Author Question: If you lived along the shoreline, on which side of a groin, relative to the longshore current, would ... (Read 18 times)

hubes95 · **on:** Jul 16, 2018

If you lived along the shoreline, on which side of a groin, relative to the longshore current, would you prefer to locate your home? Why?

What will be an ideal response?

Question 2

How do longshore currents cause sediment deposition or erosion along the shoreline?

What will be an ideal response?

Brenm · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

I would prefer my home to be on the up-current side of the groin because the beach there will get larger over time as sand transported by the longshore current is trapped behind the groin. In contrast, the beach on the down-current side of the groin will be sediment-starved and will likely erode away over time.

Answer to Question 2

Longshore currents erode sediment where the current exerts sufficient shear stress to pick up the sediment grains. Deposition usually occurs where current velocity decreases, the waves approach from a different direction, or where the currents are interrupted by irregularities in the shoreline, such as headlands, groins, and jetties.