A portion of Australia's Great Barrier Reef photographed from the International Space Station. The Flinders Reef area of the Great Barrier Reef is one of 11 sites around the world where scientists are looking for decisive geological evidence of a new epoch called the anthropocene. M. Justin Wilkinson, Texas State U., Jacobs Contract at NASA-JSC/NASA Humans have changed the Earth in such profound ways that scientists say we have entered a new geological period: the Anthropocene Epoch. But when did the new epoch officially begin? And how, exactly, should it be defined? Those are the questions that geologists are pursuing with increasing urgency at sites around the world. Teams are studying 11 locations on five continents, looking for a place where rock, mud or ice perfectly capture the global impact of humans.