natural calamities
TRANSCRIPT
A natural disaster is the effect of a natural hazard- (e.g. flood, tornado, hurricane, volcanic eruption, earthquake, or landslide) that affects the environment, and leads to financial, environmental and/or human losses.
The World is always changing.
Natural disasters are changes which are so great they may cause damage to the shape of the land or to the lives of people and other living things.
Great changes happen deep inside the Earth and on its surface. The changes on the outer part of the Earth happen because of different kinds of weather.
Volcanic eruption Earthquake Cyclone or Hurricane Monsoons Avalanche Flood Drought Forest fire or
Bushfire Tsunami Electrical storms
A volcanic eruption is the spurting out of gases and hot lava from an opening in the Earth’s crust.
Pressure from deep inside the Earth forces
ash, gas and molten rock to the surface.
Landslides
Landslides are also very common with volcanoes. The terrible shaking of an eruption causes the loose debris on the side of the mountain to rapidly fall down its steep flank. However, debris avalanches may also be caused by earthquakes or heavy rainfall. Mount St. Helens eruption caused the largest volcano landslide in recorded history, while Mount Rainier have had at least five large avalanches within the past 6,00 years. Such massive landslides result in a complete burial of surrounding cities and the obliteration of wildlife and such.
An earthquake is a violent shaking of the ground. Sometimes it is so strong that the ground splits apart.
When parts of the earth, called plates, move against each other giant shock waves move upwards towards the surface causing the earthquake.
A Cyclone is a fierce storm with storm winds that spin around it in a giant circle. During a cyclone trees can be uprooted, buildings can be destroyed and cars can be overturned.
A flood is caused by an overflow of water which covers the land that is usually dry.
Floods are caused by heavy rain or by snow melting and the rivers burst their banks and overflow.
Costal floods are caused by high tides, a rise in sea level, storm waves or tsunami (earthquakes under the sea).
A drought is the lack of rain for a long time.
In 1968 a drought began in Africa. Children born during this year were five years old before rain fell again.
Effects
•Drought, of itself, is a devastating event, leading to crop loss and possible topsoil loss
•Drought can weaken an ecosystem by stressing plant and animal resources.
•Flora and fauna not able to find adequate resources are more vulnerable to predation and disease
•Dry conditions can increase not just the number but the severity of fires
Fires can burn out of control in areas of forest or bush land. Fires are caused by lightning, sparks of electricity or careless people. Wind may blow a bushfire to areas where people live.
Fire effects are the physical, chemical, and biological impacts of fire on ecosystem resources and the environment. abiotic effects of fire include its role in changing air quality, water quality, soil properties, and nutrient cycling. Biotic effects include altering vegetation and related impacts on wildlife.
A tsunami is a series of tremendous waves generated by a massive underwater disturbance.
Tsunamis can move at speeds as high as 500 miles per hour.
Tsunamis are capable of causing a substantial amount of damage.
One tsunami can destroy an entire coastal village and remove all the sand from a beach and sand that took hundreds of years to accumulate.
Electrical storms are composed of lightning and thunder, typically accompanied by heavy precipitation.
Each storm forms in large cumulonimbus clouds (thunderheads) stretching one to five miles in diameter with a height of 25,000 feet.
Electrical storms
A tree split in half by lightning
A forest fire caused by an electrical storm
Lightning over a city at night Lightning striking a tall [email protected]
