November 25: Rough weather, icebergs, deploying the ROV
November 25, 2006
On board the RV Yuzhmorgeologiya
Steaming through the Bransfield Strait
It has been an extremely busy day! The weather has begun to deteriorate, but in this case that means returning to its norm. Fortunately the seas are still calm enough to permit transport by Zodiac, so Andrew, Del and I returned to the Korean base for another visit to the penguin colony and to use their Internet connection. The rest of the team was involved testing the newly acquired Remotely Operated Vehicle (ROV). Dr. Dziak has generously offered to relate today’s experiences with you.
Bob Dziak writes: The ship has been anchored near the Korean Antarctic Base in Marion Cove for the past two days, but we plan to continue our hydrophone mooring recovery this afternoon. With the morning free, we decided to do a test deployment of our Remotely Operated Vehicle (ROV) in the iceberg-laden bay. The Koreans sent one of their Zodiacs to the ship, and we loaded our equipment and scrambled down the 20 ft high rope ladder into the inflatable. The seas were choppy because of a sustained 20-knot wind, but we zoomed off to the nearest iceberg some 10 minutes from the ship. Onboard the Zodiac from the Sounds of the Southern Ocean Expedition were Haru Matsumoto, Joe Haxel, and myself to handle the ROV work. Kate Stafford also came along to deploy our portable hydrophone to record the sounds of ice noise and marine mammal calls in the cove. The Zodiac was expertly driven by Mr. Yu from the Korean polar base who saw to it our work was safely accomplished.
Grounded iceberg in Marion Bay; Zodiac in the foreground
The sky was grey and the Zodiac bounced in the choppy seas occasionally spraying our goggles and mustang suits with the frigid Antarctic water. It was exhilarating; I loved it! I was happy and excited that we were finally on our way to do the camera work after the many months of preparation. And the stunning scenery of Marion Cove with the enormous glaciers calving into the bay just added to the thrill of the moment. We first stopped the Zodiac in the center (and deepest) part of the cove to test the ROV’s maneuverability in open water away from any troublesome ice.
The ROV is essentially a video camera housed in a pressure-protected case that can be submerged up to 1000 feet of water. The unit has three thrusters mounted to it to allow the operator to control the vehicle’s vertical ascent/descent as well as provide left-right horizontal control. We set up the ROV equipment which includes a LCD monitor so we can see what the camera is recording at all times, a DVD writer, and 450 feet of cable to keep the ROV attached to the Zodiac. One of our main concerns was how the extreme cold would affect the ROV operations (as well as the recording and viewing capability), and so far everything worked like clockwork.
We placed the ROV in the water, did a few brief maneuverability tests, then hit the down thrust and sent it to the bottom. After all this time, I was dieing to see the seafloor! The camera quickly sank to 50 feet and settled on the bottom. The seafloor here was surprisingly full of life. Krill and amphipods darted in and out of the field of view. There were many types of algae and kelp in a variety of colors. Since the camera was only 50 feet deep, the bright lights of the ROV made the water a pale aqua color, making it look as though we were working in the tropics! There was also a surprisingly large amount of light colored particles (either sediment or organic material) being whisked through the field of view the cove currents. The good news was the ROV operations were unaffected by the currents here, and we anticipate the currents in Deception Island will be even milder. We kept the ROV in this location for several minutes while we tested each thruster and practiced zooming and focusing the camera. I was very pleased to see the camera produced exceptionally clear, crisp images. If everything goes smoothly at Deception, we should get some fantastic footage.
After this initial stop, we pulled up the ROV and motored the Zodiac over to a collection of small icebergs tucked into a little embayment at the west side of Marion Cove. This spot provided protection from the wind and waves, making the ROV work much more manageable. The icebergs here were stunning. Although only a few tens of feet high, they were the deep, deep blue that one only sees when the ice is truly ancient. It is as though we are looking back into the history of Antarctica itself.
We were rapidly running out of time allotted to perform our test before we needed to get back to the ship. We quickly put the ROV into the water and drove it down to the base of the iceberg where it was resting on the seafloor. The water was shallow at our first stop, only 15 feet, so the background light was very bright. We had the ROV circle the small bergs, zooming up and down along the ice face from the base to the water surface. The ice images, interestingly, kept coming in and out of focus on the LCD monitor. I think this is because the ice and water are nearly the same color and also because the ice surface undulates, causing the ice surface to continually fall in and out of the field of view. But the video itself did not have this affect.
After we had satisfied ourselves that we had put the ROV through its paces, we brought the ROV back onboard the Zodiac and roared off to the ship. I must say that during the ROV my excitement must have kept me warm, but on the open water trip back to the ship the numbing of the cold had set in. Thankfully it was a short trip, and soon enough we were on the ship, just in time for a filling lunch of hot chicken soup. While getting our gear off the Zodiac, I looked around at each person and saw that each of us was smiling ear-to-ear thinking of what an amazing experience we just had. What an incredible way to spend a Saturday morning, and this is just the beginning!! Thus with success declared, we set off to recover our next hydrophone in the Bransfield Strait – saying a short-live good bye to King Sejong Station.
Dr. Del Bohnenstiehl returning to penguin colony