Aftershock Warning Issued for Japan's Sanriku Coast Following M7.7 Earthquake

Seismic activity continues off Japan's Sanriku coast after a magnitude 7.7 earthquake on April 20, with 28 tremors of magnitude 1 or higher recorded. The Japan Meteorological Agency has issued an aftershock warning for the Hokkaido-Sanriku offshore area, urging continued preparedness due to increased potential for a massive earthquake along the Chishima and Japan Trenches.