Hazards Test 1
Terms
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- Mitigation
- Prevention of a natural hazard from becoming a natural disaster
- Do people tend to reoccupy natural disaster locations? Why?
- Yes, opportunities, faith, fatalism, etc
- Magnitude varies over what?
- space and time
- As magnitude _________, frequency __________
- increases, decreases
- Return Period
- the number of years between same-sized events
- Low-fatality hazards
- Floods, tornadoes
- High-fatality hazards
- Earthquakes, hurricanes
- Exponential Growth
- Lots of population growth in a short period of time
- Doubling time
- The number of years it takes for a population to doublw
- What is our doubling time?
- 53 years
- What will the human population be in 2050?
- 9 billion
- Energy Sources of Disasters
- Asteroids, gravity, internal energy, the sun
- Water is what kind of molecule?
- Polar
- How much does water expand by when it freezes?
- 9%
- Plate tectonics theory
- epicenters are along fault lines
- Divergent boundary
- Two plates are pulling away from one another
- Convergent boundary
- two colliding plates
- Transform fault
- two plates slide past one another
- Young spreading center and the plates involved
- East African rift valley; African and Somali
- Turkey is famous for what kind of fault?
- Transform
- What kind of fault is the dead sea fault?
- Transform
- What causes an earthquake?
- Fault movements, volcanoes, meteorite impact, nuclear bombs, undersea landslides
- What is the difference between a hanging wall and a footwall in a mine shaft?
- Footwall is the one you walk on, hanging wall is above your head
- Normal Fault
- Looks like you could step down, the footwall rose up
- Reverse Fault
- The hanging wall rose up
- What can P-Waves move through?
- Solids, liquids, and gases
- What can S-Waves move through?
- Solids
- Magnitude
- Estimate of the energy release of an earthquake
- Moment magnitude
- Used for large or far away earthquakes-amount of movement on the fault
- 9 N.American earthquake regions
- Pacific NW, W. Great Basin, Intermountain belt, Rio Grande Rift, Intraplate Central, Intraplate East, Hawaii
- How many times did Ancient rifts occur in Central U.S?
- 3
- Viscosity
- Resistance to flow
- Low viscosity?
- Low resistance to flow, more fluid like
- Why does magma explode at subduction zones more than spreading centers?
- The magma is more viscous and the gases can't escape as easily
- How is magma generated?
- Lower pressure, raise tem and water content
- What are some ways energy exists?
- heat, light, water, electricity, chemical
- 1st Law of Thermodynamics
- Energy can neither be created nor destroyed
- Why is gravity centered in a planetary body?
- That's where the attracting mass is
- How old is the Earth?
- 4.5 billion years/4500 million years
- Do all objects radiate energy?
- Yes
- Insoluation
- More solar radiation in certain areas
- Latent heat
- Carried in water vapor, releases during condensation
- Isostacy
- principle of buoyancy
- How many plates are there?
- Seven
- Is Iceland's boundary young or old?
- Old
- Dip-slip fault
- caused by a pushing or pulling force
- For P waves, the greater the density and resistance, the...
- greater the speed
- What does S wave speed depend on?
- density and shearing
- What are the L waves?
- Love and Rayleigh
- LOVE
- travel through solids, faster than Raleigh
- Raleigh
- eliptical motion, moves through solids and liquids
- Intensity scales were named after whom?
- Mercalli and Richter
- Tsunami
- harbor wave created by earthquakes or landslides
- Seismic Gap Method
- predicting earthquakes based on old earthquakes
- What three plates are subducting under the NA plate?
- Juan de Fuca, Gorda, Explorer
- Why are failed rifts hard to study?
- They are deeply buried