//The Restless Earth

Question 1

what is earths crust and and plates?

Answer 1

Inner core: hot but solid from extreme pressure
Outer corse: hot and molten
Mantle: semi-molten rocks flow in moving currents
Crust: outer shell of earth made of solid rock
Plates colliding: currents of molten rock move plates towards each other = ocean trenches, fold mountains, earthquakes
Plates separating: currents of molten rock drag plates apart, volcanic material rises = volcanic islands, volcanic mountains, mid-ocean ridges

Question 2

How are fold mountains formed?

Answer 2

• Plates collide= tremendous compression where they meet = crust becomes slowly buckled and arches upwards
• Alpine folding, Magillycuddy Reeks

Question 3

Explain what happens when there is in earthquake and what are the effects?

Answer 3

-Earthquakes = plates colliding/slip past each other = rock beneath surface bends and suddenly cracks
-Shock waves spread out from focus (where cracks occur) causing the earth to tremble for several seconds.
-Strongest at epicentre
Effects: Buildings collapse, tsunamis, gas pipes break=fires, roads crack

Question 4

What happens during a tsunami?

Answer 4

Undersea earthquake = powerful, high sea waves (30m high)

Indonesia 2004- 300,000 people killed

Question 5

Explain earthquakes in San Francisco

Answer 5

• Situated where Pacific and North American plates collide
• 1989 earthquake hit 7.1 on Richter scale
• Earthquake-proof buildings and wide roads

Question 6

Explain the mid-Atlantic ridge and volcanic islands and types of volcanos

Answer 6

• Atlantic Ocean= American and African/Eurasian plates move apart
• Island is a volcanic island with several volcanic mountains
• Active volcanos erupt regularly eg. Etna (Italy)
• Dormant volcanos haven’t erupted in a long time but may again (Cotopaxi)
• Extict valances haven’t erupted in historic times (Slemish)

Question 7

What is the pacific ring of fire and how are volcanoes useful?
Parts of volcanos

Answer 7

-Large earthquake and volcanic zone in the Pacific Ocean

Magma chamber -vent -crator

Question 8

Positive/Negative effects of volcanos

Answer 8

Pos: provide nutrients, Volcanic ash contains minerals, very fine ash it is able to break down quickly mix into soil. fetile after lava decomposes
Neg: wreck villages, poisonous gas

Question 9

How are volcanoes formed?

Answer 9

magma from within the Earth’s upper mantle works its way to the surface.
At the surface, it erupts- lava flows, ash deposits.
Over time, volcano continues to erupt, get bigger