Flotilla of icebergs New Zealand NIWA scientists believe they have traced the history of the icebergs discovered drifting about 260km south of Stewart Island. The 100-odd icebergs were likely descendants of A-43, a superberg that broke off the Ronne Ice Shelf, south of the Falkland Islands, in May 2000. At 167km long, A-43 would have stretched from Auckland to Whangarei. But A-43 didnât last long, splitting apart as it drifted into the Scotia Sea, in the southern Atlantic. By January 2005, it measured about 51km by 21km and had a new name, A-43A. NIWA believes A-43A then drifted east, about 13,500km on a circum-polar current around Antarctica, eventually washing up between the Auckland Islands and Stewart Island. The icebergs are now believed to be heading northward, caught by the Southland Current, which runs up the east of the South Island to about Mid-Canterbury before flowing out towards the Chatham Islands.