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 solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...

Biography

Gilbert was born in

Rochester, New York Rochester () is a City (New York), city in the U.S. state of New York (state), New York, the county seat, seat of Monroe County, New York, Monroe County, and the fourth-most populous in the state after New York City, Buffalo, New York, Buffalo, ...

and graduated from the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of ...

. During the

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

, 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

He then joined the Powell Survey of the

Rocky Mountain The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

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 creation of the U.S. Geological Survey 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 ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

), of which the

Great Salt Lake The Great Salt Lake is the largest saltwater lake in the Western Hemisphere and the eighth-largest terminal lake in the world. It lies in the northern part of the U.S. state of Utah and has a substantial impact upon the local climate, particu ...

is a remnant. He named that lake after the army captain Benjamin L.E. de Bonneville, who had explored this region previously. The type of

river delta A river delta is a landform shaped like a triangle, created by deposition of sediment that is carried by a river and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rare ...

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 for a crater in Arizona, now known as

Meteor Crater Meteor Crater, or Barringer Crater, is a meteorite impact crater about east of Flagstaff and west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are offi ...

but then referred to as Coon Butte. For a number of 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 solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object ...

. Gilbert based his conclusions on a belief that for an impact crater, the volume of the crater including the meteorite should be more than the ejected material on the rim and also a belief that if it was a meteorite then iron should create magnetic anomalies. Gilbert's calculations showed that the volume of the crater and the debris on the rim were roughly equal. Further there were no magnetic anomalies. Gilbert 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 the paper was published in the Society's bulletin. Gilbert would publicize these conclusions in a series of lectures in 1895. Subsequent investigations would reveal 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

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

1906 San Francisco earthquake At 05:12 Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated moment magnitude of 7.9 and a maximum Mercalli intensity of XI (''Extreme''). High-intensity ...

, Gilbert 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 sub-discipline of

geomorphology Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or ...

, having contributed to the understanding of landscape evolution,

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

, river incision and

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

ation. Gilbert 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 their ...

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", "Sea of Tears") is a vast 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 colli ...

on the moon, and correctly interpreted them in 1893 as

ejecta Ejecta (from the Latin: "things thrown out", singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma ...

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 in 1900. He was elected as a member to the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

in 1902. He was awarded the Charles P. Daly Medal by the American Geographical Society 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 The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitch ...

(1892 and 1909).Eckel, Edwin, 1982, GSA Memoir 155, The Geological Society of America — Life History of a Learned Society, . 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).

Crater Crater may refer to: Landforms * Impact crater, a depression caused by two celestial bodies impacting each other, such as a meteorite hitting a planet * Explosion crater, a hole formed in the ground produced by an explosion near or below the surf ...

s on the

moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

and on

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

are named in his honor, as is Mount Gilbert in Alaska, and another Mount Gilbert in California.

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 1898). *
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. Stephen J. Pyne (1949–present) is an emeritus professor at Arizona State University, specializing in environmental history, the history of exploration, and especially the history of fire. Education Pyne received his bachelor's degree at Stanford ...

''Grove Karl Gilbert: A Great Engine of Research''. Austin:

University of Texas Press The University of Texas Press (or UT Press) is a university press that is part of the University of Texas at Austin. Established in 1950, the Press publishes scholarly books and journals in several areas, including Latin American studies, Te ...

, 1980.

External links

* {{DEFAULTSORT:Gilbert, Grove 1843 births 1918 deaths American geologists 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