Physical - Hazardous Environments Flashcards
Hazard
def
an event that threatens or actually causes damage and destruction to people, their property and settlements
Why are some places more vulnerable to Hazards [4]
- Some places experience more than one type of natural hazards events
- Some places experience natural disasters more frequently than others
- In some places, hazards are stronger and more destructive than others
- Some places are able to cope to the impact of disasters better
Geological Hazards [3]
Earthquakes
Volcanic eruption
Landslides
Climatic Hazards
Storms
Flood
Drought
Biological Hazards
Fires
Pests
Diseases
Technological Hazards
Nuclear Explosion
Transport accident
Pollution
Formation of a tropical cyclone [5]
- High temperatures of air rise from the surface of the sea
- The rising causes local thunderstorms
- Small storms come together to create a strong flow of rapidly rising air
- Produces an are of increasingly low pressure
- Shear winds cause it to rotate, setting the tropical cyclone into motion
Features of the eye of a tropical cyclone
Calm, low pressure
Conditions for a tropical Cyclone to develop [5]
- Deep layer of warm(>27), humid and unstable air
- Supply of heat an moisture from the surface of the sea
- The sea must be at its warmest (summer)
- Circular motion of the air encouraged by the Coriolis Force
- Small changes in wind speed and direction with changes in altitude (shear)
Distribution of tropical cyclones
Formed close to the equator, mostly reach unto within the tropics
Characteristics of a tropical Cyclone [3]
- Strong winds
- Triggers landslides and mudslides
- Storm Surges
Types of plate margins [4]
Collision: Land moving towards land, creates mountains
Destructive convergent: Oceanic and continental move together, oceanic submerges below
Constructive: Two plates move apart, volcanic eruptions, new land created
Conservative: Sliding across in different directions or speeds
What causes tectonic plates to move
Convection currents in the magma
Volcanic eruption characteristics [5]
- Lava Flow
- Ash cloud
- Rockfall
- Gas emmision
- Pyroclastic flow
Earthquake epicenter vs focus
Focus: Point where pressure builds up
Epicenter: Above focus on ground level
Hazard of earthquakes[4]
- Shake buildings
- Cause them to fall apart and collapse
- Causes damage to people and property
- Damages gas, electricity, fire
Tsunami
Underwater earthquake
Volcanic Eruption Scale
Volcanic Explosivity Index, 1-8, measures volume of gas etc
Earthquake scale
Mercalli Scale (Impact seen)
Richter Scale (Energy released)
Factors affecting damage caused by an earthquake [7]
- Energy of earthquake
- Size of area affected
- Population density
- Duration of event
- Warning
- Preparation
- Ability to cope
Impact of an earthquake [4+3]
—primary—
- Collapsed Buildings
- People injured by falling material
- Broken water/gas pipes
- Downed electricity power lines
—secondary—
- Aftershocks
- Tsunamis
- Fires
Impacts of Volcanic Eruption [3+3]
- Buildings, roads, crops destroyed by lava flows
- Death and injuries resulting directly from lava, ash and gas
- Contamination of water supplies by ash
_______ - Lahars created by mud, ash and water mixing
- Fires caused by lava and pyroclastic flow
- Economic losses, psychological trauma
Scale Tropical Cyclones
Safir Sympson Scale (1-5)
Impacts of Tropical Cyclones
physical, social, economic, environmental
Physical: Damage by wind, rain, storm surges
Social: Death, disruption of life
Economic: Infrastructure, businesses damaged
Environmental: Landslides, soil erosion, flooding
