The year 1755 presented Lisbon with what looked like doomsday: "Men and women ran around half naked. Some dying, some missing body parts, covered in blood and dust, they filled the air with horrendous screams...", eye witnesses of the time portrayed a scenario like Southern Asia.
Here and there the earth's crust clashed against the ocean floor. 30 metres under the Indian Ocean the continental plates shifted by 1000 kilometres - a lurch that, according to NASA, even made the earth turn 3 millionths of a second faster. It was the Azores bedplate of the mid-Atlantic ridge (to which Iceland also belongs) just off the coast of Europe, which triggered a strength 9 seismic shock.
"A quake like that is, however, rare in the Atlantic, but when it happens it is very strong. And it is not predictable", explains the Viennese seismologist Dr. Edmund Fiegweil: "At worst, the ensuing tidal wave would destroy the coast of Portugal and Morocco." But even France and regions of the Netherlands reclaimed from the sea would also be affected. The straits of Gibraltar protect the Mediterranean's endangered towns such as Venice relatively well. But even in the Mediterranean there are underwater landslides and, especially around Sicily, seaquakes and volcanic eruptions that could trigger a tsunami.
"In principle, flat coasts are particularly endangered by tidal waves", explains Dr. Fiegweil: "Often 100 kilometres wide, a tsunami travels across the open sea with a speed of 200 metres per second and a height of just up to 2 metres. The flatter the water, the more it is slowed down. Then with higher speeds the ensuing masses of water pile up over the slower ones to form a giant wave of over 40 metres in height that hits the land at a speed of just 40 to 50 km/h but with obliterative impact."
For years, there have been warning systems that signal the erupting tidal wave and thus give at least a small advance warning time and are installed in the pacific ocean. In Hawaii the evacuation zones for a case of emergency can be found in every telephone book. This system was however too expensive for the affected countries in the Indian Ocean. And even off Europe’s coast, despite the catastrophe 250 years ago, up until today people would rather place their hopes on guardian angels, following to the motto: It will never happen...