Earth Sciences 1022A/B Lecture 19: Earth Science Lecture March 22 2016

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Stephen R Hicock

Document Summary

Waves bend as they approach an irregular shoreline so that erosion focuses on headland deposition occurs in bays: wave refraction. Most waves hit the shire at an angle and move sediment along beaches by the zig-zag patter of swash and backwash called beach drift. Oblique waves in the surf zone produce longshore currents that flow parallel to the shore: move most of the sediment in transport that is supplied mainly by rivers. Erosional feature include (depending on geology and wave activity: wave-cut cliffs. By cutting action of surf against the base of cliffs causing them to collapse and retreat. Leaves a wave-cut platform as debris is swept out to sea: arches. Where waves cut caves into the sides of headlands until the caves join. Eventually arch collapses and leaves a stack sitting alone on the wave-cut platform. Depositional features depend on sediment supply and current activity: spits.