Measuring earthquakes is a really hard job that needs to be done right. Seismologists use a tool called a seismograph. This helps them to read how bad an earthquake is or how very little damage it can do. Seismographs are extremely sensitive, picking up even the slightest of movements.
Once the seismologists have seen the needle pick up the earthquake they rate it on how big or small the earthquake really is. They rank the earthquake on two scales. The Richter Scale and the Mercalli Scale. The Richter Scale is telling the siesmologist the number of how bad the earthquake really is and they then transfer this onto the Mercalli Scale which is more modern and tells the seismologist in one word how bad it is. For example a 4.0 earthquake on the Richter Scale would be considered a moderate earthquake on the Mercalli Scale. This means that the earthquake would be felt indoors and might be felt outdoors.
An earthquake struck the Indian Ocean on the 26th December 2004 rating a 9.1 - 9.3 on the Richter scale. This earthquake was described as a ruinous earthquake on the Mercalli scale. It was described as a ruinous earthquake because there was quite a panic through all the countries and places affected.
The places affected during this earthquake were Indonesia, Sri Lanka, India, Thailand, Maldives, Malaysia, Madagascar, Somalia, Kenya, Tanzania, Sounth Africa.
The Damage that occurred
This earthquake caused a tsunami 15-30 meters high (50-100ft). This tsunami damaged most countries bordering the Indian Ocean, killing 230,000 - 280,000 people in 14 countries. Along with these deaths 14 other people went missing. Communities, farms and towns where destroyed, leaving people homeless and hungry.
THE DAMAGE OCCURRED BECAUSE
The damage of this quake was caused by the Indio-Australian plate going below the Eurasian plate which caused the Tsunami above.