Tectonic Plates

Question 1

What is a transform boundary?

Answer 1

They slide past each other in parallel

• the crust is not created or destroyed
• movement is not smooth (stuck and slip)
• they cause earthquakes

Question 2

What is a divergent boundary?

Answer 2

They push in opposite directions

• they cause volcanos and mountains
• they create igneous rock
• mostly found is the ocean creating mountain ranges
• can create islands

Question 3

What is a convergent boundary?

Answer 3

They push together

• when ocean plate meets continental plate subduction occurs (as well as when two ocean plates meet)
• the heavier oceanic plate slide underneath the other plate
• the oceanic crust melts when it meets the mantle forming magma
• volcanos and ocean trenches form

Question 4

What are tectonic plates

Answer 4

• eight large tectonic plates and some small ones
• they make up the earths crust
• they are always moving
• knock, slide, glide

Question 5

Earthquakes

Answer 5

• usually, occur along fault lines or faults where tectonic plates meet
• a natural way for earth to release internal pressure large and small
• impulsive movements create an earthquake at a point called the focus
• form this location seismic waves are sent out in all directions
• where those waves meet the surface above the focus is called the epicenter
• the waves weaken as they travel away
• aftershocks can occur for weeks

Question 6

fault line + examples of fault movement

Answer 6

lines where tectonic plate meet
Thrust fault - plate above to travel upwards
Strike-slip fault - plates move horizontally
Normal fault - the plate above the fault moves down and away

Question 7

Tsunamis

Answer 7

• it is a series of waves
• waves often caused by earthquakes below the sea flour
• the water must be displaced
• when it gets closer to the shore the height of the wave increases

Question 8

Are all earthquakes the same size?

Answer 8

No, because it depends on the size of the movement and size of the plates.

Question 9

What causes the vibrations felt during an earthquake?

Answer 9

-Tectonic plates moving under stress causing massive forces

Question 10

what is the epicenter?

Answer 10

-it’s the surface location directly above the focus

Question 11

How are earthquakes measured?

Answer 11

• In 1935 Charles Richter created a scale from 1-10 and modified in 1977
• earthquake damage in measured using the Modified Mercalli Scale I - XII

Question 12

What happened to Mount St Helens in 1980?

Answer 12

• Mount st Helens is on the boundary of the ring of fire.
• erupted 1980 - devastating
• caused by an earthquake triggering a landslip and volcanic eruption

Question 13

Volcanic eruptions

Answer 13

• 75% all volcanoes and 90% of all earthquakes occur along the Pacific Ring of fire
• the ring stretches about 40000 kilometers and hugs the coast of north and south America, Russia, China, Japan, some Pacific Islands, New Zealand and New Guinea

Question 14

What are two ways lava can alter a landscape?

Answer 14

• hardens to create rocks

- can destroy landmarks