(1843-1918) American Geomorphologist
G. Karl Gilbert is one of the most famous American geologists of the 19th century and one of the founders of the U.S. Geological Survey. His geologic research of the American West during the late 19th century and early 20th century is historic. During his expeditions, Gilbert crossed Death Valley on foot and by mule, traveled along the steep, upstream terrain through the Grand Canyon, documented the Basin and Range Province of New Mexico, Arizona, and Utah, and explored the deserts of Nevada. He was even in the San Francisco earthquake of 1906 and fully documented the event. He is famous for the meticulous and detailed drawings and field notes that he kept on almost every geological, and on a lesser scale, biological feature he observed during his travels.
Karl Gilbert was a geomorphologist who developed many of the fundamental concepts that would define the discipline for many years. In his famous work, “Report on the Geology of the Henry Mountains,” he determined that an intrusive body (laccolith) may deform its host rock. However, the real contribution was the expansion of John Wesley Powell’s concept of subaerial erosion and base level into a fundamental theory. He emphasized lateral planation in this expansion. This idea would later be expanded into the theory of geographic cycles. Gilbert also studied graded streams. He showed that either by cutting down their beds or building them up with sediment, streams would always make room for themselves. On a long-term basis, they will transport exactly the load of sediment that is delivered to them from above. To quantify his observations, Gilbert conducted a series of flume experiments at the University of California at Berkeley from 1907-1909. This work was done largely to explain the sedimentary effects of hydraulic mining on the Sacramento River and San Francisco Bay and the great power of humans as geologic agents.
Gilbert was the first to describe the Basin and Range Province in terms of block faulting through extension. His real interest was the huge glacial Lake Bonneville, the ancestor of the Great Salt Lake, and the displaced shorelines as related to isostatic rebound. This interest in glaciation led him to participate in the Harriman Expedition to Alaska in 1899. He accompanied John Muir in studying the features of alpine glaciers. He described the effects of climate and topography on the motion of glaciers in his book, Glaciers and Glaciation. Gilbert even proposed an impact origin for the craters on the Moon in yet another famous study.
Grove Karl Gilbert was born on May 6, 1843, in Rochester, New York. He excelled in school in both academic achievements and social graces. Even with his family’s limited resources, Gilbert graduated from high school at age 15, and went on to attend the University of Rochester, New York. While in college, his curriculum consisted of mathematics, Greek, Latin, logic, and one geology class. That one class was all that was needed to pique Gilbert’s interest. In 1862, Gilbert graduated from college while the Civil War was beginning to tear the country apart. Either due to poor health or his dislike for violence, Gilbert did not enlist in the army. In 1863, with mounting student loans and no way to repay them, Gilbert accepted a position as a schoolteacher with the public school system in Jackson,
G. K. Gilbert studies a rock exposure at Monterey Formation in California in 1906
Michigan. He lived with his sister on the outskirts of Jackson. Gilbert did not adapt well to teaching unruly teenage schoolboys and returned to his hometown of Rochester before the school year ended. Gilbert found a position as a clerk with Ward’s Cosmos Hall, a natural-science center, where he worked for the next five years (1863-1868). Even though Gilbert was inexperienced, he spent hours studying and documenting fossil samples.
The famous New York State geologist James Hall was leading an expedition to excavate a mastodon along the Mohawk River for Ward’s. In late 1863, Hall injured his hip and Gilbert was given the opportunity to lead the expedition. As the expedition continued, it was evident that the skeleton was incomplete. Even though most of Gilbert’s early work concentrated on paleontology, his real interest was in surficial geology. During the excavation process, he discovered potholes in the riverbed and began investigating their formation, as well as their association with a nearby retreating waterfall.
In 1869, Gilbert was hired by the Geological Survey of Ohio to conduct fieldwork. In 1871, Lieutenant G. M. Wheeler offered him a position as geologist with the newly formed Wheeler Geological Survey. The Wheeler Survey was one of four geological surveys (Hayden, King, Powell, Wheeler) that each had jurisdiction over a geographic area of the United States. The Wheeler Survey specialized in military and engineering goals. He met John Wesley Powell while completing the Wheeler Reports in Washington, D.C. In 1874, Gilbert moved to the Powell Survey. The four geological surveys were combined into the U.S. Geological Survey in 1878 and Gilbert and Powell were two of the original six geologists in charge. G. K. Gilbert spent the next three decades with the U.S. Geological Survey, including the position of the second director (1881-1892). Gilbert was married to Fanny Porter in 1874. They had three children, but his daughter died in 1883 and soon after, his wife became an invalid. She died in 1899. G. Karl Gilbert died on May 1, 1918, in Jackson, Michigan.
G. Karl Gilbert has some 400 scholarly publications of all varieties to his credit. Many of these are benchmarks of geomorphology, among other areas. He received numerous honors and awards in recognition of these contributions. He was a member of the National Academy of Sciences. He was awarded honorary doctoral degrees from the University of Rochester, the University of Wisconsin at Madison, and the University of Pennsylvania, among others. He received the Wollaston Medal from the Geological Society of London, the Walker Grand Prize from the Boston Society of Natural History, and the Hubbard Medal from the National Geographic Society, among others. Gilbert is the only person ever to have been elected president of the Geological Society of America twice (1892 and 1909). He was also president of the Society of American Naturalists, the American Geographic Society, and the Philosophical Society and Geological Society of Washington, D.C., among others. He has awards named in his honor from the Geological Society of America, the U.S. Geological Survey, and the Association of American Geographers.
