Natural+Occurrences

// Natural // **Occurrences

** __** El Nino **__  El Nino is the event where the eastern waters of the Pacific Ocean become much warmer than usual, especially around December. El Nino is Spanish for 'The Child'. Since El Nino occurs during the end of the year, they have named it 'The Child' after the birth of Jesus Christ (Sample, 2006). Usually, the western waters of the Pacific Ocean are much warmer than the eastern, but the temperatures essentially switch. As a result of this 'switch', the water in the eastern Pacific Ocean evaporates more quickly, known as convection. And once the water vapor cools, it will precipitate. Since the rise in heat temperature increases the rate of convection, this increases the amount of vapor in the air. This large amount of water vapor causes large rainfall. Around this time, the trade winds blowing towards the west weaken, allowing the cloud systems to travel closer to South America (Sample, 2006). Scientists have found a correlation between the intensity of El Nino and the certain weather patterns in far distant regions. The air pressures also change, usually the western part of the Pacific Ocean has lower pressure and the easter part of the Pacific Ocean has higher pressure, but in the case of El Nino, it is reversed. The reverse of pressures is called the Southern Oscillation. When scientists realized that the reverse of pressures and El Nino were both linked and related, they coined the term El Nino Southern Oscillation (ENSO), and the most catastrophic El Nino events are those in the warm phases of ENSO. (Kreger, 2004)

Since catastrophic El Nino events and the ENSO follow certain changes in the climate and sea. Scientists are able to detect when an ENSO event might occur Here are a few of the indicators
 * Scatterometers and radiometers from satellites measure the intensity of the surface of the ocean
 * Satellites can observe and record cloud systems and rainfall amounts
 * Sea Surface Height and Temperature, using radar altimeters and infrared
 * Phytoplankton Production can be seen through the Coastal Zone Color Scanner
 * Changing pressures between west and east Pacific Ocean

The El Nino event is an unnormal change in the global patterns, and it affects countries that do not expect such flooding and rainfall, such as those in South America. The worst El Nino event was the 1982-1983 El Nino, which caused massive flooding and droughts, leaving 1,100 dead and 8 billion dollars in damage (Sample, 2006).**__

Monsoons and Tsunamis __**

The word monsoon is derived from the Muslim word 'mausin' which can be interpreted as season. Monsoons cycle in seasons, and is caused by changes in the wind between land and sea, but are mostly associated with heavy rainfall and dry seasons. The most common monsoons are found in Asia, especially in the country of India, and the eastern countries bordering India. The main cause is the rate of heating air. During the land, comprised of beach and shore, heats air more quickly, and the air rises. Meanwhile, the cold air from the water moves in. At night, the land is colder than water, and the air flows towards the ocean. The monsoon, technically begins in April, but the raining only occurs in late May. In the time between April and May, the monsoon is preparing a large temperature difference between the land and the ocean. It can be as much as 20 degrees Celsius, which is about 68 degrees Fahrenheit. As the winds with water vapor blow onto land, clouds start to form over southeast Asia. The exact time when the rainfall begin varies, which makes the farmer's life more complicated, since too much rain will harm the crops, but too little rain will starve the crops. (The Asian Monsoon, 2008)

Tsunamis are a series or groups of large waves that were created by a huge disturbance either close to the shore or in the middle of the ocean. The disturbance can be a rift or a shift in the tectonic plates. A disturbance can include earthquakes, landslides, volcanic eruptions, explosions, or anything that displaces a substantial amount of water. The displaced water creates an gap, which needs to be filled, and this sudden change in equilibrium can create tsunamis. Tsunamis can travel as fast as 590 mph, and can approach wavelengths of up to 60 miles. Tsunamis can destroy houses, flip cars, and send debris and boulders far inland. The most recent tsunami was in the 21st century in December 2004 occurring in the Indian Ocean. (Tsunamis, 2008)

**__ Earthquakes and Volcanic Eruptions __**

The earth is covered in large land crust masses called tectonic plates. Earthquakes happen between two tectonic plates at a fault zone, and the two plates suddenly move. They are colliding with one another, and friction and force are holding them together. But once enough force and strain is applied to them, the bonds can break releasing large amount of energy such as seismic waves. This energy will cause rifts or mountains on the physical landscape of the earth. Since the tectonic plates are always moving and having force applied to each one, there are a number of different ways tectonic plates can interact with one another. Volcanic eruptions are related to earthquakes since they both are caused by the movement of tectonic plates, and earthquakes are likely to form in volcanic spots. Volcanoes are much like earthquakes, but they also have magma spouting from the mantle. The most likely place for a volcano is the "Ring of Fire" which is the outline of the Pacific Ocean, bordering th east coast of Asia, and the west coasts of the Americas. The most recent earthquake was the one that occurred in Szechuan Province in China with a seismic scale of 7.9 on the Richter scale. (Topinka, 2001)

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