What is Supraglacial sediment?

What is Supraglacial sediment?

Supraglacial sediments are primarily derived from freeze-thaw eroded material that has fallen onto the ice from rocky slopes above. These sediments form lateral moraines (Figure 16.1) and, where two glaciers meet, medial moraines.

What is a Supraglacial stream?

A meltwater river that flows over the surface of the ice in a glacier or ice cap. From: supraglacial stream in A Dictionary of Environment and Conservation »

What is Supraglacial transport?

Supraglacial sources include rock or snow avalanches from valley sides or mountain peaks that rise above an ice sheet/cap surface (these are known as nunataks). This material is also commonly termed passively transported debris because there is little modification of rock debris transported on the glacier surface.

How are Supraglacial lakes formed?

Supraglacial lakes (SGLs) form when meltwater ponds in depressions on the surface of a glacier or ice sheet1. They range in size from a just a few metres to tens of kilometres in area1,2,3,4 and they play an important role in an ice sheet’s mass balance.

What are glacial lakes called?

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.

What is Supraglacial meltwater?

Abstract. Supraglacial meltwater channels that flow on the surfaces of glaciers, ice sheets, and ice shelves connect ice surface climatology with subglacial processes, ice dynamics, and eustatic sea level changes.

Why are glacier streams curvy?

As the stream flows, the debris is deposited along the riverbed. After many years, the debris in the riverbed accumulates upward, forming a ridge in the shape of the stream. Sometimes the streams are very curvy, depending on their path beneath the glacier. The slower the stream, the greater the chance for a deposit.

What is the material that is transported with glaciers called?

A moraine is material left behind by a moving glacier. This material is usually soil and rock. Just as rivers carry along all sorts of debris and silt that eventually builds up to form deltas, glaciers transport all sorts of dirt and boulders that build up to form moraines.

Why are supraglacial lakes important?

Supraglacial lakes are important because they can influence ice flow and mass balance in three ways. Secondly, supraglacial lakes can cause short-term ice flow accelerations when they drain through the ice sheet6. The meltwater can reach the bed of the ice sheet, and encourage basal sliding and thus faster ice flow.

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