Types of plates boundaries

Divergent, Convergent and Transform

EARTHQUAKES EPICENTER

PLATE BOUNDARIES

Types of Plate Boundaries

•Convergent

•Divergent

•Transform

CONVERGENT BOUNDARIES

Act 3. Head on Collision

OBJECTIVES:

•Explain the process that occur along convergent boundaries.

•Determine the consequences of colliding plates.

Act. 3

A.Continental-Oceanic

B.Oceanic-Oceanic

C.Continental-Continental

Before answering the questions choose one and draw a model that shows all its features.

Part A. Continental-Oceanic

• Q15-Q20.

Convergence:Continental Oceanic

Volcanic Activity due to Plate subduction

Remember:

•During the convergence of an oceanic and continental plate, the denseroceanic plate slides under the continental plate. The process is called subduction.

•Geologic events such as formation of volcanoes and trenches as well as occurrence of earthquake will take place because of this process.

Part B: Oceanic-Oceanic

• Q21-Q23.

Part B. Oceanic-Oceanic

Eastern Caribbean

Remember: • When two oceanic plates converge they

also undergo subduction process. This gives rise to the formation of volcanic island arcs, trenches and generates shallow, intermediate or deep earthquakes.

• Strong earthquakes generated at the ocean floor may cause displacement of large volume of water and launch big waves called tsunami.

Part C. Continent-Continent

• Q24-Q27

Part C. Continent-Continent

Continental-Continental: Himalayas

Remember:

•When two continental plates meet head-on, neither is subducted. Instead, the crust tends to buckle and be pushed upward causing formation of mountain ranges and other highlands.

Bring: (by grp)

•Printed photographs of RIFT VALLEYS and OCEANIC RIDGES.

(at least 2 each)

DIVERGENT BOUNDARIES

Act 4: Going Separate Ways

OBJECTIVES:

•Explain the processes that occur along divergent boundaries.

•Determine the results of plates that are moving apart.

Procedure:

•Analyze the photographs/pictures of rift valleys and oceanic ridges you brought, and answer the ffquestions:

Q28. What are common in the four pictures?

Q29. Millions of years ago, the landmasses in each picture were once connected. What do you think is happening to the earth’s crust in those pictures?

Q30. If this event continues for million of years, what do you think will be the effect on the crust?

Q31. Complete the drawing below to illustrate your answer in Q30.

At Present After millions of years

Answer:

Q28-Q31.

Red Sea

Oceanic Divergent Boundary

Mid-Atlantic Ridge

Continental Divergent Boundary

Red Sea / E. African Rift

Continental Divergent Boundary: Baja California

Remember:

•Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle.

Remember:

• Effects that are found at a divergent boundary between oceanic plates include: a submarine mountain range such as the mid-Atlantic Ridge; volcanic activity in the form of fissure eruptions; shallow earthquake activity; creation of new seafloor; and a widening ocean basin.

Remember:

•If a divergent boundary is between continental plates, the effects are: rift valley formation which will soon develop into linear sea; shallow earthquake activities, and numerous normal faults.

Bring the ff: (by group)

4 packs of wafer/biscuit

( 2 wafer same size; another 2 wafer same size)

Masking tape

sandpaper

TRANSFORM BOUNDARIES

Recall: Describe

•Fault

•Faulting

•Reverse Fault

•Transform Fault

•Normal Fault

FAULT

•a fracture, fissure, or a zone of weakness where ground movement or displacement has occurred or may occur again.

FAULTING

• is the cause of TECTONIC EARTHQUAKES

Types of Fault:

Act. 5: Slide and Shake

OBJECTIVE:

•Determine the effect of transform-fault boundary on the Earth’s crust.

Procedure:

1. Create 4 blocks of clay. (2 blocks same size, another 2 same size)

2. Divide and cut the sand paper into 2.

3. Place the sand paper below the blocks of clay. (1 inch bigger-all sides)

4. Arrange the blocks as shown in the illustration belo

Block of Clay

Cut part of the sand paper

(below)

Not included (Pull the sand paper

instead)

5. Slowly pull Blocks 2 and 3 (pull the sand paper) to the direction indicated by the arrow. Observe the motion of the blocks.

Answer the ff. questions after the Act.

Q32. Were you able to pull the blocks of clay easily? Why or why not?

Q33. What can you say about the relative motion of blocks 1 and 2? How about blocks 3 and 4?

Q34. How will you describe the interaction between blocks 2 and 3 as you pull each block?

Q35. What is the interaction between blocks 1 and 3? How about between blocks 2 and 4?

Answer:

Q32-Q35

•Most transform faults join two segments of a mid-ocean ridge (represented by the gaps between 1 and 2, and between 3

and 4). Remember that the presence of a ridge is an indication of diverging plates, and as the plates diverge between the two segments of the mid-ocean ridge, the adjacent slabs of crust are grinding past each other (blocks 2 and 3, blocks 1 and 3, and blocks 2 and 4).

Continental Transform Boundary: San Andreas

Act. 6: Hot Spot

Bring:

Printed copy of Act.6 pages 31-32(grp)

2 sheets of bond paper (grp)

1 bottle denatured alcohol (class)

CAUTION: HOT! HOT! HOT!HOTSPOT!

Make your area free from combustible materials.

Girls should tie their hair.

Be careful in handling the test tube. The mouth is ALWAYS pointing AWAY from anybody.

Handle the alcohol lamp with care. Know how to put the fire off properly.

During the activity....

DON’T TOUCH THE TUBE WITH BARE HANDS!

DON’T PLAY WITH THE FIRE!

DON’T GET BURNED!

Answer: Q36-Q40

Hot Spots

The hotspotis also known as a magma chamber, it is located in the mantle.

The Hotspotthen explodes, creating avolcano.

The plate then moves. Notice the volcano moves with the plate, but the hotspot stays were it was.

The Hotspotthen explodes again, forming a new volcano.

The plate moves again, starting the process over.

Another volcano is then created forming a Volcanic Chain.

Ocean

Hotspot: Hawaii

Remember:

• Transform-fault boundaries are where two plates are sliding horizontally past one another.

•Most transform faults are found on the ocean floor. They commonly offset active spreading ridges, producing zigzag plate margins, and generally defined by shallow earthquakes.