Antarctica
The Global Environment and Marine Department of the Japanese Meteorological Agency recently corrected the long term trend in the annual mean sea ice extent in the Antarctic area, reporting more than a 25% adjustment (15,000 sq km to 19,000 sq km). So while chunks the size of Manhattan may break off from time to time, about 300 Manhattans of new ice get added annually. Researchers also add that the annual maximum and annual mean sea ice extents have shown a long term trend of increase since 1979. (1)