Colossal Iceberg Is Anticipated to Calve from Antarctic Peninsula

An enormous chunk of ice is barely hanging onto the Larsen C ice shelf on the Antarctic Peninsula.  The rift that separates the iceberg from the Larsen C ice shelf, the fourth largest ice shelf in Antarctica, is 50 miles long, and 10 miles wide at one point.   Daniela Jansen, a member of Project MIDAS, an Antarctica research team, believes that the iceberg is “very close” to breaking loose from the Larsen C ice shelf.

 

The sheer size of the iceberg and the Larsen C ice shelf is astounding.  According to Project MIDAS, an Antarctica research team that observes climate trends around the continent, the iceberg has an area of 1,900 square miles meaning that it is larger than the  state of Rhode Island.  Moreover, the  Larsen C ice shelf has an area of approximately 8,000 square miles large, which means it is slightly smaller than state of New Jersey.  In fact, the Larsen C ice shelf is larger than both Larsen A and Larsen B ice shelves, which disintegrated in 1995 and 2002, respectively.  After the iceberg breaks off from the Larsen C ice shelf, researchers are worried that the Larsen C, despite its massive area, could face the same fate as Larsen A and B and begin to rapidly disintegrate.  David Vaughan OBE, the Director of Science at the British Antarctic Survey (BAS) summarizes: “the calving of this large iceberg could be the first step of the collapse of [the] Larsen C ice shelf, which would result in the disintegration of a huge area of ice into a number of icebergs and smaller fragments.”

The cause behind the iceberg’s imminent calving is contested at this time.  Many researchers argue that the reason behind the calving is climate change.  Indeed, there is concrete scientific evidence that proves that global warming is causing the Antarctic ice shelves to thin.  However, according to BAS, there is not enough evidence to blame global warming as the only cause of the iceberg’s expected calving from Larsen C.  In fact, ice shelf calving is a key on-going component of the Antarctic ecosystem.  It is completely natural and has been occurring for millions of years.  Under normal conditions, an ice shelf would produce a giant iceberg every couple of decades to replace the icebergs that have broken away.  Nevertheless, more icebergs are calving and disintegrating at a higher frequency and speed as a result of the increasing ocean temperature.  The Larsen A and Larsen B ice shelves calved six years apart from each other.  This rapid rate of calving is alarming; the balance of the the glacial ecosystem on the Antarctic Peninsula seems to be in big trouble. Until the Antarctic researchers determine  accurate and concrete reasons why the iceberg is calving, it is reasonable to infer that climate change is the cause of it. St. Luke’s professor, Janet Jochem, raises concerns about this event in the context of climate change. She states, “[This is] another fact that provides evidence [of climate change]. It’s concerning.” For these reasons and others, some St. Luke’s students have expressed desire for an environmental science class in the Upper School to discuss these issues. As this event progresses, it will be an interesting issue for the St. Luke’s community to discuss.

The impending calving of this iceberg has altered the plans for the safety of the ground and the field researchers stationed on the Antarctic Peninsula.  For example, the BAS decided not to set up camp on the Larsen C ice shelf this year.  Vaughan commented “because of the uncertainty surrounding the stability of the Larsen C ice shelf, we chose not to camp on the ice this season.  Researchers can now only do day trips from our Rothera Research Station with an aircraft nearby on standby.”

Despite the fact that the British Antarctic Survey decided not to set up camps due to the iceberg’s worsening conditions, they still have access to satellite technology.  From more than 200 miles above the ground, BAS satellites provide useful images that depict the changing conditions of the Larsen C ice shelf.  “We use regular satellite images provided by the European Sentinel satellites to monitor cracks in the ice shelf. These images are perfect for following these changes since they provide detailed information, day or night and regardless of cloud cover,” Dr. Andrew Fleming, the Remote Sensing Manager at BAS, commented.  The pictures that the satellite produces includes one that shows the 50 mile long rift that is 10 miles wide.

There are many questions that scientists can’t answer as they monitor the iceberg.  The time when the iceberg will calve is still unknown.  Dan McGrath, a glaciologist at Colorado State University, said the iceberg will encounter a zone of thick ice, and as a result its rate of breaking away from Larsen C will slow down at some point.  But one thing remains undisputed: the iceberg will calve.  Researchers in Antarctica will have to wait patiently for nature take its course, and will then have to determine the true impact of the event on the stability of the polar ice cap.

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