Recent Indonesia quake added pressure to key fault
Seismologists say last week's powerful earthquake off western Indonesia increased pressure on the source of the devastating 2004 tsunami: a fault that could unleash another monster wave sometime in the next few decades.
Last week's 8.6-magnitude earthquake also showed that tsunami-ravaged Aceh province, close to the epicenter, remains unprepared for the next Big One. Though the quake caused little damage, the country's disaster-management chief acknowledged that evacuation efforts were "a big mess."
Indonesia, located on the "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin, has unleashed some of the deadliest seismic events of the past century. But the 9.1-magnitude quake that struck in 2004, triggering a 100-foot-high tsunami and killing 230,000 people, caught scientists off guard because its fault, west of Sumatra island, had long been quiet.
Since then scientists have conducted a flurry of research, looking at tsunami sand deposits, uplifted coral and GPS data. By observing past patterns of quakes, which tend to be cyclical, they better understand what might happen next, though it's impossible to make predictions with any certainty.
He said a separate section of the fault, hundreds of miles kilometers to the south, also could snap within the next 30 years, sending a tsunami slamming into Padang, a low-lying Sumatran city of 1 million. Last week's quake was a "strike slip" quake, which means it thrust from side to side, not vertically, and therefore did not generate a large tsunami.
Countries along the Indian Ocean have spent millions of dollars installing buoys capable of detecting waves generated by seismic activity, and building up a vast communications network, from alarms on beaches to systems that deliver warnings by TV, radio, Internet and mobile phone text message.
raffic was at a complete standstill as the provincial capital, Banda Aceh, emptied out, people screaming and crying as they piled into cars and motorbikes to try to get to high ground. Many said that after two hours they had only moved six miles.