A Disaster to Be Remembered

on December 26, 2004, a large earthquake off Sumatra gave rise to horrendous tsunamis. At the beginning of the year I had said that 2004 was going to be a year of great change, but it ended on a note of terror that even I had not imagined. Every time the news reported on the number of victims, I had the unbearable feeling that the final toll was going to be many times higher.

And indeed, in mid-January 2005, the United Nations Office for the Coordination of Humanitarian Affairs revealed that the number of dead and missing from the earthquake and tsunamis exceeded 180,000 persons. Moreover, many victims were travelers on their holidays, because the disaster area is popular as a winter retreat among people in Europe, and especially Scandinavia, who love the region as a kind of paradise on Earth.

The beautiful islands of the Indian Ocean, which float like pearls just above sea level, were helpless in the face of a magnitude 9 earthquake and huge tsunamis that reached a maximum height of 40 meters. The unprepared residents of these islands and the disaster area, where information about earthquakes and tsunamis is completely lacking, just did not know what had hit them.

As I have mentioned before, I am fascinated by geology. Puzzled as to why the earthquake had occurred off Sumatra, I studied a map of the region. There is the Sunda Trench formed by mantle convection, but compared with the Pacific Plate, its scale is small. Nevertheless, the enormous earthquake struck off the northernmost tip of Sumatra in the Greater Sunda Islands, causing the huge tsunamis.

History shows that the energy that accumulates in the Japan Trench is released every 70 - 100 years, but one can speculate that the Sumatra earthquake was caused by the buildup of energy over a much longer period of time. Stories about tsunamis should have been handed down among the inhabitants of the islands in the form of folktales and so on, but judging by the news of the disaster at any rate, this was not the case. The fact that stories about the terror of tsunamis had not been passed on by their ancestors suggests that the islands had not experienced a tsunami for a very, very long time, and certainly not in living memory. That is probably why there were so many victims.

Looking at the map, I find some things to be rather strange. Of course, from an expert’s point of view, I’m sure that they are not strange at all but perfectly natural. But all the same, for example, why did the huge tsunami caused by the earthquake in Chile hit the Sanriku Coast in northern Japan? The islands of Hawaii lay in the path of the tsunami, but they suffered relatively little damage. Instead, the tsunami moved at high speed in a 25-degree northwesterly direction. I thought that was very odd.

Another thing that interested me was the layout of the Hawaiian islands, which are famous as young volcanic islands releasing the energy of mantle convection. They are arranged in a chain facing 25 degree northwest. This might be related to the inclination of the Earth and the flow of the mantle. At the same time, at trenches where the mantle dips, it seems as though, due to the rotation of the Earth, the energy to the western side is greater. In Chile and the United States, the size of the depression created the Andes and the Rocky Mountains. The accumulation of energy, it seems, was much greater than in the Japan Trench or the Mariana Trench. I couldn’t help but think that there is something common here with the fact that the tsunamis caused by the earthquake off Sumatra wreaked so much havoc in Sri Lanka and India.

Abnormal meteorological conditions are continuing around the world as a result of the meandering westerly winds. I pray that February 2005 will bring calmer times.