(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