The USGS said the shaker, which struck at 6:45 p.m. Costa Rica time, was centered 38 miles south-southeast of the town of Liberia and 88 miles west of the capital San Jose.
No major damage was immediately reported, but Costa Rican newspaper Tico Times said the shaking was felt across the entire nation.
Costa Rican seismologists told the Times the quake was centered along the same fault line on the Nicoya Peninsula that generated a 7.6 quake Sept. 5. Marino Protti, lead scientist at the seismological agency Ovsicori, told the Times last month's temblor did not relieve all of the pressure that had been building up along the fault and that another big quake had been considered possible.
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