Cause and Effect of Catastrophes

Research Class notes

FloodsCause and Effect

How floods form:• Often caused by extreme

weather – thunderstorms, snow and ice melts, hurricanes

Main features: Overflowing of water

onto land that is normally dry

Can last a few minutes (flash flood) to months

Weather relatedChanges in habitats – destruction of habitats, water contamination, loss of animals due to drowning

Changes in landforms: mudslides, erosion of land

Other impacts: loss of life, disease, property loss or damage, destruction of crops and livestock.

HurricaneCause and Effect

How hurricanes form:• Created by moist, warm air in a

convection current – warm and cool air masses join and spiral upward creating high wind speeds

Main features: Wind speeds of 74 mph or

more, extreme rain fall, dangerous storm surge, flooding, ocean water can enter river ways

Can produce tornadoes

Weather related• Develops over ocean/Sea waters –

Atlantic, Caribbean, Gulf of Mexico.Changes in habitats – salt water invades freshwater killing off plant life, and drowning animals. Erosion destroys habitats.

Changes in landforms: large storm surge waves erode beach land.

Other impacts: flooding and land debris washes out to sea, wind speed uproots trees and strips leaves from plants, tear down buildings. Human deaths due to drowning

TornadoCause and Effect

How tornadoes form:• Thunderstorms produces by

cold front movement – funnel from cumulonimbus clouds reach the surface of the ground

Main features: Violently rotating columns of

air – 250 mph or more, funnel shape – 1 mile to 50 miles long

Large hail, strong winds Waterspout – tornado over

water

Weather relatedChanges in habitats – uproots trees, remove top soil down to bare rock,

Changes in landforms – removes top layer of dirt

Other impacts – kills humans and animals, destroys buildings and vehicles and hail damage

Drought

a period of dryness especially when prolonged; specifically :one that causes extensive damage to crops or prevents their successful growth

DroughtCause and Effect

How Droughts Form:• Dry Weather lasting 2-3

years

Main features: Lack of moisture for an

extended period of time Water shortages

Weather relatedChanges in habitats – plant life dies, increase forest fires, shortage of water, heat waves and stress to ecosystemsOther impacts -- crop failure, livestock death, energy shortage, water shortage, dry soils, high evaporation

Earthquake

A sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust

EarthquakeCause and Effect

How earthquakes form:• Shifts in Earth’s crust –

tectonic plate movement or volcanic activity. Plates break and snap into new positions

Main features: Large cracks open in the

ground, bodies of water disappear, land can rise or fall, landslides, avalanches, fires, or tsunamis

Geologic in natureChanges in habitats – lost of habitats

Changes in landforms – liquefying of ground causing landslides, avalanches, fires, or tsunamis.

Other impacts – Humans – property damage and loss of life

Tsunami

A tsunami is a large ocean wave usually caused by an underwater earthquake or a volcanic explosion.

TsunamiCause and Effect

How Tsunamis Form:• Ocean waves produced by

earthquakes, volcanic eruptions, meteorite impact or underwater landslides.

Main Features: Series of large waves

traveling 450-600 mph in open ocean

On shore speed slows but height of wave increases with lots of debris

Geological in natureChanges in habitats – extreme environmental destruction of habitats

Other impacts – human tragedy by drowning, flooding, water contamination, lost of housing and fires due to broken gas lines

Volcano

A volcano is a landform (usually a mountain) where molten rock erupts through the surface of the planet.

VolcanoCause and Effect

How Volcanoes Form:• Opening in Earth’s crust

where molten rock escapes out due to pressure from gases within the magma

Main Features: Hazards – landslides,

mudflows, lava flow, earthquakes, fire, explosions, flash flood, and tsunamis

Eruptions sends volcanic ash into the air that can spread thousands of miles

Geologic in nature Changes in habitats – can destroy plants, cover soil, contaminate water supply and decrease air quality

Changes in landforms – lava flow covers over plants and soil creating new land (rock). Landslides and mudflows will change the land

Other impacts – produce more greenhouse gases, destroy animals and insects, collapsed roofs, disrupt machinery, and cause plane engine failure while flying

Benefit – soil not covered by lava gains nutrients from the ash allowing plant life to return. New land is formed

Wildfire

any large fire that spreads rapidly and is hard to extinguish.

WildfiresCause and Effect

How Wildfires forms:• Lightning or human activities –

campfires, cigarettes, arson

Main Features: Burns through millions of acres

of forest

Produces strong winds

Severity depends on moisture, ground cover, wind, temperature, type of land,

Geologic in nature and/or caused by humans

Changes to habitats and populations – destroys animal habitats, burns out plant life

Changes in landforms – clears land of vegetation

Other impacts – affects air and water quality.

Benefit – increases nutrients of soil and can bring new animal life over time