Natural Disasters

1. Natural Disasters By Jorja Selway

2. Earthquakes • An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth’s crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. • At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground. When the epicentre of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a Tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity. • In its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its focus or hypocentre. The epicentre is the point at ground level directly above the hypocenter.

3. One of the most devastating Earthquakes in recorded history occurred on 23 January 1556 in the Shaanxi province, China, killing more than 830,000 people. Most of the population in the area at the time lived in Yaodongs, artificial caves in Loess Cliffs, many of which collapsed during the catastrophe with great loss of life. • The 1976 Tangshan earthquake, with a death toll estimated to be between 240,000 to 655,000, is believed to be the largest earthquake of the 20th century by death toll. • The 1960 Chilean Earthquake is the largest earthquake that has been measured on a seismograph, reaching 9.5 magnitude on 22 May 1960. Its epicentre was near Cañete, Chile. The energy released was approximately twice that of the next most powerful earthquake, the Good Friday Earthquake, which was centred in Prince William Sound, Alaska.  • The ten largest recorded earthquakes have all been Megathrust Earthquakes; however, of these ten, only the 2004 Indian Ocean Earthquake is simultaneously one of the deadliest earthquakes in history. • Earthquakes that caused the greatest loss of life, while powerful, were deadly because of their proximity to either heavily populated areas or the ocean, where earthquakes often create Tsunamis that can devastate communities thousands of kilometres away. Regions most at risk for great loss of life include those where earthquakes are relatively rare but powerful, and poor areas with little or no seismic building codes.

5. Tsunami’s A Tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear), landslides, glacier calving, meteorite impacts  and other disturbances above or below water all have the potential to generate a Tsunami.

6. Tsunami in Japan Japan was hit by a 9.0 magnitude earthquacke on March 11, 2011, that triggered a deadly 23-foot tsunami in the country's north. The giant waves deluged cities and rural areas alike, sweeping away cars, homes, buildings, a train, and boats, leaving a path of death and devastation in its wake. Video footage showed cars racing away from surging waves. The earthquake—the largest in Japan's history—struck about 230 miles northeast of Tokyo. The Pacific Tsunami Warning Center issued warnings for Russia, Taiwan, Hawaii, Indonesia, the Marshall Islands, Papua New Guinea, Australia, and the west coasts the U.S., Mexico, Central America, and South America. According to the official toll, the disasters left 15,839 dead, 5,950 injured, and 3,642 missing. Japan's Tsunami Triggered an Enormous Whirlpool

7. Volcanic eruption’s • A volcano is a landform (usually a mountain) where molten rock erupts through the surface of the planet.  • In simple terms a volcano is a mountain that opens downward to a pool of molten rock (magma) below the surface of the earth. It is a hole in the Earth from which molten rock and gas erupt. There are around 1510 'active' volcanoes in the world. We currently know of 80 or more which are under the oceans.

9. Hurricane’s What is a hurricane?A hurricane is a huge storm! It can be up to 600 miles across and have strong winds spiraling inward and upward at speeds of 75 to 200 mph. Each hurricane usually lasts for over a week, moving 10-20 miles per hour over the open ocean. Hurricanes gather heat and energy through contact with warm ocean waters. Evaporation from the seawater increases their power. Hurricanes rotate in a counter-clockwise direction around an "eye" in the Northern Hemisphere and clockwise direction in the Southern Hemisphere. The center of the storm or "eye" is the calmest part. It has only light winds and fair weather. When they come onto land, the heavy rain, strong winds and large waves can damage buildings, trees and cars.

10. Twister’s/Tornado’s • A tornado is a dark funnel-shaped cloud made up of violently rotating winds that can reach speeds of up to 300 mph. A tornado is a violent rotating column of air extending from a thunderstorm to the ground. The most violent tornadoes are capable of tremendous destruction with wind speeds of up to 300 mph. They can destroy large buildings, uproot trees and hurl vehicles hundreds of yards. They can also drive straw into trees. Damage paths can be in excess of one mile wide to 50 miles long. In an average year, 1000 tornadoes are reported nationwide.

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