Download Objective: Students will diagram faults, waves and volcanoes in

3­28­29­11.notebook
3/28(A) & 3/29(B)
March 25, 2011
pg.8a
Faults, Volcanoes, and Earthquakes
Objective: Students will diagram faults, waves and volcanoes in relation to the plates in the Earth.
Due today: 3.3 Study Guide
Warm-Up:
Skim pages 120B-127B to answer the following
questions.
1. How is an earthquake magnitude scale related to
the amounts of energy released by earthquakes?
2. What are the major dangers to people from an
earthquake?
3. Name three methods of improving a building's
safety before an earthquake.
4. If you lived in an area where earthquakes were
common, what could you do to make your room
safer?
Mar 18­4:13 PM
Class­work:
1. Warm­Up/Discuss
2. Introduce Earthquake Proof Building Project
3. Discuss 3.3 Notes
4. Yellowstone Power Point
5. Chapter 4 & 5 Questions
Mar 18­4:20 PM
• The world's longest ridge, the ______________________ runs the length
of the Atlantic Ocean.
• Here the North and South American plates are moving away from the
_______________ and ________________ plates.
• The rift valley is 15 miles wide and 6 miles deep. Deeper than the
______________________.
Sea Floor Rock and Magnetic Reversals
• The Earth's geographic and magnetic poles are not in the same place.
• Earth's magnetic poles ______________ places every so often. The
North Pole becomes the _____________________ and the South Pole
becomes the __________________.
• The switch in direction is called a __________________________.
• What causes these reversals?
____________________________________________________________
____________________________________________________________
• Does this cause the Earth's geographic poles to change place? _____
Oct 20­11:03 AM
Mar 18­4:15 PM
3.3 Notes: Plate Move Apart
Tectonic Plates have different boundaries.
Three types of boundaries are:
1. divergent boundaries = occur where plate move ___________
Where are most of these boundaries found? __________
2. convergent boundaries (mountains/subduction) = occur where plates
____ _____________.
3. transform boundaries = occur where plates _________ past each
other.
The sea floor spreads apart at divergent boundaries.
• ________ _______________ = a gap formed when ridges continue to
widen (molten material rises to build ________________)
Mid Ocean Ridges and Rift Valleys
• mid ocean ridges are the ______________ chain of mountains on Earth
• most contain a ____ _____________ along their center
• Rift Valleys form as plates move ______________
• Rising magma fills the crack, and the rock cools.
• As more magma flows into the crack, the rock splits, is pushed aside and
produces ___________ on either side of the rift valley.
Oct 20­10:54 AM
• Scientists found that each magnetic reversal is recorded in the
__________________________.
• As molten material rises and cools, some magnetic minerals
________________ with the Earth's magnetic field.
• When the material hardens, these minerals are fixed in place like
tiny ________________ pointing north and south.
• Whenever the magnetic field changes, the cooling minerals
_____________ the change.
• The records of _______________________ line up like stripes in
the rock.
• The records are the _________ on either side of the ridge.
• The oldest rock record reversals happened more than
___________ years ago.
Diagram:
Oct 20­11:07 AM
1
3­28­29­11.notebook
Continents split apart at divergent boundaries.
• Like the sea floor, continents also spread apart at a
__________________________.
• The boundary begins to form when hot material rises up
from deep in the ____________.
• Heat causes the crust to bulge _____________.
• The crust cracks as it _______________ and a __________
______ forms.
• Magma rises through the cracked, thinned crust forming
_________________.
• As the rift valley grows wider, the continent begins to
_________________.
• If the rift valley continues to widen, the thinned valley floor
_______ lower until it is ___________ sea level.
• Water from nearby oceans or rivers may fill the valley
forming a ___________ or a ___________.
Oct 20­11:11 AM
Chapters 4 & 5
1. Earthquakes occur along faults.
Draw an example of each type of fault-normal, reverse and
•
strike-slip-Be sure to include arrows in your drawing.
What type of fault is shown in the picture on page 132B (left
•
side of the page)? How do you know?
2. Draw and label the diagram on page 112B.
3. How do scientists locate an Earthquake? (pg.117B)
4. Why do most earthquakes occur at or near tectonic plate
boundaries?
5. Most mountains form along plate boundaries. Draw a Venn
diagram comparing and contrasting Folded Mountains with FaultBlock Mountains.
6. Where are most volcanoes located and why are they located
there?
7. What is the relationship between volcanoes and subduction
zones in the Ring of Fire?
8. Name and describe the materials that come out of a volanco?
Mar 19­2:14 PM
March 25, 2011
Hot Spots can be used to track plate movements.
• Hot spots = heated rock rises in plumes or thin columns from
the _______________.
• ______________ often develop above the plume (a stream of
magma rising from the mantle)
• hot spots generally stay in one place while the
____________________ above it keeps moving (hot spots offer a
way to measure plate __________________)
• if a plate stays in a hot spot long enough, the rock above it will
_________________
• in time, a volcano will form at the surface of the plate
Oct 20­11:16 AM
Homework:
• Finish Chapter 4 & 5 Review Questions at home.
Mar 19­2:10 PM
2
Attachments
08.Earthquakes_and_Earths_Interior.ppt