A 7.6-magnitude earthquake struck in the sea off Japan’s main island of Honshu late Monday, injuring at least 30 people, generating a local tsunami, and prompting authorities to suspend the release of treated radioactive water from the crippled Fukushima Daiichi nuclear plant. In an unusual move, Japan’s Meteorological Agency issued its first-ever ‘follow-up earthquake advisory’ early Tuesday, warning that the risk of an even larger earthquake in the next week is higher than normal.

A 7.5 -magnitude earthquake struck the northernmost prefecture of Japan's main Honshu island on Monday night, and tsunami warnings were lifted several hours later.

A 7.6-magnitude earthquake struck in the sea off Japan’s main island of Honshu late Monday, injuring at least 30 people, generating a local tsunami, and prompting authorities to…