John Tilton Hack (1913–1991) was an American geologist and geomorphologist known for his contributions to establish the dynamic equilibrium concept in landscapes. He was a student of Kirk Bryan. He retired from the United States Geological Survey in 1981.[1]

Hack graduated from Harvard University, where he received his bachelors and master's degrees and doctorate in geomorphology.[2]


  1. ^ Osterkamp, W.R.; Hupp, C.R. "Memorial to John T. Hack" (PDF). Memorials. 23: 59–61.
  2. ^ Obituary