HAZARDS Flashcards
What is a natural hazard?
A natural event that threatens people or has the potential to cause damage, destruction and death.
What are the key hazards?
Earthquakes, Volcanoes, Hurricanes(tropical storms), Heavy snow, Climate change, Heat waves
What is hazard risk?
The probability or chance that a natural hazard may take place.
What is the hazard risk in Indonesia?
More than 75% of the population live within 100km of a volcano.
Where do earthquakes and volcanoes often take place?
On plate boundaries.
What are the four types of plate boundaries?
Constructive, Destructive, Collision, Conservative
What is a constructive plate boundary?
2 plates moving away leaving a gap in the middle for magma to rise up through.
What is a destructive plate boundary?
2 plates moving towards eachother. The heavier Oceanic plate pushes down beneath the continental plate (forms ocean trench).
What is a collision plate boundary?
When 2 plates of similar density move together (i.e. a continental plate). This causes the material between them to buckle and rise up, forming fold mountains.
What is a conservative plate boundary?
Where 2 plates do not directly meet but slide past eachother along a fault (weakness).
On what plate boundaries do volcanoes form?
Constructive and Destructive.
Name a plate boundary where earthquakes occur?
Destructive, Conservative, Collision.
On what plate boundaries do fold mountains form?
Collision.
What are the characteristics of the continental crust?
Thicker, Less dense, Older.
What are the characteristics of the oceanic crust?
Thinner, Denser, Younger.
Why are some disasters worse than others?
Level of vulnerability in an area, Resilience of the people affected, Frequency, Level of inequality etc.
What is magnitude?
The size of an EQ.
What is frequency?
How often it will occur.
What does predict mean?
Using evidence and monitoring to predict when and where earthquakes may happen.
What are 3 things that can predict earthquakes?
Animals, Seismographs, Tiltmeter.
How do animals predict earthquakes?
They can predict earthquakes by picking up on water/ magnetic changes.
How do seismographs predict earthquakes?
They can pick up minor tremors occurring before the main event.
How does a tiltmeter predict an earthquake?
They check for any movement in the rocks.
How does protection help with earthquakes?
By designing buildings that will withstand tectonic hazards.
What are shear walls and shear core?
Concrete walls with steel bars in them. This reduces rocking movement and makes buildings less likely to collapse.
What is cross bracing?
Steel bars or braised used in an X-shaped. They make the building stronger, reducing movement in an earthquake.
What are base isolators?
Big shock absorbers in the foundations of a building. They move and stretch under the pressure to absorb the shock.
What is a tuned mass damper?
It’s a giant metal ball which counteracts any movement from earthquakes.
What are the tectonic hazards?
Earthquakes, Tsunamis and volcanic eruptions
What are the atmospheric hazards?
Hurricanes, Heatwaves, Droughts and Flooding.
What are the geographical hazards?
Landslides.
What is distribution?
Where something is.
