6-Feb Slow Passage Through Heavy Pack Ice
We are well inside the pack ice barrier now and well inside the Ross Sea, slowly picking our way through narrow fingers of navigable waters between the built up pack ice - where we can find them. The sea temperature has dropped further to minus 1.5 degrees, just above the freezing point of seawater and the engine room bilges are are freezing up. We have changed over to the next set of double bottom FO bunker tanks which have been diluted with10% kerosene. This was added during bunkering in Wellington so as to avoid the diesel waxing in these extra cold temps.
Looking out of my porthole, it is snowing again and miles of snow-white islands of broken pack ice are drifting by. The occasional one has a sea leopard and lazy seal waving to us with its upturned flipper or small groups of puzzled penguins.
I met Bob, the “Ice Pilot”, today, a special deck officer who has expertise in sailing through ice and years of experience in Antarctic ice navigation under his belt. He was Captain for many years with Greenpeace on their Antarctic missions. The Tangaroa is not an icebreaker as such, but does have an ‘ice rating’. This ice rating allows it to break through 0.3 metres of year-old sea ice but anything thicker we can simply shove out of our way. However we do limit our ice contact, where‑ever possible.
The Ross Ice Shelf itself is about the size of France and like so much of this area was also discovered by James Ross in 1841 and was later named after him. On the 5th of January 1841, a British Admiralty team, led by Ross in the three-masted ships, Erebus and the Terror with specially strengthened wooden hulls, were going through the pack ice in an attempt to determine the position of the South Magnetic Pole. However they soon came up against the edge of the enormous ice shelf. Sir James Clark Ross, remarked at the time ”Well, there's no more chance of sailing through that than through the cliffs of Dover”. Ross, who in 1831 had located the North Magnetic Pole, spent the next two years vainly searching for a sea passage to the South Pole.
Both Amundsen and Scott crossed this ice shelf to reach the Pole in 1911. Scott's polar party, which had embarked from Ross Island, later died on the ice shelf during their return trek in 1912. They died in what scientists now believe was a freak cold period. "The new study of the weather on the Ross Ice Shelf, only carried out in the past decade or so, shows Scott really was unlucky. He travelled through an exceptionally cold spell, some 20 degrees Fahrenheit colder than usual."
The Ross Ice Shelf is the largest ice shelf of Antarctica and is about the size of France. The ice shelf is the main outlet for several major glaciers draining the West Antarctic Ice Sheet and contains the equivalent of 5 metres of sea level rise in its above-sea-level ice."
The presence of the shelves actually acts as "breaks" for the glaciers. These shelves serve another important purpose - they moderate the amount of melting that occurs on the glaciers' surfaces. Once their ice shelves are removed, the glaciers will increase in speed due to meltwater affecting it and because of the reduction of braking forces. They may then begin to dump more ice into the ocean than they gather as snow in their catchments thus unbalancing the equilibrium.
The near vertical ice front at the edge, where the ice shelf meets the open Ross Sea, rises about 30 metres + high above the sea level and is more than 600 km long. The ice mass is about 800 km wide and 970km long. In some places further in on the ice shelf, namely its southern areas, the ice shelf can be almost 750 metres thick with more than 90 percent of the floating ice being below the water level. The Ross Ice Shelf pushes out into the sea at the rate of between 1.5 metres and 3 metres a day. At the same time as the glaciers feed ice into the shelf, the freezing of seawater below the ice mass increases the thickness of the ice.I have been struggling a little with the watercolours. I think it’s because the atmosphere is so dry. The humidity is in fact zero. It is so dry in fact that the carpets in our cabins tend to shrink. I keep trying. I am now painting the scenes that appear outside my porthole.
Looking out of my porthole, it is snowing again and miles of snow-white islands of broken pack ice are drifting by. The occasional one has a sea leopard and lazy seal waving to us with its upturned flipper or small groups of puzzled penguins.
I met Bob, the “Ice Pilot”, today, a special deck officer who has expertise in sailing through ice and years of experience in Antarctic ice navigation under his belt. He was Captain for many years with Greenpeace on their Antarctic missions. The Tangaroa is not an icebreaker as such, but does have an ‘ice rating’. This ice rating allows it to break through 0.3 metres of year-old sea ice but anything thicker we can simply shove out of our way. However we do limit our ice contact, where‑ever possible.
The Ross Ice Shelf itself is about the size of France and like so much of this area was also discovered by James Ross in 1841 and was later named after him. On the 5th of January 1841, a British Admiralty team, led by Ross in the three-masted ships, Erebus and the Terror with specially strengthened wooden hulls, were going through the pack ice in an attempt to determine the position of the South Magnetic Pole. However they soon came up against the edge of the enormous ice shelf. Sir James Clark Ross, remarked at the time ”Well, there's no more chance of sailing through that than through the cliffs of Dover”. Ross, who in 1831 had located the North Magnetic Pole, spent the next two years vainly searching for a sea passage to the South Pole.
Both Amundsen and Scott crossed this ice shelf to reach the Pole in 1911. Scott's polar party, which had embarked from Ross Island, later died on the ice shelf during their return trek in 1912. They died in what scientists now believe was a freak cold period. "The new study of the weather on the Ross Ice Shelf, only carried out in the past decade or so, shows Scott really was unlucky. He travelled through an exceptionally cold spell, some 20 degrees Fahrenheit colder than usual."
The Ross Ice Shelf is the largest ice shelf of Antarctica and is about the size of France. The ice shelf is the main outlet for several major glaciers draining the West Antarctic Ice Sheet and contains the equivalent of 5 metres of sea level rise in its above-sea-level ice."
The presence of the shelves actually acts as "breaks" for the glaciers. These shelves serve another important purpose - they moderate the amount of melting that occurs on the glaciers' surfaces. Once their ice shelves are removed, the glaciers will increase in speed due to meltwater affecting it and because of the reduction of braking forces. They may then begin to dump more ice into the ocean than they gather as snow in their catchments thus unbalancing the equilibrium.
The near vertical ice front at the edge, where the ice shelf meets the open Ross Sea, rises about 30 metres + high above the sea level and is more than 600 km long. The ice mass is about 800 km wide and 970km long. In some places further in on the ice shelf, namely its southern areas, the ice shelf can be almost 750 metres thick with more than 90 percent of the floating ice being below the water level. The Ross Ice Shelf pushes out into the sea at the rate of between 1.5 metres and 3 metres a day. At the same time as the glaciers feed ice into the shelf, the freezing of seawater below the ice mass increases the thickness of the ice.I have been struggling a little with the watercolours. I think it’s because the atmosphere is so dry. The humidity is in fact zero. It is so dry in fact that the carpets in our cabins tend to shrink. I keep trying. I am now painting the scenes that appear outside my porthole.
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