3D-mapping sub reveals new info on Antarctic ice melt

24 Nov 2014

The AUV SeaBED robot surveys beneath Antarctic sea ice. Image via Digital Journal/WHOI

A 3D-mapping robot submarine has created the most detailed map of Antarctic sea ice to date, in what could prove crucial for measuring the rate of its melting and movement.

Using its SeaBED autonomous underwater vehicle (AUV), a team of researchers from the Woods Hole Oceanographic Institution (WHOI) have been able to create the 3D maps in high-resolution which have helped fill in the gaps that had existed in science’s understanding of the way Antarctic ice melts and shifts.

Until now, many of the largest surveys of the ice had been conducted by divers who are limited to depths of a maximum of 50m, while SeaBED is capable of reaching the shelf edge and continental slope at depth of between 1,000m and 2,000m.

Even with the help of divers, and even satellites, there was still little-to-know understanding of the areas where the ice was at its thickest which has now been combined with SeaBED’s finding to create the most detailed map to date.

A design and software challenge

The 2m-long submarine is considerably different to most similar AUVs because its sonar and camera are not facing downwards towards the sea floor, but is rather focused upwards to measure the flow of the sea ice.

Speaking of the craft’s design, the WHOI team said it was a challenge both in terms of its external hardware and its software to create the high-tech machine which includes a WHOI MicroModem for acoustic communication and navigation, and a SeaBird CTD sensor for measuring salinity and water temperature and the craft’s main computer is a 1.2GHz Pentium processor, running Ubuntu Linux 8.04.

“SeaBED’s manoeuvrability and stability made it ideal for this application where we were doing detailed floe-scale mapping and deploying, as well as recovering in close-packed ice conditions,” said Hanumant Singh, an engineering scientist at WHOI. “It would have been tough to do many of the missions we did, especially under the conditions we encountered, with some of the larger vehicles.”

Colm Gorey was a senior journalist with Silicon Republic