Hazardous Earth Flashcards
What are the three types of circulation cells in the atmosphere?
- Polar cell (poles)
- Ferrel cell
- Hadley cell (equator)
Outline the process that causes circulation cells to distribute warm air:
1) Warm moist air rises at the equator, creating a low pressure belt
2) Cool air condenses and moves out 30° North and South before sinking, creating a high pressure belt
3) The cool air either moves back to the equator or towards the poles
4) At 60° warm and cold winds meet, causing the warm air to rise and the cold air at the poles (high pressure) to return to the equator as surface winds.
What are ocean currents and what to they do? Give 1 named example:
Convection currents which drag cold surface water down and draw warmer salty water from the equator over it in a cycle.
They transfer heat energy around the ocean.
Warm current: North Atlantic Drift or Gulf Stream
What is the Coriolis Effect?
A phenomenon that causes fluids (water and air) to curve as they travel across the Earth’s surface.
Why does the equator spin faster than the poles?
The Earth spins on an axis and is a sphere. The equator is where it is the widest so it has to travel further in a the same amount of time.
Which direction do hurricanes spin in?
Northern Hemisphere= Anti-clockwise
Southern Hemisphere= Clockwise
Which direction does the Earth spin in?
West to East
Why do hurricanes spin?
Areas of high pressure rush towards areas of low pressure (the eye) but are constantly deflected because the Coriolis effect pushes them slightly off path.
Where are jet streams found on Earth?
Troposphere
What types of jet streams are there?
Polar streams (7-12 km) Subtropical streams (10-16 km)
What causes the ITCZ (intertropical convergence zone)?
It forms within the tropics when two masses of low pressure air (trade winds) converge and rise before cooling (high pressure) and sinking in the upper troposphere. This repeats as the land in the Sahara and the Gulf of Guinea is very warm, heating the cool air.
What are orbital changes and how do they effect the climate?
The milankovitch cycles are the different ways which the Earth moves around the Sun.
- Eccentricity= the changing path of the Earth’s orbit; either circular (interglacial) or elliptical (glacial)
- Axial Tilt= the angle which the Earth’s axis is tilted at
- Precession= the wobbling of the axis of the Earth
These affect the amount of radiation reaching the Earth
What is volcanism and how does it affect the climate?
Large scale volcanic eruption eject huge volumes of ash and dust, partially blocking/ reflecting the suns rays and causing cooler periods
What is solar variation and how does it affect the climate?
A changing amount of radiation that the sun produces over time.
- Glacial= lower solar activity
- Interglacial= higher solar activity
What are surface impacts and how do they affect the climate?
Asteroid collisions impacting the Earths surface, ejecting large amounts of ash and dust and rapidly cooling the Earths surface by blocking out sunlight.
E.g. the comet that wiped out the dinosaurs
What evidence is there for natural climate change?
Ice cores- water isotopes and CO2 levels
Tree rings- the warmer the temperature, the thicker the ring
Historical sources- diaries, religious records and other historical documents can check the accuracy of other records
Give an example of sea level rise:
Tuvalu- Flooding
Give an example of warming oceans:
Caribbean- Tropical storms
Give an example of global rising temperatures:
Greenland- Temp rise by 3 degrees
Give an example of declining arctic ice:
Greenland
Give an example of increased extreme weather events:
Australia- forest fires
Name 3 greenhouse gases:
- Carbon dioxide
- Methane
- Nitrous oxides
Outline the natural greenhouse effect:
1) Short wave radiation comes from the sun
2) Some long wave radiation is lost to space
3) Other long wave radiation is absorbed by greenhouse gases so is trapped in the atmosphere
(This is the greenhouse effect)
Which human activities make the greenhouse effect stronger?
Farming- Livestock, Trees
Industry- Industrial processes, waste products
Transport- More cars, lorries, congestion
Energy Production- Carbon dioxide released in combustion
Why do climate change predictions vary?
We dont know what populations will be
We dont know if fossil fuels will be used
We dont know how lifestyles will change
The temperatures will rise between 1.1 and 6.4 degrees
Give reasons for the locations of tropical cyclones:
- Good latitude: 5- 30°
- Good temperature: 26.5°C
- Low wind shear
- Humid/ lots of moisture
- Long days near equator
Give locations and names for each type of tropical cyclone:
- Hurricane: Just north of equator, near America
- Cyclone: Below equator, Africa to Australia
- Typhoon: South Asia
Why do tropical cyclones dissipate?
- Loss of fuel source (over land, especially mountains)
- In an area of cold water
- Meet opposing winds
Remember: If the cyclone goes back onto water it regains its fuel source
What is the scale for measuring HURRICANES?
Saffir- Simpson Hurricane Scale
Which physical hazards come from a hurricane?
