Concerns are growing in regards to the growing crack on the Nansen ice shelf along a stretch of the Antarctic coast, which first appeared approximately two years ago. Since it was first spotted, the size of the fissure has grown considerably and many are worried that it may break free and form an iceberg that will be more than twice the size of Manhattan.
In 2013, scientists noticed that the massive Nansen ice shelf - measuring approximately 50 kilometers long and 35 kilometers across - possessed a crack that ran parallel to the coast, and satellite images from last year show that the crack has grown much bigger since then. If the structure breaks from the continent, it could make its way into Terra Nova Bay in the Southern Ocean.
"There's a huge crack, miles long and sometimes over a hundred yards wide, which runs more or less parallel to the front of the ice shelf," said geologist Ryan Walker. "Over the winter, the sea surface freezes and traps small icebergs in the crack, producing a fascinatingly broken ices cape."
Recent satellite images show that despite the growing crack, the ice shelf is still attached to the coast, meaning that it's not likely to separate anytime soon. However, there is the possibility that strong winter winds will prevent the water beyond the shelf from freezing, which could increase the likelihood of a separation.
Christine Dow, a geologist who observed the ice shelf back in December along with Walker, hopes to return to the site by the summer and continue observations.
"I'm really interested to see whether this feature is occurring because of the topography around the ice shelf, or whether it was initially created by surface water flowing into a small ice surface crack," she said. "We're planning an intensive survey of this feature in the coming years and will hopefully get a handle on the causes."
Although the dislodging of an ice shelf from a coast may seem like a bad omen, it's not necessarily due to climate change. Sometimes, ice can break free from its coast naturally, typically growing back again after. However, there are some ice shelf retreats that have been linked to climate change. Further observations will need to be conducted in order to get a better grasp of what's causing the cracking of the Nansen ice shelf.
