General

Question 0

Wegener’s Evidence?

Answer 0

The fit of Africa and South America. - gaps due to erosion and overlaps due to deposition.
Glaciation: only makes sense if continents were together.
Measosauras fossils: found in Africa and South America. Gap to large to swim and no land bridges.

Question 1

What is Alfred Wegener’s theory of continental drift?

Answer 1

All continents were joined together called Pangea.
Then split into 2 continents Laurasia, and Gondwanaland.
Split into many continents.

Question 2

Palaeomagnetism?

Answer 2

Continental drift evidence.
Magnetic material in solidified rocks points north.
The earth magnetic field rotates, making the rocks point in opposite directions.
This is symmetrical on both sides which shows the plates are moving apart.

Question 3

Hot spots

Answer 3

Intraplate
Surface manifestations of magma that rises to the surface.
Punches through the lithosphere.
Chain of volcano’s.
Lithosphere moves volcano of hotspot - extinct.
Example Hawaii
Eroded down into seamounts and guyots.

Question 4

Horst and grabben

Answer 4

Tectonic plates diverge apart due to rising magma and convection currents.
Grabben subsides due to gravity.
Magma may rise up faults, leading to volcanic activity.
Shallow earthquakes.

Question 5

Converging plate boundary

Answer 5

Subduction: less dense plate carried under another.

Convection currents carry plates towards one another.

Question 6

Oceanic - continental

Answer 6

Subduction of oceanic plate as less dense.
Partial melting of oceanic plate.
Less dense magma rises, through weakness in the rock.
Forms volcano on surface.
Volcano explosive because high silica magma (andesitic)

Question 7

Features of convergent plate boundaries?

Answer 7

Benioff zone: earthquakes (friction)
Deep ocean trench
Batholiths: magma cooled below surface.
Volcano

Question 8

Primary waves

Answer 8

Travel the fastest.
Are compressional waves.
Can travel through solids and liquids.

Question 9

Secondary waves

Answer 9

Body waves.
Transverse waves.
Arrive behind P waves.
Cannot travel through liquids.

Question 10

Surface waves?

Answer 10

Love and reyleigh.
Long waves, more damaging, as closer to the surface.
(L) vibrate ground sideways.
(R) causes a ground rolling motion.

Question 11

Focus and epicentre

Answer 11

Focus: point within the earth where the pressure was released/ earthquake occurred.
Epicentre: the point on the earths surface, directly above the focus.

Question 12

Difference between richter and mercalli scale?

Answer 12

Richter: measures the magnitude of an earthquake.
Mercalli: measures the intensity of an earthquake.

Question 13

Earthquake consequence: TSUNAMI

Answer 13

Earthquakes cause a large displacement of water. Which causes waves traveling high and fast.
Causes loss of lives, destroyed infrastructure, and spread of disease.

Question 14

Earthquake consequences: LANDSLIDES

Answer 14

Vibrations from earthquakes cause sediment on hills to collapse.
Can lead to deaths, loss of possessions, and homes destroyed.

Question 15

Earthquake consequences: LIQUEFRACTION

Answer 15

Vibrations cause sediments to act as liquids, and objects above will sink.

Question 16

Earthquake consequences: BUILDINGS DESTROYED.

Answer 16

Poorly built buildings can pancake which leads to death

Causes homelessness and loss of possessions.

Question 17

Earthquake consequences: pipelines destroyed

Answer 17

Could contain water, electricity and gas.

Could lead to a spread of disease, explosions and spread of fires.

Question 18

Earthquake consequences: INFRASTRUCTURE DESTROYED

Answer 18

Roadways destroyed prevents supplies getting into an effected area.
No medical supplies, services, food, and water can get into the area.