The fastest and the most fierce winds on the Earth: Tornadoes
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A tornado is a strong, small-scale air vortex, unstable weather conditions in the strong convection movement of air generated by the thunderstorm cloud base extending to the ground funnel cloud (tornado) created a strong cyclone , the wind up to 12 and above, up to 100 meters per second or more, usually accompanied by thunderstorms, sometimes accompanied by hail.
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Air around the tornado's axis rotation quickly, reducing extreme pressure by the tornado center attracted tens of meters thick near the surface a thin layer of air, the air was inhaled from all directions at the bottom of the vortex, and then into the axis Heart-up vortex. Tornadoes in the wind is always cyclonic, and its center of pressure can be lower than the surrounding air pressure 10%.

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Tornadoes are associated with high-speed rotation of the funnel-shaped cloud of strong wind vortex, wind speed near its center up to 100m / s ~ 200m / s, maximum 300m / s, than the typhoon (from the ocean) the maximum wind speed near the center of several large times. Central pressure is very low, as low as 400hPa, the lowest up to 200hPa. It has great sucking effect, can the sea (lake) water suction from the sea (lake) side to form a water column, and then connecting with the cloud, commonly known as "Dragon water." As the tornado is extremely thin internal air, and the temperature rapidly decreases, water vapor quickly condenses, forming funnel cloud is an important reason. Funnel cloud diameter, the average is only about 250m. Instability resulting from a strong tornado in cumulonimbus. Its formation was strongly increased with the warm air, cold air south, the terrain effects, and so on. Its life history is short, the general maintenance of 10 minutes to 12 hours, but its amazing destructive power, able to uproot trees, buildings blown down, or the part of the surface material to air volume.

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The conformation of Tornado

Tornadoes is natural phenomenon is a product of thunderstorm clouds. Specifically, a huge thunderstorm tornado is a small part of the energy in a small area in a concentrated form of release. Tornado formation can be divided into four phases:

(1) the instability of the atmosphere produce a strong rising air currents, as the biggest rapids in the flow of transit, it was further strengthened.

(2) As with the vertical velocity and the direction of the wind shear interaction are increased by air in the middle troposphere begin rotating, the formation of mesoscale cyclones.

(3) With the development of mesoscale cyclones in the ground and up to stretch, and strengthen its own thinner. Meanwhile, a small area of enhanced counseling together, that is born within the formation of tornadoes in the cyclone, cyclone produced the same process, forming a tornado core.

Sea Tornado

(4)Tornadoes and cyclones in the core of the Rotary is different, because it is strong enough to make tornadoes has been extended to the ground. When the development of the vortex to reach ground level, the sharp decline in surface pressure, surface wind speed increased rapidly to form a tornado.

Tornadoes often occur in summer lightning storm, the most common especially in the afternoon to evening. Attack range of small diameter cyclones typically between 10 meters to several meters. Tornado survival time to only a few minutes, more than a few hours. Wind particularly in wind speed near the center of up to 100-200 m / sec. Extremely destructive, tornado through the place, often occur uprooted trees, overturned cars, destroyed buildings and other phenomena, sometimes people take away a very serious hazard.

Tornado hazard:

In the United States in 1995, Oklahoma A have occurred in the city of a moire tornadoes, heavy objects such as the roof was blown out like hundreds of miles away. Most pieces fall tornadoes left channel, by weight, often ranging from the landing zone is clear. Lesser fragments may fly more than 300 kilometers away before landing.

Attacks in the strongest tornado, the house as the roof will be like to fly hang gliders. Once the roof was swept away, the house will follow the collapse of the rest. Therefore, building housing, if we can enhance the stability of the roof will help prevent the enormous losses caused by a tornado crossing.

Tornado attack suddenly and violently, resulting in the wind is strongest on the ground. In the U.S., the number of tornado deaths each year after the lightning. It is also very serious damage to buildings, often devastating.

By:Ren Xian

Total solar eclipse


Total solar eclipse is a solar eclipse, the moon that the sun was all covered in astronomical phenomena. If the sun and the moon, the Earth just three or close to a straight line up, the moon blocking the sun shines up the earth, the moon just behind the shadows fall on Earth, when a solar eclipse phenomenon. Moon Shadow on Earth where people are beginning to see the sun gradually weakened, the sun's shadow covered surface is round, the sky turned dark, full cover, the sky can be seen in the brightest stars and planets, a few minutes later, from the gradually exposed edge of the moon shadow the sun began to students light, complex circle. Smaller than the Earth as the moon, and only in shadow on the people to see the total solar eclipse.

