GESCI 201 Natural Disasters Exam 4 Flashcards
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
Scraping sand off the bottom of teh sea floor and dumping it on the beach; can make water cloudy and disturb sea life.
Beach renourishment
The movement of sand on the beach caused by direction of wind and wave movement which causes the sand to shift down the beach.
Longshore drift
A manmade structure (sand, rocks, cement) to help mitigate the effects of longshore drifts with the purpose of keeping harbors or passageways open for boats (not blocked by sand)
Jettie
A structure that is constructed perpendicular to the coastline built with concrete walls, mounds of rocks to heop mitigate the effects of longshore drift
Groins
- destruction of property
* economic losses (tourism)
Hazards of coastal erosion
*burned over 36% of the park (approx 100,000 acres)
*park policy was to allow naturally caused fires to burn because fire is important to the
long-term health of the forest
*also prohibited removal of dead and fallen trees, fuel accumulated on the forest floor
making the fire impossible to fight .
*burned from June 14 to September 11 when a light snowfall extinguished it.
Yellowstone Fire, 1988
Facts:
- Deadliest natural disaster in US history,
- $30 million economic toll
- 6000 people died
- low-elevation barrier island made it worse because maximum elevation was only 11 feet but storm surge was 15; no natural protection.
- after raised the entire island and sea wall 12-15 feet tall
Galveston Hurricane, 1900
Facts:
- Struck Louisiana and Mississippi (New Orleans) as a category 3
- Levees broke causing massive flooding
- Costliest American disaster; about $108 billion
- killed over 1800 people
- maximum storm surge was 28 feet
Hurricane Katrina, 2005
Facts:
-Death toll between 300,000 and 500,000 making it the deadliest storm in modern
times.
-Storm surge of 10 meters (33 feet); area sits at sea level
-since have built concrete storm shelters with capacity for hundreds of people
-first relief concert ever held by George Harrison (Beatles) and continues to create
revenue for.
Bhola Cyclone, Bangladesh, 1970
- Struck Louisiana and Mississippi
- Record for the highest windspeed to hit the US at 175 mph but could have been higher.
- One of only three Category 5 hurricanes to make landfall in the US
- Death toll 259
- Economic toll $1.4 billion (unadjusted).
- most deaths caused by drowning, landslides.
Hurricane Camille, 1969
- Went through Jamaica, Cuba and then up the Eastern US Seaboard to New Jersey
- Max winds 115 mph
- storm surge caused extensive damage on the NJ shore and flooded parts of NYC
- Death toll 2333
- Economic toll $69 billion, one of the costliest in US history
Hurricane Sandy, 2012
Facts:
- hundreds (approx 360) of tornadoes across the Southeaster US between April 25-28
- Most expensive tornado OUTBREAK in US history
- death toll 324, thousands injured
- economic toll over $12 billion
Tornado Outbreak, April 2011
Facts:
- EF-5
- Death toll 158
- Destroyed schools, hospital, lds stake center (sturdy buildings)
- Most expensive SINGLE tornado
Joplin, MO Tornado, May 2011
Facts:
- Affected Missouri, Illinois, Indiana
- EF5
- Deadliest tornado in US history (around 700 people)
- 235 mile tornado path on ground, longest in in US History (until Dec 2021-Kentucky)
- School was in session killed over 70 students
- tornado was hidden in rain clouds so people couldn’t see it coming.
Tri-State Tornado, 1925
