(A) Hazards Flashcards
Natural hazards definition
When a natural event (something that would happen without man kind) interferes with and affects human life.
4 Types of natural hazard
Tectonic
Atmospheric
Geomorphological
Biological
Tectonic definition and examples
To do with changes and movements in tectonic plates
Earthquakes
Tsunamis
Volcanoes
Atmospheric definition and examples
To do with extreme of weather
Hurricanes
Drought
Snow storms
Geomorphological definition and examples
Something that occurs on the earths surface
Flooding
Landslides
Avalanches
Biological definition and examples
Involving living organisms
Forest fires
Spread of disease
Why are some natural hazards difficult to categorize
What’s an example of this
One can occur due to more than one event
For example tsunami may happen because of an earthquake, but also due to a landslide, making it both tectonic and geomorphological
2 Factors effecting hazard risk
Where you live on earth
Global warming
3 types of plate margins
Constructive boundary
Destructive boundary
Conservative boundary
Constructive boundary definition
Two plates move away from each other, so magma rises from the mantle to fill the gap. This eventually cools to form new crust. Thus volcanoes are formed.
Destructive boundary definition
Two plates move toward each other. The oceanic plate is denser so sinks under continental plate and is destroyed. Deep ocean tranches are formed and volcanoes are at the surface. When the plates stick, pressure builds up and a sudden release causes an earthquake.
Conservative boundary definition
Plates move past each other sideways, if the 2 plates stick pressure will build up, and a sudden release caused an earthquake.
Describe distribution of earthquakes
Most frequently distributed in belts/lines, this is because they are found along plate boundaries.
Some are found around Pacific Ocean on the ring of fire in countries such as Japan , china, and chile (75%).
There are also clusters in east Africa, whilst others are frequently dispersed around the world.
What is the focus
The place where the earthquake has occurred underground
What is the epicentre
The closest point to the focus (directly above)
Why do some earthquakes cause more destruction than others
Population density
Poor countries have poorly built buildings and few emergency facilities/equipment
Depth of focus
Magnitude of earthquake (richter scale)
Definition and example of primary effects of earthquakes
The immediate damaged caused
Collapsing bridges/buildings/roads
Death/injury
Panic and shock of people affected
Definition and example of secondary effects of earthquakes
After effects of an earthquake Fires caused by broken cables Tsunamis, Landslides, avalanches Economic impacts Disease, famine
Definition and examples of immediate responses
Short term responses that occur during the following days of an earthquake Hide under tables Evacuation Emergency aid Search/rescue teams
Definition and examples of long term responses to earthquakes
Occur for the next few months or even years, and schemes/plans are put in place Rebuilding programs (hospitals, schools, houses) Reconstruction of roads and bridges Reconstruction of electricity lines
How can risk of earthquake activity be reduced ( 3 p’s)
Predict (by monitoring)
Preparation/planning
Protection
How can an earthquake be predicted
Geologists can identify when plates haven’t moved for a long time
Small foreshocks before main quake occurs which can be measured by seismographs
Small cracks appear in rocks
Animal behavior
Using historical evidence
How can you prepare for an earthquake
Radio and tv stations ready to give out advice
Emergency plan to help injured
Hospitals etc. not built in earthquake zones
Schools rehearse drills
Architects follow rules for safe buildings
How to protect from an earthquake
Build earthquake proof buildings
Characteristics of earthquake proof buildings
Weights on roof to refuse movement Steal frames that sway with earth Window shutters to prevent falling glass Open areas for people to assemble when evacuated Foundations sunk deep into bed rock Roads providing quick access
3 names for tropical storms, and why they are called them
Hurricanes- found in USA and Caribbean
Cyclones- found in Asia and Australia
Typhoon - found in the Philippines
6 steps for formation of tropical storm
Storm on the warm ocean Air drawn to centre of the storm Evaporation Warm air rises and cools Air condenses to form clouds 15-20km above sea, winds spiral outwards
Why do tropical storms spin
Warm air rises, and the Coriolis effect causes air to bend and spin.
