Natural Hazards & Risk Flashcards
Define: Hazard
A source of potential harm
What is a sequential hazard?
A single hazard that triggers additional hazards
A chain reaction
What differentiates a natural hazard vs a man-made or influenced hazard
natural: originating from natural processes in the biosphere
Man Made: hazards that arise or are influenced by human activity
Define: Risk
The probability of harmful consequences occurring
Risk is the result of the interactions of ________ and __________
hazards and vulnerability
Define: Consequence
The negative result of the interaction of a hazard with the human population or life
Define: Probability
The likelihood or degree of certainty that something will occour
Define: Vulnerability
The set of conditions and processes which affect the susceptibility of a human population to the consequences of a hazard
What are the three types of vulnerability
- Exposure
- Resistance
- Resilience
Define: Exposure and provide an example
Degree to which population or property is at risk
Ex: By living close to the ocean you are more vulnerable to the hazards of tropical storms
Define: Resistance and provide an example
Measures take to prevent, avoid, or reduce loss
Ex: Reinforcing rock slopes to help stabilize, reducing vulnerability to landslides
Define: Resilience and provide an example
Ability to recover to prior state or achieve desired post-disaster state
Ex: Ability to rebuild a town after a tornado
Define: Mitigation
Any effort to reduce the risk and minimize vulnerability of a hazard
If you have low exposure to a hazard and a high capacity to cope, what is your vulnerability?
Very low
If you have a high exposure to a hazard and a low capacity to cope, what is your vulnerability?
High
Describe the 6th mass extinction event? What factors are driving this?
The next mass extinction event that is currently in progress
loss of biodiversity, climate change, human influence
Describe how human contributions affect the magnitude of catastrophes?
With human influence the magnitude of disaster and probability is higher with human contribution than without
Define: Geology as a science
Combination of observational and laboratory sciences to explain natural phenomena
When did the solar system form?
4.567 Billion years ago
Briefly describe the formation of the solar system? What is the process called?
- A cloud of dust/particles orbiting around the sun
- small particles collided to form asteroids and planets
The process is called accretion
What materials are the planets closest to the sun made out of?
rockier, more metallic feeder material
Why do planets have differentiated internal layered structure?
Materials separated due to density and chemical affinity
What materials are the planets farthest to the sun made out of?
Gas, ice rich feeder material
What is the asthenosphere?
The upper mantle
partly molten
plastic
What are the (basic) layers of the Earth?
- crust
- mantle
- core
What is the lithosphere?
top part of the mantle and overlying crust
rides on top of the asthenosphere
What are the three types of rocks?
Igneous
Sedimentary
Metamorphic
How do igneous rocks form
forms via the solidification and crystallization of cooling magma
What is the difference between intrusive and extrusive igneous rocks?
intrusive take longer to crystalize resulting in rocks with more identifiable grains
Extrusive crystalize rapidly resulting in fine grained crystals
How do sedimentary rocks form?
via compacted or cemented grains of sediment that become lithified
What is strata?
when sediment is deposited in horizontal beds forming layers
How can we tell the difference between sedimentary grains that have travelled far vs not very far?
The longer the rock has been transported the more fine the grains and more round/smooth and vice versa for short transport grains
What is the law of original horizontality?
sediment layers are deposited horizontally
How do metamorphic rocks form?
via the recrystallization of preexisting rock
What is the law of superposition?
the sediment on the top layer is younger than the rock below
What is the law of cross-cutting relationships?
if a rock cuts through existing rock, the rock cutting through is younger
What is the law of inclusion?
inclusions in sedimentary rock are younger than the sedimentary rock it is included in
Describe the basics of the rock cycle (5 steps)
- new rock is formed via crystallization of magma (igneous rock)
- igenous rock weathers releasing sediment grains
- sediments transport and are deposited in layers
- sediment becomes lithified
- some sediment remelts into the crust
