1. Chapter 5: Section 2 Surface Processes and Landscapes
Earth Science
Chapter 5: Section 2
Surface Processes and Landscapes

2. Introduction to Oceans
Currents are made by wind & density diffs.
Currents distribute Earth’s solar energy.
Carry heat energy from lower latitudes to higher latitudes & cold water to lower latitudes
Erosion and deposition by wave action cause changes in shoreline features like beaches, sandbars, and barrier islands.
Wave action rounds sediments by abrasion.

3. Ocean Currents

4. Erosion and Deposition by Wave Action

5. Ocean Currents
Tsunamis – large waves caused by submarine landslides or volcanic eruptions
Wavelengths can be 100 miles long
Heights can reach 100 feet
Indonesian Tsunami of December 26, 2004
Ruptured over a length of at least 250 miles
Traveled at about 1.2 miles per second
Wave heights greater than 30 feet

6. Ocean Currents

7. Ocean Currents

8. Ocean Currents

9. Ocean Currents

10. Glaciers Two types of glaciers:
Valley (alpine) glaciers - confined to a valley and flows from higher to lower elevations.
Most present day glaciers are valley glaciers.
Continental ice sheets - thick mass of ice that covers over 50,000 square kilometers of land.
Only two exist today
Antarctica and Greenland

11. Glaciers

12. Glacial Erosion
Glaciers move down slope under the influence of gravity and their own weight.
Steeper the slope the faster the movement.
When a glacier melts faster than it moves downslope it moves backward (recedes)
When a glacier slides over rock, the rock beneath the glacier is abraded.
Sharp corners of rocks dragged along make long parallel scratches (striations).

13. Glaciers

14. Glacial Erosion Glaciers carve U-shaped valleys Cirque Horn Arete
Hanging valleys form from tributaries
Cirque
Bowl shaped erosional scar
Horn
Sharp peak remaining from 3 or more cirques
Arete
Ridge remaining from 2 cirques

15. Glacial Erosion

16. Glacial Erosion

17. Glacial Deposition Till Outwash Erratic
Unsorted rock deposited directly by a glacier.
Outwash
Rock material deposited directly from the meltwater of the glacier.
Erratic
Large rock that is different from rock beneath

18. Glacial Deposition Moraine
Mass of glacial till left behind after a glacier has melted.
Terminal moraine – farthest advance of glaciers
Recessional moraine – built up where the glacier recedes for a while, then becomes stationary
Lateral moraine – pile of till along sides

19. Glacial Deposition
Drumlin – elongated hills formed from a glacier passing over old ground moraine
Outwash plain – sorted deposits carried by meltwater of glacier
Kames – short, steep-sided hills of outwash
Kettle hole – formed from ice block that melts
Many are filled with water creating deep lakes
Esker – sinuous deposits from rivers of meltwater

20. Glacial Deposition

21. Glacial Deposition

22. Glacial Deposition

23. Glacial Deposition

24. Wind Action A dune is a mound or ridge of sand deposited by the wind.
As the wind rises up the long side of the dune, the wind speed increases, therefore its carrying power increases (erosion increases).
As the wind moves over the top of the dune and spreads out, its wind speed and carrying power decreases (deposition increases).

25. Wind Action

26. Landscape Development and Environmental Change

27. Landscape Development
Forces that raise Earth’s surface are called uplifting forces
Forces that lower the elevation of Earth’s surface are called leveling forces
Climatic changes effect landscapes
The drier the climate the more angular the landscape
Bedrock patterns influence landscape

30. Stream Drainage Patterns

31. Time Landscapes pass through stages over time Young Mature Old
Erosion is beginning
Steep fast-moving streams & v-shaped valleys
Mature
Low rounded hills and broad flat valleys
Streams stop eroding downward & start sidecutting
Old
Uplands have been eroded almost to sea level
Poor drainage, small gradient, many meanders