EAS212 Lecture Notes - Lecture 20: Beach Nourishment, Wave-Cut Platform, Sea Level Rise

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS212
• Professor: Juliana Marson

Document Summary

Composition of sand: whatever material is locally available (shells, corals, glass, different minerals) 18,000 years ago elongated sand ridges were submerged (b) developed from spits (c) vertical growth of longshore bar. Deltas: some rivers carry more sediment to the ocean than longshore currents can distribute develop a delta deposit at their mouths, river-dominated delta: low wave and tide energy (e. g. mississipi. Delta: wave-dominated delta: wave energy is high; wave erosion and strong longshore drift relatively straight coast (e. g. , sao francisco. Delta: tide-dominated delta: strong ebb and flood currents rearrange sediment into long, linear submarine ridges and islands that tend to fan out from the river mouth (e. g. , ganges delta) Alternatives to hard stabilization: hard stabilization have negative environmental consequences, construction restriction, beach replenishment sand is added to the beach, solution for: dam deprives beach of sand beach starvation, very expensive, relocation. Shore = zone between lowest tide level and highest elevation affected by storm waves.