Dozens of people were killed today when a powerful 7.2 earthquake hit Turkey, and Rihanna took to her Twitter account to send a message of love and prayer to those victims. Meanwhile, Demi Lovato spread a positive message about staying sober, and Mariah Carey sent out a mushy love note to her husband and "dem babies." Jazmine Sullivan and Nicki Minaj offered life lessons, Justin Bieber and Skylar Grey reminded fans about some exciting new releases and more. Scroll through the list below to find out what's going on in the pop Twitter world today!