Formations
Tornado
Most tornadoes form from thunderstorms. You need warm, moist air from the Gulf of Mexico and cool, dry air from Canada. When these two air masses meet, they create instability in the atmosphere. A change in wind direction and an increase in wind speed with increasing height creates an invisible, horizontal spinning effect in the lower atmosphere. Rising air within the updraft tilts the rotating air from horizontal to vertical. An area of rotation, 2-6 miles wide, now extends through much of the storm. Most strong and violent tornadoes form within this area of strong rotation.
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I would like to give thanks to this site: http://www.weatherwizkids.com/weather-tornado.htm
Hurricane
Warm air, together with moisture from
evaporation from the ocean surface rises, creating low pressure on the
water surface, which is immediately replaced by cooler air. This process
continues, and the resulting moisture-laden clouds begin to expand.
Thunderstorms with rains form. The thunderstorms with rains begin to move slowly with mild western winds (too much winds will disperse the buildup). In a day or two, stronger vertical currents build up over the ocean surface upward. More warm air rises and the winds begin to move in circular manner, caused by the earth’s rotation. The rising warm air causes pressure to decrease at higher altitudes. The entire system is now in circular motion around a central point. This is called a tropical depression and they have a wind speeds going up to about 38 miles per hour. n a couple of days, as the system moves over more warmer waters, the clouds expand even more, and the winds begin to speed up. Gale force winds, thunderstorms and heavy rains are in full force at this point. This may be called a tropical storm, and they have wind speeds up to 74miles per hour. Continuing its movement westward, the tropical storm may be moving over even warmer waters. The energy from the warm ocean, in the form of very warm air rising and the gushing of cooler air replacing it throws the entire storm into a fury of powerful, huge and monstrous spiral storm that can be seen from space. The spiral has a calm center called the eye. The eye, is surrounded by a towering and extremely dangerous vertical movement of thunderstorms. This is called the eye wall. The winds of the eye wall is so powerful that it spins and carries huge amounts of ocean water as it moves ashore. Now it is a HURRICANE.
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I will like to give thanks to this site: http://eschooltoday.com/natural-disasters/hurricanes/how-do-hurricanes-form.html
Tsunami
Undersea earthquakes, which typically occur at boundaries between Earth’s tectonic plates, cause the water above to be moved up or down. Tsunami waves are formed as the displaced water, which acts under the influence of gravity, attempts to find a stable position again. Undersea landslides, which can be caused by large earthquakes, can also cause tsunami waves to form as water attempts to find a stable position. Undersea volcano eruptions can create enough force to uplift the water column and generate a tsunami. When movement along a fault moves the seafloor upward, water is also pushed upward and becomes tsunami waves. As the waves approach shallower water, they become higher. More rarely, a tsunami can be generated by a giant meteor impact with the ocean.
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I would like to give thanks to this site: http://www.windows2universe.org/earth/tsunami2.html
Monsoon
A monsoon is not just any heavy rain that lasts for a long time. Rather, a monsoon is like a giant sea-breeze. A normal sea breeze changes daily, with the day-to-night change of land temperature as the sun rises and sets; monsoons change seasonally. Figure A compares seasonal shifts in the monsoon circulation. Most of the time during the summer, the land is warmer than the ocean. This causes air to rise over the land and air to blow in from the ocean to fill the void left by the air that rose. As you know, rising air leads to cloud formation and precipitation. These monsoon clouds that form are full of moisture from the ocean, so they can produce heavy rainfall for long periods of time. Because the land stays warmer than the ocean for most of the summer and the ocean is a constant source of moisture, these heavy rains last for months at a time. A monsoon climate is marked by dry winters and wet summers. About a quarter of the globe experiences a monsoon climate.
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Mudslides
Earthquakes, volcanic eruptions, and changes in groundwater levels, alternate freezing and thawing, and the steepening of slopes by erosion all contribute to mudslides. Construction and reckless modification of land – such as not draining an area properly before building on or near it – can also create the conditions ripe for a mudslide, Highland said. During a fire, burning plants release gas that permeates the soil. Then roots weaken. After a fire, the gas
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As you can see that mudslides are vary dangerous they can move houses, trees, and even boulders.