Explanation

Explanation

Definition and purposes of Explanation
Explanation is a text which tells processes relating to forming of natural, social, scientific and cultural phenomena. Explanation text is to say 'why' and 'how' about the forming of the phenomena. It is often found in science, geography and history text books.

Generic structure of Explanation
General statement; stating the phenomenon issues which are to be explained.
Sequenced explanation; stating a series of steps which explain the phenomena.

Language Feature of Explanation
Featuring generic participant; sun, rain, etc
Using chronological connection; to begin with, next, etc
Using passive voice pattern
Using simple present tense

Exampel Teks Explanation
Text 1
The Process of Rain
Water in the earth is kept in many places like the ocean, the ocean, the river and the lake. But don't be wrong, the plants leaves and the land also kept water.
Each day, this water will evaporate with help of the sun. The process where water evaporates from plants is called transpiration. Afterwards the vapour will experience the process of condensation where the vapour will condense and turn into a cloud. The form of the cloud always changes according to weather conditions.
The clouds will move to different locations with the help of wind that bellows vertically or horizontally. The movement of the vertical wind results in the cloud forming big 'lumps'. After that, the wind increases the size of the cloud and each cloud will overlap. Finally the cloud will reach the atmosphere that has a lower temperature. Here the particles of water and ice is formed.
Eventually, the wind can not support the weight of the cloud and so the cloud that is full with water will experience a process called precipitation or the process where rain or hail falls to earth.
Text 2
Tsunami
Tsunami is a Japanese word, meaning, “harbor wave” and is used as the scientific term for a seismic sea wave generated by an undersea earthquake or possibly an undersea. Landslide or volcanic eruption. When the ocean floor is tilted or offset during an earthquake, a set of waves is created similar to the concentric waves generated by an object dropped into the water. Most tsunamis originate along the Ring of Fire, a zone of volcanoes and seismic activity, 32,500 km (24,000 ml) long that encircles the Pacific Ocean . Since 1819, about 40 tsunamis have struck the Hawaiian Islands .
A tsunami can have wave¬lengths or widths of 100 to 200 km (60 to 120 ml), and may travel hundreds of kilometres across the deep ocean, reaching Encarta Encyclopedia speeds of about 725 to 800 km/h (about 450 to 500 mph). Upon entering shallow coastal waters, the wave, which may have been only about half a meter (a foot or two) high out at sea, suddenly grows rapidly. When the wave reaches the shore, it may be 15 m (50 ft) high or more. Tsunamis have tremendous energy because of the great volume of water affected. They are capable of obliterating coastal settlements.
Tsunamis should not be confused with storm surges, which are domes of water that rise underneath hurricanes or cyclones and cause extensive coastal flooding when the storms reach land. Storm surges are particularly devastating if they occur at high tide. A cyclone and accompanying storm surge killed an estimated 500,000 people in Bangladesh in 1970.


Text 3
How It Works
Frogs are delightful creatures. Our country is home to more than 220 named species and they can be found in almost any Australian landscape. Most frogs lay eggs on land or in the water. Then, after the eggs hatch,
Tadpoles enter the water for two weeks to six months, depending on the temperature, before emerging as froglet (baby frog). Not all frogs do this. The hip~ pocket frog is a very interesting example of parental care. After the female hip-pocket frog has spawned, the male will lie on her eggs and about eight tadpoles wriggle up into each pocket where they grow into baby frogs. Australia ’s two species of gastric brooding frogs are even more amazing. They swallow their fertilised eggs and hatch the tadpoles in their stomachs. Six weeks later the _froglets emerge from their mother’s mouth.


Text 4
PETROLEUM PRODUCT
Petroleum products, such as gasoline, kerosene, home heating oil, residual fuel oil and lubricating oils, come from one source - crude oil found below the earth’s surface, as well as under large bodies of water, from a few hundred feet below the surface to as deep as 25,000 feet into the earth’s interior. Sometimes crude oil is secured by drilling a hole through the earth, but more dry holes are drilled than those producing oil. Pressure at the source or pumping forces crude oil to the surface.
Crude oil welts flow at varying rates, from ten to thousands of barrels per hour. Petroleum products vary greatly in physical appearance: thin, thick, transparent, or opaque. Their chemical composition is made up of only two elements: carbon and hydrogen, which form compounds called hydrocarbons. Other chemical elements found in union with the hydrocarbons are few and are classified as impurities. Trace elements are also found, but these are of such minute quantities that they are disregarded. The combination of carbon and hydrogen forms many thousands of compounds, which are possible because of the various positions, and varied joining of these two atoms in the hydrocarbon molecule.
The various petroleum products are refined from the crude oil by heating and condensing the vapours. These products are the so-chatted tight oils, such as gasoline, kerosene and distillate oil. The residue remaining after the tight oils are distilled is known as heavy or residual fuel oil and is used mostly for burning under boilers. Additional complicated refining processes rearrange the chemical structure of the hydrocarbons to produce other products, some of which are used to upgrade and increase the octane rating of various types of gasoline.
Text 5
Early Dams
Dams have been built on rivers and streams all over the world for thousands of years. In the Egyptian desert cast of the Nile River are the remains of a masonry dam that probably dates back to 2500 BC. Other ancient darns have been found in present day Iraq , Syria , and Arabia . Most of these dams were used for collecting and storing water for irrigating the fields in the dry desert regions.
Early dams were built with rocks, earth, and wood. These dams worked fairly well unless the pressure of the water became too great, or they were overtopped by high flows of water; Then the dam would be washed away. Gradually men learned how to design dams that could withstand great pressure. New materials were added ’to strengthen the darns.