Download presentation
Presentation is loading. Please wait.
Published byJamar Lisle Modified over 9 years ago
1
The first prelim will be held during regular class time on Thursday 21 February A short in-class review will be held Tuesday 19 February to go over student submitted questions Submit review questions to Yianna Samuel (ys88@cornell.edu) by Friday 15 February Important Announcement
2
Why Study Waves?
3
Wave Prediction and Shipping
4
Wave Prediction and Construction of Coastal Structures
5
Wave Prediction and Construction of Off-Shore Structures
6
Wave-Induced Beach Erosion and Sediment Transport
7
Wave Prediction and Recreation
8
Fundamental Principles
9
Wave Parameters Wave Period = Time it Takes a Wave Crest to Travel one Wavelength (units of time) Wave Frequency = Number of Crests Passing A Fixed Location per Unit Time (units of 1/time) Wave Speed = Distance a Wave Crest Travels per Unit Time (units of distance/time) Wave Steepness = Wave Height/Wavelength
10
Constructive, Destructive and Mixed Addition of Two Waves Constructive Destructive Mixed
11
Ideal Deep-Water Waves Propagate Energy not Mass
12
Two Critical Points to Note About Wave Speeds Deep-Water Waves (Bottom Depth > L/2) –Speed is a Function of Wavelength Only –Waves with Longer Wavelength move faster than Waves with Shorter Wavelength Shallow-Water Waves (Bottom Depth < L/20) –Speed is a Function of Depth Only –Waves Travel Slower in Shallower Water Irrespective of Wavelength as long as Depth < L/20 _________________ Note that there is also an intermediate region (L/20 < Depth < L/2) where Wave Speed is a Function of Both Wavelength & Depth Note: L = wavelength
13
Speed of Deep-Water and Shallow- Water Waves as a Function of Wavelength and Depth
14
Deep-Water and Shallow-Water Wave Regions
15
The Size of Wind Generated Waves is a Function of: 1.Wind Speed 2.Duration of Wind 3.Fetch - the distance over which wind can blow without obstruction
16
The Importance of Fetch
17
Full Developed Waves (Unlimited by Fetch and Duration)
18
Lateral Spreading of Wave Energy from a Storm Source (95% of Energy Contained Within ±45 o of Storm Direction)
19
Wave Measurement Methods
20
Wave Height Measured with Bottom-Moored Pressure Sensor
21
Significant Wave Heights Derived from the Shape of the Returned Beam on the Topex-Poseidon Altimeter
22
The Distribution of Wave Energy as a Function of Wave Period or Wavelength…
23
Distribution of Wave Energy in the Ocean as a Function of Wave Frequency or Wavelength
24
Some Interesting Things About Waves…
25
Wave Dispersion: Self Sorting of Deep-Water Waves Leaving a Storm Region based on Wavelength. It Occurs Because Longer Wavelength Waves Travel Faster than Shorter Wavelength Waves (for Deep Water).
26
Bending of Shallow-Water Wave Fronts Due to Change in Bottom Depth. The Leading Edge of a Wave Front Enters Shallower Water and Slows While the Remaining Front Continues at Higher Speed. The Net Result is a Rotation of Wave Fronts To Become Parallel with Bottom Depth Contours. Wave Refraction:
27
Consequence of Wave Refraction Focusing and Defocusing of Wave Energy on Headlands and Bays, Respectively
28
Wave Diffraction
30
Along Shore Sediment Transport
31
Along-Shore Sediment Transport Obstructed by Groins
32
Initiation and Propagation of a Tsunami
36
Motion of Seiche Caused by a Storm Over a Semi-Enclosed Body of Water
37
Internal Waves Travel along Density Discontinuities in the Ocean Interior
38
Thin Layers of Phytoplankton Oscillating with an Internal Wave Formed along the Continental Shelf
39
Kelvin and Rossby Waves - Planetary Waves -
40
Rossby Waves in the Equatorial Pacific
41
1.Waves Propagate Energy and not Mass 2.Waves Add Constructively or Destructively 3.Deep-Water Wave Speed is a Function of Wavelength 4.Shallow-Water Wave Speed is a Function of Bottom Depth 5.Wave Dispersion: Sorting of Deep-Water Waves Based on Wavelength 6.Wave Refraction: Bending of Shallow-Water Waves Based on Depth 7.Wave Height Determined by: Wind Speed, Wind Duration and Fetch Summary Points
42
8.Waves Hitting a Shore Obliquely Will Cause along Shore Transport of Sediment 9.Constructed Structures such a Groins will Block the Along Shore Sediment Transport 10.Tsunami are Generated by Underwater Earthquakes or Landslides and Propagate across Whole Ocean Basins 11.Seiches are Standing Waves formed in Semi- Enclosed Bodies of Water 12.Internal Waves Propagate along Density Discontinuities (Pycnoclines) in the Ocean Interior 13.Kelvin and Rossby Waves are Important Planetary Wave
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.