Author Question: How do sediments move along a beach? ... (Read 52 times)

james · **on:** Aug 22, 2018

How do sediments move along a beach?

Question 2

The primary force responsible for surface currents is ____.
A) precipitation
B) wind
C) heat
D) gravity

braelync · **Reply #1 on:** Aug 22, 2018

Answer to Question 1

The movement of sediments along the coast is called longshore drift. It is driven by wave action, but it can also be current driven.
Water hits beaches at an angle due to sediment accumulations. Although the water comes up at an angle, gravity dictates that it runs straight when it returns downhill from the shore. Sand grains disturbed by the wave will follow the water's path, moving upward along the beach.
This transport is longshore and runs parallel to the coast.
Sediments are also driven by currents. They are transported in the surf zone in a longshore current. Breaking waves distribute a portion of their energy away from the direction of approach. This energy fuels a narrow current with suspended sediments in it.
The net direction on both coasts of the United States is south due to the direction waves normally approaching from the north.

Answer to Question 2

B