Final answer:
The orientation of a coastline primarily influences wave direction, which affects how waves interact with the shore, leading to varying degrees of erosion and changes to the shoreline's appearance.
Step-by-step explanation:
The orientation of a coastline affects the appearance of a shoreline primarily because it influences Wave direction. This is because the orientation determines how waves approach the shore. If a coastline is oriented such that it faces open water, it can experience direct wave action, which often leads to increased erosion and changes in the shoreline. However, if the coastline is protected by its orientation or lack of exposure to long stretches of open water, it may be less affected by waves and maintain a more stable appearance.
As waves reach shallow water near the coast, an effect called shoaling occurs, where the water depth decreases and the energy of the waves is compressed into a smaller volume. This results in higher waves. Different coastlines will experience varying degrees of this effect based on their orientation relative to incoming waves. Thus, the direction from which waves hit the coast can lead to significant differences in the way shorelines are shaped over time.