Download Plate Tectonics Webquest (9/16) - Liberty Union High School District

Name: _____________________________________________ Date: _____________________________ Period: ______
Plate Tectonics Webquest
Earth’s Structure Review
Use your notes and http://www.learner.org/interactives/dynamicearth/structure.html to answer the following review
questions.
1. Label the layers of Earth in the diagram to the right.
2. The lithosphere is made up of the ______________
and a tiny bit of the ___________ _____________.
3. The plates of the lithosphere move (or float) on this
hot, malleable ______________ ______________
zone in the upper mantle, directly underneath the
lithosphere. This is known as the ______________.
4. The layer of Earth that is the only liquid layer is the
___________________ _____________________.
Types of Plate Boundaries
There are three types of plate boundaries and a fourth, “plate boundary zone” in which the type of plate boundary is not
clearly identified. Use the website: http://www.learner.org/interactives/dynamicearth/plate.html to answer the
following questions.
5. The place where two plates meet is called a _____________________ and they have different names depending
on how the plates are moving in relationship to one another.
a. What are the three types of boundaries? Sketch the direction of plate movement for each and list
example(s).
Collision! Use the website: http://www.learner.org/interactives/dynamicearth/slip.html to answer the following
questions.
6. What happens are convergent boundaries?
These events are linked to the types of plates (_________________ or ________________) that are interacting.
7. At some convergent boundaries, an oceanic plate collides with a continental plate. What happens between the
plates and why?
8. Define subduction zone: _______________________________________________________________________
and trench: __________________________________________________________________________________
9. What is a volcano and how is it formed?
10. What happens when two continental plates collide?
11. What happens at divergent boundaries?
12. What is seafloor spreading?
13. What is a rift and how is it related to plate formation?
14. What is unique about transform boundaries compared to convergent or divergent? What does it result in?
15. What is an earthquake?
Take the “plate interatives challenge” to quiz yourself and identify vocabulary/concepts you will need to review
further.
To review the effect of earthquakes on the environmental and humans, use the following interactive to review the
vocabulary: http://www.iknowthat.com/mhscience/Earthquakes/Fixed.htm
16. What is the epicenter of an earthquake?
17. Why are fault zones (areas where earthquakes are common) also called areas of seismic activity?
18. What is a seismograph and how is it related to the Richter scale?
DO THE MATH: Plate Movement
If two cities lie on different tectonic plates, and
those plates are moving so that the cities are
approaching each other, how many years will it take for
the two cities to be situated adjacent to each other?
Los Angeles is 630 km (380 miles) southeast of
San Francisco. The plate under L.A. is moving
northward at about 36 mm per year relative to the
plate under San Fran. Given this average rate of plate
movement, how long will take for L.A. to be located
next to San Fran?
The distance traveled is 630 km, and the net
distance moves is 36 mm per year. We can use this
formula to determine the answer:
time = distance
rate
630 km = 630,000 m = 630,000,000 mm
630,000,000 mm = 17,500,000 years
36 mm/year
We could also put these dimensional
relationships together as follows and then cancel units
that occur in both the numerator and the denominator.
We are left with an answer in number of years:
630 km x 1000 m x 1000 mm x 1 year = 17,500,000 years
1 km1 m
36 mm
It will take about 18 million years for Los Angeles to be
located alongside San Francisco.
19. If a tectonic plate moved 25 km in a million years, how many cm does it move each year?
20. Assume a city on that plate (City A), is located 390 km away from City B (located on another plate). How long will
it take for the cities to be adjacent to each other? (Convert km to cm, and use the rate from question 1 to solve the
problem).