module 6 g10 earth science

1. Quarter 1 – Module 6:
Possible Causes of
Plate Movement

2. Content Standard:
The learners demonstrate an understanding
of the relationship among the locations of
volcanoes, earthquake epicenters, and
mountain ranges.
MELC:
Describe the possible causes of plate
movement
(S10ES – Ia-j-36.5)

3. Guide questions
1. What are the two types of plates?
2. How do plates move?
3. What geologic features are formed?
4. What causes the movement of the plates?

5. Geologic process

6. What is an Oceanic Trench?
◦ Oceanic trenches are
topographic depressions of the sea
floor, relatively narrow in width, but very long.
◦ These oceanographic features
are the deepest parts of the
ocean floor.
◦ These are the distinctive
features of the convergent plate
boundaries.

8. The Philippine Trench (also Philippine Deep, Mindanao Trench,
and Mindanao Deep) is a submarine trench to the east of the
Philippines.
Philippine sea plate subduct beneath Philippine mobile belt
It has a length of approximately 1,320 kilometers (820 miles)
and a width of about 30 km (19 mi) from the center of the
Philippine island of Luzon.
The maximum depth of Philippine Trench is 10,545 m (34,596
ft).

11. Possible Causes of Plate Movement
1.Convection Current
2.Ridge Push
3.Slab Pull

12. Possible Causes of Plate Movement
There are three forces working to move the plates.
1. Convection Current 2. Ridge Push 3. Slab Pull

13. Possible Causes of Plate Movement
There are three forces working to move the plates.
1. Convection Current
2. Ridge Push
3. Slab Pull

14. Possible Causes of Plate Movement
Heated mantle material is shown rising from deep inside
the mantle, while cooler mantle material sinks, creating a
convection current.
It is thought that this type of current is responsible for the
movements of the plates of Earth's crust.
Convection Current

15. Possible Causes of Plate Movement
This process can also take place in the Earth’s mantle. The
temperature difference in the mantle causes the
movement of the molten materials.
The hot, less dense materials rise and the cooler, denser
materials sink.
This process of rising and sinking molten materials is
called MANTLE CONVECTION.
Convection Current

16. Mechanisms for Plate Motion
forces cause two plates to pull apart on the surface.
The lithosphere rocks SLIDE away from the ridge, due to
gravity, down the sloping asthenosphere.
The asthenosphere is less dense than the rocks above it
making it possible for the cooled lithosphere rocks above it
to slide down the slope of the asthenosphere.
Ridge-Push

17. Mechanisms for Plate Motion
The process continues in the ridge where new molten
magma wells up and becomes the new lithosphere.
This force that the rocks exert at the ridge to spread the
lithosphere is called RIDGE PUSH.
Ridge-Push
It refers to the pushing force that plates experience as
they slide down the raised asthenosphere underneath Mid
Ocean Ridges.

18. Mechanisms for Plate Motion
forces pull the plates down.
The force that the sinking plate exerts on the rest of the
plate is called SLAB PULL.
 The edge of the subducting plate is much colder and
heavier than the mantle, so, it continues to sink pulling the
rest of the plate connected to it.
Slab-Pull

19. Mechanisms for Plate Motion
As the plate moves away from the diverging boundary, it
ages and cools, thus becoming much denser.
The cold, dense lithosphere then sinks down into the
asthenosphere (at subduction zones) and "pulls" the rest of
the plate along with it.
Slab-Pull

20. Mechanisms for Plate Motion
Occur only in Mid-oceanic Ridges.
Slab-Pull and Push Ridge

21. Theories of Plate Tectonic Movements
Seafloor Spreading Theory
 proposed by Harry Hess (1960)
 is a geologic process in which tectonic
plates—large slabs of Earth's
lithosphere—split apart from each
other.
 is the mechanism by which new
oceanic lithosphere is created at and
moves away from divergent plate
boundaries.

22. Theories of Plate Tectonic Movements
Seafloor Spreading Theory
 Mantle convection is the slow,
churning motion of Earth’s
mantle.
 Convection currents carry heat
from the lower mantle and core
to the lithosphere.
 Convection currents also
“recycle” lithospheric materials
back to the mantle.
 Seafloor spreading occurs at
divergent plate boundaries.

23. Theories of Plate Tectonic Movements
GUIDE CARD
Seafloor Spreading Theory
 As tectonic plates slowly move away
from each other, heat from the
mantle’s convection currents makes
the crust more plastic and less dense.
 The less-dense material rises, often
forming a mountain or elevated area of
the seafloor.
 Eventually, the crust cracks. Hot
magma fueled by mantle convection
bubbles up to fill these fractures and
spills onto the crust.
 This bubbled-up magma is cooled by
frigid seawater to form igneous rock.
This rock (basalt) becomes a new part
of Earth’s crust.

24. Theories of Plate Tectonic Movements
GUIDE CARD
Seafloor Spreading Theory
 Mid-Ocean Ridges Seafloor spreading
occurs along mid-ocean ridges—large
mountain ranges rising from the
ocean floor.
 The Mid-Atlantic Ridge
 separates the North American plate
from the Eurasian plate, and the
South American plate from the
African plate.

25. Theories of Plate Tectonic Movements
GUIDE CARD
Seafloor Spreading Theory
 The East Pacific Rise is a mid-ocean
ridge that runs through the eastern
Pacific Ocean and separates the
Pacific plate from the North
American plate, the Cocos plate, the
Nazca plate, and the Antarctic plate.
 The Southeast Indian Ridge marks
where the southern Indo-Australian
plate forms a divergent boundary
with the Antarctic plate.

26. Theories of Plate Tectonic Movements
GUIDE CARD
Seafloor Spreading Theory
 The Mid-Atlantic Ridge, for instance,
is a slow-spreading center. It
spreads 2-5 centimeters (.8-2
inches) every year and forms
an ocean trench about the size of
the Grand Canyon.
 The East Pacific Rise, on the other
hand, is a fast-spreading center. It
spreads about 6-16 centimeters (3-6
inches) every year.

27. Seafloor Spreading Theory

28. 1. What geologic features formed at
divergent plate boundaries?
A. mid-ocean ridges
B. convergent rifts
C. seafloor separations
D.none of these are correct

29. 2. What causes ridge-push to occur?
A. hot buoyant mantle beneath the ridge
B. large quantities of volcanic rock near
the ridge
C. Both of these are correct
D. Neither of these is correct

30. 3. What is ridge-push?
A. A force causing plates to move away from
divergent plate boundaries
B. A force causing plates to dive into the
mantle
C. A force causing plates to slide past one
another
D. A force that rips plates apart

31. 4. The mantle of Earth is made
partly of magma. When magma
rises and sinks, this is called
______________.
A. ion current
B. a hot spot
C. a volcanic eruption
D. a convection current

32. Seafloor Spreading Theory
1. What causes ridge-push to occur?
1.hot buoyant mantle beneath the ridge
2.large quantities of volcanic rock near the ridge
3.Both of these are correct
4.Neither of these are correct
• .
• Scientists think that convection currents that move the plates
flow in Earth's
• answer choices
• Continental crust
• Oceanic crust
• mantle
• outer core

33. 5. When the force of gravity pulls a
lithospheric plate downward and away
from a ridge pushing it toward a trench.
A. Sea Floor Spreading
B. Subduction
C. Ridge Push
D. Slab Pull