Wilkins Ice Shelf

The floating ice shelves that existing in the Antarctic Peninsula (Figure 1) , are sensitive to changes in atmospheric temperature and ocean circulation. In the Antarctic Peninsula, global warming has been rapid over the past 50 years and the total area of its ice shelves has been reduced by more than 28000 km² (Cook and Vaughan, 2010). The northwestern margin of the Antarctic Peninsula is experiencing one of the fastest deglaciation processes on the planet ( Scambos et al, 2015).
The Wilkins Ice Shelf (Figure 2) located on the western margin of the peninsula, had an area of ??13680 km² before the collapse of 2008, when it experienced a sharp loss (Humbert et al, 2010), which reached about 6,000 km² (Scambos et al, 2009).

 

Our laboratory has studied the changes experienced by floating ice shelves on the peninsula, with satellite imagery, aerial survey and land expeditions (Wendt et al, 2010). Between February 28 and March 9, 2008, a portion of 570 km² of the Ice Shelf Wilkins (70°S / 75°W) collapsed and was transformed into thousands of small blocks of ice, indicating once Moreover, the effects of global warming being observed in the Antarctic Peninsula. This platform had been falling in the area since the early 90s, however, at an event a few hours between 28 and 29 February 2008, he suffered the collapse of most of the ice bridge that kept attached to Charcot Island. This collapse no direct impact on the mean sea level, because being a floating platform, its volume is integrated into the global ocean. Notwithstanding the above, it was found that once the collapse of such platforms occurs , glaciers that feed experience a strong acceleration in its flow and thinning ice thickness (Rignot et al, 2004), it does have an impact on the level of global sea.

 


Figure 1. Antarctic Peninsula, main bases and Ice Shelf Wilkins (Source: CECs) 

 


Figure 2. The Wilkins Ice Shelf before the collapse (light blue) and glaciers that feed it (brown). The background image is a mosaic MODIS 2000. The arrow indicates the area collapsed in February/March 2008 (Source: CECs). 

 


Figure 3. Front changes in the Wilkins Ice Shelf between 1947 and 2016, from the collapse of 2008 disappeared the ice bridge between Charcot island and island Latady  (Source: CECs)

 


Figure 4. Comparison pictures in the Wilkins Ice Shelf in 2008 (Source: NSIDC) 

 


Figure 5. Comparison pre and post collapse in 2009 (Source: CECs)

 


Figure 6. Areal changes of the bridge between Charcot island and island Latady in the Wilkins Ice Shelf  

 


Figure 7. Opening cracks in the bridge between Charcot Island and Latady 

 


 

Figure 8. Sequence Envisat radar images from the European Space Agency , ESA, showing the collapse of the floating platform Wilkins ice between February and March 2008.

 

----------------------------------------------------------
Previous collapses 
---------------------------------------------------------- 


 Collapse of Larsen B ice shelf, Antarctic  Peninsula

 


In January 2002, spectacular events were detected in the floating ice shelves of the Antarctic Peninsula . The main event , the almost complete disintegration of the Larsen B platform , one of the largest events of its kind in the last 30 years.

 

Thanks to satellite image analysis , it was proved the disintegration of an area of ??3,250 km² (similar to the province of Concepcion, Chile) over a period of just 35 days. This collapse is attributed to a regional increase in atmospheric temperatures , on the order of 0.5 °C per decade.

 

All images belong to  National Snow & Ice Data Center: 

 

January 31, 2002 
31 enero 2002 

February 17, 2002 
17 febrero de 2002 

February 23, 2002 
23 febrero de 2002 

March 5, 2002 
05 marzo de 2002

 

 

 

Previous calving events from Antarctica  


The last images have been downloaded from the site of the U.S. National Ice Center

c-161.jpg (115269 bytes)

 

 

a43a44.jpg (79390 bytes)

 

 

ROS00081b.gif (92649 bytes) 

Landslides in the Pine Island Glacier in 2001 
 

 

Larsen B breakup, 31-01 to 7-03-2002 MODIS images from NASA's Terra satellite, National Snow and Ice Data Center, University of Colorado, Boulder. 
 

 

Ice flow velocities of Larsen B, 1996-2003 (Rignot et al., 2004) 
 

 

 

References

 

Cook, A. J. and Vaughan, D. G.: Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years, The Cryosphere, 4, 77–98, doi:10.5194/tc-4-77-2010, 2010.

 

Humbert et al, 2010. Deformation and failure of the ice bridge on the Wilkins Ice Shelf, Antarctica. Annals of Glaciology 51(55), 49-55.

 

Rignot, E., Casassa G., Gogineni, P. Krabill, W. Rivera A. & Thomas, R. (2004): "Accelerated ice discharge from the Antarctic Peninsula following the collapse of Larsen B ice shelf." Geophysical Research Letters, 31, L18401, doi:10.1029/2004GL020697.

 

Scambos, T. and 7 others. 2009. Ice shelf disintegration by plate bending and hydro-fracture: satellite observations and model results of the 2008 Wilkins ice shelf break-ups. Earth Planet. Sci. Lett., 280(1–4), 51–60.

 

Wendt, J., A. Rivera, A. Wendt, F. Bown, R. Zamora, G. Casassa & C. Bravo (2010): "Recent ice-surface-elevation changes of Fleming Glacier in response to the removal of the Wordie Ice Shelf, Antarctic Peninsula." Annals of Glaciology, 51(55), 97-102.