Over the past few weeks, some fairly big bits of New Zealand have been washing up along the coast of far north Queensland. They’ve travelled more than 4,000 kilometres over the past year or so, and come from a major volcanic eruption that might never have been noticed but for a passenger who looked out of an aeroplane window at just the right moment.
We’re talking about lumps of pumice, one about 600 square metres, that began washing up around the Low Isles last month. We’ve also had reports of pumice being found along the Cairns coast, and at Prince of Wales Island in the Torres Strait.
The rocks were created by an underwater volcanic eruption near New Zealand in July last year. The Havre Seamount, in the Kermadec Islands, went off, ejecting a huge amount of pumice that formed a “raft” measuring 20,000 square kilometres. We might never have known of the eruption, but two weeks later a keen-eyed tourist flying back to New Zealand from Samoa spotted the pumice raft from a plane window.
Dr Scott Bryan specialises in pumice rafts at the Queensland University of Technology. He says rafts of porous volcanic rock are a remarkable, but poorly understood, natural phenomenon that play a unique role in transporting marine species across oceans. If you find some of the pumice around FNQ Scott would love to hear about it.