Antarctica iceberg series#

iceberg studies can be treated as calibration experiments of how ice shelves may react to further climate change, (2) to better understand abrupt climate-change mechanisms (Heinrich events) ( Reference HemmingHemming, 2004) in which iceberg calving and associated freshwater flux are essential elements, (3) for comparison with Antarctic mass budget so that estimates might be made of the ratio of iceberg discharge to melt from the continent (e.g. Thus, there are now further reasons to examine iceberg distribution and dissolution rates: (1) as an indicator of melt or freeze rates at the underside of the polar ice shelves given a warmer atmosphere and ocean than exists at present, i.e.

We have seen the partial collapse of the Larsen Ice Shelf ( Reference Rott, Skvarca and NaglerRott and others, 1996, Reference Rott, Rack, Nagler and Skvarca1998, Reference Rott, Rack and Skvarca2002), realized that as much as 20–30% of the ice discharge from the Antarctic continent may be in the form of basal meltwater ( Reference Jacobs, Hellmer and JenkinsJacobs and others, 1996) and found new evidence of ice-sheet thinning in the Pine Island and Thwaites Glacier drainage basins ( Reference Wingham, Ridout, Scharroo, Arthern and ShumWingham and others, 1998 Reference RignotRignot, 2001 Reference ZwallyZwally and others, 2002). Reference Lazzara, Jezek, Scambos, MacAyeal and van der VeenLazzara and others, 1999).

In recent years several large icebergs have broken away from the Antarctic continent (e.g. There, the utilization of the icebergs poses problems perhaps greater than the initial harvesting ( Reference Lawson and Russell-HeadLawson and Russell-Head, 1983). Reference Weeks and CampbellWeeks and Campbell, 1973 Reference SchwerdtfegerSchwerdtfeger, 1979 Reference Robe and ColbeckRobe, 1980), the consensus was that icebergs might, for a cost comparable with desalination, be diverted as they drifted in the known ocean currents, to a Southern Hemisphere location where they might be utilized. 1, 1980), the rise and fall of a small informal but informative journal ( Iceberg Research, 1982–91, published by the Scott Polar Research Institute, Cambridge, UK) and several landmark publications (e.g.

Antarctica iceberg series#

Following a series of conferences ( Reference HusseinyHusseiny, 1978 Reference RussellRussell, 1979 Annals of Glaciology, vol.

This amounts to a contribution equivalent to precipitation of ~15.5 cm a –1, accounting for ~2% of the total iceberg discharge from the Antarctic ice sheet.Īn upsurge of interest two to three decades ago in the distribution, dissolution and physical characteristics of icebergs was prompted primarily by a perceived possibility that Antarctic icebergs might be utilized as a freshwater source suitable to quench the thirst of large cities. Iceberg dissolution rates are found to be ~0.03–0.05 m d –1 and the total mass contribution of fresh water to the ocean as the icebergs traverse our 30° of longitude study sector is ~32 Gt. This allows estimation of total dissolution, in terms of iceberg numbers and volume, within 10° longitudinal sectors and, with knowledge of drift speeds, iceberg movement rates and freshwater input across the sector. The discussion leads us to the point where we can define an area, bounded to the north by the maximum sea-ice limit and to the south by the Antarctic Divergence, in which icebergs are confined as they drift eastward. Using ‘snapshots’ of the iceberg population to provide an idea of the iceberg life cycle, the distribution of icebergs between 60 and 150° E is discussed in terms of calving regions and ocean currents. The Australian Antarctic Program’s iceberg dataset (from ship-based observations), including information from the austral summer seasons 1984/85 to 1999/2000, is examined and used to extend earlier studies.