animation of tidal elevations in the pacific. tides and tsunamis gravitational forces of moon and...
TRANSCRIPT
![Page 1: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/1.jpg)
Animation of Tidal Elevations in the Pacific
![Page 2: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/2.jpg)
Tides and Tsunamis
• Gravitational forces of moon and sun• Equilibrium theory of Tides• Dynamic theory of Tides (Reality): tidal
patterns, confined basins
• Tsunamis: generating forces• Effects of tsunamis• Warning systems, defenses
![Page 3: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/3.jpg)
Equilibrium Theory
Tides are always in equilibrium withthe gravitational pull of the moon andEarth is a planet covered in water.
Assumption
![Page 4: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/4.jpg)
![Page 5: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/5.jpg)
Gravity and centrifugal force(also called “tractive forces”)
Together:The earth-moon system
Equilibrium theory of tides
![Page 6: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/6.jpg)
Tides: The moon and the sun together
Spring tide
Neap tide
![Page 7: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/7.jpg)
![Page 8: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/8.jpg)
![Page 9: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/9.jpg)
semidiurnal
diurnal
composite
+
=
![Page 10: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/10.jpg)
Dynamic Theory
Waves travel at a fixed waves speedThere are continents and rotation
Needs to account for:
![Page 11: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/11.jpg)
![Page 13: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/13.jpg)
Tidal circulation
• Tides progress around basins, counterclockwise in S hemisphere and clockwise in N hemisphere
![Page 14: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/14.jpg)
Animation of Tidal Elevations in the Pacific
![Page 15: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/15.jpg)
Inertia + continents cause the tidal motion on the planet to differ markedly from the “motion” of the forces.
We can calculate the water motion knowing the forces, but we cannot say that the shape of the water is the same as the “shape” of the forces.
For this reason tides must not be visualized as bulges standing under the sun and moon.
But rather as very long waves over the sea forced by the gravitational-centrifugal forces associated with the moon-sun-earth system.
![Page 16: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/16.jpg)
Tides in confined basins• Increase tidal range (the difference
between high and low tide)
• Examples--Bay of Fundy, Canada--Northern Gulf of California, Mexico
• Tidal bores - wave of water moving upstream - result of high-tide crest entering confined inlet
![Page 17: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/17.jpg)
![Page 18: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/18.jpg)
Bay of Fundy: map
• 2.416
![Page 19: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/19.jpg)
Bay of Fundy tides
• Extreme tides (10m or more) found where small marine basin adjoins large ocean– Bay of Fundy, Nova Scotia– Gulf of California
• (in most places, tides are 1 to a few meters in range)
![Page 20: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/20.jpg)
Shock Waves and Tidal Bores are similar!
![Page 21: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/21.jpg)
Tidal bore: Severn River, England
• 2.452
![Page 22: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/22.jpg)
Tidal ecosystems
• Rise and fall of tides creates stressful environments for intertidal marine organisms
![Page 23: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/23.jpg)
Tidal ecosystems
• Others take refuge in tide pools, where water remains even at low tide
![Page 24: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/24.jpg)
TsunamiJapanese for harbor (tsu) wave (nami)
Caused by displacements of water•landslides into the sea•submarine earthquakes•submarine volcanoes•asteroid impacts
“Shallow-water” wave: disturbs water all the way to bottom
![Page 25: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/25.jpg)
Tsunami of April 1, 1946
Earthquake triggers tsunami with devastating local and distant effects
![Page 26: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/26.jpg)
The speed of the tsunami wave
C = sqrt(g d)
C = speed,
g = acceleration due to gravity (9.8 m/sec/sec)
d = depth (depth of Pacific ~4,600 m)
C= sqrt(9.8 * 4,600)
Speed = 212 meters per second; 472 mph
Alaska to Hawaii in 5 hours!
![Page 27: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/27.jpg)
Locally, the tsunami washed away the 5-story lighthouse at Scotch Cap, Alaska
Before… and after
![Page 28: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/28.jpg)
Hilo, Hawaii, 1946: Tsunami crossed the north Pacific to become one of Hawaii’s worst natural disasters
![Page 29: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/29.jpg)
Hilo, Hawaii, 1946
![Page 30: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/30.jpg)
Tsunami breaking over main pier in Hilo, 1946
This man did not survive
![Page 31: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/31.jpg)
Chile earthquake, 1960numerical simulation of tsunami
8.5 hours
1.5 hours 16.5 hours
23.5 hours
![Page 32: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/32.jpg)
Aftermath of local tsunami: Chiloe, Chile, 1960
![Page 33: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/33.jpg)
Distant effects of the Chile earthquake: tidal wave aftermath, Hilo Hawaii
![Page 34: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/34.jpg)
More tsunami damage in Hilo, 1960
![Page 35: Animation of Tidal Elevations in the Pacific. Tides and Tsunamis Gravitational forces of moon and sun Equilibrium theory of Tides Dynamic theory of Tides](https://reader035.vdocuments.net/reader035/viewer/2022062309/56649c815503460f949390ab/html5/thumbnails/35.jpg)
Tsunamis: what can be done?• Early warning system for evacuation (if EQ is distant)• Coastal zoning. Get development out of the way. Example: Hilo,
Hawaii• Defense. Protective walls. Example: Taro, Japan