Most recently, I discovered that there is a region of the Antarctic Peninsula known as Wilkins Sound. Great name (same as mine!), I thought, so I looked into it. Named after Australian explorer, Sir George Hubert Wilkins, Wilkins Sound is mainly occupied by the Wilkins Ice Shelf, which is a rectangular segment of floating ice covering approximately 6,000 square miles, which is roughly the size of Jamaica. So how is this mighty shelf holding up against climate change? Unfortunately, not as well as the iceberg that the Titanic crashed into.
It is quite normal for icebergs to break off of ice shelves, but when you have major break-up events, you lose a lot of mass all at once, which causes the ice shelf not to grow anymore. After the ice-bridge collapse in 2009, which held the Wilkins Ice Shelf in place, it has been experiencing this ice break-up. The good news is that ice shelf break-up does not affect rising sea levels because ice shelves are already submerged in the ocean and therefore, displacing their own weight. The bad news is that the ice shelf break up can increase glacier flow, which does affect rising sea levels by adding the weight of the glacier onto the ocean surface as well. Once these ice shelves break off, can they grow back? I am pleased to report that yes, ice shelves can grow back, but it will take a very long time because it depends on the inflow of glaciers, not the melting.
The Wilkins Ice Shelf is not the only shelf along the Antarctic Peninsula being affected by climate change. 9 other shelves have been affected by warming ocean temperatures. Approximately 2,500 square miles of ice have broken off, resulting in the maps of Antarctica having to be re-drawn. Antarctica’s ice sheets contain enough water to raise the water level by 57 meters. The Antarctic Peninsula’s average temperature has increased by 3°C since 1950, making it one of fastest warming places on the planet. If the rate of warming does not slow down, more than the maps of Antarctica will have to be re-drawn.
“It really could go at any minute.” David Vaughan
The scientific community is monitoring the Antarctic Peninsula using satellites to detect the development of rifts (cracks). Scientists are also doing field studies in order to gain a better understanding of the properties of the ice, including speed of shelf formation, thickness, density, fracture toughness, and other properties that may help prevent future break-ups. All hope is not lost for these ice shelves. If developing nations can work out a treaty to reduce greenhouse gas emissions, it could slow climate change long enough to let the ice shelves grow back, bigger and stronger than before.
For more information on ice shelves and ice shelf break-up, visit this NASA website.