On Shaky Ground

And the quakes don't stop.

At least three earthquakes topping magnitude 6.0 have shook Indonesia since the December 26 earthquake that produced the giant tsunami that left more than 300,000 bodies either dead or missing in its wake. The latest in this series hit at lunchtime on May 14 in the Nias region on the west coast of the island nation.

It registered a magnitude 6.9, but did not cause any deaths or produce a tsunami. Experts said it was unlikely that the quake would trigger a tsunami because of its strength and the fact it occurred relatively close to the earth's surface.

This most recent earthquake, and the two that preceded it, was most likely an aftershock effect of the December 26 quake. Major earthquakes tend to cluster in areas called subduction zones - where two or more plates of the Earth's crust grind and overlap. The December 26 quake took place in one of these zones, and increased the stress in the area, making it likely that more earthquakes would occur along its line.

So far, none of the secondary quakes have created a tsunami - they either haven't been strong enough or haven't occurred in just the right area to produce one. However, since it is possible that another tsunami could strike, governments are working to build better warning systems throughout the Pacific and Indian Oceans.

To keep track of the latest tsunami news, check out LiveScience's Tsunami Special Report.