Tectonic Landscapes

Question 1

Describe the pattern of earthquake and volcano distribution

Answer 1

The two are often found in the same places, they tend to occur in narrow bands that are found:
in the middle of oceans eg. Atlantic
along the edges of continents eg. west coast of America

Question 2

What is a hotspot and an example?

Answer 2

A hotspot is a place where very hot magma rises within the mantle to the crust, but not necessarily at a plate boundary
An example is the Hawaiian Islands in the Pacific Ocean

Question 3

What causes plates to move?

Answer 3

Plates are moved by convection currents that form in the mantle when hot magma rises and pushes cooler magma down in a repeating cycle. These currents will drag the places in different directions.

Question 4

What are the three types of plate boundaries (both names)?

Answer 4

Convergent/destructive
Divergent/constructive
Conservative/transform

Question 5

What are the characteristics of the different types of convergent (destructive) plate boundaries and examples?

Answer 5

Two oceanic: denser one subducts below, volcanoes occur and volcanic islands. eg Pacific plate subducting below Phillipines plate

Oceanic-continental: oceanic plate dragged down, forms volcanoes(weaknesses), fold mountains and earthquakes . eg. Nazca plate conversing below South American plate

Two continental: both pushed up, leads to earthquakes and fold mountain ranges. eg. Eurasian plate and Indo-Australian plate (Himalayas)

Question 6

What is evidence for continental drift?

Answer 6

1. rock patterns-same layer patterns found in different continents
2. fossil evidence- same fossils in different continents
3. continent shape- can fit together like a jigsaw

Question 7

What are the characteristics of a divergent plate boundary+ example?

Answer 7

two plates move apart and new crust is created
less violent earthquakes and volcanoes occur
Oceanic:new sea floor is created eg. mid-Atlantic ridge
Continental: rift valley created eg. east Africa

Question 8

What are the characteristics of a conservative plate boundary + example?

Answer 8

two plates sliding past each other
no crust destroyed or created (no volcanoes)
plates get stuck and cause earthquakes
eg. North American plate and Pacific plate (San Andreas Fault, California)

Question 9

What scales can be used to measure earthquakes?

Answer 9

The Richter Scale and The Mercalli Scale

Question 10

What is the Richter Scale?

Answer 10

measures the magnitude of an earthquake
is logarithmic (each number 10 times bigger)
no upper limit
seismometers are used

Question 11

What is the Mercalli Scale?

Answer 11

measures effects, impacts and damage caused by an earthquake

goes from I-XII (1-12)

Question 12

What is the epicentre?

Answer 12

The point on the ground directly above the focus

Question 13

What is the focus?

Answer 13

central point where earthquake happens, deep under ground

Question 14

How do volcanoes negatively affect people?

Answer 14

destroys buildings, crops, bridges, roads, railways
disrupts communication
disrupts air travel
can kill people and other living things

Question 15

Why do people live near volcanoes?

Answer 15

1. Geo-thermal energy- steam from underground for power. Iceland- cheap and kind to environment
2. Fertile soil- rich in nutrients, ideal for farming eg. Sicily farming on Mount Etna slopes
3. Tourism- creates many jobs, work in hotels etc. (hot springs and geysers) eg. blue lagoon in Iceland
4. Valuable resources- lava contains minerals eg. gold, silver, diamonds, copper

Question 16

Why do people live in earthquake zones?

Answer 16

1. Hi-tech industry- high income, big companies eg. California (Apple)
2. Attracted to landscape- climate, beaches, surfing: good summers(low rainfall) and mild winters (10 degrees)
3. High standard of living- lots of work available, high quality medical care, education and services

Question 17

CASE STUDY of an volcano eruption

Answer 17

The chances peak, soufriere hills, Montserrat
an island in the Caribbean(british overseas territory)
erupted in 1995 and 1997
huge quantities of lava, ash and pyroclastic flows

Question 18

What is a pyroclastic flow?

Answer 18

high speed clouds of hot gases,ash and rock fragments at up to 600 degrees celsius

Question 19

What were the social effects of the Montserrat eruptions?

Answer 19

twenty three people died
half the population evacuated
half population eventually left the island
southern exclusion zone

Question 20

What were the environmental effects of the Montserrat eruptions?

Answer 20

two thirds of island covered in ash
crops and animals destroyed
fires caused in forests by volcanic gases igniting
rivers flooded because they were blocked with ash

Question 21

What were the economic effects of the Montserrat eruptions?

Answer 21

the port and airport were closed
affect the tourist industry
people had to leave jobs and businesses

Question 22

What were the responses to the Montserrat eruptions?

Answer 22

£41 million in aid was donated by british government
money was given to people to help them move away
montserrat volcano observatory was set up to monitor the volcano
risk assessments were undertaken to help locals prepare for future eruptions

Question 23

How and why is Montserrat tectonically active?

Answer 23

convergent destructive plate boundary
atlantic plate being forced under caribbean plate
oceanic plate is denser

Question 24

how difficult is it to predict when are where a tectonic event will occur

Answer 24

volcanoes are easier to predict
high risk areas are constantly monitored
earthquakes are harder to predict as they do not occur at a single visible point

Question 25

How can volcanoes be monitored?

Answer 25

gas monitoring
ground deformation
ground vibrations
slope angle monitoring