Calving of Glaciers – UPSC GS1

Calving is the glaciological term for the mechanical loss (or simply, breaking off) of ice from a glacier margin.

Calving is most common when a glacier flows into water (i.e. lakes or the ocean) but can also occur on dry land, where it is known as dry calving.

Before calving occurs, smaller cracks and fractures in glacier ice grow into larger crevasses.

The growth of crevasses effectively divides the ice into blocks that subsequently fall from the snout into an adjacent lake (where they are known as icebergs).

Glacier Snout: It is the lowest end of a glacier, also called glacier terminus or toe.

In lake-terminating (or freshwater) glaciers, calving is often a very efficient process of ablation and is therefore an important control on glacier mass balance.

Ablation: It implies combined processes (such as sublimation, fusion or melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field.

Glacier mass balance: It is simply the gain and loss of ice from the glacier system.

Global warming has increased the frequency of this process.

Up to the end of the 20th century, the Larsen Ice Shelf had been stable for more than 10,000 years.

In 1995, however, a huge chunk broke off, followed by another in 2002. This was followed by the breakup of the nearby Wilkins Ice Shelf in 2008 and 2009, and A68a in 2017.

When water seeps into cracks at the surface, splitting the ice farther down – was almost certainly the main culprit in each case.

Hydrofracturing is a water well development process that involves injecting high pressure water via the well into the bedrock formation immediately surrounding it.

It was originally developed for the oil and gas industry to increase oil and gas well production.

On a global scale, drilling or hydrofracturing result in significant greenhouse gas emissions, leading to global warming.