June 8, 2002 More Melting in the Antarctic Giant Icebergs Calve into the Ocean Three giant icebergs split off from two ice shelves in Antarctica earlier this year, according to the National Ice Center (NIC), a joint operation of the U.S. Navy, the National Oceanic and Atmospheric Administration, and the U.S. Coast Guard. Two of the icebergs, designated C-18 and C-19, apparently broke off the Ross Ice Shelf in late April or early May. The other major iceberg to calve, named D-17, broke off the Lazarev Ice Shelf about a week later. Icebergs are named for the quadrant of Antarctica in which they were originally sighted. C-18 is the eighteenth berg reported in the C quadrant since the NIC began keeping records in 1976. It is roughly 75.9 kilometers (41 nautical miles) long by 7.4 kilometers (4 nautical miles) wide, making it about 10 times larger than Manhattan. C-19 (see image on right), is the larger of the two Ross Ice Shelf icebergs, estimated to be 199 kilometers (108 nautical miles) long by 30.5 kilometers (17 nautical miles) wide, which is almost as large as Chesapeake Bay. C-19 broke away relatively close to Ross Island, where McMurdo Station, the National Science Foundation's (NSF) logistics hub in Antarctica, is located, bringing the event close to "home." Scientists estimate this calving returns the Ross Ice Shelf to about the size it was in 1911, when it was first mapped by British explorer Robert Falcon Scott's party. The other iceberg, D-17, calved off the Lazarev Ice Shelf and fell into the Eastern Weddell Sea. It is estimated to be 55.5 kilometers (30 nautical miles) long by 11.1 kilometers (six nautical miles) wide, which is about the size of St. Lucia Island in the Carribean Sea. Douglas MacAyeal, an NSF-funded researcher at the University of Chicago, explained that the process of icebergs' calving is part of a natural cycle in which ice shelves grow and then portions break off into the water. Scientists generally distinguish this process from the Larsen B Ice Shelf collapse, reported earlier this year in Spirit of Ma'at's Announcements section, believing that one to be connected with a documented rise in temperature on the most northern (i.e., closest to the equator) peninsula on the Antarctic continent. For updated satellite images of iceberg C-19 from AMRC, see: Antarctic Meteorological Research Center Icebergs References: National Snow and Ice Data Center Antarctic Meteorological Research Center NIC press release National Oceanographic and Atmospheric Administration National Science Foundation CNN Back to AnnouncementsTop of PageHome