While on a routine maritime patrol mission yesterday between Samoa and New Zealand, a Royal New Zealand Air Force P-3 Orion spotted a rather unusual field of debris floating on the surface of the ocean southwest of Raoul Island.
It was rocks… lots and lots of rocks. Pumice more specificially, and it covered an area 250 nautical miles in length and 30 nautical miles wide.
Pumice is formed when super heated, highly pressurized lava is quickly cooled, trapping air bubbles inside it.
Try to picture a can of soda instantly freezing solid as soon as you open the top, that’s pretty much how pumice is formed. Dissolved gases in the lava don’t have time to escape before the rock hardens.
According to GNS Science, the underwater volcano Monowai has been active along the Kermadec Arc and the pumice could be a result of that activity.
While transiting from Auckland to Raoul Island, HMNZS Canterbury changed course to intercepted the floating rock field to gather samples to determine which volcano they came from.