The map was carved in the cave floor and represents a complex water-flow system. Archaeologists believe this could be an ancient hydrological masterpiece — possibly the world’s first 3D model ...

During the last ice age, massive continental ice sheets up to ... Reviews of Geophysics 46, 1-39 (2008). Conkright, M. E. World Ocean Atlas 2001: Objective Analyses, Data Statistics, and Figures.