Two Earthquakes in Two Days: Coincidence? Connection? Conspiracy?

There is devastating news coming out of the South Pacific again, where the death toll from yesterday's 7.6 magnitude earthquake in Sumatra has topped 500. Just a day before that, an 8.0 magnitude earthquake struck off the coast of Samoa, triggering a tsunami that flattened whole towns and killed nearly 200 people.

Before any conspiracy theorists start sounding off about the coming apocalypse, it should be noted that the two earthquakes occurred in the most volatile region on the planet. It's part of the Ring of Fire, which stretches from Indonesia to Chile. Nine out of every 10 earthquakes in the world take place there. And in the immediate sense, seismologists are saying, the quakes are probably unrelated. They were caused by slippages in faults on two completely different tectonic plates that took place nearly a full day apart. Stresses from the first couldn't have built up that much further along the fault to trigger the second. And surface waves from the first quake would have reached Sumatra long before the second quake happened there.

But that's not to say they're completely unrelated. A study published just yesterday in found that the earthquake that triggered the monstrous 2004 tsunami was so destructive that it weakened fault lines around the world─reaching all the way to California's San Andreas Fault, 5,000 miles away. Since then, the researchers say, there has been an "unusually high" number of earthquakes around the world, suggesting that especially big quakes might beget more quakes. What's more, a California Institute of Technology researcher who studies seismic activity in Asia notes that a cycle of earthquakes in the region that started in 2007 is likely to produce an even bigger disaster sometime in the coming years. "There's no city on earth that's had more wake-up calls than Padang," he told Bloomberg, predicting that the next one could hit a magnitude of up to 8.8. "They've had five or six major earthquakes in the last 10 years, and a bigger one to come." Given that 2004's quake, at 9.1, was not much more than that, officials throughout the South Pacific had better be doing some serious thinking about disaster preparedness.