7.4-magnitude earthquake strikes off Japan's northeast coast, tsunami warning issued

A 7.4-magnitude earthquake struck off the northeastern coast of Japan on April 20, 2026, triggering a tsunami warning with waves expected to reach up to 3 meters (10 feet) in Iwate, Hokkaido, and surrounding prefectures. The Japan Meteorological Agency (JMA) advised immediate evacuation of coastal regions.

Key points

• Earthquake struck at 4:53 p.m. local time in Pacific waters off Iwate prefecture, approximately 10 kilometers deep
• Tsunami waves of up to 3 meters expected to hit Iwate, Hokkaido, Aomori, Miyagi, and Fukushima prefectures, with waves potentially striking repeatedly
• Tremor was strong enough to shake large buildings in Tokyo, hundreds of kilometers from the epicenter
• Japan's Prime Minister's office established a crisis management team to monitor the situation
• Japan experiences approximately 1,500 earthquakes annually and accounts for about 18 percent of the world's seismic activity

Why it matters

Japan sits atop four major tectonic plates along the Pacific Ring of Fire, making it one of the world's most seismically active regions. The 2011 magnitude-9.0 earthquake and tsunami killed 18,500 people and caused a devastating nuclear meltdown at Fukushima, underscoring the critical importance of rapid response systems.