During the Second Punic War, Hannibal, in a brazen move, led a massive army over the Alps, surprising the Romans from the supposedly impenetrable northern border. The exact route Hannibal took is unknown, although some geographic information can be gleaned from historical accounts such as those of the Roman writer Polybius. Armed with this information, and the knowledge that tens of thousands of men, horses and elephants must have left some trace, geoscientists are hunting down possible locations using deduction and chemistry to test hypotheses.

In the August issue of EARTH Magazine, explore some of geology's most historic images, and hear from experts about what made these depictions so valuable to the field and why they continue to be useful educational resources.

Alexandria, VA – Geoscientists using every resource available to them — from bare-earth LIDAR technology to knowledge of turn-of-the-century fashion — have helped correct a 100-year-old mistake about where the San Andreas Fault rupture point was for the historic 1906 earthquake.