The strong shaking struck as the country was also becoming alarmed by the mounting number of deaths associated with a spreading influenza epidemic.
The quake occurred at 11:46 a.m. local time from an epicenter 40 miles (60 km) northeast of Acapulco and 160 miles (260 km) south of Mexico City.
The epicenter was at a depth of more than 20 miles (35 km), which prevented significant damage or injuries in the region.
CNN producer Lonzo Cook said he overheard at least one person trying to make light of twin environmental assaults by saying, “This is the apocalypse. First the swine flu, and now this.”
Mexico City shook for more than 30 seconds, but most residents appeared to take the seismic event in good spirits, according to Cook.