Download Activity 47: Spreading Plates

Activity 47: Spreading Plates
Activity 48: Other Types of Plate Motion
 Challenge:
 What happens when the earth’s plates move
apart over time?
 What happens as the earth’s plates collide or
slide past each other?
 Key Vocabulary:
 Divergent Boundary
 Convergent Boundary
 Transform Boundary
See these definitions in Activity
45
1. Glue in Students Sheets 47.1 and 48.1 into your
notebooks.
2. Go to the following webpage:
http://sepuplhs.org/middle/iaes/students/simulations/se
pup_plate5.html
To get to this site, you can go to my webpage and on
the left tabs, choose “websites” The link is there
Procedure:
Follow the procedures provided on pages D-49
and D-52 using the webpage.
Make sure you are filling out your Student
Sheets as you are working. We will go over
the answers tomorrow!
When you are finished your need to complete
Analysis questions:
Activity 47: #1-3 on page D-50
Activity 48: #1-3 on page D-52-53
Nothing except
mantle convection
A single earthquake
Slight spreading movement
of continental lithosphere
Several earthquakes along
divergent boundary
Slight rise of magma into center
of continental lithosphere
Several earthquakes
Increased rise of magma into
center of continental lithosphere
Appearance of a valley on earth’s
surface.
Nothing except
mantle convection
NONE
NONE
NONE
Many earthquakes
Magma rising to surface
Appearance of a valley on surface
Oceanic lithosphere begins to form
along divergent boundary
Small amount of water
appears in center of
valley
A lot of earthquakes
Underwater volcanoes form along
divergent boundary as magma rises
2 large volcanic islands form
Oceanic lithosphere is clearly visible @
center of spreading boundary
Valley fills with water,
resulting in what could
either be a lake or ocean
Transform Boundary
Many earthquakes along transform
boundary.
Continental lithosphere of 2 plates
slide past each other
Direction of river begins to change
eventually changing its course
Old course becomes abandoned river
bed.
Convergent (Continent – Continent)
Many earthquakes
Continental plates collide, forming large
mountains and a thicker continental
lithosphere where the plates collide.
Mantle convection continues
NONE
Convergent (Oceanic – Continental)
•
•
•
•
Many Earthquakes
Oceanic lithosphere SUBDUCTS and
melts into mantle, while oceanic
lithosphere of other plate crumples
Magma erupts to surface, underwater
VOLCANOES and eventually
VOLCANIC ISLANDS form
Mantle convection continues.
Entire boundary is within the
ocean.
Activity 47 Analysis:
1. Water between spreading plates comes from surrounding
water and rain. Water always flows to the lowest elevation
2. In this activity, it took at least one million years for a narrow
valley to from and it took 5 million years to observe bigger
changes, such as a wider valley and the formation of the
first volcano.
3. a. In 1,000 years there will still be 7 continents because
plates don’t move that far in 1,000 years.
b. In 20 million years, it may be possible to see some
change in the shape and possibly the number of
continents at that time.
Activity 48 Analysis:
1. At convergent boundaries, geological processes vary due
to the type of lithosphere involved:
Continental-Continental – Pushes both plates up to
make MOUNTAINS.
Oceanic-Continental – SUBDUCTION occurs as more
dense oceanic crust goes below continental crust.
2. A. The formation of the Himalayan Mountains is an
example of a continental-continental convergent
boundary
B. The formation of Greenland, a volcanic island country
in the northern Atlantic Ocean is an example of a
Divergent Boundary
Type of plate
motion
Scientific
term for
boundary
type
Earthquakes
Volcanoes
Mountain
Formation
Colliding
Convergent
X
X
X
Sliding
Transform
X
Spreading
Divergent
X
X
X
(volcanic)