Constructive & Deconstructive Processes

Changes Caused By Wind 1. What is weathering? -process of wearing away rocks by natural means; rain & wind

2. What is a sand dune and where are they found 2. What is a sand dune and where are they found? -a sand hill that is made and shaped by wind; beaches, deserts, and on lake shores

Constructive Processes 3. What is erosion? -moving sediment by wind, water, or ice 4. How can water cause a river’s banks to change? -Rapidly flowing water erodes the river’s banks and makes the river wider;

5. Describe deposition. The process by which sediment drops out of water. 6. What is a delta? How does it form? A delta is an area of new land at the mouth of a river. It forms by deposits of sand at the mouth of the river.

7. Describe a sinkhole. A sinkhole is a large hole caused by underground erosion due to the weight of material above; usually found where limestone is common (Florida) 8. What is a landslide? Gravity making the soil, mud, and rocks move quickly down a slope or land.

9. How do plants affect Earth’s landforms 9. How do plants affect Earth’s landforms? When a seeds germinates on a rocky slope, it sends roots into tiny cracks or hole in the rock. The roots grow and becomes large enough to break the rock into smaller pieces.

10. What is a barrier island 10. What is a barrier island? - a long, narrow island that forms along the coast that has several sandy barrier islands formed by deposition by waves. 11. Explain floodplains. -rivers that deposit sediment outside their banks will create floodplains.

12. Explain longshore currents. - a current that moves parallel to the shore; waves wash sediment onto the shore; Some of that sediment remains to form a beach.

13. Explain what a glacier is and how it can be constructive 13. Explain what a glacier is and how it can be constructive. - a huge sheet of slowly moving ice that is thousands of feet thick; as they move over land, they scrape away soil and rock under them; when they melt, they leave soil and rock behind forming drumlins and moraines.

14. Explain the difference between a moraine and a drumlin. - a moraine is a ridge of sediment and rock left behind when a glacier melts; a drumlin is a long oval shaped mound of soil and rock formed from glacial deposits. Glacial moraine Glacial drumlin

Earthquakes 15. Describe plates. - are blocks of crust and upper mantle rock that is fit together like puzzle pieces; plates float on the softer rock of the mantle; they can form valleys, mountains, or volcanoes.

16. Explain a fault. - a crack/ break in the rock of Earth’s crust; some faults occur in the middle of plates, but most are found near the edges of plates. (San Andreas Fault) 17. What is an epicenter? - point on Earth’s surface directly above the focus

19. Who studies earthquakes? - a person who studies 18. What is a focus? - the place within the crust where energy is release during an earthquake 19. Who studies earthquakes? - a person who studies earthquakes is a seismologist; these scientists use a Richter scale to measure the magnitude or, amount of energy released.

Volcanoes 20. What is a volcano? - a mountain that forms from magma reaching Earth’s surface; they can create and destroy landforms; lava is hot, melted rock that pours from volcanoes; flows down the volcano and reaches the cool ocean, it becomes solid rock.

21. What causes a chain of volcanoes to form 21. What causes a chain of volcanoes to form? -the movement of a plate over a hot spot

Mountains 22. How do mountains form? - where plates come together, part of the crust is forced up; when pressure is applied to the edges of a plate, rock in the middle of the plate may be forced up;

Deconstructive Processes 23. Explain mechanical weathering. - breaks rock into smaller pieces without it changing chemically; can happen in many ways 24. Explain chemical weathering. - changes rock into one or more new substances; animals can and make new substances

25. Describe erosion by water 25. Describe erosion by water. - rivers remove rock and soil from their channels; overtime, they carve out river valleys which can create V-Shaped valleys (deep canyons)

26. Describe erosion by glaciers. - glaciers erode rock and soil as they scrape over Earth’s surface; sometimes glaciers form in narrow valleys; as the move, they widen and deepen these valleys; the valley then has a U- shape; these glaciers can also scoop out holes than can fill with water and become lakes

27. Describe erosion by wind 27. Describe erosion by wind. - wind erodes sand by blowing it away; it smashes sand against rock surfaces; this polishes and wears away rock; this is greatest in desert pavement.

28. Describe erosion by ocean waves 28. Describe erosion by ocean waves. -waves can remove sand to and from beaches; this is a problem for many coastlines. 29. What are some results of ocean waves? - sea stacks are pillars of stone in the sea that form from headlands; a headland is a point of land that just out into the ocean

-sea arch are formed by waves knocking away softer rock; as the rock continues to wear away, the top of the arch collapses and forms a sea stack;

Controlling Constructive & Destructive Processes 30. Describe some ways that control the effects of erosion. A. dam – a structure built across a river to control its flow.

B. groin – a structure built at right angles to the beach; it traps sand that moves along the shore with longshore currents; can make erosion worse downstream C. Seawall – a structure built parallel to the shore; it absorbs the pounding of waves protecting coast behind it

D. beach nourishment – beaches that erosion has eaten away are reclaimed; sands from ocean or nearby rivers placed on the beach to rebuild E. contour plowing – a method in which farmers plow across the sides of hills instead of down their slopes

F. terracing- is a method in which farmers plant crops on terraces built on hillsides; both methods prevent soil from washing downhill G. Storm drain management- a system of drains that prevents flooding during heavy rainstorms