Lost Svalbard ice buoy shows waves push floes together

Data from a measuring case left on the sea ice north of Svalbard in 2020, and found two years later in Iceland, gave the first demonstration of how waves beneath the ice move it at the surface, the University of Oslo said. The result suggests that collisions between ice floes help damp waves at the ice edge. That process is poorly charted, and the gap matters for climate and ecosystem models of the north.

Six instrument cases were placed along the ice edge in summer 2020 during an expedition to the Yermak Plateau. Their batteries lasted about two months, and satellite transmission drained power, so the key records of waves meeting the ice stayed inside the cases. Professor Atle Jensen said the cost of retrieval was so high that the team considered them lost, the university said.

Two years later an archaeologist in Iceland, Lísabet Guðmundsdóttir, emailed him a photo of a rusty case and asked whether it was his. Jensen talked her through copying the memory card and sending the files. The electronics were largely ruined, but the data survived. He said the data showed what the team had believed but never confirmed.

The card held 142 files, each a 20-minute burst of motion and GPS data logged every four hours, according to ECOticias, which reported that the case was found near Hafnir on the Skagi peninsula. Four files showed statistically significant spikes, and two showed sharp sideways jolts consistent with floe collisions, it said. The buoy typically sat about 80 kilometres inside the ice edge. The authors caution that the sample is too small to extrapolate from.

A German tourist has located a second case in Iceland and sent its GPS coordinates, the university said. As of late September, three recovery attempts had been made, and bad weather had halted further efforts. Jensen hopes two logging points will show how floes move relative to each other.

Coverage: ECOticias - El Periódico Verde