The Spirit of Mawson - Australasian Antarctic Expedition 2013 - 2014

Australasian Antarctic Expedition

Days 10 – We’ve reached Antarctica!

Posted by Chris - 17 December 2013

Travelling through the sea ice

After a fraught morning ploughing our way through the sea ice, the Shokalskiy finally broke into a huge area of open water. The contrast couldn’t have been more different. Over the past few days we have become surprisingly comfortable with crashing and shaking our way through sea ice. Now there is only the gentle throb of the ship’s engine. Captain Davis, Mawson’s second-in-command and future best man, was palpably relieved when he saw a similar sight to us in his first final approach to Commonwealth Bay: ‘We coasted along this barrier [the Mertz Glacier] up to its western end, and were then delighted to see open water extending away to the Southward inside a small fringe of pack; also a fine water sky to the southward.’ It’s reassuring to know we are travelling the same path as the original AAE.

At first glance, the presence of open water in these latitudes does seem rather odd. Why is the area not covered with sea ice all the way to the continent? It’s existence is thanks to a combination of circumstances that includes water depth, temperature and wind, lending themselves to the generation of ice at the surface and cold, salty water below – both of which subsequently flow north; the resulting briny, deep water is one of the drivers of our planet’s ocean circulation system. There are several places where this Antarctic Bottom Water is formed – often shorted to AABW by oceanographers – but the Mertz Polynya is one of the most significant globally. With the more extensive sea ice cover in Commonwealth Bay, the size of the polynya has been reduced but it still seems enormous as we sail through.

During the next three hours the Shokalskiy was dwarfed by a new phenomena. As we increased our speed in the calm open water, our ship weaved her way south past flat-topped tower blocks of bergs that had been set adrift from the continent. The height of these awe-inspiring blocks of ice was some 60 metres above the surface. A humbling reminder of just how small you are! The team have ramped up a gear. Chris led the organization of equipment, including our all terrain Argos in anticipation for landing while I prepared the scientists for what work they might undertake over the next few days. We were completely preoccupied minds when the continent and its rising dome of ice appeared on the horizon, fronted by an enormous amount of sea ice...and Adelie penguins. We seem to be in some sort of penguin heaven. I have never seen so many, squawking and crowing at one another, with large groups swimming along the sea ice edge, effortlessly arching through the air before diving below the surface. We had made it through the sea ice and reached the edge of the continent. The Shokalskiy could go no further south.