7.7 quake hits north of Japan; brings slightly elevated risk of mega-quake

A large earthquake prompted a short-lived tsunami warning and a slightly higher-than-average risk of a mega-quake.

The Cabinet Office, along with the Japan Meteorological Agency, said the risk of a mega-quake was increased from the typical .1 % to 1% over the next week near the Chishima Trough, The Associated Press reported.

Earthquake map — 7.7 magnitude earthquake jolts northeastern Japan An infographic titled "7.7 magnitude earthquake jolts northeastern Japan. The Japan Meteorological Agency has revised the earthquake's magnitude from 7.5 to 7.7. (Photo by Elif Acar/Anadolu via Getty Images) (Anadolu/Anadolu via Getty Images)

While not predicting a mega-quake, the agencies said that residents should prepare just in case, as they go about their typical business for about the next week, the BBC reported.

No mega-quake happened when a similar advisory was issued after December’s 7.5-magnitude quake.

A tsunami warning was issued but was later downgraded to an advisory, according to the BBC. An advisory is the lowest alert level.

One person was hurt when they fell in Aomori on Monday, the AP reported.