lecture 10

Question 1

What are swell and surf zone in the context of ocean waves?

Answer 1

Swell refers to waves generated in the sea by storm winds, which travel out of the storm area. Surf zone is the nearshore zone of breaking waves where waves lose energy near shore.

Question 2

What is wave refraction and how does it affect waves as they approach the shore?

Answer 2

Wave refraction is the ‘bending’ of waves as they hit the seafloor and slow down, causing them to align nearly parallel to the shoreline. It results in wave energy converging on headlands (causing erosion) and dispersing in bays (leading to sediment deposition).

Question 3

What is wave dispersion?

Answer 3

Wave dispersion occurs as waves leave an area, separating by size with larger waves traveling faster than smaller ones, forming a wave train of waves moving in the same direction.

Question 4

What types of wave interference exist?

Answer 4

There are constructive interference (waves of the same wavelength come together in phase, creating larger waves), destructive interference (overlapping waves of opposite phase cancel each other out), and mixed interference (overlapping waves of different lengths and heights create complex patterns)

Question 5

What causes rogue waves?

Answer 5

Rogue waves are massive, spontaneous ocean waves, likely caused by super-rare multi-constructive interference among swells from different storms, resulting in extremely high waves.

Question 6

What is a tsunami and how is it generated?

Answer 6

A tsunami is a seismic sea wave caused by earthquakes, huge turbidity currents, or volcanic events. It’s a gravity wave that affects the entire water column, not noticeable in the ocean but significant in shallow water.

Question 7

What happens as a tsunami approaches the coast?

Answer 7

As a tsunami approaches the shore, water drains off the land, lowering sea levels significantly below even the lowest tide. Tsunamis are usually a series of waves occurring over hours with speeds up to 4 m/s.

Question 8

Where do tsunamis most commonly occur?

Answer 8

86% of tsunamis occur in the Pacific Ocean, especially near convergent plate boundaries, affecting global locations and varying in size.