DESTRUCTIVE FORCES

Mr. Auchstetter’s World Cultures

5 Major Types of Destructive Forces

Hurricanes Volcanoes Earthquakes Tornadoes Tsunamis

Hurricanes

Hurricane Info A hurricane is a severe tropical storm that

forms in the shape of a top or a pinwheel. Hurricanes need warm tropical oceans (82

desgrees), moisture and light winds above them.

If the right conditions last long enough, a hurricane can produce violent winds, incredible waves, torrential rains and floods. Winds can reach above 155 mph.

Hurricane Info Hurricanes rotate in a counterclockwise

direction around what is called an "eye." In order to be considered a hurricane,

winds must reach 74 mph.

Hurricane Names

The Earth’s Layers

Volcanoes A volcano is a vent in the Earth's surface

through which magma (molten rock) and gases erupt.

RING OF FIRE

Ring of Fire (cont’d)

Plate Tectonics

Earthquakes Earthquakes are a transfer of stress that is built

up from the friction of the shifting of the tectonic plates.

The Richter scale is calculated from the amplitude of the largest seismic wave recorded for the earthquake.

Each whole number you go up on the Richter scale, the amplitude of the ground motion recorded by a seismograph goes up ten times.

http://www.iris.edu/gifs/animations/faults.htm

Earthquakes

Tornadoes Tornadoes are produced when cool dry air

meets warm humid air. This causes the atmosphere to become unstable.

Tornadoes are known to produce hail and a greenish sky.

Tornadoes

The Fujita Scale vs. the Enhanced F-Scale

F Number

Fastest 1/4-mile (mph)

3 Second Gust (mph)

EF Number

3 Second Gust (mph)

EF Number

3 Second Gust (mph)

0 40-72 45-78 0 65-85 0 65-85

1 73-112 79-117 1 86-109 1 86-110

2 113-157 118-161 2 110-137 2 111-135

3 158-207 162-209 3 138-167 3 136-165

4 208-260 210-261 4 168-199 4 166-200

5 261-318 262-317 5 200-234 5 Over 200

Tsunami

A tsunami is a series of large waves of extremely long wavelength and period usually generated by a violent, impulsive undersea disturbance or activity near the coast or in the ocean.

Tsunamis can be formed from earthquakes and volcanic eruptions.

Tsunami