Sunday, April 25, 2010

What Is Tsunami ?

1. What is the Tsunami ?

The word Tsunami (Tsu: Wave; Nami: Harbor) is from Japanese and was accepted as a international word to describe a series of wave. Tsunami can eliminate all the things on its way. ( Building, vehicles and human…. )

2. How did the Tsunami generated ?

There are many causes to create a Tsunami but the six main reasons is :

* Earthquakes

* Volcanic Eruptions
* Underwater Explosions
* Landslides
* Mass Movements
* Meteor Impacts

This is a video shows how Tsunami was formed :

Higher views :

3. More Information :

Tsunami has plenty of information that can be use to predict it also information that been researched :

The speed : Tsunami can reached the speed at 800-900km/h in average so that it could cross the whole ocean in a few hours with the speed of an airplane like this. Notice that the average speed of normal wave is just 90 km/h. In addition ,the closer to the land the more speed is reduced and the more height is increased.

The height : From the horizon, Tsunami is just a 7 cm white line but when it come closer, it can rise up to 30 meter or over. For example, the Tsunami attacked Lituya Bay in Alaska reached 525 meters . So it almost cannot be seen from the land by eyes leads to the damages it causes is unpredictable.

4. The differences between a regular wave and the Tsunami:

The flow : The regular wave is a circle-flowing wave but the Tsunami is a straight-flowing one so that make it more dangerous.

The movement : Regular waves are generated by the wind and normally it just a movement of the surface. In the Tsunami case, it is a movement of a whole body of water which causes by the reasons mentioned above.

Cycle ( time between 2 continuous waves ) and wavelength ( distance between 2 continuous waves ) : Cycle of the regular wave is from about 5 – 20 seconds and the wavelength is from 100 – 200 meters but if it is a Tsunami, the cycle can increased to 10 – 120 minutes and up to 500 km for the wavelength. With long timing and the long distance like that, Tsunami again unpredictable.

5. Why does the Tsunami can make such a huge damage ?

The regular waves which is generated by the wind are just move its surface and be impacted by many causes lead to losing its energy too. Tsunamis movement are below the surface so its energy is almost intact due to the damage from the earthquake, volcano,... can be impact to the land from a far distance.

6. The signs show that there is a Tsunami coming !!

Tsunami is hardly to be detected from the shore so that here is a sign that will tell the Tsunami is coming :

The water slowly roll up with waves but not break and not as powerful as the waves of the coming storm.
There will be sponge and the water will suddenly sprint down.
Sometime there will be H2S in the water.



Sunday, April 18, 2010

Chimborazo - The highest point from the Center

With 8.848m height compared with the sea level, Everest is known as the world's highest mountain but this is not the highest compared with the center of the earth. Although lower than the Everest 2.500m but mount Chimborazo in Ecuador is the highest point from the center of the Earth.

The reason of this different is because the earth is not round, the globe is a sphere flattened at both side so our planet should be wider at the equator. Chimborazo point one degree different to the equator due to it should have a height of 6384 km from the earth center (2 km higher than Mount Everest).

Information :
Image :


I. The air pressure distribution:

1. The causes of changing air pressure:

- Air pressure: compression of air into the Earth's surface.

- Changing of air pressure: height, temperature, humidity.

2. The distribution of the air pressure belt on the Earth:

- The belt of high pressure, low pressure distribution and symmetrical through the low air pressure belt near Equator.

II. Types of wind:

1. West winds temperate:

- Blowing from high pressure to low pressure reach tropical to temperate latitudes

- Operation hours: a year round.

- Mainly to the west.

- Nature of the wind: Humidity, together with rain.

2. Trade winds:

- Range of activating: Blow from high pressure to reach the tropical low pressure area near Equator.

- Operation hours: a year round.

- Direction: North East (northern hemisphere) South East (southern hemisphere).

- The nature of the wind: Dry, less rain.

3. Monsoon:

- A type of wind which blow in the opposite direction in two different seasons with two different properties.

- This type doesn’t have air pressure belt.

- Blowing in the hot tropics (India, South-East Asia...) and East of the continent as the middle latitudes such as East Asia, South-East United States ...

- There are two kinds of monsoons:

+ Monsoon is caused by the difference in temperature and air pressure in the two hemispheres.

4. Local wind:

a. Land wind, sea breeze:

- Formation at the coast.

- Change direction by day and night.

- In day, the wind blowing from sea to land. At night, it will reverse.

b. The Foehn:

- A type of wind through the mountains when denatured become dry and hot.

Information :
Image :

Saturday, April 17, 2010

Population Distribution

I – Population density

1. Concept

Population distribution is the arrangement of the population on a certain area in accordance with conditions and requirements of the society.
Population distribution over a territory is described by the population density which is calculated by the rate between the numbers of people on an area to the total population. The unit of the population density is persons/km2.

2. Features

a) The evolution of population distribution over time.

b) Population distribution is uneven

According to the statistics in 2005, the Earth has 6.477 million and the average population density is 48 persons/km2. However, population distribution is uneven, there are very populous region and also has a sparse population areas or even none resident.

3. The Factors affecting population distribution

Population distribution is a social phenomenon exist by the combined affection of series of factors. In addition, the factor helps to decide how the population distribute is the level of the labor force, the property of the economy then to the cause of natural conditions, history of the exploitation of that area, the migrations...

II – Types of colony

1. Concept
Colony is the specific expression of the population distribution over the Earth's surface, including the network of population exists on a certain territory.

2. Classification and characteristics

Due to effects of urbanization and industrialization, the rural populations today are a lot of changes on the function, structure and development. Apart from main activity is agriculture, rural populations also has other functions such as industry (mainly processing the agricultural products), industry, tourism ... In the result, the rate of those who do not do agriculture is increasing. The urbanization process also makes the architecture, rural planning becomes a kind of architecture, urban planning.

III - Urbanization

1. Concept

Urbanization is a process of economic and social which has a sign is a rapid increase in number and size of the urban population, the gathering of population in cities, especially large city also the spreading of urban lifestyle.

2. Features

The urbanization process has three main features:

a) The trend of increasing urban population

b) Residents focus on large cities

Number of cities with a population over 1 million are now appear more and more. Nowaday, the world has more than 270 cities over 1 million people, 50 cities with a population exceeding 5 million.

c) The widespread of the Urban lifestyle

Along with the development of the urbanization process, urban lifestyle is widespread and affect the lifestyle of the rural population in many aspects.

3. Affections of urbanization to economic - social development and environmental

a) Positive effects

Urbanization not only contribute to accelerate economic growth, economic restructuring and labor structure but also make a change of the distribution of population and labor force, changing the process of birth, death and marriage in urban...

b) Negative impact

Urbanization, if not derived from industrialization, inappropriate weight to the process of industrialization, the influx of residents moving from rural to urban to rural areas would lose a large part of human resources. Meanwhile, job shortages, poverty in growing cities, living conditions increasingly shortages, environmental pollution which could lead to many negative phenomena in economic life - society.

Images :