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Hurricanes PowerPoint Presentation


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  1. Hurricanes

  2. What is a storm? • Air is heated up creating low pressure • Air rises • Cools and condenses • Air from high pressure move to low pressure • This air rises, “fueling” the storm • Winds push the storm out to sea

  3. What is a hurricane • storm system • low pressure center • surrounding thunderstorms. • Hurricanes strengthen over oceans • What they are called depends on their location of formation. • Hurricane in the Atlantic ocean • Tropical cyclone in the Pacific and Indian oceans • Typhoon in the Northwest Pacific ocean • Willy Willies in Australia

  4. How they form • Begins with a thunderstorm blown out to sea. • Then it must have: • 1. ocean waters must be warm to put heat and moisture into the overlying atmosphere • 2. moisture from sea water evaporation must combine with that heat and energy • 3. a wind pattern

  5. hurricane takes in air from surrounding areas this new air replaces the lost old air • die out over land masses • destructive force lie in their storm surges. • also have some destructive force in their winds and rains. • The hurricanes spin counter clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere* • *Due to coriolis effect, when rising it reverses • *Winds become slower toward the poles theory •

  6. How we measure hurricanes • A hurricane is measured using the Saffir-Simpson scale • We measure their intensity through their wind speed and storm surge height. • A storm surge is the rise of water that is associated with an incoming storm.

  7. Their anatomy • Eye- low-pressure, center of the hurricane • Eye wall- area around the eye, includes the most violent storms • Rain Bands- thunderstorm bands that circulate out from the eye • Coriolis effect- natural phenomenon that causes winds to veer right in the northern hemisphere and left in the southern due to spin • Rain shields- completely solid or nearly solid areas of rain that are heavier the closer to the eye

  8. Random facts • After god Huracan • Can release power up to the amount of a couple of Atomic bombs • Hurricane season during summer • Naming • Originally only phonetic names • Then only women • Changed to alternate • Used to be named after saints

  9. Their effect on waters • Aquatic environments • Cause sediment erosion removing many habitats/homes • Salt water intrusion killing many freshwater fish • Flood waters filled with many industrial products that poison organisms • Fisheries can be totally destroyed by winds • Effect on coastal ocean is the scraping of the bottom due to large waves • Little effect on open ocean due to tidal flow • Normally can rebound in 3 years

  10. Their effect on land • Terrestrial environments • Wetlands destroyed the most due to the erosion or shift of barrier islands • Mangrove forests destroyed by winds, destroying many animal’s habitats • Sea grass beds, which are for feeding and nesting are often destroyed • Also causes massive damage to human structures

  11. Examples • Bhola cyclone- 1970 in Bangladesh killed 300,000 to 500,000 though only Cat. 3 • Galveston hurricane- 1900 in Galveston, TX killed 6,000 cost 500 million dollars, destroyed 3,600 Cat. 4 • Hurricane Katrina- Cat. 5, 1,833 killed, costliest hurricane in U.S. history 108 billion dollars

  12. Detection/Prevention • Aircrafts-fly near the hurricane to collect information • Ships-measure the heat of the sea around the storm also collect information. • Satellites- take pictures showing the direction and speed of the storm also measure temperature and rainfall in and estimate its strength and course.

  13. Detection/Prevention • Doppler radar- show location and intensity of precipitation and the wind motions • Levee prevent the floods from coming • Reinforcing buildings help with strong winds

  14. Questions • If I was on the southern coast of Brazil in fall should I be worried about being hit by a hurricane? • Where are the most violent storms? • How do hurricane’s destroy ocean life in the coastal waters? • What is the name of the scale we use to measure hurricanes? • Overview: