Grove Karl Gilbert (May 6, 1843 – May 1, 1918), known by the abbreviated name G. K. Gilbert in academic literature, was an American

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

Biography

Gilbert was born in

Rochester, New York Rochester is a city in and the county seat, seat of government of Monroe County, New York, United States. It is the List of municipalities in New York, fourth-most populous city and 10th most-populated municipality in New York, with a populati ...

, and graduated from the

University of Rochester The University of Rochester is a private university, private research university in Rochester, New York, United States. It was founded in 1850 and moved into its current campus, next to the Genesee River in 1930. With approximately 30,000 full ...

. During the

American Civil War The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...

, he was twice listed for the draft, but his name was drawn neither time. In 1871, he joined George M. Wheeler's geographical survey as its first geologist.

Rockies geologist

Gilbert joined the Powell Survey of the Rocky Mountain Region in 1874, becoming Powell's primary assistant, and stayed with the survey until 1879. During this time he published an important monograph, ''The Geology of the Henry Mountains'' (1877). After the U.S. Geological Survey was created in 1879, he was appointed to the position of Senior Geologist and worked for the USGS until his death (including a term as acting director). Gilbert published a study of the former ancient Lake Bonneville in 1890 (the lake existed during the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

), of which the Great Salt Lake is a remnant. He named it after the army captain Benjamin Bonneville, who had explored the region. The type of

river delta A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creat ...

that Gilbert described at this location has since become known to geomorphologists as a Gilbert delta."Geological and Petrophysical Characterization of the Ferron Sandstone for 3-D Simulation of a Fluvial-deltaic Reservoir". By Thomas C. Chidsey, Thomas C. Chidsey, Jr (ed), Utah Geological Survey, 2002. . pp. 2–17
Partial text
on Google Books.

Meteor crater

In 1891, Gilbert examined the origins of a crater in Arizona, now known as Meteor Crater but then as Coon Butte. For several reasons, and against his intuition, he concluded it was the result of a volcanic steam explosion rather than an impact of a

meteorite A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...

. Gilbert based his conclusion on the beliefs that the volume of an impact crater including the meteorite should be more than the ejected material on the rim and that, if it was a meteorite, iron should create magnetic anomalies. Gilbert's calculations showed that the crater's volume and the debris on the rim were roughly equal, and that there were no magnetic anomalies. He argued that the meteorite fragments found on the rim were just "coincidence". In 1892, Gilbert delivered his paper "The Moon's Face; A Study of the Origin of Its Features" as his retiring President's lecture to the Philosophical Society of Washington, and it was published in the Society's bulletin. He publicized these conclusions in a series of lectures in 1895. Later investigations revealed that it was in fact a meteor crater, but that interpretation was not well established until the mid-20th century. As part of his interest in crater origins, Gilbert also studied the moon's craters and concluded they were caused by impact events rather than volcanoes, although he wondered why the craters were round and not oval as expected for an oblique impact. The interpretation of lunar craters as of impact origin was also debated until the mid-20th century.

Geomorphology

Gilbert joined the Harriman Alaska Expedition in 1899. Two weeks after the

1906 San Francisco earthquake At 05:12 AM Pacific Time Zone, Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated Moment magnitude scale, moment magnitude of 7.9 and a maximum Mercalli inte ...

, he 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 subdiscipline of

geomorphology Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand wh ...

, having contributed to the understanding of landscape evolution,

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

, river incision, and

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

ation. He was a

planetary science Planetary science (or more rarely, planetology) is the scientific study of planets (including Earth), celestial bodies (such as moons, asteroids, comets) and planetary systems (in particular those of the Solar System) and the processes of ...

pioneer, correctly identifying lunar craters as caused by impacts, and carrying out early impact-cratering experiments. He coined the term ''sculpture'' for a pattern of radial ridges surrounding

Mare Imbrium Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains") is a vast lunar mare, lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the collision ...

on the moon, and correctly interpreted them in 1892 as

ejecta Ejecta (; ) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic rock, pyroclastic materials (tephra) that came out of a explosive eruption, volcanic explosion and magma eruption v ...

from a giant impact. Gilbert was one of the more influential early American geologists.

Awards

He won the Wollaston Medal from the

Geological Society of London The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 Fellows. Fe ...

in 1900. He was elected as a member to the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

in 1902. He was awarded the Charles P. Daly Medal by the

American Geographical Society The American Geographical Society (AGS) is an organization of professional geographers, founded in 1851 in New York City. Most fellows of the society are United States, Americans, but among them have always been a significant number of fellows f ...

in 1910. Gilbert was well-esteemed by all American geologists during his lifetime, and he is the only geologist to ever be elected twice as President of the Geological Society of America (1892 and 1909). Because of Gilbert's prescient insights into planetary geology, the Geological Society of America created the G.K. Gilbert Award for planetary geology in 1983. Gilbert's wide-ranging scientific ideas were so profound that the Geological Society of America published GSA Special Paper 183 on his research (Yochelson, E.L., editor, 1980, The Scientific Ideas of G.K. Gilbert, fourteen separate biographical chapters, 148 pages). Gilbert also served as the president of the American Society of Naturalists from 1885 to 1886. Craters on the

moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

and on

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

are named in his honor, as is Mount Gilbert in Alaska, a second Mount Gilbert in California, and Gilbert Peak in the Uinta Mountains of Utah.

Publications

*
Report on the geology of the Henry mountains
(1877) *
Lake Bonneville" US Geological Survey Monograph No. 1
1890. 438 p. *
The Moon's face: a study of the origin of its features"
Bulletin of the Philosophical Society of Washington (January 1893). *
The Underground Water of the Arkansas Valley in Eastern Colorado
(1896) *
Harriman Alaska Expedition, Volume 3: Glaciers and glaciation
(1899) *
The San Francisco Earthquake and Fire of April 18, 1906, and Their Effects on Structures and ...
(1907) *
The transportation of débris by running water
US Geological Survey Professional Paper No. 86 (1914) *
Bolinas
USGS photographs of San Andreas fault taken by Gilbert (1906) *
Studies of Basin-Range structure"
U.S. Geological Survey Professional Paper 153 (1928)

References

Secondary sources

* Pyne, Stephen J. ''Grove Karl Gilbert: A Great Engine of Research''. Austin:

University of Texas Press The University of Texas Press (or UT Press) is the university press of the University of Texas at Austin. Established in 1950, the Press publishes scholarly and trade books in several areas, including Latin American studies, Caribbean, Caribbea ...

, 1980.

External links

* {{DEFAULTSORT:Gilbert, Grove 1843 births 1918 deaths American geomorphologists Tectonicists Grand Canyon history University of Rochester alumni Scientists from Rochester, New York United States Geological Survey personnel Wollaston Medal winners Foreign members of the Royal Society National Geographic Society founders Presidents of the American Association of Geographers Presidents of the Geological Society of America Presidents of the American Society of Naturalists Members of the American Philosophical Society