How Do Glaciers Accumulate?

Introduction

• Glaciers are massive bodies of ice that form when the accumulation of snow and ice exceeds melting and sublimation over an extended period.

Snow Accumulation

• Snowfall: Glaciers begin to accumulate when snowfall exceeds snowmelt. This initial layer of snow serves as the foundation for glacier growth.
• Compression: Over time, successive layers of snow accumulate and compress the underlying snow, transforming it into firn, a granular type of ice.

Formation of Glacial Ice

• Firn Formation: As firn accumulates, it undergoes compaction due to the weight of overlying snow. This compaction forces air out of the snow, causing it to become denser and eventually transform into glacial ice.
• Glacial Flow: Under the influence of gravity, the glacial ice begins to flow downhill, creating the characteristic slow movement of glaciers.

Factors Affecting Glacier Accumulation

• Climate: Glacier accumulation is heavily influenced by the climate of the region. Colder climates with heavy snowfall contribute to glacier growth.
• Altitude: Higher altitudes experience lower temperatures, favouring glacier accumulation.
• Snowfall Rate: Regions with higher snowfall rates contribute to faster glacier growth.

Glacier Terminus and Ablation

• Terminus: The terminus of a glacier is the point at which the glacier ends. Below this point, melting and sublimation exceed accumulation, leading to glacier retreat.
• Ablation: Ablation includes processes such as melting, sublimation, and calving (breaking off of glacier ice into water). These processes reduce the glacier's size.

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How Do Glaciers Accumulate?