Canberra: Scientists on Monday said that a vast "raft" of volcanic rocks stretching over 150 sq.km has been found drifting through the Pacific Ocean. The sea of pumice is the size of 20,000 football fields which was first reported by Australian sailors earlier in August. Pumice is a lightweight, bubble-rich rock that can float in water. It is produced when magma is cooled rapidly.

According to experts, the mass has likely come from an underwater volcano near Tonga which erupted around August 7 as seen in the satellite images. In that case, sailors have been warned to stay clear of the potential hazard.