Question 14.AP.3: OSCILLATIONS IN A HARBOR Why do passing ocean waves sometime...
OSCILLATIONS IN A HARBOR
Why do passing ocean waves sometimes cause the water in a harbor to undergo very large oscillations, called a seiche (pronounced saysh)?
Water in a harbor is enclosed and possesses a natural frequency based on the size of the harbor. This is similar to the natural frequency of the enclosed air in a bottle, which can be excited by blowing across the edge of the opening. Ocean waves pass by the opening of the harbor at a certain frequency. If this frequency matches that of the enclosed harbor, then a large standing wave can be set up in the water by resonance. This situation can be simulated by carrying a fish tank filled with water. If your walking frequency matches the natural frequency of the water as it sloshes back and forth, a large standing wave develops in the fish tank.