Natural disasters
-----Earth’s crying
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Types
Sudden disaster(突发性灾害）:
Earthquake, volcano eruption（火山爆发）, mudslide（泥 石流）, tsunami（海啸）, typhoon, flood
Gradual disaster（渐变性灾害）:
Ground subsidence（地面沉降）, land desertification（土 地沙漠化）, drought, the coastline change（海岸线变化）
Environment disaster（环境灾害）:
The change of ozone layer（臭氧层变化）, pollution of water, soil erosion（水土流失）, acid rain（酸雨）
What’s earthquake
1
2
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves（地震波）. Sometimes an earthquake has foreshocks. There are smaller earthquakes that happen in the same place as the larger earthquake that follows.
earthquake
tsunami
mud-rock flow
seismic sea wave / tsunami
volcanic eruption
thunderstorm
Tsunami
1.Area
2.Reason
3.Influence
Area
①Alps to the Himalayas ②Pacific Rim
What shall we do if an earthquake happens?
Ways on self-rescue
drop onto the ground
keep away from the power lines
keep away from the signs
keep away from the buildings
3
Scientists can’t tell that an earthquake is a foreshock until the larger earthquake happens.
What do you think may happen before an earthquake?
• 1) The weather will become worse than usual. There will be strong wind, heavy rain and bright light in the sky and so on. • 2) Animals will become nervous. e.g. mice will run about; fish jump out of ponds; cows, pigs, horses and dogs will be upset. • 3) Water in rivers and wells will rises and falls. • 4) We will see cracks in the wells and the smelly gas will come out of the cracks. • …
How much do you know about an ed…… People lost their homes….
Many things were destroyed…..
The Origin of Earthquake:
Earthquakes happen because the outer layer of the earth (the crust) is slowly being deformed by stresses that are placed on the crust. These stresses build up along locked portions of the crust where e art h q u ak e f a ul t s( 断 层 ) ar e . Eventually the stresses become too great for one of the faults to withstand( 承受 ), and the crust suddenly moves, like a spring that has been wound too tightly. This sudden movement of the ground is called an earthquake.
Earthquake Hazard
• uproot trees and knock off buildings • make the rivers change their courses • make the transportation system break down • cause power line failures • cause loss of life and property • trigger landslides,flooding and tsunamis • may cause infective deseases
So, we should be alert and take effective actions to protect ourselves in case of unexpected attack of nature.
hold onto the furniture
hide under the furniture
hide in the corner of the house
drop onto the ground
People in the disaster
People in the disaster
I feel the pain, but feel no despair!!! Our wills unite like a fortress.
Reason
Indonesia tsunami印尼海 啸, India plate印度板块 Eurasian plate欧亚板块, fault line断层, fluctuation波动, consequently结果
Influence
House
Car
Building
On the December 26, 2004, a strong earthquake hit the Indian Ocean. And the earthquake and tsunami cause over 300 000 deaths and many injuries, and millions of people are made homeless.
A difficult help come from all quarters.
To sum up:
Nowadays, as the industry and economic development,
natural disasters have become more and more frequently, environment also become more degradation.
• 2008,5.12 : Sichuan Province, China: The
7.9-magnitude disaster destroied millions of buildings and caused an estimated $86 billion worth of damage
Discussion
deadliest earthquake on record in china
• 1976: Tangshan, China: nearly the second
• 2004: Indian Ocean Tsunami: on Dec. 26,
2004 a 9.2 magnitude earthquake rocked the bottom of the Indian Ocean, the official death toll was 227,898
So, environmental protection is paid more and more attention by people. Varies of measures are taken to protect the environment to avoid destruction of human activities.
Some serious earthquakes in the history
• 1923: Kanto, Japan:
on September 1, 1923, an earthquake measuring 7.9 sent shockwaves through the Tokyo-Yokohama area and caused Nearly 143,000 people died.