During 2010 and 2011, we studied the effects of the continental uplift that resulted from the earthquake of 27F on the physical landscape and the macrofauna of sandy beaches located in front of coastal armoring along Peninsula de Arauco and nearby areas. The mean width of uplifted beaches during the period following 27F was up to 12,5 times higher than beach widths observed before the earthquake and the beach face slope of uplifted beaches decreased. At those beaches that had coastal armoring located closer to high tides before the earthquake, the restored upper and mid shore beach levels (previously occupied by seawalls and rocky revetments) were rapidly colonized by crustacean species, which typically inhabit at similar intertidal levels of unarmored beaches of Chile. Field samplings carried out promptly after large scale disturbances have occurred, are relevant to increase knowledge on the interaction between that natural phenomenon's and coastal artificial infrastructure.