HAZARDOUS EARTH

Question 1

What is the outer core made of

Answer 1

iron and nickel

Question 2

What is the mantle made up of

Answer 2

Silicon based rocks

Question 3

The part of the mantle nearest the core is

Answer 3

quite rigid

Question 4

the layer of the mantle away from the core is

Answer 4

called the asthenosphere

semi molten

Question 5

at the very top of the mantle it is

Answer 5

rigid again

Question 6

the crust is made of

Answer 6

silicon based rocks again

Question 7

explain the 2 types of crust

Answer 7

oceanic - thinner, more dense

continental crust - thicker, less dense

Question 8

the crust is divided into

Answer 8

slabs called tectonic plates

Question 9

why do tectonic plates move

Answer 9

the convection currents cause drag on them

Question 10

the three types of plate boundary

Answer 10

convergent
divergent
conservative

Question 11

convergent boundary

Answer 11

oceanic plate is forced under continental one

forced into the mantle and destroyed

creates volcanoes and ocean trenches

Question 12

what plate boundary makes mountain ranges

Answer 12

usually convergent, the ground is folded and forced upwards

Question 13

example of convergent plate boundary

Answer 13

along the west coast of south africa

Question 14

divergent plate boundary

Answer 14

theyre moving away from each other.

magma rises through gap and cools to make new crust

Question 15

example of divergent plate boundary

Answer 15

mid atlantic ridge

Question 16

conservative plate boundary

Answer 16

two plates slide past each other

either opposite directions or different speeds

Question 17

example of conservative plate boundary

Answer 17

west USA coast

Question 18

how are volcanoes made by convergent and divergent plates

Answer 18

convergent:

pool of magma forms
rises through cracks/vents
magma erupts onto the surface

divergent:

rises through gap
when erupt, it emits lava and gases. some emit lots of ash, which can cover land and block the sun and form pyroclastic flows.

(super heated currents of gas ash and rock)

Question 19

how are volcanoes found away from boundaries?

Answer 19

plume of hot magma from mantle moves towards surface

creates unnaturally large flow of heat from mantle to crust

sometimes it can break through crust and reach surface

theres an eruption and a volcano is made

Question 20

composite volcanoes

Answer 20

form at convergent boundaries

subducted oceanic crust has allota water. the water reacts with magma and creates gases, which causes subducted crust to erupt

they have:

explosive eruptions
ashy explosions
andesitic lava
high silica content
thick
sticky
lava cant flow far, so its steep sided

Question 21

shield volcano

Answer 21

occur at hotspots or divergent boundaries

not explosive, only lava

they have:

basaltic lava
low silica content
runny
flows quickly
spreads a wide area
low gentle volcano

Question 22

what is an earthquake

Answer 22

sudden jerks of plates moving due to tension built up

Question 23

scale for earthquakes

Answer 23

moment magnitude scale

Question 24

ways to predict earthquakes

Answer 24

lasers for tectonic movement

seismometers feel vibrations in earth crust

measure gases that escape from cracks in crust

rocks will crack and expand due to pressure before a quake

Question 25

ways to predict volcanoes erupting

Answer 25

change in shape due to magma building up

tiny earthquakes

thermal imaging cameras, temp increases before erupting

analyse gases escaping from volcano, emits lots of gas before

Question 26

what can wealthier countires do to prepare?

Answer 26

emergency service practise

buildings designed to withstand
(reinforced concrete/special foundations)

people educated

governments plan evac routes

emergency supplies stockpiled

Question 27

short term relief after disaster

Answer 27

food, drink shelter
recover dead bodies(disease)
treat victims
rescue those trapped
provide supplies gas, electricity