14 December 2006

I-TASC Antarctic Expedition 2006-07

Yesterday we saw our first icebergs. They were spotted early in the morning but not by us. We didn’t see our first icebergs until about 1900. Then there were two large icebergs in the distance. After dinner, the I-TASC crew went to the bridge and spoke with the officer there. He showed us the radar where we could easily see many large pieces of ice. From the radar, we could look through the mist in the direction of the radar blips and search for the floating mountains.

I spoke with one of the officers and he was saying it’s not the big icebergs they are worried about. It’s the ‘growlers’ which cause problems. Growlers are smaller pieces of ice broken from icebergs, or the last remnants of a melting iceberg, which sit on or just below the surface. The officers are more concerned about seeing these so they can avoid hitting them. Big bergs can be easily seen and avoided but the little ones do not appear on the radar and must be spotted by eye. For this reason, there are constantly two people (not officers but paid crew) that sit on the bridge 24/7 (from yesterday) and look for ice. They have binoculars and if they see something they inform an officer.

The movement of the ice isn’t as easy to judge by eye as you might expect. The ship is constantly adjusting its course as the wind and swell push the boat slightly one way or another and the ship must constantly make adjustments for this. Hence nothing is static and points of reference are difficult to trust. Additionally, the movement of the ice can either be most influenced by the wind _or_ the current, depending on whether there is a┬álarger surface area above or below the surface. Hence, the ice moves erratically and watching the trails on the radar you can see the plotted paths of some bergs seem to move against the general flow, making navigation by radar something less like using mapquest and more like a game of frogger….

I watched one episode of this interestedly. I could see on the radar there was an iceberg straight ahead of us. I could also see some growlers in our path. The growlers are difficult to spot as the sea is a bit rough, so there are white caps of foam everywhere. The growlers can most easily be seen by looking for constant white spots in the sea ahead – to my New Zealand eye they are reminiscent of how reefs appear from a distance, with a constant rolling whiteness amongst the waves. The officer was quietly having a cup of tea and the spotters saw the ice and called him on a small handheld radio. As they called him it was amazing to witness how quickly the visibility can change at sea. In less than one second, the visibility was cut from about 2km to about 500 meters – it was the outlying cloud moving in like a quick fade, and less than half a minute later the visibility was again about 2km. Also, once you know what to look for, you start seeing ice everywhere. A course was then set to avoid the iceberg ahead and we all watched as the growlers ran harmlessly past. The ship always tries to avoid the bergs by a mile or so as the trailing path of the icebergs often has growlers that have broken off.

I talked with the officer and he was saying that they do hit the growlers. Although no one really gives a straight answer as to how dangerous this is – I have had two good replies from different people, one said “you will definitely know you have hit one”, and the other said, “well, you will at least spill your coffee.” The officer I spoke with had once worked on a boat where the captain made the officer in charge pay a 6 pack of beer for any growler they hit that woke him while he slept. Apparently, it was a good method for improving growler avoidance.

The officer also explained to me, that as we go further into the belt of ice, the ship gets steered like a car going through an obstacle course. The ship can be turned in about 2 or 3 ship lengths so it is quite quick to respond and in the worst case they simply stop the boat.

The sea got up a lot last night and it seems we were rolling in every direction simultaneously. Sometimes the rolls were very marked. I couldn’t help but ponder the effectiveness of spotting growlers by eye in rough seas at night. Consequently, I didn’t get much sleep. It’s 09.50, I will now get a coffee and have a shower, then I will go berg spotting.

…its now about 1500 and I spent a good 1.5 hours after lunch on the monkey deck watching icebergs. We are apparently traversing a belt of ice and then we move into the pack ice. There is now ice everywhere. At one point I saw a thin white line on our horizon (about 4km), I thought it might be the oncoming pack ice but it was just a large collection of growlers floating together. The boat altered course about 5 degrees to avoid it and then came back once we passed. Right now, I think we are just on 60 degrees south. This afternoon we are going to discuss some ideas First Born has about documentation and read some of the tech manuals.

Print Friendly, PDF & Email

Leave a Reply

Your email address will not be published. Required fields are marked *