A RNZAF flight on Wednesday November 16 has reported floating pumice to the west of Minerva Reef in an area about 600 km SE of Fiji and 500 km SW of Tonga. We are not aware of any active submarine volcanoes in this area. The nearest active submarine volcano is Monowai (400 km SE) and we know it was active on November 10-11. Monowai usually does not produce pumice rafts, just discoloured plumes.
We have analysed some satellite images from the area using https://worldview.earthdata.nasa.gov/ and can see the pumice rafts in images from November 15 and 16. They extend for more than 100 km in the images. We have not as yet been able to ‘back track’ the pumice in older images to confirm a source location. The pumice is generally seen around 179°W and 179°E and 23° 20” S.
In October 2012 a much larger pumice raft was found (https://goo.gl/8A7c57) and later we found out it came from Harve submarine volcano.