Biggest aftershock hits Chile on inauguration day

The largest aftershock since Chile's devastating earthquake rocked the South American country Thursday minutes before the inauguration of President Sebastian Pinera.

The 7.2-magnitude aftershock was stronger than the 12 January quake that devastated the Haitian capital. It happened along the same fault zone as Chile's magnitude-8.8 quake on 27 February, said geophysicist Don Blakeman at the U.S. Geological Survey in Golden, Colorado.

"When we get quakes in the 8 range, we would expect to see maybe a couple of aftershocks in the 7 range," he said.

Blakeman said Chile now can expect to feel "aftershocks of the aftershock."

"It's not a sign of anything different happening. But what does occur when you get these large aftershocks, typically we have a whole series of aftershocks again," Blakeman said.

The temblor rocked buildings and shook windows in the capital, and provoked nervous smiles among dignitaries arriving for the ceremony at the congressional building in coastal Valparaiso. Bolivian President Evo Morales seemed briefly disoriented and Peru's Alan Garcia joked that it gave them "a moment to dance."

Buildings emptied and streets crowded with people seeking higher ground in coastal Constitucion, a city wiped out by the tsunami that followed the quake. Pinera planned to visit the city shortly after his swearing-in.