3.1.1.2 Tectonic hazards

Question 1

what is a plate margin

Answer 1

where two plates meet

Question 2

what happens in a constructive plate figure

Answer 2

• two plates moving apart
• magma forces its way to the surface
• rocks crack in the surface, triggering earthquakes
• magma is very hot and fluid, allowing it toflow long distances
• forms broad and flat volcanoes

Question 3

what happens in a conservative plate figure

Answer 3

• two plates rubbing against each other
• stress buulds up
• causes random friction to be released and form earthquakes
• no volcanic activity

Question 4

what happens in a destructive plate figure

Answer 4

• denser plate (ocean) subducts beenath the other
• the friction triggers powerful earhquakes
• viscous magma rises
• forms tall and conical volcanoes
• violent erruptions, producing vast ash clouds and deadly pyroclastic flows

Question 5

what happens in a destructive collision plate figure

Answer 5

• no subduction
• two low density plates collide
• crumbling and uplifting crust
• forms fold mountains
• no volcanoes as there’s no magma

Question 6

why do tectonic plates move

Answer 6

• radioactive decay generates heat, warming the mantle
• hot rock rises towards the surface and cools down
• becomes cooler and denser as it returns to the mantle as it cannot past the crust
• repeats

Question 7

features of an oceanic plate

Answer 7

• relatively newer
• thinner, dense
• basaltic (formed from basalt – a block lava flow)
• contructive margin

Question 8

features of a continental plate

Answer 8

• older
• heavier, thicker
• granitic, formed from granite
• destructive plate margins