The similar but opposing contours of Earth’s continental land mass shorelines has been observed since chart making began. It was not until early in the 20th century that German meteorologist Alfred Wegener proposed the theory of continental drift, and understanding that the planet’s crustal plates are created at the mid-ocean ridge boundaries came in the second half of this century. Today, study of the mid-ocean ridge system—whose 40,000-mile length makes it Earth’s largest geographical feature—forms a significant sector of oceanographic science. Our two issues for 1998 offer Oceanus readers insight into the mid-ocean ridge investigations of Woods Hole Oceanographic Institution scientists and their colleagues.