Transcript A, B - AlmaMiddleSchoolScience

Old Man River Lab
Rivers carry liquid precipitation (rain) from sloped
surfaces (watersheds) to ponds, lakes and eventually,
the ocean. Rivers have several features to them that
allow the prediction of their behavior and the effects
they have on humans. Please read and observe all the
following pictures and use the information in the
following slides to answer the questions that follow the
lab.
Young, fast
flowing river
Middle age,
moderate
flowing river
Old age, slow
flowing river
As the speed of the water decreases, the
ability to move larger objects also decreases
The pattern of
sediments deposited
by the stream as
it enters the ocean
Water moves faster at the curves,
and erosion occurs. (Undercut
steep banks)
Water moves slower on the inside
of a curve, and deposition occurs.
(Sand Bars)
Rivers have three courses
generally. The upper
course is a young deep
“V” steeply descending
cut, the middle course
tends to wander from side
to side in what are
called meanders, and in the
lower course the river
broadens even more and
because of this slows down
in velocity, before depositing
its silt into the ocean or lake
as a delta.
The highest velocity of water flow
or speed is found in the middle of
the river course or at the outside
curve. (See pictures to left)
100 ml
Graduated
cylinder
River
model
Overflow
Beaker
Beaker
with
SiO2
STEP 1- Set up your lab materials
to look exactly like this!
H2O
beaker
source
Pour the white silicon dioxide (SiO2-Sand) starting at the stream source
into the stream bed 1mm thick. (Just enough to cover the bottom of the
stream)
Continue pouring the sand all the way down
to the mouth of the river where it will form a
delta.
Fill a graduated cylinder to
100 ml and the overflow
beaker to bottom of the
spout.
Mississippi Watershed
Continue to pour the water into the
overflow beaker, without filling it to the
point where water escape the top edge.
Continue to pour until the graduated
cylinder is empty.
Observe the patterns carved by the water
movement into the sand and answer the
following questions on the data sheet.
(Next slides)
Copy and paste this into Internet explorer (i.e.)
http://polaris.umuc.edu/cvu/envm/hydro/hydrologic-flash.html
Use the information given in the
previous Power Point slides to answer
the following questions.
The map below shows a meandering river. Points A and B are locations on the banks
of the river.
1. What are the dominant processes occurring at locations A and B?
(1) deposition at location A; erosion at location B
(2) erosion at location A; deposition at location B
(3) deposition at both locations A and B
(4) erosion at both locations A and B
The diagram below shows points A, B, C, and D on a meandering stream.
2. At which point does the
greatest stream
erosion occur?
(1) A
(2) B
(3) C
(4) D
3. The block diagram
to the right
represents a deeply
eroded dome.
4.
5. Compared to the stream velocity between point X and point Y, the stream
velocity
between point Y and point Z is most likely
(1) greater, since the slope of the land decreases
(2) greater, since the slope of the land increases
(3) less, since the slope of the land decreases
(4) less, since the slope of the land increases
6. The map to the right
shows a meandering
river. A–A′ is the location
of a cross section. The
arrows show the
direction of the river flow.
The cross section below illustrates the general sorting of sediment by a river as it
flows from a mountain to a plain.
7. Which factor most likely caused the sediment to be sorted in the pattern
shown?
(1) velocity of the river water
(2) hardness of the surface bedrock
(3) mineral composition of the sediment
(4) temperature of the water
8. The diagram to the right, shows a meandering
stream.
At which two locations is the rate of erosion
greater than the rate of deposition?
(1) A and B
(2) B and C
(3) C and D
(4) D and A
9. A decrease in the velocity of this stream
will most likely cause an increase in
(1) the amount of sediment carried by the stream
(2) the size of the particles carried by the stream
(3) deposition within the stream channel
(4) abrasion of the stream channel
10. During transport by this river, a sediment particle
will most likely become
(1) more rounded
(2) more dense
(3) heavier
(4) larger
11. Which change would most likely increase the velocity of the river?
(1) a decrease in the slope of the river
(2) a decrease in the temperature of the river
(3) an increase in the river’s slope
(4) an increase in the width of the river
The graph to the right shows the
percent by mass of the earth’s
crust. Each letter represents an
element.
11. Which elements are
represented by letters a and b
respectively?
(1) aluminum and iron
(2) calcium and nitrogen
(3) potassium and sodium
(4) oxygen and silicon
12. The two most abundant elements by mass in
Earth’s crust are oxygen and
(1) potassium
(2) hydrogen
(3) nitrogen
(4) silicon
13. Which graph to the right
best shows the radioactive
decay of carbon-14?
The diagram represents the landscape features associated with a
meandering river. Letters W, X, Y, and Z represent locations on the floodplain.
14.
A stream entering a lake deposits sediments on
the lake bottom in the pattern shown on the map
below.
15. Which corner of the map is nearest to the point
where the stream flows into the lake?
(1) northeast (NE)
(2) northwest (NW)
(3) southeast (SE)
(4) southwest (SW)
16. Which profile best shows the general depositional pattern that occurs when
water from a stream enters the ocean?
The diagram to the right shows a
meandering stream flowing across
nearly flat topography and over loose
sediments.
17.
18. The gases in Earth’s early atmosphere
are inferred to have come primarily from
(1) meteor showers
(2) melting of glacial ice
(3) volcanic eruptions
(4) evaporation of seawater
The map below shows the path of a river. The
arrow shows the direction the river is flowing.
Letters A and B identify the banks of the river.
19. The water depth is greater near bank A than
bank B because the water velocity near bank A is
(1) faster, causing deposition to occur
(2) faster, causing erosion to occur
(3) slower, causing deposition to occur
(4) slower, causing erosion to occur
The cross section below shows a stream flowing downhill. Points A through
D are locations in the stream.
20. At which point would the most
deposition occur?
(1) A
(2) B
(3) C
(4) D
21. Which cross section
along line XY best
represents the shape of
the stream bottom?
The diagram shows a section of a meander in a
stream. The arrows show the direction of stream
flow.
22. The stream bank on the outside of this meander is
steeper than the stream bank on the inside of this
meander because the water on the outside of this
meander is moving
(1) slower, causing deposition
(2) faster, causing deposition
(3) slower, causing erosion
(4) faster, causing erosion
23. The map below shows a river emptying
into an ocean, producing a delta. Which
graph best represents the relationship
between the distance from the river delta
into the ocean and the average size of
sediments deposited on the ocean floor?
Diagrams A, B, and C represent three different river valleys.
24. Which bar graph best represents
the relative gradients of the main rivers
shown in diagrams A, B, and C?
The map below shows the bend of a large meandering
stream. The arrows show the direction of stream flow.
Letters A, B, and C are positions on the streambed where
erosion and deposition data were collected.
25. Which table best represents the locations where
erosion and deposition are dominant
and where an equilibrium exists between the two
processes? [A check mark (✓)
represents the dominant process for each lettered
location.]
The students in the diagram above are about to do a river study
What two techniques could they use to gather information about
the characteristics of the river at AB on the sketch?
Justify your choice of techniques.
Here is an example of a possible response:
Data- They could measure the depth every 50 cm across the section.
Reason- to see if the channel is deeper on the outside of the bend
Data- They could use a float to measure the speed of the inside and outside of the bend.
Reason- to see if water flows faster on the outside of the bend
Data- They could take a sketch or photograph at points A and B.
Reason- to show the contrast between river cliffs and slip off slopes
(Notice how the answers relate to the information in the sketch.)