GESCI 201 Natural Disasters Exam 4 Flashcards
(38 cards)
A cyclonic storm that occurs in the ocean.
Hurricane
From warm water(81 degrees F or greater) and as the warm water evaporates the thermal energy is converted into kinetic energy which gets the spinning going
Where do hurricanes get their energy?
June thru November (usually late summer because water has had several months to warm up
When is hurricane season in the Atlantic?
Ocean water that is blow on land (not from precipitation); deadliest hazard of a hurricane
Storm Surge
The closer you are to the shoreline and lower elevation of the coast
What increases the risk of storm surge?
- Landslides
- Precipitation, flooding from,
- storm surge
- tornadoes
- wind
Potential hazards from a hurricane
- elevated building codes
- building with garage on ground floor
- building house up on stilts
- using building materials that can withstand flooding and wind
- stay inside, away from windows, no basements
- anchor or remove things outside that could be blown around
- evacuate
Mitigation for hurricanes
Wind scale categories to measure wind speed (F1-F5)
Saffir-Simpson Scale
At 75 mph
At what wind speed does a tropical storm become a hurricane?
No one really knows exactly; What we do know is the following:
- they originate from unstable air masses
- low pressure and high pressure air coming together
- it is trying to move air from the lower atmosphere to the higher atmosphere to even thing out.
- low pressure center causes the spinning (like a vortex; causes the cyclone shape
How do tornadoes form?
Used to categorize tornadoes based on the damage done, can’t measure wind speed directly
Fujita (F) scale
Categorizes tornadoes by the types of buildings and damage done to them
EF Scale
- Basement is safe; make sure nothing heavy place on floors above
- get into an interior room with no windows like a bathroom or closet
- Use building materials that will withstand wind
- drills in frequently occurring areas
- Sirens
Tornado mitigation
When the conditions are right for this type of storm to occur one of these is issued.
Tornado watch
One of these has been spotted OR there is a rotation in the weather radar image.
Tornado warning
*Occur most in tornado alley and the eastern US but can occur anywhere.
*Occur mostly in spring when warm air is coming up from the Gulf of Mexico and cold air
is coming down from the North; but can happen any time.
Location and season tornadoes are most likely to occur
When the ground collapses, usually in areas with lots of limestone, and moisture
- Occur most in:
- Florida(sinkhole alley)
- Kentucky
- Indiana
- can occur other places but happens less often
Sinkholes
The type of rock that can cause sinkholes because it dissolves in water.
Limestone
Gradual sinking of land, usually due to groundwater withdrawal
Subsidence
- Central California
- Mexico City
- Tucson, AZ
- Venice, Italy
Places where subsidence is the biggest problem
- removal of groundwater, oil or gas causes grains to settle down, pack down and sink
- largely human exacerbated
Causes of subsidence
- tilted or leaning building (leaning tower of piza)
- broken water/gas lines
- cracks in ground or pavement
What are signs of subsidence?
Removal of sediment on the shoreline
Coastal Erosion
-loss of sediment being fed or added to the beach because rivers are dammed upriver;
rivers deliver the sediment but can’t if blocked
-rising sea levels due to climate change (melting glaciers)
-storms
Causes making coastal erosion occur faster
