Pumice stones, which have drifted ashore in Okinawa Prefecture after an undersea eruption last summer, have become something of a fixture of the coastal landscape. But luckily, they won't be around forever.
Experts say that the drifting of pumice stones from the Fukutoku-Okanoba underwater volcano in the Ogasawara Islands has already passed its peak and is likely to stop entirely between April and June.
Meanwhile, pumice stones from an undersea volcanic eruption off Tonga in the South Pacific in January are unlikely to hit Okinawa, they say.