Transcript Inquiry 15.3 – data table, procedure

Inquiry 15.3
Investigating Faults With Models
PROCEDURE
1. Discuss with your group what you already
know about faults. What questions do you
have about faults?
2. Look at the Fault Laboratory. You will use
this model to investigate movement along a
fault where blocks of rock slide past one
another. What do you think will happen
when a force is applied to the blocks?
Discuss your hypothesis with your group.
3. Work with your group to design an
experiment that demonstrates how
frictional resistance along a fault
affects how rock moves during an
earthquake. Record the materials and
procedure you will use, how you will
control all variables except the one
you are testing, what you will look for,
and what you will measure.
4. Note that you will con- duct trials with
no Velcro strips and with one, two, and
three strips.
5. Collect your materials. Use Figure 15.8 to set
up your Fault LaboratoryTM. Check that each
of the following steps is completed:
a. Carefully place the block with the hole so
that the long strip of soft, looped Velcro is
facing the “fault.” Use the bolt, washers, and
wing nut to fix, or secure, the block with the
hole to the box.
b. Notice how each side of the block has a
different number of strips of “hooked” Velcro.
For each test, you will rotate the block so
there is more hooked Velcro (or frictional
resistance) between the two blocks.
C. Slide the solid block (with no hole) in place
next to the fixed block. Make certain the soft
loop Velcro on both blocks is touching and
secure. Use one to two tongue depressors as
spacers between the tote tray and solid,
unfixed block only if the blocks are loose. This
will push the blocks together
D. Make a loop or tightly knot the cord to the
hook on the solid, unfixed block.
E. Use a loop or tightly knot the cord to the
spring scale.
6. Pull on the spring scale, which will
apply a sliding force to the unfixed
block. How much force do you have to
apply to the block before the fault
ruptures (that is, before the block moves
abruptly)? Record the maximum force in
your data table under “0,” since you are
not using any hooked Velcro on the
blocks, and there is very little frictional
resistance along your fault. Conduct
three trials.
7. Now rotate the unfixed block so there is one
strip of hooked Velcro along the fault. Repeat
Procedure Step 6. Conduct three trials.
Record your force data each time under “1” in
your notebook.
8. Now repeat procedure with two strips of
hooked Velcro, recording data under “2” in
your notebook.
9. Finally, rotate the block again and test the
force using three strips of hooked Velcro.
Repeat procedure and conduct three trials.
Record your data under “3” in your notebook.
10. Reset block fixed block to “0” side and clean
up.
REFLECTING ON WHAT
YOU’VE DONE
A. How did the amount of friction along
the fault affect the amount of force
needed to rupture the fault? Use data
to support your answer.
B. B. Under what conditions did the
blocks rupture more abruptly?
C. C. Under what conditions did the block
slip (move slowly) but not rupture?
D. Is there any sign on the earth’s surface
that the earth is moving slowly beneath
the crust? (Look at Figure 15.9 and use
the caption to answer this question.)
E. How would you define the word “fault?”