The U.S. National Ice Center (USNIC) has confirmed that iceberg A-80D (figure 1, below) calved from iceberg A-80A in the Weddell Sea. As of February 24, A-80A was centered at 72°02' South and 59°17' West and measured 12 nautical miles on its longest axis and 8 nautical miles on its widest axis. A-80D was centered at 72°11' South and 59°20' West and measured 7 nautical miles on its longest axis and 5 nautical miles on its widest axis.

The initial break was seen in satellite imagery on 24 February. A-80A first calved from the Larsen-D Ice Shelf in November 2022 along with A-80B and A-80C. A-80B and A-80C are no longer large enough to track..

The calving event was spotted and confirmed by USNIC Analyst Katherine Quinn using the Sentinel-1A image below

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 = 0-90W (Bellingshausen/Weddell Sea)
B = 90W-180 (Amundsen/Eastern Ross Sea)
C = 180-90E (Western Ross Sea/Wilkesland)
D = 90E-0 (Amery/Eastern Weddell Sea)

When first sighted, an iceberg’s point of origin is documented by the USNIC. The letter of the quadrant, along with a sequential number, is assigned to the iceberg. For example, C-19 is sequentially the 19th iceberg tracked by the USNIC in Antarctica between 180-90E (Quadrant C). Icebergs with letter suffixes have calved from already named icebergs, where the letters are added in sequential order. For example, C-19D, is the 4th iceberg to calve off the original C-19 iceberg.

Iceberg positions are analyzed weekly and are available on the USNIC webpage at: https://usicecenter.gov/Products/AntarcIcebergs

USNIC is a multi-agency center—subordinate to Naval Meteorology and Oceanography Command—operated by the Navy, NOAA, and Coast Guard and provides global to tactical scale ice and snow products, ice forecasting, and related environmental intelligence services for the United States government.

Naval Meteorology and Oceanography Command directs and oversees more than 2,500 globally-distributed military and civilian personnel who collect, process and exploit environmental information to assist Fleet and Joint Commanders in all warfare areas to make better decisions faster than the adversary.

For more information, please contact:
National Ice Center
Command Duty Officer
Voice: (301) 943-6977
E-mail: nic.cdo@noaa.gov
Twitter: @usnatice
Facebook: @usnatice

The U.S. National Ice Center is a tri-agency center operated by the Navy, NOAA, and Coast Guard and provides global to tactical scale ice and snow products, ice forecasting, and related environmental intelligence services for the United States government.