Living on a Fault Line

Others in the city are less fatalistic. A group of academics, doctors and businesspeople have set up the Tsunami Alert Society. The group aims to educate the populace about the dangers of an inundation and organizes training and equipment needed to minimize the potential loss of life. "Our target is to get people to realize that living in Padang means they have to know what to do if there is a tsunami," says Febrin Anas Ismail, dean of the Engineering Faculty at Andalas University in Padang. "Just like when you are about to fly on a plane, you should know that you have to fasten your seat belt and so on."

So far, the group has carried out three evacuation drills, one of which saw 3,000 people walk to high ground in half an hour, about the time scientists estimate it will take before a tsunami hits if an earthquake comes. "Our aim is to carry out a general evacuation drill for the whole city by the end of the year," Febrin says. The group's members say they have received nothing from the local government except permission to carry out the drills. "The government prefers to calm people down rather than prepare them for the worst," says civil servant Hediyanto Husaini. "There's no sense of emergency despite the scientists' serious warnings. They won't do anything until people get killed in hundreds of thousands."

Calf-deep in a muddy field outside the village of Maligi north of Padang, Charles Rubin and two colleagues are doing their best to make sure that never happens. They hope to use the geological record to measure the size and frequency of previous tsunamis that have hit the west coast of Sumatra. Rubin raises a meter-and-a-half-long steel shaft above his head and plunges the sharpened end downward. As a score of curious villagers watch, he twists the shaft and then slowly extracts it. About a meter of the pole is cut away, leaving only a semi-circular channel, now filled with a cored-out column of earth. Using a pocket knife, Rubin scrapes the round surface of the core flat, exposing a cross-sectional view of the field's geological history for the last thousand or so years. In between two layers of pulpy dark-chocolate-brown peat is a distinct band of grey about two centimeters wide.

"This looks like sand to me," Rubin says excitedly. "It's definitely a candidate for dating." He pokes gently at the grey material, its flaky granular composition visibly distinct from the compost-like peat around it. Carbon-14 dating will determine to within about 50 years when the sand was laid down. If it coincides with one of the big three Padang earthquakes in the past 700 years, Rubin and his team will seek to calculate the size of the tsunami from the thickness of the band of sand.

"If we can find out how big the past tsunamis were, then we can go a long way to letting people living here know what to expect," Rubin says with satisfaction. "We may even discover they were all only in the one- or two-meter range," agrees Sieh. "Or even that there were no tsunamis at all after the earthquakes. Wouldn't that be wonderful?" It would. But for Sumatra's long-threatened people, the past portends a worrying future.