Three massive icebergs have calved from the Ronne Ice Shelf in the Weddell Sea, the National Ice Center in Suitland, Md., reports. The center is a tri-agency activity with representation from the U.S. Navy, NOAA, and the U.S. Coast Guard

The dimensions and locations of the icebergs are:

• A-43A: 107x21 Statute Miles (168x33KM) centered at: 7510S 05858W
• A-43B: 53x23 Statute Miles (84x35KM) centered at: 7657S 05513W
• A-44: 41x20 Statute Miles (60x32KM) centered at: 7624S 05326W

Iceberg A-43 was detected using the Defense Meteorological Satellite Program's Optical Linescan Sensor (DMSP OLS) infrared imagery on May 5. It is known to have calved from the Ronne Ice Shelf sometime during the afternoon or evening of May 4, as satellite imagery indicates that the ice shelf was still intact on the morning of May 4. Iceberg A-44 calved in the afternoon or evening of May 6, at or near the time that A-43 broke in half.

The National Ice Center provides worldwide operational sea ice analyses and forecasts tailored to meet the requirements of U.S. national interests. The center tracks icebergs using remotely sensed data provided in-part by satellites operated by NOAA and the Department of Defense.

Iceberg names are derived from the Antarctic quadrant in which they were originally sighted. The quadrants are divided counter-clockwise in the following manner:

• A = 0 to 90 degrees West longitude (Bellinghausen/Weddell Sea)
• B = 90 West to 180 (Amundsen/Eastern Ross Sea)
• C = 180 to 90 East (Western Ross Sea/Wilkesland)
• D = 90 East to 0 (Amery/Eastern Weddell Sea)

When an iceberg is first sighted, the National Ice Center documents its point of origin. The letter of the quadrant, along with a sequential number, is assigned to the iceberg. For example, A-44 is the 44th iceberg the ice center has found in Antarctica Quadrant A.