Well, that’s a wrap. Usually on the Amundsen I have some solid downtime to write trip updates as we go, since the ice island work is pretty spread out. That wasn’t the case this time around. The iceberg mapping team had no shortage of work over the past 3 weeks. It seemed that we were constantly in the right place at the right time. We may have also benefited from the fact that environmental conditions (i.e., no quality sea ice) were unfavourable for others` work on the ship – thus giving us more surveying days (sorry Kerri and Lauren!).
We worked on 6 icebergs in total. Weather and sea ice conditions made it impossible to complete a ‘full’ survey of any one iceberg, but I am ecstatic by the amount of work which was accomplished. A full day would have included photo surveying from the helicopter and using the barge for laser scanning (for the icebergs’ above-water face) and multibeam sonar surveying (under-water portion) as well as oceanographic sampling to collect data for iceberg drift analysis. Some weather condition on any given day would confound things – either we wouldn’t be able to get high enough with the helicopter due to low cloud ceilings or there would be too much (‘non-quality’) sea ice for the barge to be deployed. On those days when the latter was the case we’d still conduct the laser scanning from the barge – just while the barge was still sitting on the Amundsen’s deck! The team from Laval who ran the multibeam were instrumental in helping us with this, since operations with the helicopter and the ship were often overlapping. Unfortunately, their underwater surveying was what was cancelled out in this situation, as you really do need to have the barge in the water for that to occur!
Sixteen beacons/GPS units were deployed on the six icebergs. These will be used for drift modeling but a German student on board, as well as us to help correct for the icebergs’ drift while we were surveying them. Photogrammetry surveys were conducted on five of the bergs. We tried to repeatedly survey the same pieces so that I can determine how precise (how close we get to the same answer) our future 3D models are. This will give us our model error, which I’ll then use to say that we could detect deterioration above this minimal level. The same goes for the laser scanning surveys, which we conducted on four of the icebergs.
Right now we are heavy into the data processing side of things. The correction for iceberg drift and rotation during surveying is proving to be a tricky puzzle. We’re working out our correction method on a sample dataset which we took from a survey of the Amundsen itself. Once this is figured out, I’ll work on the 3D model comparisons that are mentioned above, and we’ll also work with the Laval team to integrate their underwater iceberg survey so that we can demonstrate our ability to produce a full 3D map of an iceberg. And from that… potentially ask for further funding to conduct a dedicated iceberg/ice island study to use these tested methods to actually study deterioration over a longer period of time.
But actually, right now were are transiting home on the St. Lawrence. We all took a break from our computer screens yesterday to enjoy a traditional end-of-cruise BBQ on the helicopter deck. Today we are hoping to see some whales and other wildlife as we pass through the Sagueney . Then tomorrow, we’re back in port!
And with that, I’ll be signing off for the summer as the next field adventures aren’t scheduled until October.
Have a great spring and summer everyone!