It was only in late December that scientists announced that a massive rift in the Larsen C Ice Shelf in Antarctica had grown by 11 miles. Three weeks along, the rift has gone on to lengthen by six miles more. Scientists believe that a calving of the Delaware-sized iceberg is imminent in the next few months.
As it stands, only 12 miles of ice is connecting the iceberg from the main ice shelf. When the inevitable calving ensues, Larsen C, the fourth largest ice shelf in Antarctica, will lose 10 percent of its floating ice. What’s more, once the ice breaks off from the shelf, Antarctica’s landscape is expected to be more unstable than it is prior to the rift.
Project Midas in continuous in their monitoring of the rift and the assessment of the impact of such a huge calving that hasn’t been seen since the turn of the century. “The rift is likely to break off in the next few months-if it doesn’t, I’ll be amazed,” said Adrian Luckman of Project Midas.
Danger behind Larsen C calving
The huge part of Larsen C that is on the brink of calving is floating ice, which technically means that even if it breaks, it will not affect the sea levels. It will simply float away from Larsen C and onto the Southern Ocean. However, what concerns scientists is the calving’s effect on the land ice remaining on the shelf.
The sea ice attached to the land ice acts as a sort of barrier between land ice and the sea. As it floats on the sea’s surface right beside the land ice, it blocks the glaciers and land ice from dropping directly onto the water, thus preventing a rise in sea levels. A calving of this magnitude could mean a rise of 10 centimeters in global sea levels.
Ice shelf collapse caused by warmer temperatures?
Glaciers and ice shelves form a stable system, but if exposed to warmer temperatures, the system could collapse. As the ice melts, small pools of water accumulate in the surface of the shelf. If the temperature persists and does not refreeze the pools, the water seeps into tiny cracks in the ice and over time causes significant damage to the shelf’s structure. In another manner, an ice shelf can also experience melting from beneath the surface when warm waters slightly disengage the base of the ice from its parent land.
Normally, these phenomena are seasonal and would normalize once the summer season is over. There is no consensus among researchers whether warming temperatures are to blame, but they are all monitoring the rift closely for any further developments.