GEO 1111 Lecture Notes - Lecture 18: Longshore Drift, Surf Zone, Orbit

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Robert Jack Cornett

Document Summary

Classification of waves = wind waves ( 1-30 seconds) ---- storm(30sto 5 min)---tsunamis(5-12) tides( 12h-24h) Orbital motion = water partiles that are affected by waves follow a circul path. The impact od one wave(crest+ trough) results in a very small net forward tranlations. Or(cid:272)ital dia(cid:373)eter de(cid:272)resea (cid:449)ith depth, at /(cid:1006) or(cid:271)ital (cid:373)otio(cid:374) is al(cid:373)ost zero. Deep (cid:449)ater (cid:449)a(cid:448)es= (cid:449)a(cid:448)e u(cid:374)affe(cid:272)ted (cid:271)y the o(cid:272)ea(cid:374) floo(cid:449) (cid:894) depth> /(cid:1006) (cid:895) Shallow (cid:449)ater (cid:449)a(cid:448)es = (cid:449)a(cid:448)es affe(cid:272)ted (cid:271)y o(cid:272)ea(cid:374) floor (cid:895) dept is < /(cid:1006) (cid:895) Near the hsore, u see breakers ( colaapsing waves) in the surf zones. Wave refreaction = the bending of waves as they meet bottom & change veolocity: wa(cid:448)e refra(cid:272)tio(cid:374) e at headla(cid:374)ds i(cid:374)(cid:272)reased erosio(cid:374, wa(cid:448)e refra(cid:272)tio(cid:374) e at (cid:271)ays i(cid:374)(cid:272)reased deposition =wave erosion straightens an irregular shoreline. Obliquely breaking waves generate longshore currents and longshore drift. Longshore currents: coastparallel currents in the surf zone. Water related nautral disaters: storm surges ( associated with hurricans) 2.