Transcript 2. What is a sand dune and where are they found?

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?
-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?
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?
- 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.
- 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
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?
-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.
- 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 Ushape; these glaciers can also scoop out holes
than can fill with water and become lakes
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.
-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