Mapping the Arctic Ocean Floor

A Natural Resources Canada ice camp set up for an appurtenance field experiment

Mapping the Arctic Ocean floor to determine the outer limit of the continental shelf is a key step in supporting Canada’s jurisdictional claim in the Arctic. DRDC Atlantic assisted in the mapping work by helping Natural Resources Canada (NRCan) and the Department of Fisheries and Oceans (DFO) to extend their surveys into the more remote northern regions.

NRCan and DFO have been conducting Arctic surveys for the past three years. Their goal is to substantiate Canada’s submission to the United Nations Convention on the Law of the Sea (UNCLOS) concerning jurisdiction over the area beyond the 200-Mile Exclusive Economic Zone in the North. The implementation of Article 76 of the UNCLOS requires the analysis and interpretation of the depth of the sea floor and the thickness of the underlying sedimentary layer, as well as determining the appurtenance of submarine elevations (plateaux, rises, caps, banks) by ascertaining whether they are natural prolongations of the land territory of the coastal state.

One of the geobuoys embedded in the ice

NRCan and DFO scientists were using sound waves to probe the geological characteristics of undersea ridges and sediments. However, they had difficulty mapping the more remote reaches of the survey due to the logistics of deploying and recovering instruments in those areas. Using technology developed for submarine surveillance in the Arctic and deployed by a Canadian Forces CP-140 Aurora, DRDC Atlantic helped the scientists to significantly extend the range of the survey into the remote areas.

The Aurora dropped seismic receivers known as geobuoys. The sensors embedded themselves in the ice and then transmitted the under-ice ocean-acoustic data back to the aircraft, where they were recorded and processed. Rather than listening for submarines, the geobuoys detected the sound waves generated by NRCan personnel at ice camps further south.

DRDC Atlantic helped to develop the concept, assess the suitability of the geobuoy for this experiment and plan the scientific aspects of the mission. DRDC Atlantic personnel also participated in the Aurora flights.