Thursday, 1 November 2012

Sidescan a go-go!

A (fairly) promising weather window provided us with the opportunity to deploy the side-scan sonar; a piece of equipment that is used to identify seabed features, such as iceberg ploughmark zones.

After some promising test runs of the sidescan sonar, we set out to build up a picture of seabed features heading down the southern slope of Wyville-Thomson Ridge between approximately 400 and 650m. The resulting sidescan sonar image revealed some fairly extensive areas of iceberg ploughmarks, ridges, furrows and rises between 400 and 550m, and what appeared to be finer sediments in the deeper depths.

After one successful tow of the sidescan sonar, the fin of the tow fish became loose and fell off, this resulted in a nail biting 120 degrees swing of the device in the water column! However, after recovering the sidescan sonar back on deck, the fins were quickly replaced and secured.

The plan going forward is to process the raw sidescan sonar data that has been collected, and to use this processed data to help select the locations where we will undertake video and camera tows.
Charlotte undertaking coordinate conversions
Side scan sonar feed from the Wyville-Thomson Ridge showing iceberg ploughmarks

Rainy deployment of the side-scan sonar