Amy Robach left her fans slightly fearing for her safety as she shared a new photo on her Instagram from her adventurous travels.MORE: Amy Robach takes the plunge in daring ocean adventure away from GMA studiosThe Good Morning America host marked an incredible milestone as she touched down in Antarctica while on assignment, holding on to an icy patch of land in the daring picture.She shared a picture of herself touching the icy continent's mainland, telling fans that she'd accomplished the feat