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Zorluk: ZorOceans, Coastal Processes, and Coastal Landforms

Along a steep rocky headland, storm waves repeatedly force air under extreme pressure into narrow joints and bedding planes at the back of a sea cave. As waves surge into the cave, the rapid trapped air compression followed by explosive expansion causes vertical disintegration of the roof until an opening reaches the cliff top surface above. Which of the following coastal landforms is formed by this specific process?

  1. BlowholeCevap
  2. B
    Oxbow lake
  3. C
    Scree slope
  4. D
    Deltaic channel

Cevap

Blowhole
The correct answer describes a blowhole. Hydraulic action occurs when sea waves rush into a sea cave, compressing air trapped in fissures in the cave roof. The repeated sudden pressure changes shatter the rock above, creating a vertical shaft that penetrates the cliff surface.

Adım Adım Çözüm

1
Analyze the geomorphic process described in the stem.
The mechanism involves wave energy forcing trapped air under pressure into cave roof joints, causing vertical erosion upward through the cliff.
Air compression wedging (hydraulic action) inside sea caves acts vertically on weakness lines in the roof.
2
Identify the resulting coastal erosional landform.
Vertical breaching of a sea cave roof to the cliff top forms a shaft known as a blowhole (or gloup).
Continued upward hydraulic erosion creates a vertical vent through which sea spray is forced during high tide or heavy seas.
3
Differentiate from alternative landforms.
Fluvial features (oxbow lakes, deltaic channels) and subaerial mass wasting features (scree slopes) do not originate from coastal cave hydraulic erosion.
Oxbow lakes and deltas belong to river system deposition, while scree slopes arise from freeze-thaw weathering and slope failure.

Anahtar Kavram

Coastal erosional processes and sea cave landform development
Tahmini Süre:1m 30s
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Konular

Oceans, Coastal Processes, and Coastal Landforms

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