Geomorphology is the study of processes that shape the earth and its landscapes. It is one of the fields studied in geology. Geomorphology analyses the dynamics of change in the Earth's landscape and serves as a guide to what the surface of the land looked like in the past and to extrapolate how landscapes might be subject to change in the future.
 The Grand Canyon
The most recent conclusions of geomorphology place the time period the Grand Canyon took to be eroded at around 17 million years, during which it was most likely worn into its current shape by the Colorado River. The canyon formed because the land through which the river ran slowly rose in altitude over this period of time. This runs contrary to the testimony of the Bible, as interpreted literally by Young Earth Creationists, who hold that the canyon was eroded by the waters of a great flood during a time period of less than a year, in accordance with the story of Noah's Ark. Young Earth Creationists, of course, have no explanation for why there is a Grand Canyon in the United States and nowhere else.