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Year 2002 Icebergs
May
17, 2002, Washington D.C.-- The
National Ice Center (NIC) confirms an iceberg newly calved from the Lazarev Ice
Shelf (Figure 1). The Lazarev Ice Shelf is a large sheet of glacial ice and snow
extending from the Antarctic mainland into the southeastern Weddell Sea. D-17 is
currently located near 69.4S 15.9E and measures 30nm long by 6nm wide. The
National Ice Center confirmed calving of D-17 using the satellite image shown
from the Defense Meteorological Satellite Program's (DMSP) Operational Line Scan
(OLS) Infrared sensor.
11
May 2002 The
National Ice Center (NIC) using latest satellite image shown from the Defense
Meteorological Satellite Program's (DMSP) Operational Line Scan (OLS) Infrared
sensor (Figure 1) can now confirm size and position of newly calved iceberg
C-19.
AMRC)
University of Wisconsin - Madison The
exact location of the center of iceberg C-19 is 77.23 South 173.30 East and its
dimensions are108nm long by 17nm wide. 
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March 2002-The ASAR image covers the Antarctic
Peninsula, which extends for 1000 km in the south-north direction and is
situated between the Bellingshausen Sea on the west and the Weddell Sea on the
east. This is a region that has experienced exceptional atmospheric warming
since the 1950’s and is therefore of key interest for global change research.
Over the last 50 years an average temperature increase of 2.5°C has been
observed at the climate stations on the Peninsula.
European Space Agency Envisat image
This has triggered the
retreat and break-up of several ice shelves, culminating in the collapse of the
two northern parts of the Larsen Ice Shelf in January 1995 (Larsen A) and in
March 2002 (Larsen B). The launch of Envisat on 1 March 2002 occurred just in
time to capture the dramatic break-up of Larsen B.
MODIS sensor on NASA's Terra
Satellite
19
March 2002-Recent
Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery analyzed
at the University of Colorado's National Snow and Ice Data Center revealed that
the northern section of the Larsen B ice shelf, a large floating ice mass on the
eastern side of the Antarctic Peninsula, has shattered and separated from the
continent. The shattered ice formed a plume of thousands of icebergs adrift in
the Weddell Sea. A total of about 3,250 km2 of shelf area
disintegrated in a 35-day period beginning on 31 January 2002. Over the last
five years, the shelf has lost a total of 5,700 km2, and is now about
40 percent the size of its previous minimum stable extent.
MODIS
images courtesy of NASA's Terra satellite, supplied by Ted Scambos, National
Snow and Ice Data Center, University of Colorado, Boulder
Ice
shelves are thick plates of ice, fed by glaciers, that float on the ocean around
much of Antarctica. The Larsen B shelf was about 220 m thick.
NASA/GSFC/LaRC/JPL,
MISR Team. Satellite: Terra Sensor: MISR
In
this view, spectral variations across the scene are highlighted by using
near-infrared, red and blue data from MISR's nadir (vertical-viewing) camera.
Here, the ice within the disintegrating ice shelf appears vibrant blue. Water
has an intrinsic blue color due to the selective absorption of longer
wavelengths such as red and infrared, and the translucent properties of ice
within the collapsing shelf enables this absorption to be observed. The use of
the near-infrared band within this false-color composite accentuates the effect.
Light brownish streaks across the splintering sheet can also be discerned, and
probably indicate regions where rocks and morainal debris were exposed from the
interior of the shelf.
Based on studies
of ice flow and sediment thickness beneath the ice shelf, scientists believe
that it existed for at least 400 years prior to this event, and likely existed
since the end of the last major glaciation 12,000 years ago (see more about Dr.
Eugene Domack's research).
For
reference, the area lost in this most recent event dwarfs Rhode Island (2717 km2)
in size. In terms of volume, the amount of ice released in this short time is
720 billion tons, enough ice for about 12 trillion 10 kg bags.
January
31,2002 and March 5,2002
MODIS
images courtesy of NASA's Terra satellite, supplied by Ted Scambos, National
Snow and Ice Data Center, University of Colorado, Boulder
This
is the largest single event in a series of retreats by ice shelves in the
Peninsula over the last 30 years. The retreats are attributed to a strong
climate warming in the region. The rate of warming is approximately 0.5 degrees
Celsius per decade, and the trend has been present since at least the late
1940s. Overall in the Peninsula, extent of seven ice shelves has declined by a
total of about 13,500 km2 since 1974. This value excludes areas that
would be expected to calve under stable conditions.
March
15, 2002, Washington D.C.-- The National Ice Center (NIC)
confirms an iceberg newly calved from the Thwaites Ice Tongue.
The
Thwaites Ice Tongue is a large sheet of glacial ice and snow extending from the
Antarctic mainland into the southern Amundsen Sea. This new iceberg is named
B-22 and is currently located at 74.56S/ 107.55W. Iceberg B-22, roughly 46NM
long and 35NM wide, covers an area of approximately 2,120 square statute miles.
National Snow and Ice Data Center scientist Dr. Ted Scambos notified NIC of a
large crack in the Thwaites Tongue discovered by Jennifer Bohlander (also of
NSIDC) using MODIS data from February 10th, 2001. The crack was found to have
significantly widened in MODIS data from March 8, 2001. Analyst Judy Shaffier,
of the National Ice Center, confirmed the calving of Iceberg B22
February 04, 2002, Washington
D.C.--
The National Ice Center (NIC) discovered an iceberg newly calved from
the Matusevich Glacier Tongue in Antarctica.
The Matusevich Glacial
Tongue is a large extension of the Matusevich Glacier from the Antarctic
mainland into the northwestern Ross Sea. This new iceberg has been named C-17,
and is currently located at 69.06S/157.11E. Iceberg C-17, roughly 11NM long and
4NM wide, covers an area of approximately 58.24 square statute miles. National
Ice Center analyst Ms. Judy Shaffier spotted the new berg while performing a
weekly analysis of the Ross Sea. Ms. Shaffier located the berg using the
satellite image shown below from the Defense Meteorological Satellite Program's
(DMSP) Operational Line Scan (OLS) Visible sensor.
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