Plate Tectonics-sample answer

Question 1

Plate Tectonics overview

Answer 1

◍ Earth’s surface is constantly changing
◍ theory of PT: helps us understand why crust can be created/destroyed at plate
boundaries
◍ crust contains large sections called plates
◍ 7 major + minor plates

Question 2

Plate Movement

Answer 2

◍ move slowly -being carried along by convection currents in mantle
◍ plates may separate ,collide or slip past each other

Question 3

Destructive plate boundaries

Answer 3

◍ occur in 3 suituations
1. Oceanic +Continental plates collide (pacific +s. American)
2. Two continental plates collide ( Indian+Eurasian colliding)
3. Two oceanic plate collide(Pacific + Philippine plate)

Question 4

Subduction zone
Add Diagram

Answer 4

◍ oceanic plate collides w. continental- the heavier oceanic plate destroyed as it sinks into the mantle(subduction)
◍ Melted crust may rise as magma causing explosive volcanoes ex. Mount st. Helens US at juntion of 2 colliding pates form deep trench

Question 5

Subduction Zones 2

Answer 5

◍ 2 continental plates collided neither will sink- both destroyed by folding +uplifted form himalayes
◍ 2 oceanic plates collide -heavier plate sinks under +is destroyed ex. Island arcs Japan

Question 6

Divergent Plate Boundaries

Answer 6

◍ plates move apart -new land created(divergent/constructive)
◍ occurs mid-oceanic ridges such as Mid Atlantic ridge

Question 7

Sea Floor spreading

Answer 7

◍ North American + Eurasian pull away due to convection currents
◍ this splits crust+magma from mantle-flows out onto seabed+creates new ocean floor
◍ As lava cools forms large chains of undersea volcanic mountains eg.) Iceland