Hazard environments Flashcards
What are the four main types of hazards?
Geological, biological, climatic and technological.
Name 3 geological hazards
Earthquakes, volcanic eruptions, landslides
Name 3 biological hazards
Pests, diseases, fires
Name 3 climatic hazards
Storms, floods, droughts
Name 3 technological hazards
Nuclear explosions, transport accidents, pollution
What are the conditions needed for a tropical cyclone to develop?
-Deep layer of warm, humid and unstable air.
-Warm water above 26°C
-Coreolis force
-Wind shear
Explain how a tropical cyclone is formed
Warm, moist air is forced to rise. The air spirals upwards. Cooling and condensation produce cumulonimbus clouds and rain. Cold air in centre sinks.
What is the difference between typhoons, hurricanes and cyclones?
Their location
Between which tropics is the tropical cyclone zone?
Tropics of Capricorn and Cancer
How do cyclones cause damage on land?
flooding because of the rain, destruction of crops and buildings and storm surges
What are primary impacts of a tropical cyclone?
Direct and immediate results of high winds, torrential rain and storm surges.
What are secondary impacts of a tropical cyclone?
Costs of damage repair, spreading of waterborne diseases, loss of home and belongings, etc.
What 4 types of short-term impacts do tropical cyclones have?
Think broad categories
Physical, social, economic and environmental.
What are the short-term physical impacts of a tropical cyclone?
damage to property
What are the short-term social impacts of a tropical cyclone?
Death and injury, disruption of communities
What are the short-term economic impacts of a tropical cyclone?
Destruction of businesses, transport systems and services
What are the short-term environmental impacts of a tropical cyclone?
landslides, soil erosion, flooding, upset ecosystems
Name 2 relevant hurricane case studies
Hurricane Katrina, USA, Typhoon Haiyan, Philippines
Why are tropical cyclones the easiest storm to measure?
Because rainfall and wind speed are constantly being measured by satellites and weather stations.
Name the 4 plate margins
-Destructive/convergent
-Constructive/divergent
-Conservative/transform
-Collision
What is a destructive plate margin?
When two plates move towards each other. The edge of one plate is being destroyed as it goes underneath the other plate and the friction creates volcanoes and earthquakes.
What is a constructive plate margin?
Two plates are moving apart. Magma rises to the crust to fill the gap and creates submarine volcanoes.
What is a conservative plate margin?
When plates are sliding past each other. There’s no rising magma or subduction, so no volcanoes. Instead, the friction creates earthquakes. San Andreas Fault.
What is a collision plate margin?
Two plates meet head on and are of equal density and strength. The sediments between the plates are pushed up and from mountains, example the Himalayas.
What are hotspots?
Locations beneath the earth crust where strong and rising currents of magma (plumes) occur.
What are plumes?
Strong and rising currents of magma.
What are the 3 different forms of volcanic eruption?
Ash, gas emissions and lava flows.
What are pyroclastic flows?
Fast-moving currents of hot gas and volcanic matter (tephra) that flows along the ground away from a volcano that has erupted. Dangerous because of high t° and mobility
What gases can be emitted during a volcanic eruption?
Sulphur, carbon dioxide and cyanide.
What is an earthquake?
A sudden and brief period of intense shaking of the ground.
What is the focus?
The underground centre of the earthquake.
What is the epicenter?
The point of most damage of an earthquake
What does the amount of damage from an earthquake depend on?
Think physical factors, not human preparation
Rock type and depth of focus
What does it mean when rocks liquify?
When shockwaves from an earthquake travel through soft rock and make the rocks behave like liquid.
Which 3 ways can earthquakes be measured in?
Richter scale, Mercalli scale, moment magnitude scale.
How are volcanic eruptions measured?
Volcanic Explosivity Index
What does the Richter scale measure?
The amount of energy released during an earthquake.
What does the Mercalli scale measure?
What people experience and the amount of damage done by an earthquake.
What does the Moment Magnitude Scale measure?
The energy released by an earthquake based on the amount of rock movement along a fault or fracture surface.
What are some factors that affect how damaging an earthquake is?
How populated the area os, the size of the affected area, event duration, degree of previous preparation.
Name some primary impacts of earthquakes
Broken pipelines, collapsed buildings, people crushed to death
Name some secondary impacts of earthquakes
Tsunamis, aftershocks, fires due to ruptured gas lines
Name some primary impacts of volcanic eruptions
Buildings and crops destroyed by lava flows, contamination of water supply, injury and death
Name some secondary impacts of volcanic eruptions
Lahars, fires started by lava or pyroclastic flows, psychological trauma
What are lahars?
A mix of volcanic ash and mud with rainwater or melting snow
Name two relevant earthquake case studies
Nepal 2015, Italy 2016
Name two relevant volcanic eruption case studies
Mount Merapi 2010, Mount Ontake 2014
Why do people knowingly live in high-risk environments?
Unawareness of the risks, inability to move away due to lack of money, optimism (thinking it won’t happen to them),conscious decision
What is a hazard?
A source of danger
What is risk?
The probability of a hazard causing harmful consequences
What benefits do volcanoes offer?
Minerals, fertile soils, geothermal energy and tourism
What is risk assessment?
Deciding the probability of a hazardous event happening and the scale of its possible damage
What 3 features of a hazard are important to be aware of when assessing risk?
Distribution, frequency and scale
What is prediction?
Knowing that a hazard event is about to take place shortly
Why is it hard to predict earthquakes?
Because they happen quickly and suddenly
What is preparation?
Reducing the impacts of a possible hazard as much as possible.
Give examples of preparation for earthquakes
Construction (adapting buildings and infrastructure), warning systems, education, remote sensing and GIS
What is GIS?
Geographic information system. A computer program to store, visualize and analyze geographic data
What is inquest/appraisal?
Looking back and evaluating how well the response to a hazardous event worked.
What is the difference between emergency response and review response?
Emergency response is immediately after the event, a review response is when the whole thing is examined and questions are asked.
What are some inquest/appraisal questions?
Do the risks need to be reassessed? Do the warning systems need to be improved? Are hazard maps up to date?
