If you’re bound for Antarctica, and have a starting point as convenient as New Zealand or Patagonia, there is still one rather significant obstacle to overcome.
The Mercator projection maps pinned to the walls of our childhood classrooms have, for many of us, skewed our notions of world geography with a northern hemisphere bias — Antarctica usually being relegated to a thin white band of coastline separated from all points north by a inconspicuous strip of cyan.
But when we consider that to travel from Christchurch to McMurdo Sound is the Southern Hemisphere equivalent of flying from the Pyrenees to Svalbard, suddenly the Southern Ocean doesn’t seem quite so trivial a feature. This new perspective invites us to question whether we in Australia and New Zealand really are that far ‘down under’ after all.
To some, the Southern Ocean simply comprises the southern extensions of the Pacific, Atlantic and Indian Ocean basins and is not an ocean in its own right. There are others however, that recognise the Southern Ocean as a distinct and fundamental element of global ocean circulation. Lionel Carter, Professor of Marine Geology at the Antarctic Research Centre, is among the latter.
I first met Lionel during his time at the National Institute of Water and Atmospheric Research (NIWA), where his work focused on the deep ocean flow and seafloor sediment dynamics of the southwest Pacific region. Now, at the ARC, he is involved with deciphering records of marine environmental change during warm extremes through the ANZICE programme, and applying the results of ANDRILL to see how localised changes in the Ross Sea can affect regional ocean circulation.
In this episode we discuss the attributes that define the Southern Ocean today, how it behaved 20,000 years ago during the last glacial maximum, and whether New Zealand’s visitation by icebergs several years ago could be a sign of things to come…