On 28 May 2008, Adam LeWinter and Jeff Orlowski of the Extreme Ice Survey filmed the front of Greenland's Ilulissat Glacier break apart for about 75 minutes. Towers of ice the height of skyscrapers rolled, toppled and crashed into the fjord as the calving face, some three miles wide, retreated by about a mile. The footage became the climax of the 2012 documentary Chasing Ice.
The largest glacier calving ever filmed
According to Exposure Labs, the film's production company, the ice at the calving front stood close to 3,000 feet (about 900 m) thick, with roughly 300 to 400 feet showing above the water and the rest hidden below. In less than an hour and a half the glacier shed a volume of ice that the filmmakers compare to 3,000 US Capitol buildings. Wikipedia's entry on the film puts the loss at about 7.4 cubic kilometres.
Guinness World Records recognised the sequence as the longest-lasting and largest glacier calving event captured on film by ground-based observers. The two videographers had waited several weeks in a small tent above the glacier to catch it.
What is glacier calving?
Calving is the breaking off of ice at the edge of a glacier that ends in water. A tidewater glacier like Ilulissat flows constantly towards the sea; as its front is pushed out over deep water, cracks open and blocks, slabs and whole sections of the face collapse into the fjord, becoming icebergs. Large calving events release enough energy to register as seismic signals, the "glacial earthquakes" that geophysicists detect around Greenland.
Ilulissat Glacier: Greenland's fastest ice
The glacier has several names: Jakobshavn Isbræ in Danish, Ilulissat Glacier in English, and Sermeq Kujalleq, "the southern glacier", in Greenlandic. It drains about 6.5% of the Greenland ice sheet and produces around 10% of Greenland's icebergs.
- Speed: its front once moved about 20 m a day; in 2012 it reached more than 17,000 m a year, making it one of the fastest glaciers on Earth.
- Retreat: it pulled back 30 km between 1850 and 1964, held steady for 35 years, then began accelerating and thinning after 1997.
- World Heritage: the Ilulissat Icefjord, where it meets the sea, has been a UNESCO World Heritage Site since 2004.
The icefjord lies on Greenland's west coast, about 250 km north of the Arctic Circle, and the town of Ilulissat is the base for visiting it. There are no roads into the protected area itself: visitors explore it by boat, on foot, by helicopter or by dog sledge, all under regulated access. Go with a local operator: the fjord is crowded with drifting and collapsing icebergs.
Chasing Ice, James Balog and the Extreme Ice Survey
Chasing Ice, directed by Jeff Orlowski, premiered at the Sundance Film Festival in January 2012. It follows photographer James Balog, once sceptical about climate change, who founded the Extreme Ice Survey to record glaciers with time-lapse cameras left at Arctic sites for years at a time. The film won the Satellite Award for Best Documentary and was nominated for an Academy Award for Best Original Song, "Before My Time", performed by Scarlett Johansson and Joshua Bell.
See more moving ice in an iceberg rolling near Upsala Glacier, and slower change in slower landscape change in repeat photographs.
Related reading
- The Ilulissat Calving Sequence in Chasing Ice
- Antarctic Icebergs in Motion: Drift, Collapse and Meltwater
- A Car Recovered from an Opening in Lake Ice
- Lake Baikal Ice Percussion with irkDarbuka
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