japan, the strongest earthquake experienced in the country in over a decade. The earthquake caused nearly 470 deaths.
Second megaquake alert issued in December 2025 after 7.5 magnitude earthquake
The JMA issued a second megaquake alert in December 2025 lasting one week following a magnitude 7.5 earthquake off the northern coast. That December 8 earthquake triggered tsunami waves reaching up to 70 centimeters and injured over 40 people, with no major damage reported.
Japan experiences average of 1,500 seismic events annually
Japan experiences approximately 1,500 earthquakes per year due to its location at the junction of four major tectonic plates on the western edge of the Pacific Ring of Fire. The majority are minor, though damage varies based on location and depth below the surface.
2011 Tōhoku earthquake and tsunami killed approximately 18,500 people
Japan continues to bear the trauma of the March 2011 magnitude 9.0 earthquake that triggered a devastating tsunami, resulting in approximately 18,500 deaths and disappearances. That earthquake occurred on the Pacific coast along the Nankai Trough off Japan's coast.
Japanese Prime Minister activates crisis management cell
The Prime Minister's office activated a crisis management cell in response to the earthquake and tsunami threat, coordinating emergency response measures across affected regions.
Tsunami alert issued with waves expected to reach three meters
Japan's Meteorological Agency (JMA) issued a tsunami alert following the earthquake, warning of waves potentially reaching three meters. The first tsunami waves were expected to reach the northern coast immediately, with waves of 70-80 centimeters observed in Kuji port about 41 minutes after the initial earthquake. The JMA warned of repeated wave impacts and ordered immediate evacuation of coastal and riverside areas to elevated terrain or evacuation buildings.
7.4 magnitude earthquake strikes off northern Japan coast
A 7.4 magnitude earthquake occurred in the Pacific Ocean off the coast of northern Iwate Prefecture on April 20 at 16:53 local time (07:53 GMT). The seismic waves were powerful enough to cause tremors in buildings in Tokyo, several hundred kilometers away from the epicenter.
JMA introduced megaquake alert classification in 2024
The Japan Meteorological Agency introduced a new highest-level alert classification in 2024 to warn of the possibility of a megaquake along the Nankai Trough. An initial alert issued in 2024 lasted one week before being lifted, causing panic buying of food staples like rice and leading tourists to cancel hotel reservations.
Read the coverage
2 alternative perspectives
Japan issues aftershock warning as tsunami observations continue
Tsunami waves detected; authorities warn of week-long aftershock risk.
Japan's seismic vulnerability underscored by decades of major earthquakes
Japan's frequent seismic activity and megaquake risks drive ongoing institutional adaptation of warning and preparedness systems.
Japan activates emergency response after 7.4 magnitude earthquake
7.4 earthquake off Iwate triggers tsunami alert; Japan activates emergency response protocols.