Icebergs B-22F and B-22G Have Calved from B-22A in the Amundsen Sea

By LTJG Garner Fleming, US Navy
NIC.PAO@noaa.gov
301-943-6977
August 15, 2024

Suitland, MD — The U.S. National Ice Center (USNIC) has confirmed that icebergs B-22F and B-22G (Figure 1, below) calved from iceberg B-22A in the Amundsen Sea. As of August 15th, B-22A was centered at 72°41' South and 126°14' West and measured 33 nautical miles on its longest axis and 26 nautical miles on its widest axis. B-22F was centered at 72°36' South and 127°24' West and measured 22 nautical miles on its longest axis and 15 nautical miles on its widest axis. B-22G was centered at 72°27' South and 127°04' West and measured 9 nautical miles on its longest axis and 5 nautical miles on its widest axis. The calving event was first seen on satellite imagery on August 15, 2024. B-22 first calved from the Thwaites Glacier in 2001, calving again 2002, creating B-22A through B-22E.

The calving event was spotted and confirmed by USNIC Analyst, Isabelle Marcus 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:
U.S. 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.