lecture 5 waves and currents
DESCRIPTION
Lecture 5 Waves and Currents. Formation of Waves. Travelling Waves. Anatomy of Waves. Forces Generating Waves are Different. Wave typePeriodDisturbing forceRestoring force. CapillaryTRANSCRIPT
Lecture 5 Waves and Currents
Formation of Waves
Travelling Waves
Anatomy of Waves
Forces Generating Waves are Different
Wave type Period Disturbing force Restoring force
Capillary <0.1 sec Wind Surface tension
Forces Generating Waves are Different
Wave type Period Disturbing force Restoring force
Chop 1 – 10 sec Wind Gravity
Forces Generating Waves are Different
Wave type Period Disturbing force Restoring force
Swell 10 – 30 sec Wind Gravity
Forces Generating Waves are Different
Wave type Period Disturbing force Restoring force
Seiche 10 min – 10 hr Wind/Seismic Gravity(standing wave)
Seiche waves
Forces Generating Waves are Different - Summary
Wave type Period Disturbing force Restoring force
Capillary <0.1 sec Wind Surface tension
Chop 1 – 10 sec Wind Gravity
Swell 10 – 30 sec Wind Gravity
Seiche 10 min – 10 hr Wind/Seismic Gravity(standing wave)
Tsunami 10 min – 2 hr Seismic Gravity
Tide 12.4 or 24.8 hr Gravity Gravity
Tsunamis
http://www.youtube.com/watch?v=PBZGH3yieLc&lr=1&feature=mhum
Transition of one wave to another
Worldwide distribution of wave heights
Waves and Depth
Deep water
Shallow water
Breaking Waves
Types of Breaking Waves
Spilling
Result from waves of low steepness (long period swell) over gentle slopes.
Types of Breaking Waves
Plunging
Result from steeper waves over moderate slopes.
Types of Breaking Waves
Surging
Surging breakers surge over steeply sloping (but not vertical) beaches or rocks. Occur where the beach slope exceeds wave steepness.
Gentle – spillingModerate – plungingSteep - surging
Wave breaking
Refraction of Waves
Refraction of Waves
Refraction of Waves
Currents
Currents - Rip currents
Currents - Rip currents
Currents - Coriolis Forces
Currents - Open Ocean
Ekman Spiral
Coastal Upwelling
Coastal Upwelling
Coastal Upwelling - Phytoplankton
Coastal Upwelling - Temperature
Coastal Upwelling - Fishing
Upwelling area Fishing
0.1%
50%
Langmuir Cells
Langmuir Cells
Langmuir cells in sea ice
Next time:
Coastlines