The Giant Breaking Off Larsen C Ice Shelf – What Can We Expect?
Last week, scientists from the MIDAS Project as well as the European Space Agency signaled that a massive iceberg the size of Delaware is close to breaking off from the Larsen C ice shelf in Antarctica. The break was confirmed and studied with the help of the Copernicus Sentinel-1 satellite. The one trillion metric ton iceberg was still attached to the ice shelf by only 3 miles of ice. However, scientists were not yet sure to predict exactly when it would break off.
The rift in the Larsen C shelf was first discovered by NASA in the 60s and it only seemed to dig further into ice, especially since 2014, so essentially it was beyond stopping. In 2016, the speed of the advancing rift tripled. The rift was 124 miles long before satellites captured images of the iceberg breaking away this week. In the Project MIDAS official statement, Professor Adrian Luckman of Swansea University stated:
We have been anticipating this event for months, and have been surprised how long it took for the rift to break through the final few kilometres of ice.
Larsen C was the largest ice shelf in the Antarctic region as the detachment of the iceberg reduced it by more than 12%. Scientists currently worry about the effects of the incident, especially since the break followed a series of collapses of Larsen A and Larsen B, on a southward trajectory. Larsen C might now be destabilized and on the path to a complete disintegration.
Norwegian explorer Carl Anton Larsen sailed on the southern region of the Antarctic Peninsula in the 1800s. He discovered the ice shelf on the eastern coast and that is how it bears his name. The shelf consisted of 3 distinct sets of shelves. These were subsequently named Larsen A, Larsen B, Larsen C, and D.
In 1995 and 2002, Larsen A and Larsen B respectively suddenly fractured and disintegrated. As the glaciers that were held back by the shelves quickly followed, the attention was focused on the Larsen C ice shelf.
How Did It Happen?
Ice shelves are thick ice formations that float on the ocean. As they accumulate ice, they also tend to cave, which means that icebergs will naturally break off. The same phenomenon happened to Larsen A and Larsen B however, because the icebergs were significantly large, the ice shelves collapsed.
While there is a possibility that Larsen C will collapse in the near decades, scientists argue that the iceberg that broke off was not so large as to warrant disintegration. The scientists at Project MIDAS will continue their surveillance of the ice shelf. They will check if other rifts might form in the future. The prospects might not be entirely positive, as the Larsen ice shelf might never recover.
Meanwhile, the iceberg is still afloat and might eventually break into pieces. However, this doesn’t seem to pose a threat to any shipping routes along the Antarctic region.
Will The Break Cause Sea Levels to Rise?
Because the iceberg is floating on the surface of the ocean, it will not affect sea levels. Its unusual size is a matter of concern but it doesn’t seem to be posing any threat. The main concern is with that was left behind by the break.
Because the ice shelves are formed by continuous depositing of ice, the break can lead to ice shelves not being able to hold back the formations on land. Larsen C itself is holding back massive glaciers. If icebergs continue to break off, the shelf might not be able to hold back the glaciers.
Larsen A and Larsen B were not as large of barriers. However, if Larsen C were to collapse, all the melted ice could raise the sea levels up to an inch. Scientists have drawn similarities between Larsen B and Larsen C enough to worry about it destabilizing. However, as of now, nothing is set in stone. The evolution of the Larsen C ice shelf will be monitored by researchers in the future and they will see if it adapts to its new dimensions.
It will probably be a decade before any significant changes in the sea level might occur. In the case of the Larsen B calving, it took seven more years of erosion of the base of the ice shelf to make it unstable enough to finally collapse.
In the case of the Larsen C ice shelf, if it were to collapse, the glaciers floating in the ocean will not be a cause for alarm. Scientists predict only a raise of 1 centimeter in the sea level.
Does This Add to the Climate Change Debate?
The debate is still ongoing regarding this topic. While the Larsen C ice shelf is located in a warmer region of the Antarctic, scientists have not made a direct link to the human-induced climate change.
On the other hand, some argue that climate change was a definitive part of the Larsen A and Larsen B collapses. Among others, warmer ocean currents might be the culprits that eroded the bases of both ice shelves. So, there is the possibility that the same might have happened with Larsen C. The iceberg breaking off left it in its most retreated position in hundreds of years.
Moreover, scientists explained that a calving event usually takes 50 years to come to an end. In this case, reliable data on Larsen C goes back to only 25 years. This discourages scientists to make any predictions for the future regarding the break.
For now, there is not much the scientists can do. In the official Project MIDAS statement, Professor Adrian Luckman of Swansea University declared:
In the ensuing months and years, the ice shelf could either gradually regrow, or may suffer further calving events which may eventually lead to collapse – opinions in the scientific community are divided. Our models say it will be less stable, but any future collapse remains years or decades away.
Find out more about the Antarctic ice shelves:
- Article published by Adrian Luckman, Professor of Glaciology from the MIDAS Project
- The official MIDAS Project statement
- The geoscience behind the Larsen C ice shelf