Last updated: Monday 6th November 2017
The opening of Signy base is now complete and at about 17:30 today the RRS James Clark Ross departed Borge Bay, via the scenic Normanna Strait, and set course for Bird Island and South Georgia.
Whilst today was the best weather day that we have had, with wall to wall sunshine and little wind, it also proved to be the most problematical day as the pack ice from the south continued to move into Borge Bay and mid-morning the ship had to move anchorage and recover the cargo tender. This is just one of the reasons that working in the Antarctic is never simple and is never, ever, the same two years in a row. However, the base are now fully operational and will be cooking their first dinner of the summer and settling into the routine of island life. There next visitors won't be for about a month when HMS Protector calls.
With the weather being so stunning, the remainder of this update is just going to be pictures.
The morning started early again, with the JCR in position for 06:00. At about the same time lenticular clouds were starting for form above Coronation Island. These clouds have often been mistaken for UFOs!
Penguin!!! At long last I have managed to snap a picture of a penguin, in this case an Adélie, sitting on the pack as it surrounded the ship this morning.
The pack. Had this moved from Borge Bay into Factory Cove I would likely be telling a very different tale. This, whilst easy for the JCR to work through (we are doing that as I write, having navigated around Signy and running along the coast of Coronation Island), but the inflatable boats and cargo tender would struggle. With the thought that this was going to happen all non-essential personnel on the island, who were not staying, were brought back to the ship.
The JCR re-positioning earlier today. If you look at today's Dartcom image you can see how the pack ice has moved north, all in just a few days.
A small iceberg, grounded, just off Coronation Island.
Two days ago this view was all open water with just a few grounded bergs in sight. Now it is 10/10th pack
There will be many mentions in my updates on the subject of ice, so I thought it might be time to try and clarify just what some of the terms mean.
Sea Ice: Sea ice is ice formed by the freezing of sea water. As the freezing process continues sea ice grows in thickness, gradually loses its salt and by doing so becomes harder with age. It is usually classified by its age or stage of development. Whilst fresh water freezes at 0°C, salt water with a salinity of 35 parts per thousand or corresponding specific gravity of 1.025 freezes at -1.9°C.
The stages of development of sea ice are as follows:
1. New ice. A general term for recently formed ice which can be in the form of frazil ice, grease ice, slush, shuga, ice rind, nilas and pancake ice. Thickness to 10cm.
2. Young ice. Sea ice in transition between new ice and first year ice and typically 10 to 30cm thickness.
3. First year ice. Sea ice of not more than one year's growth developing from young ice and 30cm to 2m thickness. Thin first year ice is 30 - 70cm, medium first year ice is 70 - 120cm and thick first year ice is over 120cm.
4. Old ice. Sea ice which has survived at least on summer's melt. It can be up to 3m or more thick. Second year ice is ice that has survived the first summer, 2m or more thick. Multi-year ice is ice is ice which has survived at least two summers and is 3m or more thick.
Pack Ice: The term pack ice refers generally to any accumulation of sea ice other than fast ice and this is classified in tenths as follows:
0 to 1/10 Open water
1/10 to 3/10 Very open pack
4/10 to 6/10 Open pack
7/10 to 9/10 Close pack
9/10 to10/10 Very close pack, which can be consolidated with floes frozen together, or compact with no water visible.
Floe: A floe is a relatively flat piece of floating ice usually described as 20m or more across and can be classified to size as described below:-
Small floes - 20 to 100m across
Medium floes - 100 to 500m across
Big floes - 500m to 2km across
Vast floes - 2 to 10km across
Giant floes - over 10km across
Another Adélie penguin, and his shadow, on a small ice floe.
Whilst waiting to see how things were progressing on Signy Island, the Captain decided to have a look and see what Normanna Strait looked like as he was considering using this route when heading for South Georgia. If you look ahead where the Foremast is, that is where the strait is, between Signy and Coronation Islands.
Referring to the ice information above, here is an excellent image with a bit of new ice, with frazzle and grease ice visible. Whilst we are entering the summer months in this region, with the air and sea temperatures so low just now it is perfect for new ice to form. Normally my view is that if we see this it is time to head north, but at this time of the year I am happy to remain here.
Snow capped mountains on Coronation Island.
More snow capped mountains, this time on Signy Island.
Another view of Coronation Island this afternoon, with the pack ice close in to the island and open water further out.
.....and finally, a snow petrel.
Having picked the above pictures for the update this evening, I am confident that I could step outside and take another hundred plus as we continue to work through the pack ice, with Coronation Island to starboard and Signy Island falling behind. I will be in daily contact with the base to see how they are getting on and to hear what delicious meals they have been cooking. Each person takes a turn at evening cook, which will also include baking fresh bread each morning. I keep getting distracted by the view out of my window and am going to finish now so that I can enjoy the full view from the Bridge as the sun sets across the islands.
Noon Position Report Monday 6th November 2017
Borge Bay, South Orkney Islands
Previous updates from the current trip.
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