Final answer:
The primary direction of annual longshore drift along the east and west U.S. coasts is typically from north to south, influenced by prevailing winds and coastline shapes.
Step-by-step explanation:
The question relates to the pattern of longshore drift along the U.S. coastlines. Longshore drift is a geological process that causes sediment to be transported along the coast by the longshore current, which is the dominant current in the nearshore zone running parallel to the shore. Along the east coast of the U.S., the primary direction of longshore drift tends to be from the north to the south, while along the west coast, it generally moves from the north to the south as well. Factors such as prevailing wind direction, wave approach angle, and coastline shape contribute to the direction of longshore drift.