At its widest − from the Cape Shackleton promontory on Apparsuit Island in the north at coord, to the mouth of Upernavik Icefjord in the south Upernavik Avannarleq, Saga Map, Tage Schjøtt, 1992 Upernavik, Saga Map, Tage Schjøtt, 1992 − Tasiusaq Bay stretches for approximately 93 kilometers .