Press Releases

September 18, 2008
Japan Agency for Marine-Earth Science and Technology

Recovery of Indian Ocean m-TRITON Buoy

Japan Agency for Marine-Earth Science and Technology (JAMSTEC: Yasuhiro Kato, President) would like to announce that the Indian Ocean m-TRITON Buoy (*)drifting since July 20 this year has been recovered by JAMSTEC’s Research Vessel Yokosuka at the area of 1,000km west off of its deployed position.

1. Condition of recovered Buoy(Pic.1,2)

The wire rope was snapped around at 55m below the sea surface.

All of underwater sensors installed to the wire down to the snapped point and meteorological sensors installed on the buoy are recovered. Unfortunately, all meteorological sensors are damaged.

2. Possible cause

It is supposed that this was a human-caused incident since a sharp score was found on the insulation of the wire rope. The bare wire around at that position was exposed to sea water and eventually got rusty and snapped.

3. Report to the Japan Coast Guard

Immediately after the recovery of m-TRITON Buoy, we reported to the Japan Coast Guard that no more warning is needed to other ships about risk of collision or interference of their route.

4. Future plan

The Research Vessel Yokosuka will bring the recovered buoy to Yokosuka at the beginning of December after the undergoing researches in the Arabian Sea.
The remaining portion with underwater sensors and other devices will be recovered by the Research Vessel Kaiyo, during its buoy maintenance cruise from February to March in 2009. A maintained buoy will be deployed to the same site by the Kaiyo to resume observation there. (for the configuration of m-TRITON Buoy, please visit:

*Indian Ocean m-TRITON Buoy
m-TRITON Buoy is the oceanographic observation buoy system, which is capable of deep ocean mooring, developed by JAMSTEC for the Tropical Indian Ocean under the MEXT’s “Promotion plan of global observation system”.

Fig.1: Indian Ocean m-TRITON Buoy

Fig.2: TRITON Array

Pic.1: Damaged meteorological sensors (upper: vane anemometer (missing), right: thermohygrometer, left: ombrometer)

Pic.2: Snapped part of the wire rope


(for the recovery of the Indian Ocean m-TRITON Buoy)
Ishihara or Takahashi : e-mail;
Long-term Observation Group, Department of Applied Ocean Engineering
Marine Technology Center (MARITEC)
(For publication)
Noriyuki Murata : e-mail:
Manager, Planning Office Press Office
Japan Agency for Marine-Earth Science and Technology