North of Ilulissat and west of Alluttoq Island the bay transforms into Sullorsuaq Strait separating Qeqertarsuaq from Nuussuaq Peninsula.

Its coastline was first encountered by Europeans when Erik the Red started a settlement in 985 AD on the more habitable western coast of Greenland.

[6] Soon after the Western settlement was established, the Norsemen travelled up the coast during the summer thaw and discovered Disko Bay.

Their interest in this bay was due to its rich resources: walruses for ivory,[6][7] seals for their pelts, and whales for a variety of materials.

These products became the main source of income for the Greenlandic settlers who traded with Iceland, the British Isles, and mainland Europe.

There was such an extreme shift in temperature that Disko Bay became inaccessible even in the warmer summer months, thereby destroying the livelihood of the Greenlandic Norse.