In a cavern, hundreds of meters high, beneath a vast Antarctic ice shelf, swarms of shrimp-like creatures inhabit a recently discovered underwater ecosystem that, until recently, was hidden under the ice. Researchers from New Zealand discovered the ecosystem hundreds of kilometers from the edge of the Ross Ice Shelf, 500 meters under the ice.

Scientists from universities in Wellington, Auckland, and Otago, as well as the National Institute of Water and Atmospheric (Niwa) and the Geological and Nuclear Sciences, investigated the role the estuary could play in melting ice shelves. Their cameras were attacked by amphipods when they broke through the ice and entered the river, which was similar to lobsters, crabs, and mites.

Initially, I thought the camera was malfunctioning, but when the focus improved, I noticed a swarm of 5mm-sized arthropods,' said Niwa's Craig Stevens. Previously, scientists thought they knew what was happening on the ice shelf, but this time, big surprises emerged.

Stevens said the expedition had a discovery element in addition to the climate change motivation for the work. There's clearly an ecosystem around our equipment since all those animals were swimming around it, so we were jumping up and down.'

Huw Horgan, the project leader at Te Herenga Waka Victoria University of Wellington, was the first to spot the estuary, seeing a groove in the ice while reviewing satellite images of the Ross Ice Shelf.

Horgan said that researchers have known for some time that there are freshwater lakes and rivers under the Antarctic ice sheets, but they have yet to be surveyed.

It was like entering a hidden world when I was the first to observe and sample this river.' Researchers left instruments in the river to observe its behavior, while lab researchers studied what made the water so unique.

Further findings showed that the team had just deployed its mooring a few days before Hunga Tonga-Hunga Ha'apai erupted. Instruments on the team found a significant change in pressure as the tsunami moved through the cavity.

Stevens was reminded of how connected the planet is by seeing the eruption's effects. 'Here we are in a forgotten corner of the world, seeing real-time impacts from events that were so far away. The experience was quite remarkable.'