OCEANS Hypsometric Curve OCEANS TIDES Spring Tides Neap

OCEANS

Hypsometric Curve

OCEANS TIDES

Spring Tides Neap Tides

What phase of the moon would you expect to be associated with the highest tides? A. New Moon B. First Quarter C. Third Quarter

Tides affected by shoreline shape

WAVES

Generated by wind speed, duration, fetch Wavebase = ½ wavelength

WAVES

Shore profile is dynamic equilibrium

Wave Refraction waves bend toward slower medium

Wave energy focused on headlands = erosion Wave energy dispersed in bays = deposition

Wave refraction generates longshore current

Creates Spits Alligator point

Which way is the longshore current flowing? A. To the North B. To the South C. To the East D. To the West E. Can’t tell

Barrier Islands How formed? • Cutoff Spit • Drowned Dunes • Exposed Sand Bar

PRS Overwash causes barrier islands to move in which direction? A. Toward shore B. Toward the ocean C. Parallel to the coast

Coastal Engineering Seawalls

Beach Armor – Rip-Rap

Groins, jetties

PRS Which way is the longshore current flowing? A. To the North B. To the South C. To the East D. To the West E. Can’t tell

Beach Nourishment

GROUP PRS Why has the southern part of the island migrated onshore? A. B. C. D. E. Change of wave direction Development on southern island Rise in sealevel Inlet jetties Change in longshore current

Rip Currents

Ocean Currents Surface currents primarily driven by wind and Coriolis force

Ocean Currents Deep currents primarily driven by density due to temperature and salinity. Cold water density > warm water More Saline water density > less saline

Upwelling Zones

Ocean Upwelling: Winds drive surface waters offshore causing deep water to rise. Coastal Upwelling

EUSTATIC SEALEVEL CONTROLS

LOCAL SEALEVEL CONTROLS • Subsidence • Tectonism (mtn building) • Isostatic adjustment