Natural Disasters and Environmental Problems Earthquakes Earthquakes Hurricanes Hurricanes.
Hurricanes
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description
Hurricanes. Conditions Required for Formation. Warm, Humid Air (mT air mass) form over tropical oceans Warm Water; 80 F Mainly form in the Fall; off the coast of Africa. Why do Hurricanes travel from east to west?. None at the Equator!. - PowerPoint PPT Presentation
Transcript of Hurricanes
Conditions Required for Conditions Required for FormationFormation
• Warm, Humid Air (mT air mass)Warm, Humid Air (mT air mass)– form over tropical oceansform over tropical oceans
• Warm Water; 80 FWarm Water; 80 F
• Mainly form in the Fall; off the coast Mainly form in the Fall; off the coast of Africaof Africa
Why do Hurricanes travel Why do Hurricanes travel from east to west?from east to west?
None at theEquator!
The Stages of a HurricaneThe Stages of a Hurricane(based on changes in wind speed)(based on changes in wind speed)
1.1.Tropical DepressionTropical Depression
(L pressure system)(L pressure system)
2. Tropical Storm- gets a 2. Tropical Storm- gets a namename(39-74 mph)(39-74 mph)
3. Hurricane (over 74 mph)3. Hurricane (over 74 mph)
The Saffir-Simpson Hurricane The Saffir-Simpson Hurricane Damage Scale Damage Scale
Central Pressure
WindSpeeds
StormSurge
ObservedDamage
mb mi/hr feetinches knots meters
1>=980
>=28.9474-9564-82
4-5~1.5
some damage to trees, shrubbery, and unanchored mobile homes
2965-979
28.50-28.9196-11083-95
6-8~2.0-2.5
major damage to mobile homes; damage buildings' roofs, and blow trees down
3945-964
27.91-28.47111-13096-113
9-12~2.5-4.0
destroy mobile homes; blow down large trees; damage small buildings
4920-944
27.17-27.88131-155114-135
13-18~4.0-5.5
completely destroy mobile homes; lower floors of structures near shore are susceptible to flooding
5<920
<27.17>155>135
>18>5.5
extensive damage to homes and industrial buildings; blow away small buildings; lower floors of structures within 500 meters of shore and less than 4.5 m (15 ft) above sea level are damaged
Scale Number
Also Known as…Also Known as…
•TyphoonsTyphoons in the western Pacific in the western Pacific•Cyclones Cyclones in Australia/Indian in Australia/Indian oceanocean
•Hurricanes in the AtlanticHurricanes in the Atlantic
2011 Atlantic hurricane 2011 Atlantic hurricane seasonseason
First storm formed June 28, 2011
Last storm dissipated November 12, 2011
Strongest stormOphelia – 940 mbar (27.77 in Hg), 140 mph (220 km/h)
Total depressions 20
Total storms 19
Hurricanes 7
Major hurricanes (Cat. 3+) 3
Total fatalities 100 direct, 14 indirect
Total damage $12.2 billion
Timeline of 2011 Timeline of 2011 hurricaneshurricanes
Irene; cat 4 Aug. 20-28Irene; cat 4 Aug. 20-2855 dead; 10 billion $ 55 dead; 10 billion $ damagedamage
Katia- Aug. 25- Sept. 10; Katia- Aug. 25- Sept. 10; cat.4cat.4
Hurricane Ophelia Sept.. Hurricane Ophelia Sept.. 2011 cat. 42011 cat. 4
Parts of a hurricaneParts of a hurricane
• eye - 20-50eye - 20-50– light winds light winds – Air sinkingAir sinking– clear/broken clouds clear/broken clouds
• eye walleye wall – very strong winds very strong winds – ring of intense ring of intense
thunderstormsthunderstorms
Parts of a hurricane (cont.)Parts of a hurricane (cont.)
• Spiral Rain bands- heavy rain; windSpiral Rain bands- heavy rain; wind
Cross section of a hurricaneCross section of a hurricane
Eye Wall
Do Hurricanes affect Do Hurricanes affect Detroit?Detroit?
•Just rainJust rain
Hurricane Damage!Hurricane Damage!
Hurricane Hurricane DamageDamage
•due to due to windwind and and waterwater
•rains can cause flooding and rains can cause flooding and mud slidesmud slides
•Most deaths are due to the storm Most deaths are due to the storm surgesurge
Gulf Shores, AL (after Hurricane Ivan 2004)Gulf Shores, AL (after Hurricane Ivan 2004)
Power of Power of WindWind
Andrew 1992Andrew 1992
Ivan 2004
Iris 1991Iris 1991
STORM SURGESTORM SURGE
OCEAN WATER SUCKED UPWARD
Katrina’s storm surgeKatrina’s storm surge
Factors Affecting Storm Factors Affecting Storm SurgeSurge
•shape of the coastlineshape of the coastline
•the magnitude of the the magnitude of the hurricanehurricane
http://www.comet.ucar.edu/nsflab/web/hurricane/313.htm
What to do if a hurricane What to do if a hurricane warning is issued?warning is issued?
LEAVE THE AREALEAVE THE AREA
Hurricane forecastingHurricane forecasting
• Satellites are most useful in Satellites are most useful in detecting where hurricanes aredetecting where hurricanes are
• To predict direction they will go…To predict direction they will go…– FrontsFronts– Water temp.Water temp.– Wind directionsWind directions– Still fickle!Still fickle!
Hurricane DissolvingHurricane Dissolving
•storm passes over storm passes over coolercooler waters waters OR OR
•storm makes storm makes landfalllandfall
Once the warm water is gone so is the Once the warm water is gone so is the hurricane!hurricane!
What Determines What What Determines What is the Worst Hurricane?is the Worst Hurricane?
Winds ??Winds ??
Deaths ??Deaths ??
Cost ??Cost ??
Most Most PowerfulPowerful Atlantic Atlantic HurricanesHurricanes
Wilma- Oct. 2005Wilma- Oct. 2005lowest recorded pressure= lowest recorded pressure= 26.04”26.04”
Wilma 2005
DeadliestDeadliest Atlantic Hurricanes Atlantic Hurricanes
Galveston 1900-deadliest Galveston 1900-deadliest natural disaster in U.S. natural disaster in U.S. historyhistory
CostliestCostliest Atlantic Hurricanes Atlantic HurricanesKatrina- estimated $80 billionKatrina- estimated $80 billion
Andrew 1992Andrew 1992
Cost of hurricane damage is Cost of hurricane damage is increasing because….increasing because….
• More people are moving to hurricane More people are moving to hurricane prone areas!prone areas!
So, Which is So, Which is Worse?Worse?
HurricaneHurricane
AndrewAndrewThe Urban The Urban
StormStorm
•15 deaths15 deaths
•$26 billion in $26 billion in damagedamage
HurricaneHurricane
MitchMitchThe Rural StormThe Rural Storm
•11,000 deaths11,000 deaths
•very little very little monetary monetary damagedamage
HURRICANE KATRINA HURRICANE KATRINA 20052005
Levees brokeLevees broke
• Added to floodingAdded to flooding
• New O. below sea level!New O. below sea level!
Gulfport, MississippiGulfport, Mississippi
• Wind side of stormWind side of storm
