Volcano Islands, Japan
26.12 N, 141.10 E
summit elevation -10 m
Kaitoku Seamount (Kaitoku Kaizan), is a three-peaked submarine volcano 130 km NW of Iwo-jima, Japan.
The three peaks are the summit of a large submarine volcano. The SW, NE, and N summits have depths of 103 m, 353 m, and 506 m.
The Japanese government formally named the seamount after the eruptions in 1984. On 7th March 1984 a Japanese defense force transport plane flying 130 km N of Iwo-Jima observed discolored sea water extending 28 km WSW from a submarine eruption. Between 25th March and 30th April, over 500 T-phase acoustic waves were detected in French Polynesia. The events correlated with submarine volcanic activity at Kaitoku Seamount. After 3 months of quiet, discoloured water was observed at the volcano on 15th October 1984.
Mystery Cloud of 9th April 1984
On 9th April 1984, crews of three separate commercial aircraft en route from Tokyo to Anchorage, Alaska, observed a gigantic mushroom-like cloud 180 miles off the coast of Japan. It was described as moving rapidly up to an altitude of 18,000 m and had a diameter of 320 kilometres. Dust collected from the scene by an F-4 Phantom fighter-bomber deployed by the Air Self- Defense Force of Japan showed no ab- normal levels of radioactivity. The captain of one of the airliners, a veteran of 41 years, immediately issued a Mayday alert to Anchorage International Flight Service and put his crew on oxygen as a precautionary measure.
Hydrophones at Wake Island, and French Polynesia recorded underwater eruptions at Kaitoku Seamount in March and April. The mystery cloud was observed 1460 km NNE of the volcano.
Did Kaitoku volcano produce the mystery cloud? Kaitoku seamount was erupting at the time, but winds were not favourable, so the theory has been discounted. The source of the cloud remains a mystery.