HKDSE Geography/M2b/Waves
< HKDSE Geography | M2b
Waves start out as ripples in the sea, which are created as winds blow over water. Water moves in an orbital motion to form waves. As waves approach shore, they will be deformed as the seabed rises.They break when their orbit comes in contact with the sea bed. After breaking, the water continues to rush up the shore as swash, and thereafter rush down the shore as backwash. Load may be deposited by swash; beach materials may be eroded by backwash.
Constructive Waves vs. Destructive Waves
edit| Property | Constructive Waves | Destructive Waves |
|---|---|---|
| Property of Waves | ||
| Wave height | Lower | Taller |
| Wavelength | Longer | Shorter |
| Wave frequency | Lower | Higher |
| Velocity | Lower | Higher |
| Wave gradient | Gentler | Steeper |
| Energy | ||
| Swash | Stronger | Weaker |
| Backwash | Weaker | Stronger |
| Dominant Process | Deposition | Erosion |
| Wave energy | Weaker | Stronger |
| Shape of the coast | ||
| Depth of the seabed | Shallower | Deeper |
| Position of breaker | Farther away from the coast | Nearer to the coast |
| Shore gradient | Gentler | Steeper |
| Breaker type | Spilling breaker | Plunging breaker |