Flashcards in Lecture #1 Deck (49):
How many locations within North America are at risk of hazards?
Every location is at risk of at least 1 hazard
-Hurricanes, earthquakes, tornadoes, draught (everyone)
Examples of Non-natural disasters?
-Toxic gas release
What are the 3 main processes in which natural hazards can arise?
1. Internal forces within the earth (driven by internal energy; plate tectonics)
2. External Forces on earth surface (driven by sun energy; any weather hazard)
3. Gravitational Attraction (driven by force of gravity; downslope movement)
A process that poses a potential threat to people or the environment
the probability of an event occurring x impact on people or the environment
A brief event that causes great property damage of loss of life
A massive disatster
What differentiates a hazard from a catastrophe?
It's based on the size of the area affected
Which hazards are more likely to be more catastrophic or less?
More: tsunami, earthquake hurricanes
Less: Landslide, wildfires, tornado
What is the magnitude frequency concept?
There is an inverse relationship between magnitude and frequency
What is the impact of a hazard dependant on?
Magnitude + Frequency
-also to a lesser extent geology, population density, land use
What is a relatively safe place to be in NA?
The great lakes region
Which cycles created and modified earths surface?
the geologic cycles
What does the tectonic cycle involve?
Creation, movement and destruction of plates
How many tectonic plates are there?
7 big ones
7 little ones
Which process drives the tectonic cycle?
Earth internal energy
What is the Asthenosphere?
The upper mantle which is composed of hot magma with some flow
What is the Lithosphere?
Thin and brittle crust
What are the 2 different kinds of crust?
What are the 3 types of plate boundaries?
What do transform boundaries create?
What are hotspots?
Areas found away from plate boundaries where magma rises up from the mantle
What geological feature is indicative of a hot spot?
When magma erupts from the surface to form volcanoes
How do plume move?
They don't move, but the plate moving over top causes the structure to move
What are the 3 types of rock produced yet eh rock cycle?
-Igneous (came from ancient volcano)
-Sedimentary (weathering + erosion)
-Metamorphic (heat+ melting to form a new rock)
Definition of the Hydrologic cycle
The movement and exchange pod water around the land atmosphere and oceans by changes in state
What drives the hydrologic cycle?
Solar energy drives the movement of water
What is the Residence time?
How long a molecule stays in the atmosphere
What are the 5 major course themes?
1. Hazards can be understood through scientific investigation
2. Need to understand hazards to reduce risk
3. Hazards are linked to each other and the environment
4. Population + economic growth are increasing the risk of hazards
5. Consequences of hazards can be reduced
Why can understanding a hazard be beneficial?
If we know how it works we can know where it will occur and know how to minimize effects and predict future events
When do natural processes become hazardous?
When they distrust human activity or the environment
What is the best solution against natural processes, since we can't control them?
Mitigate loss by preparation
A specific time, date, location and magnitude of the event
A range or probability for the event (more general)
-some can be predicted and forecasted
What is risk?
the probability of the event x consequences
Damage to people , property, the environment and the economy
What is the acceptable risk?
The amount of risk that an individual or society is willing to take
How is the risk of hazards increasing?
-more people living closer to hazard areas
Which 2 countries account for 1/3 of earth population?
India and China
Why are hazards becoming more expensive?
- More neighbourhoods are in more unusual places which are closer to hazard areas and more expensive to rebuild
Economic losses are higher in which countries?
-deaths are higher in developing countries
Direct disaster effects?
Death, injury, property damage displacement of people
-lots of media attention
Indirect disaster effects?
Crop failures, starvation emotional distress, loss of employment
-effects are lingering
-less media attention
What are reactive approaches to hazards?
These involve recovery, search and rescue, providing emergency food water and shelter, rebuilding
What are proactive approaches to hazards?
-good land use planning
- strong building codes
-Artificial controls (flood walls)
Which is a better approach, proactive of reactive?
What are Natural Service Functions?
Natural events provide important benefits
What does climate change have to do with hazards?
Frequency of some natural processes will increase