A 7.6 tremblor hit Acapulco on the Pacific coast of Mexico, with a large aftershock felt in the capital, Mexico City. Phone lines were taken down by the quake, but no other major damage was reported -- although some residents said on Twitter that it was the strongest earthquake they'd felt on the fault line in more than a decade.
Shortly afterwards, on the opposite side of the ocean, a 6.7 magnitude quake was reported in the Indonesian province of Papua (the western half of the island of New Guinea).
Despite both quakes hitting coastal areas, there was no tsunami warning issued on either side of the ocean.
Reports are coming in thick and fast on Twitter, Facebook and YouTube -- so check out our Storify, below, for the latest. And let us know in the comments if you've been affected.