Uploaded on


More in: Technology
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads


Total Views
On Slideshare
From Embeds
Number of Embeds



Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide


  • 1. Depositional Shorelines A bay barrier, or bay mouth bar, seals off a lagoon from the ocean. A Tombolo is an sand bar that connects an island to the mainland. Barrier islands are long offshore sand deposits that parallel the coast. A spit connects at one end to the mainland and hooks into a bay at the other. © 2011 Pearson Education, Inc.
  • 2. Depositional Shorelines © 2011 Pearson Education, Inc.
  • 3. Depositional Shorelines Tombolo Barrier island © 2011 Pearson Education, Inc.
  • 4. Barrier Islands Common along East and Gulf coasts of the United States Do not exist along erosional shorelines Protect mainland from high wave activity Can migrate landward over time © 2011 Pearson Education, Inc.
  • 5.  Ocean beachBarrier Island  DunesAnatomy  Barrier flat  High salt marsh  Low salt marsh  Lagoon © 2011 Pearson Education, Inc.
  • 6. Barrier Island Ocean Beach – closest part of the island to the ocean Dune – stabilized by grasses; protect lagoon from strong storms Barrier flat – grassy area that forms behind dunes © 2011 Pearson Education, Inc.
  • 7. Barrier Island High and low salt marshes – biologically productive wetlands  Generate peat deposits of decaying organic matter Lagoon – water between barrier island and mainland © 2011 Pearson Education, Inc.
  • 8. Barrier Islands Migrate landward over time due to rising sea levels Older peat deposits found on ocean beach © 2011 Pearson Education, Inc.
  • 9. Deltas Triangular deposits of sediment where rivers empty into oceans or seas  Distributaries carry sediment to ocean © 2011 Pearson Education, Inc.
  • 10. Emerging Shorelines  Shorelines above current sea level  Marine terraces – flat platforms backed by cliffs © 2011 Pearson Education, Inc.
  • 11. Submerging Shorelines  Shoreline below current sea level  Features include  Drowned beaches  Submerged dune topography  Drowned river valleys (estuaries) © 2011 Pearson Education, Inc.
  • 12. Changing Sea Level Two major processes can change sea level:  Local tectonic processes  Global (eustatic) changes in sea level © 2011 Pearson Education, Inc.
  • 13. Changing Sea Level 1. Local tectonic processes  Example: the Pacific coast of the United States is currently being uplifted.  Isostatic adjustments – rebound of Earth’s crust after removal of heavy loads or sinking with application of heavy loads  Ice-loading from glaciers during ice ages © 2011 Pearson Education, Inc.
  • 14. Changing Sea Level 2. Global (eustatic) changes in sea level  Sea level changes worldwide due to Change in… a. amount of available sea water b. in ocean basin capacity © 2011 Pearson Education, Inc.
  • 15. Eustatic Changes in Sea LevelSome Mechanisms Ice ages lock seawater up in ice (glaciation) – sea level goes down Ice melting after an ice age (deglaciation) – sea level rises © 2011 Pearson Education, Inc.
  • 16. © 2011 Pearson Education, Inc.
  • 17. Pleistocene Epoch and Today From about 2 million to 10,000 years ago, a series of four ice ages affected Earth. Sea level was at least 120 meters (400 feet) below today’s sea level. If all remaining ice on Earth melted today, sea level would rise another 70 meters (230 feet). © 2011 Pearson Education, Inc.
  • 18. Global Warming and Changing Sea Level  Globally averaged temperatures – about 0.6 C (1.1 F) warmer over last 130 years  Sea level rose 10-15 cm (4-10 in) over past 100 years  As global warming continues, we will see a higher sea level. © 2011 Pearson Education, Inc.