Japan’s coastguard sent aircraft today to investigate reports of a one kilometre – (3,300-foot) high column of water vapour that shot up from the Pacific Ocean near Iwo Jima – a possible sign of volcanic activity – officials said.
Japanese troops stationed on the small island reported seeing the massive, cloudy plume rise from the sea on Saturday night about 50 kilometers (30 miles) southeast of the island, said Maritime Self-Defence Forces spokesman Hiroshi Shirai.
Defence officials who flew over the area in a helicopter said the surface of the water appeared red in the area where the column was reported, which could indicate underwater volcanic activity, Shirai said.
Coastguard aircraft crews were flying over the site in an attempt to determine what had happened, he said.
No further details were immediately available.
Japan’s Meteorological Agency said there was no danger of tsunami - potentially killer waves sometimes caused by undersea seismic activity.
Iwo Jima is about 1,120 kilometers (700 miles) southeast of Tokyo.