PADI Divemaster Certification Practice Exam

Why do tidal patterns vary from one location to another?

1. Differences in sea temperature

2. Variations in ocean basin size and geographical features

3. Different fish populations

4. Presence of underwater mountains

The correct answer is: Variations in ocean basin size and geographical features

Tidal patterns vary from one location to another primarily due to variations in ocean basin size and geographical features. The gravitational forces exerted by the moon and the sun, along with the Earth's rotation, create tidal movements. However, these tidal forces interact with the local topography of the ocean floor and the coastline, leading to variations in tidal ranges and timing. For example, narrow bays can experience significantly higher tides compared to open ocean areas because the water is funneled into a smaller space, amplifying the tidal effect. Conversely, wide continental shelves may experience lower tidal ranges due to the vast area the water has to cover. Other geographical features such as islands, underwater ridges, and even human-made structures can all influence local tidal patterns as well. While factors like sea temperature or fish populations may influence marine life or immediate water conditions, they don't significantly affect the fundamental processes that govern tide generation and variation. Additionally, underwater mountains (or seamounts) do have some effect on currents and tides, but their impact is less direct than that of the broader geographical features and ocean basin sizes. Therefore, the primary reason for the variation in tidal patterns is indeed found in the variations in ocean basin size and geographical features.