16_coast_09_post

16_coast_09_post - 16: Surface Processes 3 Tides, Waves,...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
16: Surface Processes 3 Tides, Waves, and Coastlines Rocky shoreline, Oregon.  Photo: Steve Terrill Barrier islands Photo: NASA
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Why this is important Most waves are caused by wind, which is driven by Earth’s external heat engine. Surfers off  Maui coast.  Photo: R.W.  Schlische
Background image of page 2
Why this is important 60% of global population live on or near coast. Coastlines are dynamic features that represent a huge investment in property, recreation, etc. Photo: W.K. Hamblin Photo: W.K. Hamblin
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig. 18.15 Tides Size of intertidal zone depends on… Tidal range Side view Block diagram
Background image of page 4
Tides Q1. Approximately how many  high tides occur per day? A. 1 B. 2 C. 3 D. 4 Q2. Approximately what is the  difference in time between  two successive high tides?  A. 6 B. 12 C. 18 D. 24 Q3. Is the time of high tide the  same for each day of the  month?  A. Yes B. No Q4. Is the height of high tide  the same for each day of the  month?  A. Yes B. No Time/height of low tide Time/height of high tide Time/height of low tide Time/height of high tide Hours Tide height
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig. 18.15   Tides : rise / fall of sea surface caused by gravitational pull of moon and sun  and centrifugal force caused by the revolution of the Earth-moon system  around its center of mass. Approx. 2 high tides per day due to Earth’s rotation beneath tidal bulges Tides
Background image of page 6
Tides: Analogy Top views
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Tide-generating forces Each point on Earth feels same centrifugal force due to spin of Earth-moon system around its center of mass but feels different gravitational attraction due to pull of moon (e.g., force is greatest closest to moon). Tide-generating force is sum of centrifugal force and gravitational attraction. On side of Earth closest to moon, tide-generating force vector is dominated by gravitational force and points toward moon. On opposite side, centrifugal force dominates, and tide- generating force points away from moon. Thus, two tidal bulges exist. Side views
Background image of page 8
Tides Low tide Low tide Bay of Fundy, Nova Scotia, Canada Tidal amplitude varies greatly around the world (~1-2 m in NJ, up to 16 m in Bay of Fundy). Amplitude depends on latitude and shape of coastlines. For example, the Bay of Fundy acts like a funnel that forces water higher and higher near its narrow end during high tide. High tide Map views
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig. 18.15 Tides Top view Top view   Spring tides : tides  with higher- than- normal tidal range  that are produced  when the Earth,  Moon, and sun are  aligned.    Neap tides : tides  with lower-than- normal tidal range  that are produced  when the moon is at  right-angles to the  Earth-sun system.
Background image of page 10
Review Questions 16-1.  A. True / B. False:  Coastal processes are of interest to geologists, but affect 
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 40

16_coast_09_post - 16: Surface Processes 3 Tides, Waves,...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online