Dec 4 - The Iceberg in the Harbour

One of the reasons Mawson Station was built where it was (in 1954),
is that it is has a very nice sheltered harbour in a horseshoe shape,
known, fortuitously, as "Horseshoe Harbour". The straits out in front
have quite rapid currents, and when the sea ice has melted, icebergs
trail down through there so it would not be a very good place to moor a ship.

In 1980, one iceberg floated into Horseshoe Harbour and became lodged there, and was frozen in place for the winter, but then did't float back out the next summer. This had obvious implications for the re-supply, particularly the fuel resupply which is via a long pipeline. They made several attempts to move it, attempting to lasso it and winch it to one side (nothing happened but the ropes would snap), even dynamiting it (a muffled bang, a puff of smoke and a shower of ice leaving a charred divot the size of a bathtub in the ice). When the current shifted it to one side, they tried to at least tether it there until the resupply ship had been through, and tied it up with various ropes.

One night, it went for a bit of a wander through the harbour by itself and the ropes knocked over several radio antennas, so not even that worked.

Eventually the thing just left one night, to be rediscovered 200km along the coast months later, still nicely-wrapped up in ropes.

Well, it's happened again. Last March, just after resupply, a little berg arrived and promptly got stuck right in the middle of the mouth of the harbour. It's been there all winter, and the thaw of the sea-ice is only just starting now. With luck, it will leave once the ice has thawed, but if it remains stuck firmly on the little ridge underwater, we may have a tricky re-supply process in February.