Roundup: Antarctic Sublittoral, Ice Mélange, and Glacier Mass Loss

The Effect of Glaciers on Antarctic Sublittoral

From Marine Environmental Research: “The Antarctic sublittoral is one of the most demanding habitats for polar bottom-dwelling organisms, as the disturbance of this zone is highly intense… In such areas, rocks are often an important support for local diversity, providing habitats for a number of encrusting organisms. Thus, understanding the patterns of diversity of shallow rock encrusting fauna and factors controlling it are particularly important. The structure and diversity patterns of rock encrusting fauna were examined from four ecologically contrasting sites in the shallow sublittoral (6–20 m) of Admiralty Bay (King George Island). The results revealed a rich and abundant encrusting community with bryozoans and polychaetes outcompeting representatives of other fauna such as foraminifera and Porifera.”

Learn more about the Antarctic sublittoral here.

Diagram of sublittoral zonation of rock encrusting species (Source: Florida International University).

 

Flow and Stress in Ice Mélange, World’s Largest Granular Material

From PNAS: “Ice mélange, a granular collection of broken icebergs ranging from tens of meters to hundreds of meters in size, sits in front of many of the Earth’s most active tidewater glaciers. In addition to influencing heat and mass transport in the ocean, the jam-packed mélange provides a geophysical living laboratory to test principles developed for small-scale granular materials such as sand… We show that ice mélange is a quasi-2D, creeping granular fluid which constantly jams and unjams as it advances through the fjord. Most importantly, our results show how ice mélange can act as a “granular ice shelf” which buttresses even the largest icebergs that calve into the ocean.”

Read more about ice mélange here.

An image of an ice mélange captured in aerial view (Source: NASA Earth Observatory).

 

Accelerating Glacier Mass Loss on Franz Josef Land

From Remote Sensing of Environment: “The glaciers of the Franz Josef Land (FJL) archipelago in the Russian Arctic are subjected to rapidly-warming temperatures but are small contributors to sea level. We analyze ice surface elevation data derived from satellite stereo imagery (WorldView and SPOT), radar altimetry (CryoSat-2), and a digitized 1953 cartographic map to calculate elevation change rates dhdt. Mass loss from FJL doubled between 2011 and 2015 compared to 1953–2011/2015… Glacier retreat is widespread and has led to the creation of at least one new island. Historically, ice wastage from FJL is thought to have been relatively small, but accelerating ice loss may be the new normal for this archipelago in a warming Arctic.”

Find out more about the accelerating glacier mass loss of the Russian Arctic here.

An image of Franz Josef Land (Source: Expedition Cruise Specialists).