Natural disasters are caused by soil erosion, seismic activity, air pressure, and ocean currents. These natural events have occurred since the the earth began forming and continue to cause serious damage and loss of life all over the globe. the root causes of many of the natural disasters that occur on earth can be attributed to the four factors mentioned above.
Soil erosion is a naturally occurring event caused by rain and wind. Soil erosion washes away soil and rocks in lower lying areas of the earth's surface which can be effected by by floods. Soil erosion is responsible for many floods that have taken place throughout the world.
Seismic activity caused by earth quakes have been the root cause of volcanoes erupting and typhoons. The continents sit on hug plates that occasionally shift. When these plates shift they cause an increase in pressure underneath the earths surface. In areas where volcanoes have formed by solidified magma, pressure from gasses and magma can explode or erupt to send tons of ash into the atmosphere. The famous ancient city of Pompeii was completely buried in this manner. Volcanoes are often formed along the lines of active plate margins. Underneath the ocean magma arises from within the earth's mantle and add to the edges of plates that are in collision. This causes earthquakes, which in turn brings about a tsunami, or giant tidal wave.
Changing ocean currents can result in changes of water temperature which could result in a global food shortage by killing fish and ocean plant life. The currents could also adversely effect the intensity and frequency of storms. Tornadoes are often formed by the interaction of high and low pressure air. Tornadoes have decimated many communities in an area of America known as, Tornado Alley.
Air pressure, high and low determine whether or not we have thunderstorms, rain and hurricanes. Flooding and high winds are caused by the crashing together of low and high pressure air. Damage caused by flooding and hurricanes along coastal cities and towns can be insurmountable for their victims.
Natural disasters have their root causes in the normal activities of the earth. In recent generations however, man's increased knowledge and technology has served to trigger some natural disasters. Flooding and erosion can occur in areas where mining, deforestation, and manufacturing have taken place. Global warming, which could eventually effect the ocean currents, has its roots in modern man's overuse of fossil fuels. Earthquakes can be triggered by drilling, bombing, mining, and construction.