The PowerPoint presentation which you are about to watch is sad and, in places, you may find it shocking. It was made on the 30 th December 2004 by a Geography teacher who, like you, has watched with horror as the events unfolded daily on our screens. “ This is a human tragedy on a huge scale – for once caused by the action of Nature rather than Man” William Rees Mogg

Indian Ocean Tsunami 26 th December 2004 At GMT a magnitude 9 undersea earthquake shook the sea bed off the north west coast of Sumatra. Within hours multiple tsunamis had swept across the Indian Ocean ravaging coastal regions and killing over 120,000 people.

The USGS (United States Geological Survey) record of the earthquake

The seismograph recording of the earthquake

Two tectonic plates, the Australian and Eurasian plates, meet just off Sumatra's south-west coast, grinding together and sending periodic seismic tremors through the region. At 0059 GMT a violent rupture occurred on the sea floor along a fault about 1,000km long.

Area affected The 9.0 magnitude quake, which was the strongest in the world for at least 40 years, wreaked havoc across the whole region. Walls of water, tens of metres high, slammed into coastal resorts thousands of miles apart. Surging seas and floods were reported as far away as east Africa.

Deadly wave All along the rupture the seafloor was shunted vertically by about 10 metres. This movement displaced the overlying water, generating a massive tsunami, or tidal wave. The wave then fanned out across the Indian Ocean at enormous speed.

The waves spread out on their voyage of destruction

Within half an hour the waves had reached Sumatra and Malaysia and swept ashore in Thailand. Two hours later they reached Sri Lanka and India. Within four hours they had crossed the ocean to the east coast of Africa

The power of tsunamis only becomes clear as they approach shallow water along the coast

But from the beaches few people recognised the danger of the white line on the horizon

Hildasan, 50, net-maker I was repairing some fishing nets in the harbour when I saw the waters rising. I'd never seen anything like it. I began to run for my life - I knew something was very wrong. The rumbling noise, the rising water, just didn't make sense. As I ran inland the sea seemed to be roaring in the background.

Their full force is unleashed as they break on to land

Sundar Raj, 21, fisherman I was sleeping in our boat when the sea began making a rumbling sound. I saw the water level rising. I jumped into the water and tied my boat to the wharf as the waves began lashing me from behind. I climbed on to the jetty and ran.

The killer wave strikes Kalutara Sri Lanka

“Scale of devastation Thousands are reported to have been killed, but there has been little news from the worst-hit areas where all transport and communication links were destroyed. “ bbc.co.uk The Aftermath Early reports gave no hint of the scale of the disaster…….

Low lying coastal areas were left obliterated and flooded as here in Aceh province in Sumatra, Indonesia Current reports indicate that the north and west coasts of Sumatra have experienced the worst destruction

Whole villages were flattened as here in Sri Lanka

Fishing boats, which provide essential food supplies for local people here in India, have been washed ashore

Scenes which were repeated across the Indian Ocean Sri Lanka Phuket, Thailand

Low lying areas have been left flooded with seawater which quickly becomes contaminated with sewage and decomposing bodies Male in the Maldives Banda Aceh in Sumatra, Indonesia

Millions of people have been left homeless Cuddalore, south of Madras, India Penang, Malaysia

V Govindan, 55, fish seller My house was blown nearly half a kilometre inland when the waves came. I started running with my wife and four children. I returned to the coast in the evening and saw that my home had been washed away. The signboard is still there - The board says: "Live prawns bought here". Now life is so uncertain.

Valli, 20, fish seller My family has lived for generations by the sea. Everything almost ended on Sunday as the waves lashed our house. We managed to drag most of our belongings from our huts. Then we ran and ran until we reached the fisheries office, which is now my home.

A family survey what is left of their home south of Colombo, Sri Lanka

“Paradise Lost” Idyllic beach resorts like Galle in Sri Lanka, photographed here in March 2004, have been turned into scenes of horror, devastation and death,

Now Hell on Earth Beach debris at Phuket, Thailand Phi Phi Island, Thailand

All that remains of luxury holiday accommodation on Phi Phi Island, Thailand

Devastation on Khao Lak – a once beautiful beach resort in Thailand

Communications have been completely disrupted Bus station in Galle, Sri Lanka 800 people died in a train derailed by the waves in Sri Lanka – it is the worst train disaster ever recorded.

The human toll is huge – on it stands at 125,000

Scenes of grief in India, Malaysia and Indonesia

Millions have been injured In Aceh, Indonesia, so many doctors have been killed that there are few trained medical workers to assist the injured.

Many children – foreign and local – have lost parents

Increasing numbers of homeless people need shelter, food and water

Clean drinking water is required to avoid the spread of disease

Armed police in Galle, Sri Lanka try to prevent looting

Identifying victims is a grim task Many who died can only be identified by photographs, fingerprints or DNA tests

Tourists in Phuket make contact with frantic family members

In all affected areas survivors are hungry as food supplies run out

Medicines are needed desperately The threat of disease increases

The evacuation of foreign tourists from the beach resorts begins Many are severely traumatised

A British holiday maker arrives home from the Maldives three days after the tsunami

Other survivors, such as these women and children from the Nicobar Islands, leave to a more uncertain future

Relief efforts, which have been slow to start, gather pace as the enormity of the disaster begins to be appreciated French relief workers from the Medecins Sans Frontieres organisation German relief workers prepare to depart for Sri Lanka

Indonesian Red Cross workers in Jakarta South Korean Red Cross assistance

Clean, bottled water supplies are assembled in Penang, Malaysia

Clothes are collected in Sri Lanka Distribution of food in Madras state, India

In some areas relief supplies are piling up Disruption of communications means that emergency supplies cannot be distributed efficiently

Coffins await transport to remote areas near Phuket in Thailand

Co-ordination of relief efforts from throughout the world is proving to be a major challenge Four days after the tsunami many of the worst affected areas cannot be reached

at The death toll stands at 125,000 By the time you watch this, it will be much higher.

“We view with awe a release of power on this scale. We know that this power is greater than that of our species – Nature holds us in its hands. We may be able to lessen some of its consequences, sometimes we can give advance warning of the threat but we are not in control.”

The tsunami has demonstrated that Nature, and not Mankind, is the real master.” William Rees-Mogg