Iceberg B-46 Calves off Pine Island Glacier in the Amundsen Sea

By LTJG Bryan R. Brasher, NOAA
U.S. National Ice Center
October 29, 2018

Suitland, MD — The U.S. National Ice Center (USNIC) has named a new iceberg that calved from Pine Island Glacier (PIG) in the Amundsen Sea and is another in a set of recent calvings from PIG. B-46 is located at 75°1' South, 101°8' West and measures 18 nautical miles on its longest axis and 5 nautical miles on its widest axis with an area of 66 square nautical miles. B-46 was first spotted by Rein Klazes of the Netherlands and was confirmed by U.S. Navy Ice Analyst Christopher Readinger in the Sentinel-1A image shown below. B-46 may be short lived as it appears to have already calved into several smaller pieces.

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.

The National Ice Center is a tri-agency operational center represented by the United States Navy (Department of Defense), the National Oceanic and Atmospheric Administration (Department of Commerce), and the United States Coast Guard (Department of Homeland Security). The National Ice Center mission is to provide the highest quality strategic and tactical ice services tailored to meet the operational requirements of U.S. national interests and to provide specialized meteorological and oceanographic services to United States government agencies.

Satellite image of Iceberg B-46
Figure 1: Sentinel-1A image of B-46 dated 29 October 2018

For more information, please contact:
National Ice Center
Command Duty Officer
Voice: (301) 943-6977
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.

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