Oceanography Exam III Study Guide

Ocean Waves and Coastlines

Exam III Study Strategies

You will need to be able to know the definitions for the below terms and the answers to the following questions in order to correctly answer all the multiple choice and matching questions on the midterm exam III.  Some questions (as noted) can be answered most easily with a drawing or diagram. Be sure to LABEL the important parts of your diagram.  Drawing and labeling diagrams and creating “concept maps” are very effective means of remembering and understanding information, particularly science material. 

Important Processes and Features of Waves and Coastlines

Coastal Processes and Landforms

Tides -- spring, neap, sun-moon-earth geometry, perigee, apogee
How tides affect coastal landforms, tidal range

Waves -- wave energy, fetch, how generated
Wave height, wave length, wave period, wave base
Breaker zone, surf zone, swash zone, swash and backwash
Longshore current, longshore drift

Rip currents
Wave refraction
Storm surges
Sea level change

Eustatic, (world-wide sea level change) climate change, tectonic change in ocean basins
Isostatic, (change in balance of crust over mantle) glacial forebulge, tectonic adjustment

Beach processes

Seasonal changes, wave energy
Summer beach -- steeper beach face, net deposition
Winter beach -- flatter, offshore bar, rockier, net erosion
Sediment size, sediment source (where sed comes from)

Rocky beaches versus sandy, or mud beaches

Coastal landforms


     Spit, baymouth bar, lagoon, cuspate spit, pocket beach, bay and headland coast, tombolo


      Sea cliffs, wave cut notch, wave-cut platform or planation platform, sea arch, sea stack


      Emergent, prograding, regressing:  due to tectonic uplift, lowering sea level, sediment deposition, cliffs, marine terraces

      Submergent, recession, transgression:   due to subsidence, sea level rise, erosion, tend to be irregular, estuaries, bay and headland, barrier islands

Artificial Structures


      Groin, jetty, breakwater, seawall, rip rap, pier


Important key concept questions that you need to know the answer to:


1) What is an ocean wave?   How do water particles move as a wave passes by?  What moves along with the wave?  

2) What are wind waves?  How do they form?  What are their distinct wave form characteristics?  What are the three key factors that control wind wave size?


3) How do swells develop out of a rough, stormy region of ocean?


4) What is the difference between a deep water wave and a shallow water wave? 


5) Describe the process of wave “shoaling”.    How does a set of wave forms change as it approaches the shore?

6) How, why and where do waves break?  What is the difference between a breaking “whitecap” and a breaking shore wave?

7) What is a tsunami?  How do they form?  What are their distinct wave form characteristics?


8) What are the tides?  How do they form?  What are their distinct wave form characteristics?


9) What are the three different types of daily tides found worldwide?


10) What is an amphidromic standing rotary wave?  An amphidromic point?


11) Explain the major differences between the Equilibrium Theory and the Dynamic Theory of Tides.  Which one is best and why?

12) What is the difference between an emergent coastline and a submergent coastline?  Which one would you expect to find at “active margins?”  Which at “passive margins?”  How does this relate to plate tectonics?
13) Know what longshore currents are, how they form, what direction they flow, and how they can move sediment.  (Note:  the movement of sediment by longshore current is called “littoral drift.”)


14) Know what rip currents are, how they form, what direction they flow, and how they can move sediment. 


15) How should a swimmer negotiate a rip current if caught in one?

16) If one builds a jetty out from a beach, how will the beach be affected?  Where will deposition occur?  up-current from the jetty (up-current is the direction the longshore current is coming from)) or down-current?  Where will erosion occur?

17) What is “wave refraction?”  How does wave refraction contribute to faster erosion of sea cliffs that jut out into the ocean?


18) How do waves erode coastlines? 

19) Describe how the ocean attempts to straighten out a shoreline over time.


20) What are the two major natural sources for beach sediment?  How are these sources being affected by human activities?


21) What is the major underwater feature that permanently funnels shoreline sediment to deep water offshore?


22) What effect do breakwaters have on beaches?


23) What is the difference between a jetty and a groin?   What the negative impact of building groins and jetties?


24) What are the positive and negative effects of building seawalls along coastal bluffs?

25) If you are going to build along the shoreline, what factors should you consider?