The Thwaites Ice Tongue is a large sheet of glacial ice extending
from the West Antarctic mainland into the southern Amundsen Sea.
A large crack in the Thwaites Tongue was discovered in imagery
from Terra's Moderate Resolution Imaging Spectroradiometer (MODIS).
Subsequent widening of the crack led to the calving of a large
iceberg. The development of this berg, designated B-22 by the
National Ice Center, can be observed in these images from the
Multi-angle Imaging SpectroRadiometer, also aboard Terra. The
two views were acquired by MISR's nadir (vertical-viewing)
camera on March 10 and 24, 2002.
The B-22 iceberg, located below and to the left of image center,
measures approximately 82 kilometers long x 62 kilometers wide.
Comparison of the two images shows the berg to have drifted away
from the ice shelf edge. The breakup of ice near the shelf
edge, in the area surrounding B-22, is also visible in the
later image.
These natural-color images were acquired during Terra orbits
11843 and 12047, respectively. At the right-hand edge is Pine
Island Bay, where the calving of another large iceberg (B-21)
occurred in November 2001. B-21 subsequently split into two
smaller bergs, both of which are visible to the right of B-22.
Antarctic researchers have reported an increase in the frequency
of iceberg calvings in recent years. Whether this is the result
of a regional climate variation, or connected to the global
warming trend, has not yet been established.
MISR was built and is managed by NASA's Jet Propulsion Laboratory,
Pasadena, CA, for NASA's Office of Earth Science, Washington, DC.
The Terra satellite is managed by NASA's Goddard Space Flight Center,
Greenbelt, MD. JPL is a division of the California Institute of
Technology.
Image credit: NASA/GSFC/LaRC/JPL, MISR Team.
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