Which of the following is/are coastal erosional feature(s) ? 1. Notch 2. Sea Arch 3. Cliff 4. Hook Select the correct answer using the code given below :
- (a)1, 2 and 3
- (b)2, 3 and 4
- (c)2 and 3 only
- (d)1 only
Correct — A, 1, 2 and 3. The first three are all made by the sea taking rock away. A notch is the groove waves cut into the base of a cliff or headland at the level of maximum attack. A sea arch forms when waves hollow out caves on both sides of a headland until the two break through and meet, leaving a bridge of rock. A cliff is the steep face left when waves undercut a coast and the rock above collapses. The fourth item is different in kind. A hook is a spit whose free end has been curved landward by wave refraction or by a change in wind direction — it is built of sediment carried along the shore and dropped, so it is depositional. Excluding item 4 gives the code 1, 2 and 3.
- (b)2, 3 and 4 — It swaps the notch out for the hook, which is exactly the wrong trade. The notch is the very first product of wave erosion on a rock coast, while the hook is deposited sediment.
- (c)2 and 3 only — It correctly rejects the hook but also drops the notch. A candidate who is unsure what a notch is, or who thinks of it as too small to count as a landform, tends to land here.
- (d)1 only — Far too narrow. The sea arch and the cliff are two of the most familiar erosional coastal landforms there are, and both belong on the list.
On a rocky coast the sea works from the bottom upward. Waves concentrate their energy at the level of the water and cut a notch into the base of the rock face. As the notch deepens it becomes a cave; where caves on opposite sides of a headland meet, an arch is left; when the arch roof falls, a stack stands alone; and the stack is eventually worn down to a stump. Meanwhile the undercut rock above keeps collapsing, so the cliff retreats landward and leaves a gently sloping wave-cut platform in front of it. The depositional family is quite separate — beaches, spits, hooks, bars, tombolos and barrier islands, all of them built by longshore drift dropping its load where the water slows.
The whole item turns on one word, hook, and it is the only unfamiliar term among the four. Two clues resolve it without prior knowledge. First, the other three are all things that appear where rock has been removed, so they form an obvious family and the fourth stands apart. Second, the shape itself is the clue — a hook is a curved, tapering finger of material projecting into the water, which is what a growing sediment ridge looks like and not at all what an eroded rock face looks like. On the code options, note the design: only one of them contains item 4, and it is the second most attractive, which is the usual way an examiner rewards a candidate who has actually classified the terms rather than counted them.
- A notch is the groove waves cut at the base of a cliff or headland, the first stage of coastal erosion.
- A sea arch forms when caves cut on both sides of a headland break through and meet.
- A cliff is the steep face left where the sea undercuts a coast and the rock above collapses.
- A hook is a recurved spit — built of deposited sediment, and therefore depositional.
- The full erosional sequence runs notch, cave, arch, stack, stump, with a wave-cut platform in front.
- Not recognising 'hook' and guessing rather than reasoning from the shape it describes.
- Dropping the notch because it seems too small to count as a landform.
- Assuming any feature that projects into the sea must be erosional; spits and hooks project and are depositional.
NDA sets coastal landforms as classification codes like this one, as odd-one-out items, and as agent-to-feature match lists.
Match List I with List II and select the correct answer using the code given below the Lists : List I List II (Geomorphic Agent) (Feature) A. Ground water 1. Plunge pool B. Running water 2. Horns C. Glacier 3. Playas D. Wind 4. Lapies Code : A B C D
- (a) 4 1 2 3
- (b) 3 2 1 4
- (c) 3 1 2 4
- (d) 4 2 1 3
Answer(a) 4 1 2 3
The same skill of attaching a landform to the agent and process that made it, tested across four agents rather than one. Sorting by agent first, then by erosion or deposition, answers both items.
Weathering, mass wasting, erosion and transportation are indicators of which one of the following processes?
- (a) Denudation
- (b) Endogenetic process
- (c) Diastrophism
- (d) Mountain building
Answer(a) Denudation
The vocabulary above this item. Erosion is one component of denudation, and keeping the terms in their proper hierarchy is what makes a classification question like this one straightforward.
- practice — not a real PYQ
A spit whose free end is curved landward is known as a
- (a)tombolo
- (b)hook
- (c)stack
- (d)notch
Answer(b) hook — a depositional feature, curved by wave refraction or a shift in wind direction.
- practice — not a real PYQ
A gently sloping rock surface exposed at the foot of a retreating sea cliff is called a
- (a)wave-cut platform
- (b)barrier island
- (c)sand bar
- (d)lagoon
Answer(a) wave-cut platform — left behind as the cliff is undercut and retreats landward.