Monday, March 29, 2010

~~~~::Team Members::~~~~

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Wahana team consists of three members: Nadhirah Bte Nazir (at the left), Nur Syazwani Bt Kamaruddin (in the middle), and Noorhayati Bt Harun (at the right). It took about 8 weeks to finish up this blog, and tried so hard to go through all the difficulties during the project period as the internet was so low to publish the articles in the time given. Eventually, our team was able to do the jobs and finally, the blog is ready to be explore by everyone as there are a lot of information provided. However, without the constant guidance and encouragement of our lecturer, Mdm Rosiah Binti Othman, the team would never been able to complete this blog. Thank you Madam.

Do Enjoy Yourself Exploring The Wonderful Nature Of Earth !!

Thank You…

Best Regards,
WAHANA










Thank You For Everyone..!!!

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Hope you will enjoy this blog, the blog is very useful for everyone to learn more about natural disaster. As generally known, natural disaster is the effect of a natural occuring condition that could affects the environment, involved countries, leads to financial and economy crisis and life loses. Natural disasters occur in many types and sizes such as earthquakes, tornadoes, floods, hurricanes, tsunamis, volcanoes, and lightning. These are merely a few of the beautiful yet destructive natural disaster that plague our lives. Therefore, please enjoy yourselves and have a wonderful time exploring these natural wonders.

Friday, March 26, 2010

**Types of Lightning**

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When the lightning occur, we can see the varieties of lightning. This is because lightning can be categorized into a few types.

Ground to Cloud




Ground to Cloud Lightning is familiar types of lightning that most of us see. This lightning is call ground to cloud because its discharge from the ground to the cloud. The ground act as lake of electrical charge and the cloud gain the charge. The ground need to balance the charge by gathering the opposite charge under the clouds system. When the difference between the charge increase, it break down and the lightning occurs. Usually this lightning occur from the ground and flows upwards to the clouds.










Cloud to Cloud




Cloud to Cloud Lightning occurs between two clouds or two layers of clouds. Both clouds have different or opposite charge. This opposite charge needed and must be great enough for the air to break down. When the charge is extreme, the lightning between two clouds will be happened.







Ball Lightning



Ball Lightning is one of phenomenon where a luminous sphere. This sphere is only several centimeters in the diameter. The lightning is float through the near ground and can last a few second. After that, it can explodes and the lightning occurs.





What Is Lightning?

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Lightning...




Lightning is an atmospheric discharge of electricity that accompanied with thunder. It usually occurs during thunderstorms and sometime during volcanic eruptions. When atmospheric discharge the electricity, the leader of bolt of lightning can travel at speed 60000 m/s and its temperature can reach until 30000 oC. Based on the statistic, approximately 16 million lightning storms occur in the world every years.

How Lightning Occurs?


Lightning occur due to the great difference of charge between two regions. When the difference of charge achieve a certain point, air between two regions become ionize or breaks down and cause the lightning to occurs. When this phenomena happens, the larger amount of energy is used and converted into light, heats and sound. That is why during lightning, it sound like thunder.


Monday, March 22, 2010

:: ~Causes of Tsunami~::

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Most tsunamis are generated by underwater earthquakes



Normally, tsunamis are generated by underwater earthquake, it happen when there is a sudden large displacement of water, it produced by convergent or destructive plate boundaries abruptly move and vertically displace the overlying water. Tsunamis also causes by these mechanisms, it may dissipate quickly and rarely effect distant coastlines due to the small sea area affected, the effect can caused huge effect for many human and the countries when it happen. There are three main causes of tsunamis:

1.Seismic Activity

Seismic activity is the most common cause of tsunamis. Both tectonic and subduction earthquakes in and near the ocean may create tsunamis. During a tectonic earthquake, the sea floor becomes deformed, forcing a displacement of water. In a subduction earthquake, tectonic plates slip under each other, creating a massive disturbance, also resulting in a significant displacement of water.







2.Submarine Landslides

Submarine landslides can also cause tsunamis. Submarine landslides occur during earthquakes and the implosion of underwater volcanoes. The falling sediment and rock in these landslides can also trigger massive water movement, resulting in a tsunami.


i)
Submarine earthquake













ii)
Submarine volcano













iii)
Submarine gas bubble erupting
















3.Cosmic Impacts


Cosmic impacts in the ocean are the least frequent cause of tsunamis. This is similar to throwing a rock into a pond, except on a much larger scale. When the rock hits the water, it creates small ripples of water moving away from the point of impact. In a cosmic impact, these ripples would instead be massive tsunamis, increasing in size as they near the shore.









::~Tsunami~::

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Hi...everyone, more knowledge about the Natural Disaster had been published in this blog just to share the information with everyone so that appropriate action can be taken to save life. Tsunami is the most horrifies natural disaster which causes by a strong earthquake under the ocean bed. The vibrations travel through the water and could reaches to thousands kilometers from the tragedy location. The giant tsunami effect can destroy an entire country and killing many people. The picture below showed the examples of the destructive power of tsunamis at Acheh city.


Monday, March 15, 2010

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-All About Valcano-


The word of volcano was get from the name of Vulcano Island. Volcano is a rupted of planet's

surface which allow hot magma, ash and gases to escape from below the surface.



Volcano can be divided into 3 group:

  1. Dormant - volcano that not erupted for a long time but have possibility to erupt again.
  2. Extinct - volcano that have erupted for thousands years and might be dead.
  3. Active Volcano - volcano that erupt rarely and can be erupted again soon.


Part of Volcano







  1. Large magma chamber
  2. Bedrock
  3. Conduit
  4. Base
  5. Sill
  6. Dike
  7. Layers of ash emitted by volcano
  8. Flank
  9. Layers of lava emitted by volcano
  10. Throat
  11. Parasitic cone
  12. Lava flow
  13. Vent
  14. Crater
  15. Ash cloud


Types of Volcano



Volcanoe because of repeated of ereptions. There are some tyoes of volcano based on their types of material:



  1. Stratovolcano - buils from eruptions of lava and tephra that pile up in layers like cake. These type of volcanoes form symmetrical cones withsteep sides.

  2. Cinder Cone Volcano - buils from erupting lava that rupture into small pieces. Lava pieces move downward to the ground, it cool and become harden into cinders. Cinder cone.

  3. Shield Volcano - form from eruptions of flowing lava. Lava spread up and form gentle sloping slope. These shape are resembles a warrior's shield.