Enviro Monday: Sea levels may rise due to massive iceberg breakoff in Antarctica

Scientists have been watching an enormous rift widening on the Larsen C ice shelf in Antarctica for several years.

At the beginning of 2017 the crack was about 113 kilometers long, more than 90 meters across, and 0.5 kilometers deep.

NASA reported that a huge iceberg split off from Antarctica’s Larsen C ice shelf sometime between 10 and 12 July 2017.

Scientists have been hesitant to attribute the Larsen C ice shelf breakup to rising global temperatures.

The Antarctic Peninsula is viewed as a front line for climate change. Two other ice shelves on the peninsula have collapsed over the past two decades after being stable for thousands of years.

What are ice shelves?

Ice shelves are the floating parts of glaciers in Antartica. They are not merely extensions into the ocean, but act as a crucial support for the polar ice cap. Most of the ice in Antarctica is not on water but on land, and without ice shelves, the continental ice will accelerate into the ocean and melt.

Ice breakups are known as calving

Calving occurs naturally and is essential for maintaining ice shelf balance. Without breakoffs ice shelves will grow unabated and will cover large areas of the Southern Ocean.

Ice breakups start a chain reaction

  • Calving could lead to the destabilisation of the ice shelf and surrounding glaciers, ultimately contributing to sea levels globally rising.
  • Ice shelves are floating extensions of grounded glaciers and ice sheets that reinforce and prevent ice to flow inland. When an ice shelf collapses this support disappears and inland glaciers slide into the ocean, which can rapidly affect sea levels.
  • Scientists are concerned that the Larsen C ice shelf will now break up further.
  • The latest calving event reduced the ice shelf area by more than 10 percent, leaving behind an ice shelf that is inherently unstable.
  • This can trigger new ice cracks and rifting, and cause more icebergs to break off – increasing the possibility of ice loss amid rising global temperatures.

Operation Ice Bridge

The fracture was photographed on 10 November 2016 as part of Operation Ice Bridge, an airborne survey of Antarctic ice.

  AUTHOR
Caxton Central

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