- High winds
- Intense rainfall
- Storm surges
- Coastal flooding
- Landslides
How did high winds impact people and the environment in Hurricane Katrina 2005?
- The super dome lost its roof (shelter)
- 1 million people became homeless
- Loss of shelter
-5300km3 of forest and woodland destroyed
How did high winds impact people and the environment in Typhoon Haitian 2013?
- 5 million homeless
- Coconut plantation destroyed
How did intense rainfall impact people and the environment in Hurricane Katrina 2005?
- Ninth Ward flooded, leaving residents homeless
- Increased difficulty of evacuation
-Mississippi river overflowed
How did intense rainfall impact people and the environment in Typhoon Haitian 2013?
- Homeless people couldn’t stay dry
- 71,000 hectares of farmland flooded
How did storm surges impact people and the environment in Hurricane Katrina 2005?
- Levees overflowed
- 1 million homeless
-Costal erosion
How did storm surges impact people and the environment in Typhoon Haiyan 2013?
- 5 million homeless
- Coastal erosion
How did coastal flooding impact people and the environment in Hurricane Katrina 2005?
- 80% of city flooded
- Polluted floodwaters
How did coastal flooding impact people and the environment in Typhoon Haiyan 2013?
- Spread of cholera
- 71,000 hectares of farm land was flooded
How did landslides impact people and the environment in Hurricane Katrina 2005?
- People became trapped or died from falling debris
- Falling debris contaminated water
How did landslides impact people and the environment in Typhoon Haiyan 2013?
- People trapped or died from falling debris
- Falling debris contaminated water
Where can you find evidence for cyclones?
Social media
Satellite images
Socio-economic data
Which locations are more physically vulnerable to hurricanes?
- Low lying regions
- Low relief (Storm surges)
- High relief (Landslides)
Which locations are more economically vulnerable to hurricanes?
-Less developed countries as they have worse weather prediction technology, fewer coastal defences and little to no established evacuation procedures/ response teams.
Which locations are more socially vulnerable to hurricanes?
- Areas of poverty
- Older populations
- Populations with young children
How many people were evacuated in hurricane Katrina?
80%
How many people found shelter in the super dome and convention centre in hurricane Katrina?
approximately 20%
What was the impact of damaged levees in hurricane Katrina?
80% of the city was flooded and water was trapped
How much did the total damage cost for hurricane Katrina?
$150 billion
How many jobs were lost from hurricane Katrina?
230000
How many people were killed from hurricane Katrina?
1800
Which company negatively impacted the response to hurricane Katrina and why?
FEMA were unprepared
How many houses were destroyed in hurricane Katrina?
300000
How did America forecast the hurricane?
They have a national hurricane centre
Satellite technology
How many people were made homeless from typhoon Haiyan?
1.9 million with more than 6 million displaced
How many people were killed because of typhoon Haiyan?
7500
How much did typhoon Haiyan cost in damages?
$2.9 billion
How did the Philippines forecast the typhoon?
They used tracking data and satellite information from Japan
How did each country warn and evacuate they public? America v. The Philippines
P- Public Storm Warning Signal (Responded slowly but still recognised warnings)
A- Mandatory evacuation of New Orleans but only 80% left due to age, lack of access etc.
A- Provided the Super dome for the remaining people
How did each country defend against storm surges? America v. The Philippines
A- Had levees and barriers but they were old and broken (burst)
P- No surge defences and government buildings weren’t high enough to block them
What is the Crust?
The thin layer of solid rock that cases the mantle beneath
Types of crust?
Oceanic and Continental
List the different sections of the Earth from the centre outwards.
Inner Core, Outer Core, Lower Mantle, Upper Mantle (Lithosphere, Asthenosphere) and Crust (Lithosphere)
What is the lithosphere?
A layer consisting of the crust and top layer of upper mantle
What is the asthenosphere?
The denser, mobile layer of the upper mantle
What is the physical state of the outer core?
Liquid
What physical state is the inner core?
Solid
What is the physical state of the mantle?
A viscous fluid
Where do convection currents occur?
Outer Core and Mantle
What is a convection current?
The process by which heat is transferred from the core to mantle and mantle to crust. Hotter parts of the mantle/core rise to the top of their layer. Then, they cool and sink back down.
What is the outer core made from?
Iron and Nickel
What process heats the earth from within?
Radioactive decay of elements like Uranium and Thorium in the core and mantle.
What does a divergent boundary cause?
- Small earthquakes, magnitude 5-6
- Not very explosive or dangerous volcanoes
- Occurs in fissures (cracks in crust)
- Erupts basalt lava at 1200 degrees
What is a conservative plate boundary?
Two plates sliding past one another.
What does a conservative plate boundary cause?
- Destructive earthquakes, magnitude 8.5
- Small daily tremors
- No volcanoes
What is a divergent plate boundary?
