With reference to the work of sea waves, consider the following statements: 1. Sea caves are formed when cracks in rocks become larger and wider. 2. When only the roof of the cave remains, it forms a stack. 3. Wall-like features left after the roof breaks are called sea arches. Which of the statements given above is/are correct?

Correct Option The correct option is (a). Explanation Sea waves act as active agents of erosion and deposition along coastal regions. The erosional work of sea waves creates distinct landforms through a sequential process involving the widening of cracks, the formation of cavities, and the eventual collapse of rock structures. Statement-wise Analysis - Statement 1 is Correct: Sea waves continuously strike against coastal rocks, causing cracks to develop. Over time, these cracks become larger and wider due to hydraulic action and abrasion. This leads to the formation of hollow, cave-like depressions on the rocks known as sea caves. - Statement 2 is Incorrect: As the cavities of sea caves enlarge, eventually only the roof of the cave remains, bridging the gap. This feature is known as a sea arch. A stack is formed at a later stage of erosion. - Statement 3 is Incorrect: Continued erosion eventually breaks the roof of the sea arch. When the roof collapses, isolated wall-like features are left standing in the sea. These vertical rock columns are called stacks, not sea arches. Key Takeaway: The evolution of coastal erosional landforms follows a specific sequence: Cracks → Sea Caves → Sea Arches → Stacks.

With reference to the work of sea waves,… - NCERT Class 7 Geography MCQ

NCERT Class 7 Geography — Chapter 2: Our Changing Earth

mcqmedium

With reference to the work of sea waves, consider the following statements:

Sea caves are formed when cracks in rocks become larger and wider.
When only the roof of the cave remains, it forms a stack.
Wall-like features left after the roof breaks are called sea arches.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT The Earth Our Habitat · Page 16

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

Did you get this right?

Solution

Correct Option

The correct option is (a).

Explanation

Sea waves act as active agents of erosion and deposition along coastal regions. The erosional work of sea waves creates distinct landforms through a sequential process involving the widening of cracks, the formation of cavities, and the eventual collapse of rock structures.

Statement-wise Analysis

Statement 1 is Correct: Sea waves continuously strike against coastal rocks, causing cracks to develop. Over time, these cracks become larger and wider due to hydraulic action and abrasion. This leads to the formation of hollow, cave-like depressions on the rocks known as sea caves.
Statement 2 is Incorrect: As the cavities of sea caves enlarge, eventually only the roof of the cave remains, bridging the gap. This feature is known as a sea arch. A stack is formed at a later stage of erosion.
Statement 3 is Incorrect: Continued erosion eventually breaks the roof of the sea arch. When the roof collapses, isolated wall-like features are left standing in the sea. These vertical rock columns are called stacks, not sea arches.

Key Takeaway: The evolution of coastal erosional landforms follows a specific sequence: Cracks → Sea Caves → Sea Arches → Stacks.

Your note

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