Geomorphology
He joined the Harriman Alaska Expedition in 1899. Two weeks after the 1906 San Francisco earthquake, Gilbert took a series of photographs documenting the damage along the San Andreas fault from Inverness to Bolinas.
Gilbert is considered one of the giants of the sub-discipline of geomorphology, having contributed to the understanding of landscape evolution, erosion, river incision and sedimentation. Gilbert was a planetary science pioneer, correctly identifying lunar craters as caused by impacts, and carrying out early impact-cratering experiments. Gilbert was one of the more influential early American geologists.
Read more about this topic: Grove Karl Gilbert