The Restless Earth Flashcards
What are the four layers of the earth?
Crust
Mantle
Outer core
Inner core
Name the different plates
Eurasian plate Pacific plate Indo-Australian plate Antarctic plate North American plate Nazca plate South American plate African plate
What processes happens at a destructive plate margin?
Oceanic and continental plates push together.
Denser oceanic crust is forced down into the mantle (subduction) forming and ocean trench.
Continental crust is compressed to form a crumple.
Major earthquakes occur when the plates move
What processes happen at constructive plate boundaries?
Oceanic or continental plates pull apart.
Lava erupts forming shield volcanoes.
Undersea volcanoes form mid-ocean ridges.
Minor earthquakes occur when the plates move.
What processes take place at conservative plate margins?
Plates are pushed in different directions, or in the same direction at different speeds.
Plates remain locked together until the rock breaks along a fault line.
Major earthquakes occur as stored energy is released
There are no volcanoes.
What processes take place at a collision margin?
Two continental plates collide together. When they collide the land is crumpled upwards.
What are the characteristics of a composite volcano?
Steep sloped sides, especially near the summit, due to partly thick and short viscous lava flows.
Narrow base
Infrequent but often violent eruptions
What are the characteristics of a shield volcano?
Gentle upper slopes
Composed almost entirely of relatively thin lava flows built up over a central vent
Formed by runny basaltic magma that flows easily down slope
Wide base
What are the characteristics of a super volcano?
Massive explosive eruptions of ash
The crater can be over 40 miles wide
They erupt around 1,000km cubed of materials hey have a ridge of higher land around them
How are the size of earthquakes measured?
The Richter scale
How is the size of destruction monitored?
The mercalli scale
Give an example of where fold mountains are used
The Andes, Peru, South America
What are the Andes used for?
Farming.
Mining.
Hydroelectric power.
Tourism.
What do they farm in the Andes?
Llamas for their wool, meat and milk.
Llamas also carry supplies through inaccessible areas.
Terraces are made on hillsides to grow crops easily.
What do they mine in the Andes in yanacocha?
Nickel
Gold
Silver
Tin
What types of things can tourists do in the Andes?
Visit glaciers Skiing Hiking (inca trail) Rock climbing Visit the army settlement of Machu Picchu
How were the Andes formed?
South American and Nazca plate subduction, so the the continental plate is being crumpled to form the mountains.
How is volcanic activity monitored?
Tilt meters: detecting change in slope by shifting magma
GPS: show change in land and detects change in surface temp
Give an example where there was a volcanic disaster.
Montserrat, Caribbean
When did the eruption start? And when did it end?
It started in April 1995
It ended in June 1997
List some primary effects of the Montserrat eruption
19 people killed
2/3rds of the island covered in ash
Main airport and port closed
List some of the secondary effects of the Montserrat eruption.
27 people were killed by 1997
People had to move into converted low security prison
Homes, businesses and infrastructure destroyed
List some of the immediate responses to the Montserrat eruption.
South of the island was exclusion zone
Large scale evacuation by British navy
Donations by other countries for support
Unemployment rose due to the collapse of the tourist industry
List some of the long term response to the Montserrat eruption
Exclusion zone set up in the volcanic region
A volcanic observatory was set up to monitor the volcanic activity
New roads and airport was built
Some people couldn’t return home due to their homes being in the exclusion
Give an example of an LEDC earthquake and the date.
Haiti, Port au Prince
12th January, 2010, 16:53
7.0 magnitude
List some primary effects of the Haiti earthquake
300,000 people injured Main prison destroyed so 4,000 in mates escaped Electricity supplies damaged Public were not sure what was going on Main hospital destroyed
List some of the secondary effects of the Haiti earthquake
The heat and humidity started to decay corpses left in the rubble, leading to disease
Cholera outbreak due to poor sanitation
500,000 people still living rough when rainy season began in March
Mass graves dug
List the immediate responses to the Haiti earthquake
Neighbouring Dominican Republic provided emergency water and medical supplies.
Emergency rescue teams arrived from a number of countries
United Nations troops and police were sent to help distribute aid and keep order
List the secondary responses of the Haiti earthquake
After one year there was still 1,300 camps
Money was pledged by organisations and governments to assist in rebuilding
‘Cash for Work’ programs are paying Haitians to clear rubble
Give an example of an MEDC earthquake
Los Angeles, USA
7th January, 1994
6.6 on the Richter scale
What caused the quake in LA?
The earthquake happened on a thrust fault along northern fringes of the valley. The plates were grinding past each other creating violent jolts.
List some immediate effects of the LA quake
57 deaths 1,500 people seriously injured 9000 homes/ businesses without electricity 20000 without Gas 11 major roads closed
List some long term effects of the LA quake
Roads were blocked so no transport in or out of LA
Damage to buildings/water supplies/electricity/gas
$20 billion in loss
Give some responses to the La quake
Short term: U.S.G.S (United States Geological Society) started analysing data and broadcasting information to the public
Medium term: schools reopened after a couple of weeks
information leaflets were given out
Long term: NEHRP agencies assisted local, state and federal jurisdictions to carry out recovery, reconstruction and mitigation processes
Give an example of a country where a tsunami took place
Japan’s north-eastern coast
There was a 9.0 magnitude earthquake that caused the tsunami
What caused the tsunami in Japan?
There is subduction happening with the Pacific going under the Eurasian plate.
It is at a destructive plate margins of fiction is present and the plates stick.
When the pressure builds up and is released, it causes a rapid shift in the plates and a lot of energy to be released.
List some primary impacts of the Japan tsunami.
15,854 deaths
26,992 injuries
3,155 people missing
130,000 buildings collapsed
List some secondary impacts of the Japan tsunami
300 tonnes of active material leaked from the Fukushima power plant
Boats were destroyed, so many fishing jobs were lost
List some long term impacts of the Japan tsunami
300,000 people lost their homes
People were still Irving in temporary homes 2 years after
Soil was contaminated
List some immediate responses to the tsunami
Many people went outside went the earthquake struck so many lives were saved there. However many didn’t react quickly enough to the tsunami alert from JMSA.
Many countries sent search and rescue teams to help look for survivors.
Red Cross reported $1 billion in donations
List some long term responses to the tsunami
Just six days are then tsunami motorways were being repaired
The tsunami warning system was upgraded
Research and development to reduce damage of future tsunamis and earthquakes
