Greek God Blamed For Tsunami

A man and his elephant begin clearing the debris in Banda Aceh, Indonesia, after the 2004 tsunami

September 20, 1498 — Climate change is said to have caused many of the devastating floods and fires that ravaged the world in the 21st Century. But humankind faced natural disasters long before that.

Especially tsunamis. They can be generated by any significant displacement of water in oceans or lakes, but are usually created by the movement of tectonic plates under the ocean floor, during an earthquake.

These disasters occurred so frequently around Japan that they invented a word specifically for the phenomenon: ‘tsu‘ meaning harbour and ‘nami‘ meaning wave. The wall of water referred to can also be caused by volcanic eruptions, glacial carving, meteorite impacts or landslides.

But it is not a modern event. The oldest recorded tsunami happened in 479 BC when it destroyed a Persian army that was attacking the town of Potidaea in Greece.

Herodotus, the Ancient Greek writer, geographer and historian, reported how Persian attackers were suddenly surprised “by a great flood-tide, higher, as the people of the place say, than any one of the many that had been before".

He believed the great flood was caused by the wrath of Poseidon, god of the sea, storms and earthquakes. But three years later, another Greek historian, Thucydides, wrote in his book, History of the Peloponnesian War, that such events had to be explained by ocean earthquakes. He could see no other possible cause. Few people listened to him, of course.

Fast forward a few centuries and past a number of tsunamis to September 20, 1498, when an earthquake below the Enshunada Sea, now estimated to have had a magnitude of 8.3, triggered a tsunami that engulfed the Japanese coasts of Kii, Mikawa, Suruga, Izu and Sagami.

It destroyed some 1,000 homes with waves about 10 metres (33 feet) high, and up to 31,000 people were reported to have been killed.

This was one of the country’s deadliest natural disasters, with destruction on such a scale that it caused a split, finally connecting Lake Hamana to the sea. Formerly an inland lake, after the tsunami Hamana was connected to the Pacific Ocean by a channel. A second tsunami hit the Enshunada region in October, 1707, claiming some 2,000 lives.

However, the grand-daddy of all tsunamis came on Boxing Day, 2004, when an earthquake with a magnitude of 9.1 erupted off the coast of Sumatra, Indonesia. According to scientists the explosion caused the whole planet to vibrate by as much as 10 mm (0.4 inches) and the Earth's rotation was slightly altered, possibly shortening the length of a day until recovery by an estimated 2.68 microseconds.

The earthquake was felt in Bangladesh, Sri Lanka, Myanmar, the Maldives, Thailand, India and Malaysia.

Scientists estimate that the eruption took place at a depth of 30 kilometres (18.6 miles) on a fault line about 1,300 kilometres (808 miles) long. The explosion vertically shifted the seabed for several metres and resulted in a tsunami 50 metres (164 feet) high at its peak.

It had calmed down to 5 metres (16.5 feet) when it reached inland Sumatra, but still caused catastrophic damage, leaving about 230,000 people dead. Communities along the surrounding coasts of the Indian Ocean were devastated, with deaths recorded in 14 countries, making it one of the deadliest natural disasters in history.

A rise in wave height was recorded in various places around the world including the United States, the UK and Antarctica.

In 2005 the UK despatched the Royal Navy ship HMS Scott to the earthquake zone to carry out a survey of the seabed using a high-tech multi-beam sonar system. The New Scientist magazine later revealed that the survey found the eruption had caused landslides (seabed slides?) several kilometres wide, one of which was made up of a single rock 100 metres (330 ft) high and 2 kilometres (1.2 miles) long.

Other massive slabs of rock, each weighing millions of tonnes, had been dragged as far as 10 kilometres (6 miles) along the seabed.

Today, with tsunami warning systems installed around the globe and alerts having occurred as far apart as New Zealand and Alaska, an uneasy world watches its oceans – and waits . . .

Published: January 6, 2022
Updated: January 11, 2022