Hazourdous Earth:Inside The earth Flashcards
Facts about the crust
0-60km thick
Outer layer of earth
2 types of crust : continental and oceanic
Facts about the lithosphere
Uppermost layer
Includes crust and top of mantle
Cool and brittle
Viscous
Facts about the mantle
Middle layer Crust and core 2900km thick Two large section: upper- viscous Lower- reaches outer core
Facts about asthenosphere
Part of the mantle
Hot semi molten layer beneath tectonic plate
Facts about the outer core
Liquid layer
Made up of iron and nickel
2600km radius
4000-5700 degrees Celsius
Inner core
Solid Iron and nickel Hottest part of earth 4000-5700 degrees Celsius Like engine room of earth
Two reasons why earths crust is unstable
- convection currents.This is because magma rises from the mantle due to the heat emitted from the core which causes heated rock to rise and carry the plate.
- earths crust is split into tectonic plates which means there are cracks in whic magma can move the plate easily however if there was only one plate(they were all joined up) it would be unab,e to move.
Two differences between asthenosphere and lithosphere
The asthenosphere is a semi molten layer where as L is cool and brittle. This is due to the location as A is part of the mantle which is closer to the core of the earth causing it to be hot unlike L which is further away hence cool and brittle.
A is closer top core so hotter meaning it’s rocks are plastic and flow easily however rocks in L are rigid as it is away from heat from the core of. The earth.
Facts about oceanic crust
Carries water Very thin 1-3 mikes Made of basalt Dense doesn’t float Chemically different from mantle basalt
Facts about continental crust
Forms the land
Made of thick granite
30-50 km deep
Not as dense oceanic crust
Radioactive decay
Elements that are naturally unstable give off heat ie: uranium
Steps of movement of earths plates
Heat source from core
Heat moves toward surface in plumes
Semi molten rock spreads out carrying plate
The magma cools down and sinks to be reheated
Continental drift
250 million years Argo all land masses were clustered together into a supercontinent called Pangea. These then slowly moved away to form the land massses we know today
Different plate names and how their plates move and what plates involved
Collision - move toward each other - oceanic continental
Divergent - move away from each other - oceanic oceanic
Conservative- slide past (largest earthquakes) - continental
Convergent - one moves under - continental continental
Hotspot volcanoes facts
Magma rises through mantle and melts through Lithosphere, forming a volcanoe.
This only happens in so,places due to Lithospheres thickness varying.
Facts about composite volcanoes
Wavy cone shape
Sticky viscous lava
Ash and rock bombs and poisonous gases like nitrogen oxide
Rare
6 on Richter scale
Convergent
Pacific and Phillip ends continents plate (Mt pintabu
Shield volcanoes facts
Low wide cone (broad peak) Runny lava Very gentle Frequent Divergent South American and African plates (queen Mary)
General description of earthquake
Tectonic plates are stuck together and friction is building up due to convection currents. Suddenly it moves and a burst of energy is released.
Steps for earthquake
1) movement of tectonic plates
2) concentrated along fault line which is fracture in earth crust
3) friction builds up along the plate boundaries as the move against each other until finally energy is released which is sent out as shock waves.
