Amelung and many of his colleagues are urging the Haitian government and its international donors to consider relocating the capital, which was largely reduced to rubble by the quake. The most important infrastructure should be rebuilt at a site well away from a fault line that they believe will rupture again within the next generation or two, but even closer to Port-au-Prince. "If this were a typical earthquake, the risk of future incidents would decline over the next few months," says Tim Dixon, also a geology and geophysics professor at Miami's Rosenstiel School of Marine & Atmospheric Sciences. "The stress would be relieved and we could all go back to sleep for another 250 years," which is about how long ago Haiti's Enriquillo Fault last convulsed. "But that's not the case here - our findings suggest another shoe has to drop." (See exclusive pictures from Haiti's devastating earthquake.)

That's largely because of the limited length of the fault-line rupture that caused the January earthquake. Amelung and Dixon, working with two other University of Miami geologists, Sang Hoon Hong and Shimon Wdowinski, say the quake exhibited quite a bit of odd behavior. Its rupture, for example, did not reach the earth's surface, unusual for its powerful 7.0-magnitude. But the more important question is why only the western half of the Enriquillo Fault segment that ruptured in 1751 fractured this time. (That half, about 25 miles, in length, lies right under the city of Leogane, the Jan. 12 epicenter, which is about 20 miles west of Port-au-Prince.) The result is that the eastern half of the segment - the one much closer to Port-au-Prince - is subject to that much more stress, which may cause another major quake to come sooner than later. "Even if the next earthquake is the same 7.0 magnitude," says Amelung, "it will still be more damaging to Port-au-Prince" than last month's quake was."

Amelung wants to explore how, if at all, the quake's unexpected vertical motion may have affected the January rupture's short length and potent magnitude. But whatever the cause, the scientists say Haiti can escape the devastation of a seismic sequel. Says Dixon, "We feel we have enough knowledge gathered now to recommend that [Haiti] should rebuild critical infrastructure farther to the north, out of harm's way," and where the ground often has more stable rock instead of the more alluvial soil around Port-au-Prince.

The earth scientists' case for moving the capital may actually dovetail with the arguments of social scientists. Haiti is the western hemisphere's poorest country, which is a key reason Port-au-Prince, with some 2 million residents, is one of the world's most densely populated cities. This combination of factors also helps explain why as many as 150,000 people were killed in last month's quake. Many development experts believe the city's population needs to be halved, and the rebuilding process may offer an opportunity to resettle some half million people outside the metropolis to new or existing communities that offer jobs and infrastructure.