WHAT CAUSES A TSUNAMI?

By Luke Reid, Amjuid Riaz, Chayanna Scott, Alex Thomas and

Imogen Rich.

IntroductionThis presentation will be about what causes a tsunami. We will be giving you some information about the Asian tsunami that happened in 2004. We will also be giving you some information on the tectonic plates. There is an activity for you to do also.

The Asian tsunami 2004. There was no warning systems in place so people were completely

unprepared. Millions of people became homeless. After the disaster, 20 million dollars was pledged in aid. It hit over 9.0 on the seismographs. Tsunami reached up to 800 km/h and up to 30 metres tall. The earthquake was the 3rd strongest ever recorded. Germany and Sweden lost the most people from the disaster. Some people believe that human destruction of coral reefs may have

helped to magnify the disaster. Very few animal bodies were found, some eye witnesses said that they

saw animals fleeing a few hours before. Sailors didn’t notice the waves because they only gained their few

heights when they reached the coast. The earthquake hit early in the morning of boxing day, many tourists had

been staying in the areas affected on holiday over Christmas and were subsequently killed. Although there were many deaths in the earthquake, the tsunami which followed killed significantly more.

Tectonic plates. Plate tectonics is the theory that the earth is made up of parts, or ‘plates’. These

move about due to convection currents. Convection currents are the movements of the mantle below the earth’s crust.

Heat caused by radioactive decay pushes the mantle upwards, which in turn moves the tectonic plates.

Originally, the earth only had one continent – known as Pangaea. The plates slowly drifted away from each other on the convection currents and became what we know as the continents today.

As you can see in the picture, along a line between plates – a fault line – two plates can push against each other. This is known as a destructive plate boundary.

In a destructive plate boundary, energy will build up between the two plates until on is suddenly released, causing a huge wave – a tsunami.

People nearby will feel the plate slipping as an earthquake, but won’t feel the tsunami until it reaches their coast. If there isn’t a warning system, it can be very difficult to predict a tsunami, as they don’t gain their full height until they approach the coastline.

In 2004, the tsunami started in the sea, and took quite a while to get to the shore. There were no warning systems in place so no one was prepared.

What one word describes this?

Answer: plate boundary's

Which word describes this pictures?

Answer: waves

What are these two countries that were affected?

Answer: Thailand and India

Task: cut the pictures out and order them in sequence.

Explain the sequence of a Tsunam

i.