3.3 - Depositional Landforms Flashcards
How are beaches formed?
Sediment is imout, transported, and deposited by constructive waves’ swash
Waves don’t have enough energy to carry sediment further
How do spits form?
LSD (waves coming in at an angle and being backwash at 90° by gravity) and sediment is extended offshore by constructive waves
Wind direction dictates the curve of the spit
What makes a spit recurved?
Two dominant wind directions causes two LSD directions
Wave refraction around tip of spit
How does an offshore bar form?
1) Waves break on a submerged bar
Sediment carries is despoiled and it accumulates vertically
2) Sediment carries by LSD along the coast
Waves enter low-energy part of sediment cell
Sediment gets deposited on submerged bars parallel to the shore
How do tombolos form?
Offshore island refracts approaching waves so convergence of two LSD directions on opposite side of the island
This creates a bar which extends out to mainland