All the segments above were first published in the Alaska Science Forum. Since the late 1970s, the University of Alaska Fairbanks’ Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell is a science writer for the Geophysical Institute. This summer, he hiked the path of the trans-Alaska oil pipeline from Valdez to Prudhoe Bay. He also did the trip 20 years ago.