When two plates move apart
Name an example of a conservative plate boundary
San Andreas Fault
Name the four types of plate boundary
Conservative, Divergent, Convergent and a Collision Zone
What is a convergent plate boundary?
When one plate is pulled under the other
What does a convergent plate boundary cause?
- Very destructive earthquakes, magnitude 9.5
- Tsunamis
- Very explosive, destructive, steep, cone-shaped volcanoes
Name an example of a divergent plate boundary
Iceland on the mid-Atlantic ridge
What is a collision zone boundary?
When two plates collide, forcing both upwards
Name an example of a convergent plate boundary
Andes Mountains in Peru and Chile
What does a collision zone boundary cause?
- Destructive earthquakes, magnitude 9.0
- Landslides
- Volcanoes are very rare
Name an example of a collision zone boundary
Himalayas
How do convection currents help create volcanoes?
When plates move apart, a void is created, which is filled with mantle that moves upwards due to the earth’s convection currents.
Name a section of the earth with the youngest crust
Middle of the Atlantic
Give 2 contrasting example of countries affected by severe earthquakes (case studies)
Haiti and New Zealand
What is the Richter scale and what type of scale is it?
A scale that measures the magnitude of an earthquake. It is a logarithmic scale
What is the point where earthquakes start called?
The Focus
What is the point on the ground directly above the focus called?
The Epicentre
What piece of equipment is used to measure an earthquake’s power?
A seismometer
What are the smaller earthquakes called that follow a main one?
Aftershocks
What happens when the focus of an earthquake is shallower?
A shallower focus means a more destructive earthquake
What is the hot, rising material in a convection current called?
A magma plume
What are the two main factors in the severity of an earthquake?
Magnitude of earthquake and whether the affected country is an LEDC or an MEDC.
What was the magnitude of the 2010 Haiti earthquake?
7.0
Why did so many people die in the 2010 Haiti earthquake?
- Poor architecture
- Unprepared
- People were bribed to sign of buildings despite them not meeting regulations
Primary effects of Haiti Earthquake
- 230,000 deaths
- 250000 dwellings destroyed by ground shaking
- 300000 injured
- Devastated the capital, Port-au-Prince (infrastructure)
- 4000 inmates escaped
Secondary effects of Haiti Earthquake
- 1.5 million people homeless
- $11.5 billion in damage
- 1/5 jobs lost
- Cholera outbreak killed several hundred
Responses to Haiti Earthquake
International aid sent to Haiti in the form of:
- Food
- Water
- Medical supplies
- Temporary shelters
- 1100 squalid camps with basic water and sanitation
- 810000 in aid camps
How deep was the Haiti Earthquake’s focus?
13 km deep on a conservative boundary
Where was the Haiti Earthquake’s epicentre?
25 km west of Port-au-Prince
What was the magnitude of the Christchurch earthquake?
6.3
What were the primary impacts of the Christchurch earthquake?
- 185 deaths
- 1500 to 2000 injuries
- 100000 buildings destroyed
- 10000 houses damaged
What were the secondary effects of the Christchurch earthquake?
1000s homeless
NZ$3.5 billion in damage
Schools closed for 2 weeks
5 Rugby World Cup matches couldn’t be held
What were the responses to the Christchurch earthquake?
- International aid was provided in the form of money and aid workers
- Police evacuations, search teams and rescue teams
- Temporary housing
When a tsunami nears the coast what happens to its speed and height?
It slows down, but its height increases dramatically
What are the three types of Volcano?
- Shield volcano
- Composite/Strato volcano
- Super volcano
How an you describe a volcano’s activity?
- Active (frequent eruptions)
- Dormant (temporarily inactive but not fully extinct)
- Extinct (Never likely to erupt again)
What type of boundary are shield volcanoes found?
Constructive (divergent) boundaries or at hotspots
What type of boundary are composite volcanoes found?
Destructive boundaries
What are the characteristics of a shield volcano?
- Low with gently sloping sides
- Formed by eruptions of thin, runny lava
- Frequent, gentle eruptions
What are the characteristics of a composite volcano (including eruptions)?
- Made up of alternating layers of ash and lava
- Eruptions can be pyroclastic flow instead of lava
- Pyroclastic flow can roll down the sides of the volcano at very high speeds and with temperatures over 400°C
What is a supervolcano?
It is a volcano on a massive scale.
What is pyroclastic flow?
A mixture of hot steam, ash, rock and dust.
What are the characteristics of a supervolcano?
- It erupts at least 1000 cubic km of material, whereas a large volcano erupts 1 cubic km.
- It forms a depression called a caldera, whereas a volcano produces a cone shape
- Often has a higher ridge of land around it
- Eruptions are hundreds of thousands of years apart
