what do we call the form of weathering that involves temperatures fluctuating around 0°c and is the dominant mechanical weathering process on coastlines?
LectureNotes said what do we call the form of weathering that involves temperatures fluctuating around 0°c and is the dominant mechanical weathering process on coastlines?
Answer: The form of weathering that involves temperatures fluctuating around 0°C and is the dominant mechanical weathering process on coastlines is known as freeze-thaw weathering or frost weathering.
Freeze-Thaw Weathering Explained:
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Process Overview:
- Freeze-thaw weathering occurs when water enters cracks and pores in rocks.
- When the temperature drops to 0°C or below, the water freezes and expands by approximately 9%.
- The expansion exerts pressure on the rock, causing it to crack and eventually break apart.
- When the temperature rises above 0°C, the ice melts, and the water can penetrate further into the rock.
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Temperature Fluctuations:
- This process is most effective in environments where temperatures regularly fluctuate around the freezing point, causing repeated cycles of freezing and thawing.
- Coastal areas often experience such temperature variations, especially in temperate and polar regions.
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Impact on Coastlines:
- On coastlines, freeze-thaw weathering contributes significantly to the breakdown of rock formations.
- The constant action of waves can also keep rocks wet, ensuring that water is available to penetrate cracks.
- Over time, this process can lead to the formation of features such as cliffs, rockfalls, and scree slopes.
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Importance in Geomorphology:
- Freeze-thaw weathering is a key mechanical weathering process that shapes landscapes.
- It plays a crucial role in the disintegration of rocks, contributing to soil formation and the creation of sediment.
In summary, freeze-thaw weathering is the mechanical weathering process driven by temperature fluctuations around 0°C, making it particularly effective along coastlines where such conditions are prevalent.