Lecture 1 Flashcards
Hazard
a process that poses a potential threat to people or the environment
Risk
The probability of an event occurring multiplied by the impact on people on the environment
Disaster
A brief event that causes great property damage or loss of life
Catastrophe
A massive disaster
Most likely to be catastrophic
Tsunamis, earthquakes, volcanoes, hurricanes, floods
Less likely to be catastrophic
Landslides, avalanches, wildfires, tornadoes
The impact of a hazard is a function of both its ________ and __________
Magnitude, frequency
Magnitude-Frequency Concept
There is an inverse relationship between magnitude and frequency
The Geologic Cycle
Tectonic Cycle, Rock Cycle, Hydrologic Cycle
The Tectonic Cycle
Involves the creation, movement and destruction of tectonic plates
Tectonic Plates
Large blocks of the Earth’s crust that form its outer shell; there are 14 plates
Inner Core
Extremely hot and solid
asthenosphere (upper mantle)
composed of hot magma with some flow
Lithosphere
a thin and brittle crust
The two types of crust are:
Oceanic and Continental
Oceanic Crust
dense, thin (averages 7km thickness)
Continental Crust
relatively buoyant, thick (average 30km thickness)
The ____ forms the upper part of the _______ and is broken into _________ (plates)
crust, lithosphere, fragments
What causes the movements of the plates?
convection currents within the mantle
Types of plate boundaries
convergent, divergent, transform
Divergent Plate Boundaries
- plates move away from each other
- new land is created at these locations
- divergence results in seafloor spreading and causes oceanic ridges to form
Convergent Plate Boundaries
- plates move toward each other
Convergent Plate Boundaries: Collisions involving oceanic and continental crust result in:
Subduction Zones:
- dense ocean plates sink and melt
- the melted magma rises to form volcanoes
Collisions involving two continental plates result in:
Collision Boundaries:
- neither plate sinks
- tall mountains tend to form (Himalayas)
Transform Boundaries
plates slide horizontally past each other
The zone along which the movement occurs is called a
transform vault
The Rock Cycle
- a rock is an aggregate of one or more minerals
- the rock cycle refers to a group of interrelated processes that produce the three different rock types:
- igneous, sedimentary, metamorphic
The Rock Cycle
- a rock is an aggregate of one or more minerals
- the rock cycle refers to a group of interrelated processes that produce the three different rock types:
- igneous, sedimentary, metamorphic
The Hydrologic Cycle
The movement and exchange of water among the land, atmosphere, and oceans by changes in state
What is necessary in order to reduce loss?
predication and forecasts
Prediction
A specific time, date, location and magnitude of the event
forecast
a range of probability for the event
Theme 2:
Understanding Hazardous Processes to Evaluate Risk
Theme 2:
Understanding Hazardous Processes to Evaluate Risk
Risk =
(probability of event) x (consequences)
Consequences
damage to people, property, the environment, the economy
Acceptable risk:
the amount of risk that an individual is willing to take
What determines acceptable risk?
the frequency of an event
Theme 3:
Hazards are Linked
Theme 4
The Increasing Risk of Hazards
Theme 5:
Consequences can be Reduced
Direct Effects:
deaths, injuries, displacement of people, damage to property
Indirect Effects
crop failure, starvation, emotional distress, loss of employment
Reactive Approaches to Hazards
recovery, search and rescue, providing emergency food, water, shelter and rebuilding
Proactive approaches to Hazards
land-use planning building codes insurance evacuation planning disaster preparedness artificial control
What are benefits called in Hazardous Events?
Natural Service Functions
ex: flooding provides nutrients for soil
What are the major course themes?
- Hazards can be understood
- The understanding of hazardous processes is needed to evaluate risk
- Hazards are linked to each other
- Population growth and socio-economic changes are increasing the risk from hazards
- The consequences of hazards can be reduced
What are the major course themes?
- Hazards can be understood
- The understanding of hazardous processes is needed to evaluate risk
- Hazards are linked to each other
- Population growth and socio-economic changes are increasing the risk from hazards
- The consequences of hazards can be reduced
