volcanoes and earthquakes

Question 1

What are plates created from?

Answer 1

Molten magma coming to the surface and they are made of all different types of rocks

Question 2

What is the crust divided into?

Answer 2

Plates like a jigsaw puzzle

Question 3

Name some features of the core?

Answer 3

Very dense, very hot, inner core solid, outer core liquid

Question 4

Name features of the mantle?

Answer 4

solid, dense, heat from the core moved through it

Question 5

name features of the crust?

Answer 5

outermost layer, low density, easily folded, variable thickness

Question 6

name features of the lithosphere?

Answer 6

crust+ upper part of the mantle, low density, brittle, oceanic and continetal

Question 7

name features of the asthenosphere?

Answer 7

part of the upper mantle, high density, has convection currents, when convections diverge new lithosphere when they converge lithosphere destroyed

Question 8

Constructive

Answer 8

divergent plates=new lithosphere
e.g. N. plate & Eurasian plate
Earthquakes yes= low magnitude due to magma rising
volcanoes yes= new crust, non-explosive, lots of lava

Question 9

Destructive: subduction zone

Answer 9

convergent plates= continental & oceanic
Nazca plate & S. American plate
earthquakes=yes really high magnitude the highest earthquakes have happened on subduction zone Chile (9.1)
volcanoes= yes extremely explosive, pyroclastic flows, lahars, little lava, ash, gas usually blast the top of the volcanoe

Question 10

Destructive: island arc

Answer 10

convergent plates= 2 oceanic
Caribbean plate+ N. American plate
earthquakes and volcanoes are same as subduction

Question 11

Destructive: collision zone

Answer 11

convergent plates=2 continental
Indian plate + Eurasian plate
Earthquakes yes=any magnitude but the higher they are the less frequent they are
volcanoes yes= little volcanic activity, little lava and fire fountains

Question 12

conservative/transform

Answer 12

2 plates slide side by side
N. American + pacific plate
earthquakes yes = quite frequent can have a high magnitude though
No volcanoes

Question 13

hot spots oceanic

Answer 13

plume of magma very close to the centre of the oceans surface
Hawaiian islands
earthquakes yes = low magnitude and infrequent due to rising magma
volcanoes yes=produces large volumes of lava, activity continuous

Question 14

Hot spots continental

Answer 14

plume of magma rising the surface of the centre of a continental plate
yellow stone park
earthquakes yes =but infrequent and low magnitude
volcanoes yes= infrequent but are super volcanoes produce loads of different types of lava

Question 15

What is a pyroclastic flow?

Answer 15

gas, ash large lumps of lava traveling at 200kph at

up to 100 Celsius

Question 16

What are lahars?

Answer 16

volcanic mud flows formed when ash mixes with water moving up to 100kph

Question 17

What does the sinking oceanic plate create?

Answer 17

ocean trench

Question 18

how is an earthquake formed in a subduction zone?

Answer 18

two of the plates stick together then they build up pressure and then a sudden jerk happens causing an earthquake.

Question 19

What is the name of where the melting occurs?

Answer 19

Benioff zone

Question 20

what can rise through the continental crust?

Answer 20

plutons it is very light and full of gas

Question 21

what is formed when some plutons reach the surface?

Answer 21

volcanoes

Question 22

due to the continental plate being less dense than the oceanic plate what is formed?

Answer 22

The continental plate crumbles forming fold mountains

Question 23

explain how fold mountains are formed

Answer 23

starts as a collision zone the ocean basin becomes narrower until no oceanic crust was is left and the two continental collide which = fold mountains

Question 24

how are islands formed?

Answer 24

2 oceanic plates subducts but the non subducting plate does not fold but volcanoes occur forming a curving line of islands

Question 25

What is the epicentre & focus?

Answer 25

the focus is the point where the earthquake occurred. The epicentre is the point on the earths surface immediately above the focus

Question 26

What is used to measure an earthquake?

Answer 26

seismometer

Question 27

what is attached to the seismometer?

Answer 27

Seismograph which produces a time based trace of the earthquakes movement

Question 28

how many seismometers do you need to pin point an earthquake?

Answer 28

3

Question 29

What are the names of the scales that magnitude can be measured on?

Answer 29

Richter scale and the mercalli scale

Question 30

explain the Richter scale

Answer 30

based on the amount of energy released an increase of 1 equals 30 times more energy released

Question 31

explain the mercalli scale

Answer 31

based on the observation of damage caused infinite scale