THE WORLD REMAINS FULL OF MYSTERIES: We All Nearly Missed The Largest Underwater Volcano Eruption Ever Detected.

She was flying home from a holiday in Samoa when she saw it through the airplane window: a “peculiar large mass” floating on the ocean, hundreds of kilometres off the north coast of New Zealand.

The Kiwi passenger emailed photos of the strange ocean slick to scientists, who realized what it was – a raft of floating rock spewed from an underwater volcano, produced in the largest eruption of its kind ever recorded.

“We knew it was a large-scale eruption, approximately equivalent to the biggest eruption we’ve seen on land in the 20th Century,” said volcanologist Rebecca Carey from the University of Tasmania, who co-led the first close-up investigation of the historic 2012 eruption, and together with colleagues finally published the results in a paper in 2018.

The incident, produced by an underwater volcano called the Havre Seamount, initially went unnoticed by scientists, but the floating rock platform it generated was harder to miss.

And yet it almost was.