How the Chile Earthquake Went Nuclear

jrholliday's picture

Michael Reilly at Discovery News posted an interesting article titled "How the Chile Earthquake Went Nuclear".  He writes:

If you want to grow a truly massive earthquake, you've got to give it space.

Scientists have known this basic fact for years -- more powerful earthquakes ramp up the shaking by breaking along huge stretches of faults. The magnitude 7.0 earthquake just outside Port-Au-Prince in January unzipped a 65-kilometer (40.4-mile) long section of the Enriquillo-Plantain Garden Fault. Despite the unfathomable devastation it caused, it was a second-tier quake at best.

As has been widely reported, the Chile quake was a megathrust earthquake, the largest class of tremor we know of. At magnitude 8.8, it was over 500 times more powerful than the Haiti quake.

In a preliminary analysis of data from the quake, researchers from the GFZ German Research Centre for Geosciences are starting to unravel how it got to be such a monster. Turns out, it was a chain reaction of sorts. In the first minute, activity was confined to the area around the epicenter of the quake, about 200 miles south of Santiago. In the second minute, it tore north toward Santiago and stopped, before rearing its ugly head again south of the epicenter and racing toward the city of Concepcion.

The entire article, and an interesting animation of the seismicity surrounding the 27 Feb 2010 Chilean megathrust earthquake can be found here.

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