QUESTION: With the recent devastating earthquake in Haiti, I am wondering whether there have been any advances in predicting when and where earthquakes will happen. And besides California, what earthquake-prone areas in the U.S. should I be concerned about?

ANSWER: Scientists are making progress honing their ability to forecast the likelihood of strong earthquakes along fault zones, but they cannot predict a quake's precise time, location and magnitude, said Stuart Sipkin, a geophysicist with the U.S. Geological Survey's National Earthquake Information Center in Golden, Colo.

In fact, scientists are divided over whether such predictions will ever be possible. Sipkin said some believe quakes are by their nature too random to allow for precise predictions, while others feel science simply hasn't found the right precursors that might allow them to make lifesaving quake predictions.

However, advances in the past decade using global positioning system measurements to reveal subtle changes in the earth's crust have aided science's ability to forecast the probabilities of strong quakes along many fault zones. That data, along with a fault's past history of strong quakes and the time that's elapsed since the last such temblor, help scientists calculate the amount of stress faults can take before their plates slip, causing a quake.

GPS data were key to scientists' 2008 forecast that the fault that caused January's devastating quake in Haiti was capable of causing a 7.2-magnitude earthquake, Sipkin says. The prediction came without a specific time frame.

The USGS maintains earthquake hazard maps illustrating the risk levels of quakes for the entire U.S. The high-risk zones in the agency's 2008 maps—earthquake.usgs.gov/hazards—include the West Coast, Hawaii, Alaska, Utah and the central Mississippi River Valley region.