Explain the formation of a lateral moraine

The rocky material used to construct a lateral moraine is usually a result of freeze-thaw weathering. Water gets into cracks in rocks on the mountain slopes when the temperature is above zero and subsequently freezes at night/colder periods when the temperature drops below zero. An ice particle is 9% larger than a water particle, meaning the freezing of water within a crack puts stress on the internal structure of the rock. The repetition of freezing and thawing ultimately causes the rock to break and fall down onto the side of the glacier, forming a scree slope. Additionally, the material can also form when a glacier brushes against the mountain slope, causing material to be scraped off or plucked off. Good examples of this are seen in Svalbard, Norway, but they are a common occurrence in glacial regions. This is a form of paraglacial activity. Once the material is deposited, it can be transported alongside the glacier. When the glacier melts, the long line of material is deposited, and only the lateral moraine remains.

Answered by Gerard S. Geography tutor


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