March 20, 2012 2:14 pm Caltech Seismologists: Mexico Quake in Active Subduction Zone Caltech scientists discuss recent activity in the area of southern Mexico where a magnitude-7.6 earthquake was recorded Tuesday. US & World Videos 1:14 Prince Harry photobombs Meghan Markle's selfie in Nigeria 4:41 How ‘Bachelorette' Hannah Brown knew fiancé Adam Woolard was the one 6:04 Matt Rife reveals wildest gift a fan gave him 7:23 Chrissy Teigen gets ‘sentimental' gift from John Legend every year 0:50 Man dies in 10 Fwy shooting in Covina