Indian ocean earthquakes ‘significantly underestimated’ before 2004 tsunami – experts

The risk of a large earthquake in the Indian Ocean was ‘‘significantly underestimated’’ at the time of the Boxing Day tsunami a decade ago, an expert has said.

Tim Henstock, senior lecturer in ocean and earth science at the University ofSouthampton, said only a ‘‘small number’’ of people were involved in monitoring seismic activity in the region when the massive 9.1 magnitude earthquake struck, causing the Earth to physically wobble on its axis.

The earthquake - 23,000 times more powerful than Hiroshima - caused shifts in the ocean floor which displaced enough water to fill a tank 1.6 kilometres wide, 1.6 kilometres high and more than 11 kilometres long.

Dr Henstock, below, said: ‘‘In 2004, in the Indian Ocean there really wasn’t any system in place.

‘‘There were a small number of people working on hazards in that subduction zone (when one of Earth’s tectonic plates sinks underneath another after they collide).
‘‘The risk of a big earthquake was significantly underestimated at that point in time.
‘‘Looking at Thailand, Sri Lanka and the coast of India, an early warning system would have made quite a significant difference, where there was a couple of hours of travelling time,’’ he said.

‘‘The lack of an early warning system meant people in Sri Lanka and elsewhere would not have been aware of the earthquake happening.

Dr Henstock said that while a similar-sized earthquake in the same region would only be expected in ‘‘several hundred years ... if it was repeated right now, there would certainly be a much higher chance of warning people in India, Sri Lanka and Indonesia.’’

Trevor Guymer, an advisor to the UK’s Intergovernmental Oceanographic Commission (IOC) office, added: ‘‘Such earthquakes are not possible to predict.
‘‘We might see, on average, one occur a century. It doesn’t mean it won’t happen again in a few years. The real challenge is how to maintain readiness.’’ - dailyecho