It is one of the largest icebergs ever recorded. An ice mass of 1 trillion tonnes and 6,000 square kilometers has broken off the Larsen C Ice Shelf in Antarctica. It is equivalent to the size of Cantabria, or 10 cities the size of Madrid, and now it floats adrift in the Antarctic. Scientists had been watching the impending breakout for months , following a large crack in the ice. Finally, it was detached between Monday, July 10 and Wednesday, July 12, 2017.
The Larsen C Ice Shelf , which is between 200 and 600 meters thick, floats in the ocean at the edge of the Antarctic Peninsula, slowing the flow of glaciers that feed on it.
“We have been anticipating this event for months and have been amazed at how long it took for the last few kilometers of ice to break up . We will continue to monitor both the impact of this breaking event on the Larsen C ice shelf , AND the fate of this huge iceberg. “, in the words of Professor Adrian Luckman of the University of Swansea, principal investigator of the MIDAS project (impact of melting on the dynamics of the ice shelf and its stability).
Researchers from the MIDAS Project have been monitoring the crack at Larsen C for many years, following the collapse of the Larsen A ice shelf in 1995 and the sudden rupture of the Larsen B shelf in 2002. They reported rapid advances of the fissure in January, May and June, which increased in length to more than 200 km and left the iceberg hanging by a thread of ice only 4.5 km (2.8 miles) wide, which has now finally detached itself .
The iceberg is one of the largest on record and its future progress is difficult to predict . It may remain in one piece, but is more likely to break into fragments. Some of the ice can remain in the area for decades, while parts of the iceberg can drift north into warmer waters.
What consequences will it have for fauna and salinity?
And it is not only very difficult to predict what will become of the detached ice block, but also what will be the tracking of the glacier shelf. Opinions in the scientific community are divided on this. According to Professor Adrian Luckman of the University of Swanse: “In the following months and years, the ice shelf could gradually regrow, but it may also undergo further partitioning events that can eventually lead to collapse.”
In the opinion of Ana Payo, a graduate in oceanography and environmental sciences and a doctorate in biodiversity, the detachment of the block “will not have an immediate impact on sea level .” But if the shelf loses much more of its area, it could result in glaciers flowing out of the land behind speeding its way into the ocean. As Payo explains, ” this type of blocks are the ones that contain the glacier .” As for the fauna of the area, according to Payo, “the detachment of this block will not affect them as such, but it is one more example of how habitat is being transformed. There are many species that depend on ice. “
Dr Martin O’Leary, a glaciologist at Swansea University and member of the MIDAS project team: “Although this is a natural event, and we are not aware of any link to human-induced climate change, this places to the ice shelf in a very vulnerable position. This is the furthest back the ice front has been in recorded history. We are going to watch very carefully for signs that the rest of the shelf is becoming unstable. ” .
Finally, could the melting of this iceberg affect the salinity of the oceans? The salt content of seawater is very difficult to alter, so the salinity of the sea could be affected only locally. The saline ratio of the oceans is about 35 grams per 1000 liters of water.
