Brüggen Glacier, also known as Pío XI Glacier named by Spanish explorers after a Pope, is in southern Chile and is the largest western outflow from the Southern Patagonian Ice Field.

Now about 66 km (41 mi) in length, it is the longest glacier in the southern hemisphere outside Antarctica.

[2] Unlike most glaciers worldwide, it advanced significantly from 1945 to 1976, Brüggen surged 5 km (3.1 mi) across the Eyre Fjord, reaching the western shore by 1962 and cutting off Lake Greve from the sea.

The glacier continued advancing both northward and southward in the fjord to near its present position before stabilizing.

Expedition cruise ships visit the Pio XI terminus by sailing up the fjiord from the sea.