Y9 exam

Question 0

Why do earthquakes occur?

Answer 0

Due to movement of earth’s plates. Friction and pressure cause it.

Question 1

Where do earthquakes occur?

Answer 1

Found along plate boundaries+major fault lines
Around African plate
Edge of Indo-Australian plate
Linear formation around West coast of America
Clustered in a linear pattern+long narrow belts
Hotspots eg Hawaii
Anomalies- within plates eg Eurasian-China

Question 2

What is the focus? Are deep or shallow focuses more effective?

Answer 2

The point where earthquakes originate, deep focuses cause less damage and are less felt than shallow.

Question 3

What is the epicentre?

Answer 3

The point directly above the focus, where the earthquake is most felt.

Question 4

What are shockwaves?

Answer 4

Seismic waves generated by an earthquake that move through the earth’s crust, travel out from the focus.

Question 5

Describe the primary waves

Answer 5

The first waves that travel fastest and cause back and forth movement.

Question 6

Describe secondary waves

Answer 6

They are slower and cause side to side movement

Question 7

Describe longitudinal waves.

Answer 7

They cause up and down movement

Question 8

Describe transverse waves.

Answer 8

Cause side to side movement which causes much damage.

Question 9

What is the Richter scale?

Answer 9

A logarithmic scale that measures the strength or magnitude of an earthquake. The number after is after is 10x more powerful than the one before

Question 10

What is the Mercalli scale?

Answer 10

A scale that is used with Roman numerals

Question 11

What is a fault line?

Answer 11

Line along tectonic plates slowly move towards or away from each other

Question 12

What are seismic waves?

Answer 12

A wave produced by an earthquake (usually) Earthquakes energy is released in seismic waves.

Question 13

What are the 3Ps that reduce impact of earthquakes?

Answer 13

Prediction- forecast when an earthquake will happen
Preparation- hospitals, emergency services, inhabitants practicing drills
Protection- building to an appropriate standard

Question 14

Give an example of an MEDC (more economically developed country) country, when it happened, the population and it’s magnitude on the Richter scale.

Answer 14

Kobe- Japanese earthquake, measured 7.2 on Richter scale
Tuesday 17th Jan 5.46am 1995
Kobe- 2nd most populated and industrialised area in Japan.
Population- 1.5million

Question 15

Where was the focus and epicentre for Kobe’s earthquake?

Answer 15

Focus- 16km below surface (shallow)

Epicentre- Close to a heavily populated area (so loads of damage)

Question 16

What was the cause of Kobe’s earthquake?

Answer 16

Destructive plate boundary- denser oceanic Philippines plate subducted under less dense Eurasian continental plate

Question 17

What were the primary and secondary effects of Kobe?

Answer 17

Primary- Ground shook 20s and 3mins on reclaimed land! ground moved 50cm horizontally and 1m vertically, buildings and bridges collapsed
Secondary- 6000 deaths, 30,000 injured, 300,000 homeless, refugees moved to temp. accommodation, collapsed buildings blocked roads (hard for emergency services) fires caused by fractured gas mains+sparks from cables, 7500 wooden houses burnt down

Question 18

What were the short and long term responses for Kobe?

Answer 18

Short- emergency shelter for 300,000 found in schools, town halls, parks, several days for emergency rations to arrive, rescue teams searched 10 days for survivors
Long- many moved away permanently, jobs created in construction industry (rebuilding programme), railways back in Aug, water, electricity, gas, telephone services back in Jul, most ports working next yr but Tanshin expressway down, new laws to make buildings+transport earthquake proof, more instruments installed to monitor earthquakes.

Question 19

Example of LEDC earthquake, where, magnitude, date, epicentre

Answer 19

Haiti earthquake- 12th Jan 2010 (Tues) 4:53pm. 7 on Richter scale.
Haiti- Island of Hispaniola in Caribbean Sea
Epicentre 25km south west of capital, Port-au-Prince
Strongest earthquake to hit Haiti in 200yrs

Question 20

What was the cause of the Haiti earthquake?

Answer 20

Conservative plate boundary with North of Caribbean plate and North American plate

Question 21

Why did people die in the Haiti earthquake?

Answer 21

Shallow focus
Very densely populated
Poorest country in Western Hemisphere
Buildings not earthquake-resistant
3million in Port au Prince lived in slums
Rescue teams hampered by damage to port, airport+roads

Question 22

Effects of Haiti earthquake?

Answer 22

Buildings collapsed
316000 deaths
300,000 injured
1.5 million homeless
Infrastructure damaged: port, airport, electricity network, roads, water supply 
Roads blocked with rubble

Question 23

Responses to Haiti earthquake?

Answer 23

Local used hands to dig people out of rubble
Countries sent aid but airport damaged, delays. When fixed, aid piled up but lack of fuel
Delays caused looting+violence
Rubble blocked roads
Port badly damaged
Refugee camps for the homeless
Oct 2010- cholera killed 5000, blamed Nepal, led to violence
NGO- Oxfam, Red Cross, water aid, action aid, save the children
Hurricane Tomas- Nov 5th 2010, led to flooding and increase in cholera

Question 24

What are Tsunamis?

Answer 24

Special type of wave (or series of waves) where entire depth of sea or ocean is set in motion by an event (often an earthquake) which displaces water above it and creates a huge wave

Question 25

How are tsunamis usually caused?

Answer 25

Caused by earthquakes at sea- when plates suddenly move against each other. Energy from the earthquake vertically jolts seabed by several metres, displacing hundreds of cubic km of water

Question 26

Which way do tsunami waves travel? And what are their movement?

Answer 26

Large waves move through ocean away from epicentre. At deep water, tsunamis move fast but at coastal slowly but increase height. Water pulled back from beach exposing sea bed to create wave

Question 27

Give an example of a Tsunami, date, magnitude of earthquake that caused, epicentre

Answer 27

Japan Tsunami- 11th March 2011, earthquake- 9 on Richter scale
Epicentre- 100km east of Sendai, out at sea

Question 28

Cause of Sendai tsunami? Speed of tsunami? Size and number of waves?

Answer 28

Subduction of pacific plate (200km length) under North American plate causing flick upwards of earths crust (5-10m)
Speed- 80kph across pacific 
40m high after 30m+9 more 10m ones
1000+ aftershocks
Swept up to 10km on shore

Question 29

Responses to Sendai tsunami?

Answer 29

Emergency services weren’t prepared (only for earthquakes)
Specialist search and rescue teams
100,000+ Japanese soldiers distributed essentials
Exclusion zone around Fukushima nuclear plant
Building and reconstruction
Tsunami defences extend beyond 12 m (acceptable level)

Question 30

Effects of Sendai tsunami

Answer 30

20,000+ deaths
500km2 coastal plains inundated
200,000 buildings destroyed
Ruptured gas pipes --> fires
Explosions at Fukushima nuclear plant, topped flood defences and contaminated
Electricity cut off at 6million homes
No running water in 1million homes
Heavy snow blocked by debris+landslides and aftershocks hampered relief efforts

Question 31

Define a volcano

Answer 31

An opening or vent in the earth’s surface where molten material erupts and solidifies as lava

Question 32

Where are volcanoes found?

Answer 32

On or around plate boundaries
In a linear form, long narrow belts
esp around Pacific plate (Ring of fire)
Along plate boundaries esp constructive and destructive
Mid-Atlantic ridge