In northern hemisphere they bend right so swirl anti-clockwise, but in southern bend left so swirl clockwise
What happens when storms hit land
They lose all energy that come from sea
Friction reduces speed
However they still travel 100-200 miles
4 ways of reducing effects of tropical storms
Planning
Monitoring
Prediction
Protection
Ways to plan for tropical storms
Prepare disaster supply kits Fuel in vehicles Knowing where shelters are Storing loose objects Pre-family planning
Ways to monitor tropical storms
Global hawk drones have on board radars and microwaves that help scientists understand more about the formation of storms, helping them to forecast storms
Satellites do the same thing
Ways to predict tropical storms
All weather data can be fed into a supercomputer which run models to predict the path and intensity of possible storms
Way to protect from tropical storms
Install hurricane straps in walls
Install emergency generator and shutters
Tie down wind-borne objects
Remove trees in surrounding area
Weather definition
Day to day changes in lower atmosphere
Climate definition
The average weather over a 30?year period of time which doesn’t include extremes
Extreme weather definition
This is when a weather even is significantly different from the average or usual weather pattern
5 examples of UK extreme weather
Thunderstorms Heavy snowfall Strong winds Prolonged rainfall Drought/heat wave
Reasons why people live in areas at risk from tectonic hazard
- can’t afford to move
- have good job there (farming can be better near to volcanoes due to minerals in soil)
- have family and friends there
How can scientists discover temperatures from hundreds of thousands of years ago?
- Drill in to ice to collects ice deep down from thousand of years ago
- In this ice are bubbles containing Co2
- The amount of Co2 gives us a rough idea of what the temperature was in that period
What evidence is there that climate change may be natural
There have been peaks of interglacials (warm temperatures) approximately every 100,000 years for the last 400,000 years.
It is possible we are in one of these natural peaks
3 reasons we know climate change has occurred
- Melting ice - see ice in the arctic thinned 65% since 1975
- Seasonal changes - plant and animal species behavior has changed, bird migration times have changed and studies in 90’s show birds nested 9 days earlier than in 1970
- Sea level rise - risen 10-20cm in last 100 years, due to melting ice
3 physical causes of climate change
- Sunspots
- Volcanic eruptions
- Angle of earths tilt (due to gravitational pull of moon)
How do sunspots add to climate change
Sun throws out heat which if it occurs a lot, can cause our planet to warm up
How can volcanic eruptions add to climate change
They release sulphuric dioxide and carbon dioxide
When So2 mixes with water vapor it acts as a shield and reflect sunlight
Co2 traps suns heat in earths atmosphere
How does the angle of the earths tilt add to climate change (due to gravitational pull of moon)
When the tilt increases, the climate is exaggerated (winters are colder, summer are hotter)
Earth also moves in an ellipse, so distance between it and the sun changes
If it is closes to the sun the climate is hotter
5 steps of the greenhouse effect
- sun provides energy for earth (some is unable to pass through atmosphere but most does)
- earths surface absorbs energy so warms up the planet
- some is reflected into atmosphere in the form of infra-red rays
- some is released out of atmosphere, but most is trapped due to greenhouse gasses (Co2)
- this heats up atmosphere by keeping energy in, which is known as the greenhouse effect
3 human causes of climate change
Burning fossil fuels
Agricultural activity
Deforestation
How does burning fossil fuels cause climate change
This process releases greenhouse gasses such as Co2
How does agricultural activity cause climate change
Before reaching our plates, our food is produced, stored, processed, packaged, transported, prepared, and served. At every stage, food provisioning releases greenhouse gases into the atmosphere.
How does deforestation cause climate change
Less trees to take in Co2
When trees are cut down Co2 is released
Machinery used release Co2 for fossil fuels
Positive environmental impacts of climate change
Crop yields in Europe to increase (however they will then need more irrigation/water)
Negative environmental impacts of climate change
Decrease in coral reefs as water is more acidic due to Co2, causing coral bleaching
Extended droughts in parts of the world could cause loss of vegetation, therefore wildlife and plants would be effected
Positive economic impacts of climate change
Crop yields in Europe increase therefore more profit can be generated by farmers
Negative economical impacts of climate change
Less snow on mountains, tourism on Alps, Switzerland, at interlaken skiing resort could be effected
In America, maize yields may fall by 12%
2 ways of managing climate change
Mitigation
Adaptation
What mitigation is and 4 key strategies of mitigation
Reduce the cause of climate change
- Use renewable energy source
- Re-afforestation (plant more trees)
- Carbon capture (catch any carbon that is produced and store it underground)
- International agreement (climate conference in Paris)
What adaptation to climate change is and 3 key strategies of adaptation
Responding to the changes
- building coastal protection to protect from rising sea levels
- change agricultural systems (drought resistant crops)
- manage water supplies (get water to places quickly during drought)
How many tones of Co2 is produced by burning fossil fuels per year
21.3 billion tones
Why is nitrous oxide worse than Co2 when released into atmosphere
It is 300 times more effective at capturing heat then Co2
How much more effective are forest at absorbing Co2 than crops
100 times more effective
How much forest is destroyed per year
28,000 square miles
How much has the amount of Co2 in the atmosphere increased since 1750
31%
What percentage of global warming is caused by methane release from livestock
20%
How much Co2 could be caught due to carbon capture
90% of all Co2 released
What percentage of Co2 emissions are released through use of fossil fuels
87% (this shows that it is more effective than natural causes of climate change)
