As the death toll continues to rise in the wake of both the tsunami and earthquake in Indonesia, questions are still being asked. What caused it, is there the likelihood it can occur again, and could the loss of life have been prevented. It will take months of research and underwater exploration before these questions will have a definitive answer. My question is, what can we learn from this now?
Simply put, most tsunamis are caused by thrust earthquakes. These earthquakes generally happen hundreds of kilometers from shore. Tectonic plates move up and down vertically and a large displacement of water flows straight causing damage as it pushes forward and pulls back. This tsunami however was different. In this case, it was a strike-slip fault where the plates moved horizontally. The earthquake occurred 10 kms under Sulawesi Island triggering the tsunami in the Makassar Strait. Normally these kinds of earthquakes lead to a weak tsunami, but it is being suggested that there was a large underwater landslide that caused the water to be displaced. The tsunami gathered momentum and reached 6 meters in height as it pushed its way onto the beach at Palu Bay.
Although this double disaster is thought to be rare, numerous warning bells were there. Research suggests an event took place in the early 1900’s and in 1937. There was a recently published paper in 2013 which stated it had the potential for causing an event such as this because of the long and narrow straight. There was also information suggesting the fault in Palu was well known and it had been very rapidly slipping for years. As the blame game starts, we are hearing that the agency responsible for setting off the warning sirens, removed the warning too early. There are rumours that the buoys out at sea had not been serviced in over 6 years and were faulty.
With all this information, regardless of what further research and underwater exploration reveals, the loss of life, currently estimated at 1,234 and rising, could have been lessened by education alone. Mother Nature provided her own warning sign by way of an earthquake. The people on the beach and in the city should have known to immediately seek high ground, but if you watch the footage, there was uncertainty. My guess is some were in disbelief or perhaps waiting for confirmation from technology to validate their instincts.
Some of you reading this may feel that it happened on the other side of the world, so it doesn’t affect us. You may feel we are safe in the U.S. or in Canada, but our warning signs are already there. It is predicted that a disaster much like this will not occur but re-occur along the California, Oregon, British Columbia shoreline. It has already happened about 20 times in the past 10,000 years. The last one hit on January 27, 1700. The threat of “The Big One” has been talked about for decades. It is inevitable. It will happen again, and it is estimated the wave will be over 20 meters when it first strikes land.
The questions being asked of what caused it, will it occur again, and could the loss of life have been prevented are already answered. Even with technology, disaster planning through education and training is a necessity and will save lives. The people of Palu had only 30 minutes from the time the earthquake struck until the tsunami wave hit the shore. The only question that remains now, is what will you do with your time?