In these geographies there are plentiful descriptions of landforms and landscapes
along the travel routes. In modern times this tradition has been expanded into
descriptions of regional geomorphology.
In geographic terms, geomorphology answers “what is where” on the physical
landscape and then “when” and “how.” Early on, geomorphic inquiry was intellec-
tually handcuffed by the notion that the landforms of Earth had all been impacted
by the biblical flood of Noah. In the 1700s, scientists started to question a flood
origin of landforms and began to use Hutton’s concept of uniformitarianism that
espoused series of processes acting over long times to create landforms. In that it
uses uniformitarianism to deduce the past, geomorphology can also ascend to the
pinnacle of science by providing forecasts of the evolution of future landscapes.
Since the 1960s, concepts ofplate tectonicshave revolutionized geomorphol-
ogy. The realization that there are crustal plates and they move has caused an epiph-
any in geomorphology. While geomorphologists have long realized that parts of
Earth’s crust rise and fall, plate tectonics have provided a mega-overview that has
been used to great advantage. Although not all the details are known, the parts that
are certain are of immense scientific value. Why do most large volcanoes cluster
around the rim of the Pacific Ocean? Why do oceanic ridges and trenches exist?
Why are the oldest rocks exposed at Earth’s surface younger than Earth by, perhaps,
a half a billion years? These are question for which there are now firm answers.
It should be noted that while the tectonic forces inside Earth are a major key to
understanding landforms, the planet’s atmosphere has much input to the shape of
the landscape. Most continental surface landforms are largely the result of
Geomorphology 145William Morris Davis (1850–1934)
Davis was a giant in early academic geography in the United States. He is remembered as a
geographer, geomorphologist, and a founder of the Association of American Geographers
and the National Geographic Society. He is considered one of the fathers of modern
American geography. Never finishing a PhD, Davis became a physical geography instructor
at Harvard in 1884 as geography was emerging as a discipline. Davis’ supreme insight was
the application of evolution into the landscape to the effect that he was first to devise the con-
cept of landscape evolution through development of drainage systems. First published in
1889, it is usually called the “geographic cycle” or “cycle of erosion.” Starting with a flat sur-
face above sea level, streams will erode into the landscape in a series of V-shaped valleys
(youthful landscape). Stream erosion over eons will result in a landscape all in hill and valley
(mature landscape). Finally, erosion will subdue the hills and the landscape will become a
virtually flat surface known as a peneplain (landscape of old age). Today, this model has been
superseded by equilibrium theory, which deals with forces and mass. Yet, Davis’ contribu-
tions still stand as seminal to those trying to understand landscapes.