Tokyo: The Japan Meteorological Agency issued tsunami advisories to the Izu Islands and the Ogasawara Islands, both in the Pacific, at 6:40 a.m. Monday.

Later in the morning, tsunami advisories were issued also to Chiba Prefecture, east of Tokyo, the western Japan prefecture of Kochi and the southwestern prefectures of Miyazaki and Kagoshima.

All of the advisories were lifted at noon.

A 60-centimeter tsunami was observed in Hachijojima, an island in the Izu chain, at 7:17 a.m., the agency said.

Kozushima and Miyakejima, both islands in the Izu chain, recorded tsunamis of up to 50 centimeters, the Kochi city of Tosashimizu and the Kagoshima island of Nakanoshima up to 40 centimeters, and the Chiba city of Tateyama and the Kagoshima town of Minamiosumi up to 30 centimeters.

Slight sea level changes may occur in coastal areas of Kanagawa Prefecture, south of Tokyo, the central prefectures of Shizuoka, Aichi and Mie, and the western prefectures of Wakayama and Tokushima, according to the agency.

The agency has been unable to identify the cause of the tsunamis while it is believed that an earthquake, volcanic activity or submarine landslide occurred in waters off Torishima, an island in the Izu chain, around 5:25 a.m.

There have been no reports of casualties, according to the Fire and Disaster Management Agency.

Noting that there are not many observation points near Torishima, Toshihiro Shimoyama, senior coordinator for seismological information at the meteorological agency, told a press conference that if the tsunami was caused by an earthquake, the agency has been unable to estimate its magnitude.

The agency will continue its investigation into the cause of the tsunamis.

The advisories were issued after the tsunamis started to reach coastal areas.

Seismic activity started to become vigorous around Torishima on Oct. 2. When a 6.5-magnitude earthquake occurred on Thursday, the agency issued a tsunami advisory to the Izu Islands after quickly estimating its magnitude. A 30-centimeter tsunami was observed in Hachijojima after the Thursday quake.

JIJI Press