What is the snowline on a glacier?

The snowline is the line (as in a point of elevation on a mountain) at which the amount of snow falling equals the amount of snow melting in the summer. If the climate cools enough, so that snowlines are lowered, glaciers develop in mountains, and ice sheets will develop in mid-latitudes.

How does the climate affect glaciers?

When an ice cube is exposed to a heat source, like warm water or air, it melts. So, it’s no surprise that a warming climate is causing our glaciers and ice sheets to melt.

Do glaciers form at high altitudes?

Glaciers are rivers of frozen ice, fed by snowfall at high-latitude or high-altitude locations that stay cool year round. Some glaciers slide off the edges of giant ice sheets in the Arctic and Antarctic. Glaciers are found at high altitudes or high latitudes.

How the glacial budget affects glaciers?

The glacial budget refers to the balance between the amount of inputs versus outputs affecting the glacial system. The glacier loses mass as evaporation will increase due to warmer temperatures and there will be melting at the snout. This part of a glacier is known as the zone of ablation.

What is the snowline and what does it separate?

snow line, the lower topographic limit of permanent snow cover. The snow line is an irregular line located along the ground surface where the accumulation of snowfall equals ablation (melting and evaporation). This line varies greatly in altitude and depends on several influences.

What factors influence the position of the snowline?

Factors affecting the location of the snow line are the quantity of snowfall, the steepness of the slope on which snow rests, the exposure of an area to the sun and prevailing winds, the type and velocity of the winds, and the presence or absence of large bodies of water.

What causes glaciers to move?

Glaciers move by a combination of (1) deformation of the ice itself and (2) motion at the glacier base. This means a glacier can flow up hills beneath the ice as long as the ice surface is still sloping downward. Because of this, glaciers are able to flow out of bowl-like cirques and overdeepenings in the landscape.

How does climate change affect Antarctica?

The warming of the Antarctic Peninsula is causing changes to the physical and living environment of Antarctica. The distribution of penguin colonies has changed as the sea ice conditions alter. Melting of perennial snow and ice covers has resulted in increased colonisation by plants.

How does altitude affect glaciers?

What is identified here is a powerful gradient in climatic conditions with elevation — a five- to 10-fold increase in precipitation from glacier termini around 2,500 meters above sea level, to where the snow falls that nourishes the glaciers.

How does altitude affect glacial movement?

The glaciers that had the most loss in area have average elevations lower than those glaciers at a higher elevation with less percent area loss. It means that the glaciers that are at a lower elevation are more susceptible to melting.

How does the glacial budget explain why a glacier either retreats or advances?

The glacial budget works in a similar way. The glacial budget describes how ice accumulates and melts on a glacier which ultimately determines whether a glacier advances or retreats. In the zone of melting or ablation, more ice melts then accumulates as snow during the year.

What happens when a glacial budget is balanced?

A glacier that has a balanced budget neither advances nor recedes. Zone of accumulation and zone of wastage. The upper elevations of a glacier that are perennially covered in snow are called the zone of accumulation. The lower portion of the glacier where the ice is lost is called the zone of wastage.

How does the snowline of a glacier vary by region?

There was noticeable variation between glaciers, however, with lower snowlines apparent in the southern and western regions, and higher snowlines in the northern and eastern parts of the Southern Alps. (A lower snowline indicates that more snow fell than melted; a higher snowline indicates that less snow fell than melted.)

What does a lower or higher snowline mean?

(A lower snowline indicates that more snow fell than melted; a higher snowline indicates that less snow fell than melted.) This slight gain is insignificant when compared with the losses experienced since the glacier monitoring started in 1977.

Is the length of a Glacier increasing or decreasing?

Glacier terminus position (the ‘length’ of a glacier) can be misleading when considered on its own because total volume can be decreasing even while terminus length is increasing. The survey was instigated by, and is conducted in collaboration with, the pioneer of New Zealand glaciology, Dr Trevor Chinn.

What does the annual end-of-summer survey tell us about the snowline?

NIWA’s annual end-of-summer survey of the snowline on key South Island glaciers shows, on average, a very slight net gain in the amount of snow at the top of those glaciers.