CSIR NET June 2016 Q55: Physical Oceanography
Wave refraction bends wave crests as they approach shore with an irregular coastline, concentrating wave energy on protruding headlands (where water is shallower and wave orthogonals converge) while spreading (dispersing) energy in adjacent bays (where orthogonals diverge).
As waves approach an irregular coastline, refraction causes wave energy to converge and concentrate on headlands (due to the shallower water offshore of a headland slowing and bending the wave crests toward it), while energy is spread out (diverged) in the bays. This concentrated wave energy erodes headlands at a much faster rate than the bays are eroded, and over geological time, this differential erosion straightens an initially irregular coastline.
Option 1 (reflection) describes waves bouncing off a surface, not the energy-focusing process responsible for headland erosion.
Option 2 is correct: refraction is precisely the process that concentrates wave energy on headlands.
Option 3 (diffraction) describes waves bending around obstacles or through gaps, a different phenomenon from the wave-refraction-driven headland erosion described here.
Option 4 (transmission) is not a standard coastal wave process relevant to this erosional mechanism.
Option 2 is correct: refraction is precisely the process that concentrates wave energy on headlands.
Option 3 (diffraction) describes waves bending around obstacles or through gaps, a different phenomenon from the wave-refraction-driven headland erosion described here.
Option 4 (transmission) is not a standard coastal wave process relevant to this erosional mechanism.