Science Assessment Earthquakes By Molly O'Leary


Tectonic plates

Tectonic plates are plates of solid rock that are located in the lithosphere. Tectonic plates cause earthquakes. They have three ways of movement. These are convergent, divergent and transform.

What are the causes and effects?

When tectonic plates move in a convergent movement it makes earthquakes. The divergent movement makes tsunamis and the transform movement makes mountains. All of three movements play a part in causing a devastating earthquake.

Measuring Earthquakes

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.

The IndiaN Ocean Earthquake

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 of this quake was caused by the Indio-Australian plate going below the Eurasian plate which caused the Tsunami above.

We are so lucky to not have been affected by this ruinous earthquake and tsunami as to this date It ramains the third largest and deadliest earthquake ever recorded.


Created with images by That_Soham - "cracks dry ground" • surotez9 - "concept question mark abstract" • Waifer X - "080630-1010560"

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