Final answer:
Water in both a stream and a longshore current flows continuously, shaping their environments by transporting and depositing sediments. The stream's origin is characterized by clear, nutrient-poor water with a fast current, which slows and widens downstream. The longshore current runs parallel to the shore, influencing coastal sediment deposition.
Step-by-step explanation:
Water in a stream and in a longshore current share similarities in terms of their continuous movement and their capacity to shape the environment through sediment transport. Streams have their origin at a source where the water is typically cold, low in nutrients, and clear, with a narrower channel and a faster current than downstream. The current slows as streams widen and join other tributaries, increasing sedimentation and water temperature, and leading to a murkier appearance. In contrast, a longshore current is a dominant force in the nearshore zone, typically running parallel to the shore and significantly influencing sediment deposition along the coast. These currents can create asymmetrical ripple marks on beaches similar to those found in stream environments, where the steep side of the ripple indicates the direction of the water flow. Both a stream and a longshore current are examples of how water can influence the distribution of sediments within their respective environments.