ESAHomeUnderstanding Our PlanetSecuring Our EnvironmentBenefiting Our Economy
   
About Observing the Earth
How does Earth Observation work?How to get Earth observation dataIntegrating Earth Observation in your jobEarth Observation users speak
EO programmes
The Living PlanetGMES
ESA's Earth Observing missions
Envisat overviewERS overviewEarth Explorers overviewSentinels overviewMSG overviewMetOp overviewProba-1 overviewThird Party Missions overview
Opportunities with us
Multimedia
Services
CalendarSubscribe
 
 
 
Bookmark and Share
 
 
 
 
Article Images
B-15A iceberg's close encounter monitored by Envisat
 
19 January 2005

Made up of Envisat ASAR Wide Swath Mode imagery acquired from November 2004 on, this animation depicts the steady progress of the massive B-15A iceberg towards the Drygalski ice tongue. Note also the increase in sea ice in McMurdo Sound as B-15A starts to block it. ASAR is being used to monitor the convergence on a daily basis.
 
  Opposing ice objects
 
McMurdo Sound
Download:
 HI-RES JPG (Size: 1570 kb)
This annotated ASAR image from 10 January 2005 is orientated in a northerly direction along McMurdo Sound and shows the position of the Drygalski ice tongue as well as icebergs B-15A, B-15J, C-16, the knife-like B-15K and the US McMurdo base.

Credits: ESA
 
 
This animated flyover is based on Envisat acquisitions. See the full version (Windows Media Player, 3 Mb).

The first phase is rendered using a single MERIS false-colour image from 22 January 2004, given vertical relief using a terrain model. It begins with a westerly flight over austral summer sea-ice pack in the Southern Ross Sea, arriving at the solid white border of fast ice fringing Victoria Land. It moves inland before circling, turning eastward over the Trans-Antarctic mountains before returning northwards. The peak of Mount Erebus on Ross Island passes beneath. The MERIS image zooms out to provide a view of the cluster of large icebergs grounded on the northeast shore of Ross Island.

The second phase returns four months in time to a series of 13 ASAR radar images illustrating the breakup of iceberg B-15A acquired during 11 Sept - 1 Jan 2004. In March 2001, B15A collided with iceberg C-16 and ran aground on Ross Island. With the underside of its southern end perched on the bottom and its northern end floating, the vertical motion of the tides and waves forced iceberg B15-A to repeatedly bend in the middle, eventually splitting in the middle along a zig zag fracture. The northernmost of the two large icebergs pieces is then observed to bump into southernmost C-19, with small knife-like B-15K shearing off during the collision.

The image fades back to MERIS, providing a perspective view of the Victoria Land coast. The flight resumes in a northerly direction as far as the Erebus ice tongue, highlighted as the MERIS image blends into the ASAR radar image. Since the ASAR radar is extremely sensitive to the difference in salty sea-ice and pure glacial ice, the radar image clearly delineates it, unlike in MERIS. The scene rotates to show various ice piers, turning further to look back to Ross Bay before rising to give a true satellite view.

Credits: ESA

 
 
B-15A 15 Jan
Download:
 HI-RES JPG (Size: 467 kb)  HI-RES JPG (Size: 485 kb)
This 15 January Envisat ASAR Wide Swath Mode (WSM) image shows iceberg B-15A next to the Dygalski ice tongue in McMurdo Sound. Compare to the 10 January ASAR WSM image and it becomes clear that B-15A has pretty much halted its movement.

Credits: ESA
 
 
B-15A 10 Jan
Download:
 HI-RES JPEG (Size: 2383 kb)  HI-RES TIFF (Size: 5465 kb)
This 10 January Envisat ASAR Wide Swath Mode (WSM) image shows iceberg B-15A close to the Dygalski ice tongue. The two ice bodies block ocean currents, causing the landward sea surface to ice up. Compare this to the open water on the other side of the Drygalski ice tongue.

Credits: ESA
 
 
Download:
 HI-RES JPG (Size: 876 kb)
ESA's ten-instrument Envisat environmental satellite has been observing the Earth for more than three years. Picture by EADS Astrium.

Credits: EADS Astrium
 
  Providing a wider Antarctic view
 
Antarctica
Download:
 HI-RES JPG (Size: 2528 kb)
This view of the entire continent of Antarctica is a mosaic of Envisat ASAR Global Monitoring Mode images acquired between 1 and 10 January 2005. The Ross Ice Shelf and McMurdo Sound are at the bottom side of the image. Working in GMM, the ASAR nstrument can provide regular information on areas such as Antarctica where, due to constant cloud cover, the use of optical data is unable to support scientific investigations.

Credits: ESA
 
 
CryoSat
Artist's impression of CryoSat in orbit.

Credits: ESA/P. Carril
 
 
Related news
Wide-viewing Envisat tracks 'son of B-15' iceberg's odyssey around AntarcticaIceberg's end caught by EnvisatGiants joust in the cold
Related missions
Envisat overviewEarth Explorers overview
In depth
Earthwatching: B-15A
Related links
ICEMONUS National Ice CenterThe Northern ViewIceberg page of University of Wisconsin-Madison Antarctic Meteorological Research CenterB-15K iceberg webcam
 
 
 
   Copyright 2000 - 2011 © European Space Agency. All rights reserved.