1. Geography Natural Hazards By: Annie Breier

2. Natural Hazards of the U.S. we will be discussing
Hurricanes
Earthquakes
Tornadoes
Volcanoes
Tsunamis
Winter storms
Information on natural hazards can be found at USGS

3. Hurricanes A tropical storm with winds that reach a speed of 74 mph
The eye of the storm is miles wide and extends over 400 miles
Dangers include torrential rains, high winds, and storm surges
Conditions that must be present: Low-pressure system, warm temperatures over the ocean, precipitation, and tropical wind patterns over the equator

4. The Saffir-Simpson Hurricane Scale
This scale is a 1-5 rating based on the hurricane’s intensity. It estimates the potential damage and flooding expected.
Category 1 Hurricane: Winds mph, storm surge 4-5 ft above normal. No major damage except to mobile homes and trees and some coastal flooding.
Category 2 Hurricane: Winds mph, storm surge 6-8 ft above normal. A little roof, door, and window damage.
Category 3 Hurricane: Winds mph, storm surge 9-12 ft above normal. Structural damage to residences and buildings, large trees blown down.
Category 4 Hurricane: Winds mph, storm surge ft above normal. More extensive damage with complete roof failures, trees and shrubs all blown down, complete destruction of mobile homes
Category 5 Hurricane: Winds greater than 155 mph, storm surge greater than 18 ft above normal. Complete roof failure, complete building failures, severe window and door damage

5. Earthquakes
A trembling or shaking movement of the earth’s surface. Most earthquakes are minor tremors however larger ones begin with slight tremors, then one or more violent shocks occurs.
Seismic Waves, Seismic Deformation, and Plate Tectonics all take part in the formation of earthquakes
Damage and death result from falling structures and flying glass and objects.

6. Earthquake Magnitude – Richter Scale
M=1 to 3: Recorded on seismographs, but not felt
M=3 to 4: Often felt, no damage
M=5: Widely felt, slight damage
M=6: Damage to poorly structured buildings
M=7: “Major” earthquake, causes serious damage.
M=8: “Great” earthquake, great destruction, loss of life
M=9: Rare great earthquake, major damage

7. Tornadoes
Tornadoes are the most violent storms around. The wind speeds are estimated at 250 mph or more.
A Tornado is a violently rotating column of air which extends from the base of the thunderstorm and then comes in contact with the ground.

8. Tornado Characteristics
Wind: Strong and destructive. These are the fastest winds on earth which rotate up to 300 mph
Rain/Hail: Tornadoes are associated with thunderstorms and flash flooding may occur
Total destruction of homes: destruction usually occurs with mobile homes, business, and cars
Extensive tree damage: to electric and telephone lines
Utility line breaks
Damaged or destroyed radio and television towers

9. Tornado Fujita Scale
F0 and F1 tornadoes: 70% of all tornadoes that occur in the U.S. They cause minor damage
F2 and F3 tornadoes: 28% of tornadoes in the U.S. They cause injuries and deaths
F4 and F5 tornadoes: 2% of tornadoes in the U.S. They cause 70% of death and destruction

10. Volcanoes
A vent in the earth’s surface which magma (molten rock), gases and ashes erupt from time to time.
Five Types of Volcanoes:
Composite: form impressive peaks and erupt in very explosive ways.
Shield: huge and produced by hot spots
Cinder Cones: a steep hill shape and the most common type in the world
Spatter Cones: created when fluid hot clots falls back down and forms steep-sided accumulations
Complex: made of multiple flows, ash layers, domes, or cones

11. Tsunamis
Tsunamis are waves, created by volcanic activity and landslides and travel across the ocean having extremely long wavelengths.
When it makes contact with land, the results are extensive. Erosion, inhalation of trees and coastal buildings and flooding are results of tsunamis. They are often fatal.
Tsunamis are also associated with earthquakes

12. Winter Storms Winter Storms are known as the deceptive killers
Extreme Cold: accompanies a winter storm and this can cause frostbite and hypothermia and can become life-threatening
Ice Storms: heavy storms can bring down trees, electrical wires, telephone polls, and lines.
Heavy Snow Storms: can paralyze a city and can collapse buildings. Heavy snow can lead to avalanches
Snow:
Flurries: light snow, no accumulation
Showers: snow falling for brief periods, some accumulation
Squalls: brief snow showers with gusty winds, significant accumulation
Blowing Snow: wind-driven snow, reduces visibility and drifting
Blizzard: winds over 35 mph with blowing snow

14. Activity
Students will be separated into groups to research two natural hazards in the U.S.
Students will supply definitions, occurrence, destruction, and fatalities
Letters to friends/family will be written about the region of the U.S. where the natural hazards occur and displays will be made