This video of tourists in Antarctica getting splattered by an imploding iceberg has gone viral apparently.


A brinicle is essentially an underwater icicle or ice stalactite.  Their growth and formation has been observed for the first time as part of the new BBC series Frozen Planet.  This link reveals how this was captured on film.  Here is the amazing timelapse footage of the formation of a brinicle:

For information on brinicle formation and structure read this BBC article and wikipedia entry.  A mathematical treatment of their formation can be found in this academic paper:

Martin, Seelye (1974). “Ice stalactites: comparison of a laminar flow theory with experiment”Journal of Fluid Mechanics 63 (1): 51-79. doi:10.1017/S0022112074001017

Here is an amazing animation revealing a complete picture of ice flow across Antarctica:


Follow this link for a BBC article on this map which is built from a composite of billions of radar data points collected between 1996 and 2009 by three different satellites (Europe’s Envisat, Japan’s Alos, and Canada’s Radarsat-2).

The research work which produced this fascinating insight into ice flow across the whole ice sheet has been published in the journal Science.

“We present a reference, comprehensive, high-resolution, digital mosaic of ice motion in Antarctica assembled from multiple satellite interferometric synthetic-aperture radar data acquired during the International Polar Year 2007-2009. The data reveal widespread, patterned, enhanced flow with tributary glaciers reaching hundreds to thousands of kilometers inland, over the entire continent. This view of ice-sheet motion emphasizes the importance of basal-slip–dominated tributary flow over deformation-dominated ice-sheet flow, redefines our understanding of ice-sheet dynamics, and has far-reaching implications for the reconstruction and prediction of ice-sheet evolution.”
Rignot, Mouginot, and Scheuchi. Ice Flow of the Antarctic Ice Sheet, Science, 2011.

doi: 10.1126/science.1208336 [subscription required for full article access]

Here is a Glaciological TED talk I discovered the other day.  Lee Hotz, a science columnist, talks about ice-core drilling in Antarctica.  Ice cores are often referred to as time machines, because as snow falls layer upon layer and gets compressed as ice it preserves a frozen signature of the distance past.  For example, the air pockets in snow contain information on atmospheric composition now locked within the ice column.  In fact one of the sad consequences of the disappearance of many glaciers, especially those in equatorial regions, such as on Mount Kilimanjaro, is that these valuable time capsules are literally being washed away.

For those that are further interested, Richard Alley, a famous Glaciologist, has written a popular level book on ice core drilling called the The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future:

This incredible image is a radar profile revealing the layering under a particular part of the ice-sheet of East Antarctica.  The ice in this area can be 2 miles thick and overlays the Gamburtsev mountains (depicted by the red line) which are about as large as the European Alps.  These invisible mountains have been known to exist for 50 years,  but the discovery of the huge bulge in the picture was totally unexpected.

What is thought to be happening here is that sub-glacial water at the base of the ice sheet is being forced up the valley sides, as it gains elevation the weight of the overlying ice becomes less and exerts less pressure, because of this the water rapidly turns to ice (this effect is called super-cooling) creating this freeze-on ice bulge.

Water can remain liquid at the base of the ice sheet even when it is below the normal freezing point, this is because of the immense pressure of the overlying ice.  Furthermore, friction at the ice-bed interface can generate heat as well as heat radiating from the underlying rock, this heat is then insulated by the overlying ice.  So again if the water is being forced away from these insulated heat zones or, as mentioned above, experiences a rapid pressure drop as it moves up the valley walls it will turn to ice.

This idea turns our common perception that ice-sheets grow from above, by falling snow layer-upon-layer, upside down.  Apparently about a quarter of the ice thickness in this area is grown from below.

“We usually think of ice sheets like cakes–one layer at a time added from the top. This is like someone injected a layer of frosting at the bottom–a really thick layer” Robin Bell (lead author)

Reporting here from the BBC and here from the New York Times or the press release itself from The Earth Institute, Columbia Univerisity.  The work has been published in Science and can be found here (access required).