Presentation on theme: "Earthquakes An Earthquake is a sudden shake of the Earth's crust.The vibrations may vary in magnitude. The earthquake has point of origin underground."— Presentation transcript:
Earthquakes An Earthquake is a sudden shake of the Earth's crust.The vibrations may vary in magnitude. The earthquake has point of origin underground called the "focus". The point directly above the focus on the surface is called the"epicentre".Earthquakes by themselves rarely kill people or wildlife.
Floods Floods are among the most frequent and costly natural disasters. Conditions that cause floods include heavy or steady rain for several hours or days that saturates the ground. Flash floods occur suddenly due to rapidly rising water along a stream or lowlying area. Floods
Tornadoes Some of the most violent tornadoes develop from supercell thunderstorms. A supercell thunderstorm is a long-lived thunderstorm possessing within its structure a continuously rotating updraft of air.A supercell thunderstorm is a long-lived thunderstorm possessing within its structure a continuously rotating updraft of air.These storms have the greatest tendency to produce tornadoes, some of the huge wedge shape. Generally weaker than a supercell tornado. It often forms along the leading edge of rain-cooled downdraft air emanating from a thunderstorm, known as a “gust front.” Weak and usually short-lived, a gustnado forms along the gust front of a thunderstorm, appearing as a temporary dust whirl or debris cloud.
Fire Wildfires are an uncontrolled fire burning in wildland areas. Common causes include lightning and Wildfiresrought but wildfires may also be started by human negligence or arson.
Health and diseases An epidemic is an outbreak of a contractible disease that spreads at a rapid rate through a human population. A pandemic is an epidemic whose spread is global.