Classroom presentations to accompany Understanding Earth, 3rd edition - PowerPoint PPT Presentation

Loading...

PPT – Classroom presentations to accompany Understanding Earth, 3rd edition PowerPoint presentation | free to download - id: 6166c4-ZGMwN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Classroom presentations to accompany Understanding Earth, 3rd edition

Description:

Classroom presentations to accompany Understanding Earth, 3rd edition prepared by Peter Copeland and William Dupr University of Houston Chapter 17 – PowerPoint PPT presentation

Number of Views:29
Avg rating:3.0/5.0
Slides: 63
Provided by: WilliamR168
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Classroom presentations to accompany Understanding Earth, 3rd edition


1
Classroom presentations to accompany
Understanding Earth, 3rd edition
  • prepared by
  • Peter Copeland and William Dupré
  • University of Houston

Chapter 17 The Oceans
2
The Oceans
Steve Terrill/Stock Market
3
Sandy Beach, North Carolina Barrier Island
Fig. 17.1
Peter Kresan
4
Boulder Beach, Massachusetts
Fig. 17.2
Raymond Siever
5
Wave height depends on
  • Wind velocity
  • Wind duration
  • Distance over which wind blows

6
Wave-generated Orbital Waves
Fig. 17.3
7
Wave characteristics
  • Length (L) distance between crests
  • Height (H) vertical distance between crest and
    trough
  • Period (T) time for successive waves to pass a
    fixed point

8
Velocity (V) of waves
  • V L/T

9
Waves in shallow water
  • Wave height Increases
  • Wave length decreases
  • Velocity decreases
  • Period doesnt change

10
Surf zone
  • Zone between where the waves break to point
    furthest up the shore where the waves wash up

11
Changes in Waves as they Approach the Beach
Fig. 17.4
12
Wave refraction
  • Bending of wave crests as they approach the beach
    at a non-normal angle
  • Caused by the change in velocity of waves as a
    function of water depth

13
Wave Refraction
Fig. 17.6
14
Waves Bending as they Approach the Beach
Fig. 17.5
John S. Shelton
15
Refraction at Headlands and Bays
Fig. 17.7
16
Longshore Drift
Fig. 17.8
17
Sediment transport near shore, parallel to the
beach
  • Longshore drift sediment carried by swash and
    backwash along the beach
  • Longshore currents currents parallel to the
    beach within the surf zone

18
Tides
  • Twice daily rise and fall of the sea caused
  • by the gravitational attraction between
  • earth and moon (lunar tides)
  • earth and sun (solar tides)

19
Lunar Tidal Bulges
Fig. 17.9
20
Interaction between lunar and solar tides during
the lunar month causes
  • Neap tides when two tidal components are
    out-of-phase, hence lower than usual, and
  • Spring tides when two tidal components are
    in-phase, hence higher than usual.

21
Earth-Moon-Sun Alignment and Neap-spring Tides
Neap tides
Spring tides
Fig. 17.10
22
Mont-Saint-Michel France
Exposed tidal flats
Thierry Prat/Sygma
Fig. 17.11
23
Terrace Exposed at Low Tide
Fig. 17.12
James Valentine
24
Major parts of beaches
  • Offshore from where the waves begin to feel
    bottom to the surf zone
  • Foreshore includes the surf zone, tidal flats,
    and swash zone
  • Backshore from beyond the swash zone to the
    highest level of the beach

25
Major Parts of a Beach
Fig. 17.13
26
Sand budget
  • The inputs and outputs of sediment by
  • erosion and sedimentation.

27
Sand Budget of a Beach
Fig. 17.14
28
Preventing beach erosion
  • Structural approaches (e.g., groins) typically
    cause increased erosion downcurrent of structure
  • Non-structural approaches (e.g., beach
    nourishment, land use planning) expensive, but
    dont cause erosion in new areas

29
Groin Built to Prevent Updrift Erosion Causes
Downdrift Erosion
Erosion
Deposition
Phillip Plissin/Explorer
30
Beach Nourishment, New Jersey
U.S. Corps of Engineers, New York District
31
Factors determining rates of erosion or
deposition
  • Uplift
  • Subsidence
  • Rock type
  • Sea-level changes
  • Wave heights
  • Tidal range

32
Sea Stacks
Fig. 17.15
Kevin Schafer
33
Wave-cut Terrace Exposed at Low Tide
Fig. 17.16
John S. Shelton
34
Southern Tip of Cape Cod
Fig. 17.17
Steve Durwell/The Image Bank
35
Past 160 Years of Shoreline Change, Southern Cape
Cod
Fig. 17.19
36
Partially Developed Barrier Island
Mainland Florida
Lagoon
Barrier Island
Gulf of Mexico
Fig. 17.18
Richard A. Davis, Jr
37
Uplifted Coastal Terrace
Fig. 17.20
John S. Shelton
38
Mapping the seafloor
  • Satellite measurements
  • Echo sounding profiles
  • Side-scan sonar
  • Manned and unmanned submersibles

39
From Gravity Anomaly to Seafloor Topography
D.T. Sandwell W.H.F. Smith/Scripps Institute of
Oceanography
40
Congo Submarine Canyon
Echo sounding profile
Fig. 17.22
41
Loiki Seamount Imaged Using Side-scan Sonar
Fig. 17.23
Ocean mapping Development center, University of
Rhode Island
42
The Benthic Explorer Unmanned Submersible
Fig. 17.21
T. Kleindinst/Woods Hole Oceanographic Institute
43
Topographic Profile of the North Atlantic Ocean
Fig. 17.24
44
Atlantic bathymetric features
  • Continental shelf
  • Continental slope
  • Continental rise
  • Abyssal plains
  • Seamounts
  • Mid-ocean ridge

45
Pacific bathymetric features
  • Continental shelf
  • Continental slope
  • Trench
  • Abyssal plains
  • Seamounts
  • Mid-ocean rise

46
Continental shelf
Continental slope
Continental rise
Fig. 17.25
Praxton Haxby, 1996
47
From the Continental Rise to the Mid-Atlantic
Ridge
Fig. 17.26
48
Topography of the North Atlantic Ocean
Fig. 17.27
Detail from H.C. Berannrket, based on Heezen
Tharp
49
Topographic Profile of the Western Pacific Ocean
Fig. 17.28
50
Atlantic Passive Margin Off New England
Fig. 17.29
51
Turbidity Current
  • Flow of muddy water down a slope
  • Forms deposits known as turbidites

52
Turbidity Currents
Fig. 17.30
53
Fig. 17.31a
54
Sandfall at the Head of a Submarine Canyon
Fig. 17.31b
U.S. Navy
55
Black smoker from the East Pacific Rise
D.B. Foster/Woods Hole Oceanographic Institute
56
Central Rift Valley of the Mid-Atlantic Ridge
Fig. 17.32
57
Fig. 17.32
Macdonald Fox, 1990
58
Some of the Maldive Islands in the Pacific
Atoll
Fringing Reef
Fig. 17.33
Guido Alberto Rosi/The Image Bank
59
Evolution of a Coral Reef
Fig. 17.34
60
Types of marine sediment
  • Terrigenous material eroded from the continents
  • Biochemically precipitated shells of marine
    organisms
  • Abiotic chemical precipitates

61
Oceanic Ooze
Fig. 17.35
Scripps Institute of Oceanography,University of
California, San Diego
62
Carbonate Compensation Depth
Depth below which carbonate material dissolves in
seawater
Fig. 17.36
About PowerShow.com