A 7.7-magnitude earthquake struck off the coast of Japan on Monday, triggering tsunami warnings and prompting evacuations from coastal areas, according to the BBC. The quake. Which occurred near Iwate Prefecture. Caused mild shaking but led to authorities issuing alerts for possible tsunami waves, with some areas being told to move to higher ground.

Tsunami Warnings and Evacuations

Local authorities used loudspeakers to warn residents about a possible tsunami, urging them to evacuate immediately from coastal regions and riverside areas, as reported by the BBC. Office workers in the affected areas were allowed to leave early, and a number of bullet trains were affected, with 100 homes losing power; Japan’s Cabinet Secretary Minoru Kihara stated there were no immediate reports of major damage or injuries.

Tsunami waves were expected to hit repeatedly, and residents were advised not to leave safe ground until the warning was lifted; the Japan Meteorological Agency (JMA) issued the warning, which was later downgraded to a tsunami alert and eventually removed shortly before midnight local time.

Risk of Megaquake Increases

Following the quake. The JMA warned that the likelihood of a new, larger earthquake—referred to as a ‘megaquake’ of magnitude 8.0 or greater—was relatively higher than during normal times, according to Scientific American. Although the probability of such an event was estimated at around 1 percent, this is 10 times higher than usual, according to earthquake scientist Amilcar Carrera-Cevallos.

Such a megaquake could produce a far more extreme tsunami, as noted by earthquake geologist Wendy Bohon. While no injuries or significant damage were reported after the initial quake, the risk of a larger quake remains a concern for authorities and residents alike.

Multiple Earthquakes Reported

In addition to the 7.7-magnitude quake. Other reports from Volcano Discovery indicated that a 5.4-magnitude earthquake struck near Yamada, Shimohei-gun, Iwate, Japan, at 10:56 pm local time. This quake was reported by multiple agencies, with magnitudes ranging from 5.4 to 6.1, but Similarly, a 5.3-magnitude earthquake was reported near Miyako, Miyako Shi, Iwate, Japan, at 7:49 pm local time, with some agencies reporting a magnitude of 5.2.

These smaller quakes were not expected to cause significant damage but were felt as light vibrations in the areas near the epicenters; Volcano Discovery noted that preliminary data indicated the quakes should not have caused significant damage but were likely felt by many in the affected regions.

Japan’s location on the Ring of Fire means it experiences about 1,500 earthquakes annually, with 10% of global quakes of 6.0 magnitude or higher occurring in the country. This includes the 9.0-magnitude earthquake in March 2011, which triggered the Fukushima nuclear disaster, one of the worst in history. Since then, the government has continued to issue warnings and advisories for coastal residents.

Residents in Iwate and Aomori prefectures were advised to evacuate immediately after the 7.5-magnitude quake, with tsunami waves of up to 3 meters forecast. Within an hour of the quake, waves of up to 80 cm were detected, according to Mashable India. The quake had a depth of 10 kilometers, and parts of Aomori, Iwate, and Miyagi prefectures recorded a seismic intensity of 5 on Japan’s scale of 7.

Authorities in Tokyo, which recorded a seismic intensity of 3, reported that buildings swayed for several minutes after the quake. Despite the relatively mild shaking, the situation remains under close monitoring, with officials urging residents to stay alert and follow evacuation instructions if necessary.