Grove Karl Gilbert | |
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| Born | (1843-05-06)May 6, 1843 |
| Died | May 1, 1918(1918-05-01) (aged 74) |
| Alma mater | University of Rochester |
| Known for | Gilbert delta Crater studies Epeirogenic movement Geology of the Rocky Mountains Cycle of erosion |
| Awards | Wollaston Medal(1900) Charles P. Daly Medal(1910) |
| Scientific career | |
| Fields | Geology |
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Grove Karl Gilbert (May 6, 1843 – May 1, 1918), known by the abbreviated nameG. K. Gilbert in academic literature, was an Americangeologist.
Gilbert was born inRochester, New York, the youngest of three kids of the painterGrove Sheldon Gilbert, and his wife, Eliza.[1] He graduated from theUniversity of Rochester. During theAmerican Civil War, he was twice listed for the draft, but his name was drawn neither time.[2] In 1871, he joinedGeorge M. Wheeler's geographical survey as its first geologist.
Gilbert joined thePowell Survey of theRocky Mountain Region in 1874, becoming Powell's primary assistant, and stayed with the survey until 1879.[3] During this time he published an important monograph,The Geology of theHenry Mountains (1877). After theU.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 ancientLake Bonneville in 1890 (the lake existed during thePleistocene), of which theGreat Salt Lake is a remnant. He named it after the army captainBenjamin Bonneville, who had explored the region. The type ofriver delta that Gilbert described at this location has since become known to geomorphologists as aGilbert delta.[4]
In 1891, Gilbert examined the origins of a crater in Arizona, now known asMeteor Crater but then as Coon Butte. For several reasons, and against his intuition, he concluded it was the result of avolcanic steam explosion rather than an impact of ameteorite. 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.[5] He publicized these conclusions in a series of lectures in 1895.[6] 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.[7]
Gilbert joined theHarriman Alaska Expedition in 1899. Two weeks after the1906 San Francisco earthquake, 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 ofgeomorphology, having contributed to the understanding of landscape evolution,erosion, river incision, andsedimentation. He was aplanetary science pioneer, correctly identifying lunar craters as caused by impacts, and carrying out early impact-cratering experiments.[8] He coined the termsculpture for a pattern of radial ridges surroundingMare Imbrium on the moon, and correctly interpreted them in 1892 asejecta from a giant impact.[5]: 275 Gilbert was one of the more influential early American geologists.
He won theWollaston Medal from theGeological Society of London in 1900.[9] He was elected as a member to theAmerican Philosophical Society in 1902.[10] He was awarded theCharles P. Daly Medal by theAmerican Geographical Society in 1910.[11] 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 theGeological Society of America (1892 and 1909).[12] Because of Gilbert's prescient insights into planetary geology, the Geological Society of America created theG.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 theAmerican Society of Naturalists from 1885 to 1886.[13]
Craters on themoon and onMars are named in his honor, as isMount Gilbert in Alaska, a secondMount Gilbert in California, andGilbert Peak in theUinta Mountains of Utah.
