Lago Argentino in the context of Santa Cruz Province (Argentina)

Ice calving, also known as glacier calving or iceberg calving, is the breaking of ice chunks from the edge of a glacier. It is a form of ice ablation or ice disruption. It is the sudden release and breaking away of a mass of ice from a glacier, iceberg, ice front, ice shelf, or crevasse. The ice that breaks away can be classified as an iceberg, but may also be a growler, bergy bit, or a crevasse wall breakaway.

Calving of glaciers is often accompanied by a loud cracking or booming sound before blocks of ice up to 60 metres (200 ft) high break loose and crash into the water. The entry of the ice into the water causes large, and often hazardous waves. The waves formed in locations like Johns Hopkins Glacier can be so large that boats cannot approach closer than three kilometres (1+1⁄2 nautical miles). These events have become major tourist attractions in locations such as Alaska.

In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around the ice. At the end of the last ice age about 10,000 years ago, large proglacial lakes were a widespread feature in the northern hemisphere.

The Upsala Glacier is a large valley glacier on the eastern side of the Southern Patagonian Ice Field. Its higher portion lies in a disputed territory between Chile and Argentina. While the glacier flows from north to south it has three lesser eastflowing tributary glacier: Bertacchi, Cono and Murallón.

The glacier terminus is at Upsala channel of Lago Argentino. The Upsala Glacier is well known for its rapid retreat, which Greenpeace cites as evidence for global warming. Its retreat has been ongoing since the glacier was first documented in 1810.