Focus is
Below the ground, actual place of energy eruption
Epicentre is
Closest place straight above focus on earth crust
The earthquakes energy Is released in
Seismic waves
Determine volcanic eruptions
Thermal imaging- temp of volcanoes will increase
Lasers - detect bulging crater
Seismator- measure vibrations or tremor
Measure gases
Determine earthquake
Lasers- plate movement
Seismometer - vibrations of earth
Each level on richter scale is
10x more than the other
Richter scale is what type of scale
A logoarithimatic scale
General tsunami causes
Convergent plate movement causes earthquake
Sea above focus is forced upwards
Sea movement causes tsunami
In shallow water speed decreases but height increases
Waves crash into shore devastation low lying area
Sunspot theory
Sun has sunspots (black areas on the sun surface that are more active than usual
Warmer periods such as the medieval periods may be due to change in sunspot activity
More sunspots more energy from sun
The asteroid collision
Asteroids strike earth every 500,000 years
It blasts ash, gases, and dust into the atmosphere which blacks th daunting and cools the earth
The eruption theory
Short term
Ash and gases rise high and spread around the earth in the stratosphere due to high level winds
Blanket of ash and gas stops sunlight reaching the earth which cools it
The orbital theory
Earths orbit is oblong not a perfect circle so during the orbit the earth may be closer or further away from the sun
The earths axis is tilted
The earths axis wobbles
Evidence of climate change
Tree rings - eaxch ring is a years growth space between the ring tells us how good climate was for tree
Historical sources eg photos paintings diaries
Ice cores - air bubbles are trapped in it - measure amount of co2 trapped in it
Enhanced green house effect
The impact of additional heat being retained due to increased amounts of carbon dioxide and greenhouse gases that humans have released into the atmosphere
Economic reactions to climate change
Crop yields could improve in east and south east Asia
European areas will have less tourists due to snow
Social reactions to climate change
South and Central Europe. Will have health crisis due to heat stroke
Traditional ways of life cease as sea levels rise and temp increases
Refugees of climate increase
Environmental reactions to climate change
Loss of organisms Sea levels rise Stringer and more frequent hurricanes More droughts Reduction of sea ice
LEDC case study earthquakes
Haiti
Location of Haiti earthquake
Epicentre was 25km away from Port au Prince (conservative earthquake)
Same island as Dominican republican
Key facts Haiti earthquake
12th Jan 16:53 magnitude of 7.5
Haiti primary effects
230,000 people died
300,000 injured
Hospitals and key govt buildings destroyed
Electrical supplies damaged
International airport unusable
Prison destroyed allowing 4000 inmates to escape
Haiti secondary effects
Disease and cholera due to poor sanitation
Mass graves
Economical collapse
Immediate response to Haiti earthquake
Public dub each other out due to lack of army
Looting due to delays in aid
4.3 million people provided food and water
Mass graves
Long term responses to Haiti earthquake
100 million usd from USA
300 million by EU
Water and sanitation for 1.7million people
Healthcare supplies
Why did so many people die in Haiti earthquake
No earthquake proof buildings COD mo money so it fell down immediately
What hindered the response to haiti earthquake
Poor so relied on aid which takes a long time to reach
No guard so harder to rescue people
Lack of earthquake proof buildings
MEDC case study earthquake
Japan
Japan earthquake and tsunami location
Off the east coast of Japan
Near miyaoi and Sendai
Japan earthquake key facts
2:45pm 11th March Largest in the countries history with a magnitude of 9.1 Affected Sendai, Tokyo and Kenasura 20ft high tsunami travelling at 500kmph There were warnings
Japans capacity to cope
High 40% of coast has a 10m high sea wall Hazard agency dedicated to tsunamis meant people knew 20 mins before Trained from a young age Earthquake proof buildings
Japan primary effects
1700 people dead
Many missing
Four million without power
1 million without water
Japan secondary effects
15bn USD lost
Radiation exposure of three workers in Fukushima plant
21,500 living in govt shelters
Fears of nuclear plant meltdown
Japan immediate response
340,000 displaced needing water and food and essentials
Self defence forces reacted saving lives
11bn USD donated in aid
Japan long term response
Within 6 days 3motor way was repaired and within a year the county was back to normal cos they already had long term measures in place
Ocean currents
In North America cold salty water is dense so sinks, forming a convection current that drags warm water from Gulf of Mexico near the equator down, which cools and sinks near Greenland seas then flows to the equator where it is warmed up again
High pressure
Dry and hot weather cos air is sinking
Low pressure
Cold and wet cos air is rising
Global circulation model
Cold dry air descends at the polar cell
At the start of ferrel cell warm moist air is rising
At the end of ferrel is is descending cos it’s cold & dry
Rises, descend then rises in three Hadley cells
Then descends in ferrel
The ferrel cell is thermally direct true or false
False indirect cos it is powered by Hadley and polar
Explain why some areas of Africa are desert and some are rainforest
Desert - on a high pressure belt brings dry,hot climate in subtropical belt
Rainforest - low pressure belt brings wet climate
How do greenhouse gases affect temperature
Some long wave radiation from earth to space is reflected off the gases hitting earth and heating it up
ICTZ
In tropics two large air masses converge and Hadley cells on either side move together
