Japan islanders sleepless after 900 earthquakes in two weeks

More than 900 earthquakes have shaken a remote and sparsely populated island chain in southern Japan over two weeks, keeping residents anxious and awake all night.

Seismic activity has been "very active" in the seas around the Tokara islands since 21 June, authorities said after a magnitude 5.5 earthquake struck on Wednesday.

There have been no reports of damage and no tsunami warning has been raised but authorities have advised residents to prepare to evacuate if needed.

"It's very scary to even fall asleep," one resident told the regional broadcaster MBC. "It feels like it's always shaking."

The Tokara area has experienced clusters of earthquakes in the past but the frequency of the most recent tremors has been unusual, according to local media.

Japan is one of the most seismically active nations on Earth, owing to its location on the so-called Pacific Ring of Fire, where many tectonic plates meet. It experiences about 1,500 earthquakes each year.

About 700 people live on seven of the 12 Tokara islands. There are no hospitals on some of these far-flung islands - the nearest is at least six hours by ferry to the prefectural capital, Kagoshima.

"You can hear a strange roar from the ocean before the quakes hit, especially at night. It's eerie," Chizuko Arikawa from Akusekijima island told The Asahi Shimbun.

"Everyone's exhausted. We just want it to stop," said the 54-year-old, who lives by the sea and runs a cattle farm with her husband.

"After so many quakes, it now feels like the ground is shaking even when it's not," said Isamu Sakamoto, 60, head of the local residents' association in Akusekijima.

"The quakes start with a jolt from below, then the house sways. It's sickening," he said.

In Toshima village, some residents have been sleep-deprived and tired, authorities said, as they urged the media to stop inundating locals with queries.

"We ask that you be considerate and not make excessive inquires or interviews," according to a notice on the village website.

Some guesthouses on the Tokara islands have stopped accepting tourists because of the earthquakes, Toshima Village said on its website, noting that they might be used as shelters for locals.

This series of tremors come as the country as a whole has been kept on edge by rumours that a massive, deadly quake could soon hit.

A 1999 comic book by manga artist Ryo Tatsuki has been fuelling these rumours. In a new edition released in 2021, she claimed the next big earthquake would strike on 5 July this year.

These speculations have spooked some tourists, with several media reporting a flurry of trip cancellations.

The vast majority of earthquakes that hit Japan are mild, but there are some that cause great damage, like the one in 2011 that triggered a massive tsunami into the north-east coast, killing more than 18,000 people.

However, authorities have for decades feared the "big one" - a once-in-a-century megaquake that many had grown up being warned about. Worst-case scenarios predict it could leave more than 300,000 dead.

Earlier this week, the government called for new measures, such as constructing embankments and evacuation buildings, to strengthen public readiness in case of such a disaster - but it warned that much more needs to be done.