Causes of total solar eclipse

Solar eclipse, but also as a solar eclipse is an astronomical phenomenon, when the Moon to the Sun and the Earth is between, on the parts of the earth, the moon blocking the sun, some or all of the light, looks like the sun part or all of the disappeared, hence the name. Only in the New Moon eclipse, the moon and the sun that is present when the state of cooperation.

Solar eclipse is a rare phenomenon, in three of the more rare solar eclipse is total solar eclipse, because only the Moon's umbra projection face of the earth, the people in the region to observe the solar eclipse. Total solar eclipse is a very spectacular natural phenomena, so often attracts many tourists go abroad specifically to watch total solar eclipse of the scene. For example, in 1999 the total solar eclipse occurred in Europe, attracting so many tourists specially went to watch, but also introduced special tour designed for those tourists visit.

In ancient times, humans lack the knowledge of astronomy, solar eclipse is the day that the dog days, or a symbol of disaster, held a ceremony in eclipse. However, in modern society, the solar eclipse this sense has been gradually abandoned by the people.

The last total solar eclipse in China occurred on July 22, 2009.


Introduction of the total solar eclipse

Because of moon around the earth running from west to east, so the solar eclipse is always round the edge of the beginning of the West side. When the moon's eastern edge to the sun, round face, new to the moment (that is, the eastern edge of the lunar surface and on the West edge with circumscribed moment), called the initial loss. Early losses is the beginning of the eclipse time.

Both fresh start from the early deficit, that is, a partial eclipse phase. The moon continues to run east, the sun is the moon round face cover part of the increases, the intensity of the sun and the heat dropped significantly. Month with the Japanese side of the east edge of the eastern edge of phase inner surface when cut, as both fresh. At this time the entire sun is covered with a round face, so food is not only the start of a solar eclipse.

The significant value of total solar eclipse

The reason why total solar eclipse attention, but the main reason is that the value of its huge astronomical observations.

Solar eclipse, solar eclipse in particular: is it an excellent opportunity to understand the sun. We usually see the sun, but it is part of the light ball, light ball outside of the solar atmosphere of the two important levels - the chromosphere and corona, are submerged in the bright light shining into the ball. Chromosphere is the solar atmosphere in the middle, which is in the ball of light above the 2000-km thick layer; in the sun outside, but also surrounded by very high temperatures (millions of degrees Celsius) but very thin plasma, extended area many times larger than the sun itself, this is called the corona. The brightness of the corona is only one millionth sun itself, usually it is completely hidden in the earth's atmosphere caused by scattering of light in the blue canopy. Total solar eclipse, the moon blocking the sun's light ball with a round face, dark sky in the background, have seen a red ball and silver color white corona, scientists can at this particular time, under certain conditions, observed chromosphere and corona, and shoot color balls, pictures and spectra of the corona to study the sun's physical state and chemical composition. For example, in August 18, 1868 the total solar eclipse, the French astronomer to shoot the Japanese mulberry feeding spectrum, discovered a new element "helium", the element has been in the past twenty years, the only Rem by the British chemist found on the earth element.

Solar eclipse can study the relationship between Sun and the Earth to provide a good opportunity. Sun and Earth has a very close relationship. When the sun to generate strong activity, it issued a far-ultraviolet, X-rays, particle radiation, and this will, make the earth's magnetic field, ionosphere disturbances occur, and produce a series of geophysical effects, such as magnetic storms, auroral disturbances short-wave communications interruption. In the total solar eclipse, because on the surface of the moon gradually cover the various sources, which led to changes in various geophysical phenomena, so the total solar eclipse when the various effects of the geophysical observation and research has some practical significance, observe the total solar eclipse and has become an important part of the study.

Total solar eclipse observation and research, but also help to study astronomy, physics many issues, using total solar eclipse of the opportunity to find a recent Stars and planets within the orbit of Mercury; to measure the stars near the sun passed from bending to test general relativity, can study the nature of gravity and so on.

In addition, the study of solar eclipse solar eclipse occurs when the weather changes, biological reactions have a certain significance

The history of science there are many major astronomy and physics discovery is the opportunity to make use of solar eclipse, and only through such opportunities Caixing. The most famous example is the 1919 a total solar eclipse, confirming Einstein's general relativity is correct. Albert Einstein published in 1915 appears to be very difficult to understand at the time, but also very hard to believe general relativity, this theory predicts light in the huge gravitational field will bend. Most human beings can be exposed to the gravitational field is the sun, but the sun itself issued a very strong light, faint distant stars near the sun after not turning up, simply do not see. However, if the total solar eclipse, blocking sunlight, it can be measured without turning out the light Po, Po how much bending. Opportunity to appear in 1919, but the total eclipse zone in the South Atlantic, the very remote, very hard. British astronomer Eddington enthusiasm and curiosity with a strong observation team off. Einstein observations and calculated results agree well in advance, from theory of relativity by world recognition.


