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Earth From Space: Iceberg Knocks The Block Off Drygalski Ice Tongue

Date:
April 10, 2006
Source:
European Space Agency
Summary:
An enormous iceberg, C-16, rammed into the well-known Drygalski Ice Tongue, a large sheet of glacial ice and snow in the Central Ross Sea in Antarctica, on 30 March 2006, breaking off the tongue's easternmost tip and forming a new iceberg.
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This image, acquired by Envisat's Advanced Synthetic Aperture Radar (ASAR), shows the C-16 iceberg and the Drygalski Ice Tongue after the collision that took place on 30 March 2006.
Credit: ESA

An enormous iceberg, C-16, rammed into the well-known Drygalski Ice Tongue, a large sheet of glacial ice and snow in the Central Ross Sea in Antarctica, on 30 March 2006, breaking off the tongue’s easternmost tip and forming a new iceberg.

This animation, comprised of images acquired by Envisat’s Advanced Synthetic Aperture Radar (ASAR), shows the iceberg and the ice tongue before and after the collision. On 26 March, C-16 was pinned at the southern edge of the ice tongue but had started migrating by 27 March. The collision on 30 March shows the ice tongue breaking off, and the final image on 1 April captures C-16 and the new iceberg swinging to the other side of the ice tongue.

Mark Drinkwater of ESA's Ocean and Ice Unit said: “During its passage to the coastal foot of the Drygalski Ice Tongue, C-16, which measures 18.5 kilometres by 55 kilometres, looped into and around McMurdo Sound before being carried quickly to the north.

"The surface ocean currents appear to have predominantly steered the iceberg, not the winds, thus telling us about important aspects of the adjustment in the ocean circulation since the departure of large grounded icebergs off Ross Island."

The floating Drygalski Ice Tongue, which protrudes 80 kilometres into the ocean, is connected to the David Glacier. If it were to break loose, scientists fear it could alter ocean currents and change the region’s climate.
C-16 was formed in 2000 when Iceberg B-15A, measuring 27 kilometres by 161 kilometres, bumped into the jutting edge of the Ross Ice Shelf and snapped a large piece off. The new iceberg, originally named B-20 and later changed to C-16, then ran aground north of Ross Island. Over the last three months it had escaped its perch and made its way north where it collided with the ice tongue last week.

The National Ice Center (NIC), located in Maryland, USA, names icebergs according to the quadrant in which they are originally sighted. There are four quadrants (A, B, C and D). A sequential number is then assigned to the iceberg. B-20 was first spotted in the B quadrant and was the twentieth iceberg to be logged in that area. When B-20 navigated to the C quadrant, it was renamed to C-16.

NIC named the new iceberg, the piece of the ice tongue which broke off as a result of the C-16 collision, C-25, which measures 13 kilometres by 11 kilometres.

Envisat’s ASAR acquired these images in Wide Swath Mode (WSM), providing spatial resolution of 150 metres. ASAR can pierce through clouds and local darkness and is capable of differentiating between different types of ice.


Story Source:

The above post is reprinted from materials provided by European Space Agency. Note: Materials may be edited for content and length.


Cite This Page:

European Space Agency. "Earth From Space: Iceberg Knocks The Block Off Drygalski Ice Tongue." ScienceDaily. ScienceDaily, 10 April 2006. <www.sciencedaily.com/releases/2006/04/060407145817.htm>.
European Space Agency. (2006, April 10). Earth From Space: Iceberg Knocks The Block Off Drygalski Ice Tongue. ScienceDaily. Retrieved July 2, 2015 from www.sciencedaily.com/releases/2006/04/060407145817.htm
European Space Agency. "Earth From Space: Iceberg Knocks The Block Off Drygalski Ice Tongue." ScienceDaily. www.sciencedaily.com/releases/2006/04/060407145817.htm (accessed July 2, 2015).

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