Located approximately 150 miles north of the Arctic Circle, the ilulissat icefjord is the sea mouth of Sermeq Kujalleq, one of the fastest moving active glaciers in the world. Annually, it calves over 35 km3 of ice (10% of the production of all Greenland calf ice and more than any other glacier outside Antarctica). At its eastern end is the Jakobshavn Isbræ glacier, the most productive glacier in the northern hemisphere. The iceberg calves off around 20 billion tons of icebergs every year! Studied for over 250 years, this icefjord has helped to develop our understanding of climate change and icecap glaciology. The icefjord was declared a UNESCO World Heritage Site in 2004.