By:Ren Xian

Volcano

what is volcano?

100 to 150 kilometers under the crust, there is a "liquid zone" area there is high temperature, high pressure gas containing volatile silicate melt-like substance that is magma. Once it is out of the lot from the weak surface crust to form the volcano. Can emit a variety of substances.

Causes of volcanos:
At a distance of about 32 km deep in the ground there is a large number of high-temperature liquid, its temperature high enough to melt most of the rock.
Expansion of the rock to melt, need more space. Some parts of the world, mountains in the uplift. These are mountains rising pressure following smaller, these mountains may form a lava below (also called "magma") library.

This material along the rift caused by increased uplift. Curry is greater than the pressure of the lava rock above it the pressure cap, then burst out into a volcano.
Eruption, the hot gas, liquid or solid material suddenly emerge. These substances accumulate in the openings around the formation of a conical hill. "Crater" is a volcanic cone at the top of depression, openings through to the surface. Volcanic cone is a product of Mt. Volcanic material emitted mainly gas, but like a lot of volcanic slag and ash and solid material are sprayed out.
In fact, out of volcanic rocks are volcanic magma, close to the surface when the magma rises to the height that it began to decrease the temperature and pressure, physical and chemical changes occurred, becomes a volcanic magma.

Affects:
The most powerful, the most spectacular volcanic eruptions often occur in subduction zone. The volcano may be quiet here for several hundred years later another outbreak, but once it started, power is particularly fierce. This eruption often will doom humanity.
When a large number of volcanic eruptions ejected ash and volcanic gases, causing a great impact on the climate. Because in this case, the dark and stormy day, rain or mud will be troubled by local residents for several months. Volcanic ash and volcanic gas was sprayed into the high altitude and going, they will spread to the wind far away. These volcanic materials will cover sun, leading to the temperature drop. In addition, they also filter out certain wavelengths of light, making the sun and the moon look like covered with Halo, or strange glowing colors, especially at sunrise and sunset when the formation of unusual natural landscape .
Large volcanic eruptions of ash and rain combine to form debris flows can be washed away roads, bridges, flooding nearby villages and cities, making many people homeless. Soil, rock debris slurries can be formed generally as floods inundated the city.
Although the rock is volcanic ash cloud cover, but still see the volcanic eruption had just been sprayed into the sky a huge rock.
Volcanic eruptions on the far-reaching impact of the natural landscape. Land is the world's most valuable resource, because it gave birth to a variety of plants to support all things. If the farmland covered with volcanic eruptions can give less than 20 cm thick ash, on the farmers is really Xicongtianxiang, because ash is rich in nutrients can make the land more fertile.
After the collapse of lava, moss weeds start to emerge.
Rope-like lava flows off hillsides to grow ferns.
Ash to the surrounding fertile land, the local grape harvest year after year.

However:
Although volcanoes often enormous disaster to human beings, it also has some advantages. Volcanic use of resources can bring the fun and convenience of our lives. In general, the volcanic resources are mainly reflected in its tourism value, geothermal and volcanic materials. Volcanic and geothermal are twin brothers, where generally there is volcanic geothermal resources. Geothermal energy is a cheap new energy, and pollution-free, and have been widely used. Now, from the medical, tourism, agricultural greenhouse, aquaculture has been to the civil heating, industrial processing, power generation, can see the application of geothermal energy. It had been Kamai Te volcanic geothermal area calculations, where tens of thousands of natural steam and hot water vents, the average emission of hot water and steam per second up to 2 million cubic meters a year from the Earth 40 trillion out of the heat within the calories, the equivalent of 600 million tons of coal energy. As the volcanic activity in Iceland is located in areas that can be developed for the 45 billion kwh of geothermal energy, geothermal power generation capacity up to 7.2 billion kwh in, where people make good use of this resource, although only the development of 7% of them, but had to bring many benefits to local people. Among them, the Reykjavik around three geothermal power plant to provide hot water for the 150,000 Icelanders, and electricity, while 85% of the entire Icelandic population through geothermal heating. Geothermal resources clean, greatly reducing the imports of oil and other energy sources. Since 1975, the Icelandic air quality greatly improved. Icelanders are also able to improve the efficient use of geothermal resources, including plants in greenhouse vegetable planting, the establishment of all-weather outdoor swimming pools, sidewalks and parking lot in the hot water pipes are laid in order to speed up the melting winter snows. Now, a dozen countries around the world are using geothermal energy for power generation, China has established the largest Tibetan Yangbajain geothermal test site, to obtain good results.
Volcanic activity can create a variety of minerals, the most common is the formation of sulfur mine. Terrestrial eruption of basalt, often out of natural copper and calcite crystals, submarine volcanic eruptions of basalt, often can be a huge scale iron ore and copper. In addition, our well-known diamond, and the volcano is also related to the formation. Basalt is the most widely distributed of a volcanic rock, but it also is a good building materials. Smelting of basalt known as "cast stone", can be made into a variety of plates, utensils and so on. Cast stone features the largest hard wear-resistant, acid and alkali, non-conductive and may for insulation materials.



