Warm ocean water undermining West Antarctica from below may also be weakening its ice shelves: Research

A couple of years back, two scientific studies mentioned that the West Antarctica glaciers, holding back more than 3 meters of likely sea level rise, have been melting and diminishing from below.

The reason behind the same was apparently that these glaciers are floating on the seafloor deep underneath the ocean surface, and have been lapped at due to the flows of hot ocean currents.

Since then, the main focus of researchers has been more and more on West Antarctica, and now a latest research appeared in Nature Geoscience on Monday has revealed yet another outcome of this warm water intrusion. The latest revelation has further highlighted the areas’ susceptibility.

West Antarctica’s huge glaciers and indeed, the glaciers throughout the Antarctic continent, have been held in place by protrusions known as ‘ice shelves’. They are huge and thick ice sheets, floating atop the sea and frequently get fixed to islands or other features, thus providing bracing, or stabilization, hindering the ice flow behind them. In case these floating ice shelves become weak or get fractured and shatter, then the ice behind them will flow at a fast pace into the ocean.

Generally, ice shelves are hundreds of meters thick; however, they float over water that is still deep, thus having a deep ocean cavity under them. In turn that cavity ultimately ends in a type of underwater ice wall, where the glacier comes in contact with the seafloor at a place known as the ‘grounding line’. The line is the part wherein the occurrence of the critical melt in West Antarctica is believed to be taking place.

However, this is not all that’s going on. A new study headed by Karen Alley of the National Snow and Ice Data Center at the University of Colorado in Boulder mentioned that the warm ocean water behind undermining West Antarctica from below could also be making its ice shelves weak. They seem to be carving deep channels at a slower pace within their bases, cavities ranging from 50 to 250 meters in vertical direction.