Advantages and Disadvantages of Television

Natural Disasters

Earthquakes, tsunamis and volcanoes are just some of the deadly hazards we are exposed to on Earth.
As well as being dangerous to humans, these events shape our planet and affect where and how we live. Volcanoes are thought to have played an important role in the emergence of life. They enrich soils, making the land around them good places to grow crops. Earthquakes signal the movement of Earth's tectonic plates, which build mountains (including volcanoes). Fault lines are often rich in minerals – for example, gold is found along the San Andreas Fault in California.

                         AVALANCHES

Avalanches are rapid movements of large masses of snow down a slope that commonly occur in mountainous regions.

                                           EARTHQUAKES

There are thousands of earthquakes across the Earth each day. Most are too small to be detected without monitoring equipment, but some are powerful enough to destroy a city. Sendai, Los Angles, Kobe, Christchurch and Bam are the names of some of the places that have been affected by powerful earthquakes in recent years.

                                            FLOODS

Floods have a variety of causes including heavy rainfall, tidal surges and the failure of manmade structures such as dams. During a flood an area of land that is normally dry is covered by water.

                                           WILDFIRES

Lightning triggers forest fires, or wildfires, but humans have been known to accidentally or intentionally set forests ablaze. Fast moving fires can kill large numbers of people and destroy vast areas of woodland and property.
Fires can be good for many ecosystems, which have evolved to cope with these events. A small fire can remove dead brush, but not kill older trees. Well intentioned fire fighting activities can allow brush to accumulate and leave large amounts of fuel for a future large and potentially unmanageable fire.

                            HURRICANES

Hurricanes are powerful storms that grow in size over tropical seas. Sometimes these storms lose their power before they reach land, but when they do not they can kill large numbers of people and cause widespread property damage.
Hurricane, typhoon and cyclone are regional names for the same type of storm. Weather experts call them tropical cyclones.

TORNADOES

Tornadoes, or twisters as they are often called, are violent storms that can rip paths of destruction through towns and cities and kill large numbers of people. Their characteristic funnel shapes look very dramatic in photographs and videos, though it is difficult and dangerous to get close enough to take these shots.
Tornadoes tend to occur more frequently in parts of the world such as the mid-western United States where weather patterns create the general set of conditions they need to form.

                                                      TSUNAMIS

A tsunami, sometimes referred to as a tidal wave, is a series of ocean waves created when an earthquake or other major disturbance displaces a large volume of water. Powerful tsunamis such as the 2004 Indian Ocean event can devastate coastal regions as the waves sweep far inland.
Following a quake, tsunamis can travel for thousands of miles. For example, after the 2011 Sendai earthquake in Japan, a tsunami alert was issued for almost the entire Pacific region. Places as far away as Chile were affected by the alert.A tsunami is often barely noticeable in deep ocean water, but as it approaches land and enters shallow water, the waves slow and increase in height.

                                                VOLCANOES

Volcanoes are dramatic evidence of the powerful forces at work inside the Earth. Eruptions of ash, gas and lava destroy entire cities and kill large numbers of people.
Volcanoes also add nutrients to soils, creating perfect conditions for many crops. Some types of volcano make new sections of the tectonic plates that make up the surface of the Earth. Without volcanoes and our planet's plates, the dry land we live on would not be renewed, and weathering and erosion by water, wind and ice would eventually carry it all into the oceans leaving Earth a water world.There are three common types of volcano: composite volcanoes, often the most deadly; shield volcanoes, which are large but generally less violent; and cinder cones.