March 16, 2021 - Bits and pieces of Iceberg A68 around South Georgia Island

    Follow @NASA_MODIS

   South Georgia
    Tweet
    Share

   On March 12, 2021, the Moderate Resolution Imaging Spectroradiometer
   (MODIS) on board NASA’s Terra satellite acquired a true-color image of
   South Georgia Island surrounded by several melting icebergs—including
   many bits and pieces of that once were part of one of the largest
   icebergs on record. South Georgia Island can be seen in the lower right
   quadrant of the image, with parts of what was Iceberg A68A floating
   both to the north and to the southeast of the island. Other icebergs
   and smaller bits of ice also are seen, especially northwest of South
   Georgia. A few clouds cloak parts of the island and sweep across the
   ocean both in the north and the south of the image.

   Almost four years ago, the remarkably massive Iceberg A-68 broke free
   from Antarctica’s Larsen C Ice Shelf. With a surface area of about
   5,800 square kilometers (2,239 square miles), the massive slab of ice
   was larger than the state of Delaware as well as one of the largest
   icebergs on record. When it calved, it reduced the total size of the
   Larsen C Ice Shelf by roughly twelve percent.

   Once calved, icebergs will eventually break apart as they drift towards
   warmer waters and are buffeted by winds and currents. A68 broke into
   two pieces just a few weeks after calving, but those pieces had held
   together for most of the last three-plus years, and they were slowly
   carried by currents in the direction of South Georgia Island. By
   December 2020, Iceberg A68A (the largest piece of the original ‘berg)
   was making a close approach to South Georgia Island—so close that
   scientists were concerned the giant block of ice might pose a threat to
   penguin colonies and the krill population, should it run aground close
   to the island. Caught by strong currents, lengthening daylight, and
   warming waters, A68A made a close pass by the island and began to break
   up.

   On February 10, the U.S. National Ice Center confirmed that a new
   fracture had given rise to A68P—the 16th fragment of A68 large enough
   to earn its own name. Additional smaller fragments exist but are not
   named. According to the National Oceanic and Atmospheric Administration
   (NOAA), to be classified as an iceberg, the height of the ice must be
   greater than 16 feet above sea level and the thickness must be 98-164
   feet and the ice must cover an area of at least 5,382 square feet.
   Smaller pieces may be called “bergy bits” (medium to large ice
   fragment) and “growlers”. Growlers are smaller fragments and are
   roughly the size of a truck or piano.

   Image Facts
   Satellite:  Terra
   Date Acquired: 3/12/2021
   Resolutions:  1km (317.4 KB),  500m (831.2 KB),  250m (586.6
   KB)
   Bands Used: 1,4,3
   Image Credit: MODIS Land Rapid Response Team, NASA GSFC



https://modis.gsfc.nasa.gov/gallery/individual.php?db_date=2021-03-16
 