By: Ren Xian

Martinique - you live, you become taller.

when people are teenages, the bodies are growing, but to the adult, not taller. Curiously, the world has a unique island, the island's residents figure was very tall, and visitors from abroad, as long as the live one time, also president of a few centimeters high. Because of this island, "mettle" was hailed as: "the island make people taller".

This magical island in the vast expanse of the Caribbean, called "Martinique." Every 10 years or so, the island would have puzzled the emergence of a very strange phenomenon: the island's adult men and women living in high-was a few centimeters long, the average height of adult men, up to 1.90 m, the average height of adult women are also more than 1.74 meters. If the island's young men less than 1.8 meters tall, will be companions ridiculed as a "dwarf."

This "courtesy", some from people who are too short body, is clearly a "gospel." Therefore, Martinique attracts many tourists each year visit, most of which is the short man from around the world. Shorty came to this island to live on a period of a few centimeters taller will somehow, so people called the island of Martinique as a "dwarf's Paradise."

In fact, not only people that even the island's animals, plants and insects grow more rapidly. Island ants, flies, beetles, lizards and snakes, etc., from 1948 onwards about 10 years increased by several times than usual, especially in the island's rats, like cats actually looks great.

Martinique's Pervan dam has a custom pull people - never bend. Even the most valuable items lost on the ground, and they never bend down to pick up, but unplug the plug at the back of a bamboo clip, bulging lumbar bamboo clipped.Martinique, in the Antilles in the most northern part of the Windward Islands. Is the largest of the Windward Islands, volcanoes and picturesque islands. Martinique is a French overseas territory of France that this is part of its non-infringement. St. Martin, named in the order before it's called the "horse to Nina Madinina" means "flower island" inhabited by indigenous peoples.

Undulating topography of the island, except in the central and coastal plains, a number of volcanic areas, compared with the Leeward Islands, significantly more than the rock. Its beaches (from black or white or salt and pepper colored sand composition) from sugar cane, palm trees, bananas and pineapple and other plants around. Columbus called the world's most beautiful country. Pelee volcanic peak altitude of 1397 meters, is the famous West Indies in the very active volcano. 1902 pelee volcanic eruptions, caused about 26,000 within a few minutes to 36,000 people were killed, only two survived, while the destruction at the time the largest city Saint Pierre Martinique. Tropical rain forest climate.

Island sugar cane, bananas, pineapples and other tropical fruit, with sugar, wine, oil refining, cement, timber and other industries.

Capital: Fort de France (Fort-de-France), population 100,080 (1990); area: 1100 square km;

Population: 385,000 (1995), mainly black and white mixed race; population density: 350.5 persons per square kilometer;

Language: The official language is French. Also generally Creole dialect; Religion: Roman Catholic majority of the population;

Time difference: 4 hours later than GMT, 12 hours later than Beijing;

Power: 220 volts AC, 50Hz;

Communications: Telephone: IDD apply. Country code is 596. 0033 International Code itself Martinique French national, international code of course, and France the same. Existing pay phones on the island, there are card phones. Phone cards can be purchased at post offices, airport card only phone. Mobile Phone: Dual Band GSM network. Run roaming agreements. Network providers include: France Telecom and Amis. Coverage extends to the French Antilles and French Guiana. Fax: Most hotels can fax. Internet / E-mail: local service providers (ISP), including wanadoo and the Antilles-net. Post: send a letter to Europe takes about a week. Post office opening hours are: Monday through Friday 7 am to 6 pm and Saturday mornings. Newspapers: Newspapers in French. Major dailies are: France-antille.

by Ren Xian