Download Understanding Tides: Causes, Effects, and Complexities and more Slides Geology in PDF only on Docsity! Tides Docsity.com Take‐Away Points 1. Tides in the ocean are caused by both the Sun and Moon 2. Tides occur because the Sun and Moon pull stronger on one side of the earth than the other 3. There are two tidal bulges on opposite sides of the Earth 4. Solar and Lunar tidal effects can reinforce or weaken each other 5. Actual tide motions in the oceans are very complex 6. Tides are gradually slowing the earth’s rotation Docsity.com Tides and the Boston Tea Party,
December 16, 1773
Near Earth's perihelion: strong solar tides
Near lunar perigee: strong lunar tides
Full moon on December 13: spring tide
Overall effect: unusually large tidal range
Solar and Lunar tidal effects can reinforce or weaken each other
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The Boston Tea Party, December 16,
1773
midnight 6AM noon 6PM midnight
+ + + +
Best Time
Normal Tide
Actual Tide |
Tea Party
Solar and Lunar tidal effects can reinforce or weaken each other
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Tides and the Battle of Tarawa,
November 20, 1943
Near Earth's perihelion: strong solar tides
Near lunar apogee: weak lunar tides
Near last-quarter moon: neap tide
Overall effect: unusually small tidal range
Solar and Lunar tidal effects can reinforce or weaken each other
Docsity.com
Tarawa: What the Planners Wanted
Dawn Landing
Bombardment 1
5 ft.
I
Follow-up
Supplies
Solar and Lunar tidal effects can reinforce or weaken each other
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What Actually Happened
48 hours -
Tide Range = 2 ft.
| I | | |
Nov. 20 21 22 23 24
1027 Marines killed, 2292 wounded
Solar and Lunar tidal effects can reinforce or weaken each other
Docsity.com
Tides and the
Real Oceans
5. Actual tide motions in the oceans are very complex
Docsity.com
On an ideal, frictionless Earth, tidal
T 1 d bulges would point directly at the
| e S Moon.
Affect \
Ea rt h 'S ( ) On the real Earth, friction and Oo
obstructions to ocean movement
. cause the bulges to lead the Moon.
Rotation
\ A
sh
The Moon pulls backward on the nearer
tidal bulge, slowing Earth's rotation. The
nearer bulge, in turn, pulls ahead on the
Moon, accelerating it into a higher orbit.
6. Tides are gradually slowing the earth’s rotation
Docsity.com
Take‐Away Points 1. Tides in the ocean are caused by both the Sun and Moon 2. Tides occur because the Sun and Moon pull stronger on one side of the earth than the other 3. There are two tidal bulges on opposite sides of the Earth 4. Solar and Lunar tidal effects can reinforce or weaken each other 5. Actual tide motions in the oceans are very complex 6. Tides are gradually slowing the earth’s rotation Docsity.com
