{"pageNumber":"1469","pageRowStart":"36700","pageSize":"25","recordCount":41022,"records":[{"id":70014227,"text":"70014227 - 1987 - Basin-ring spacing on the Moon, Mercury, and Mars","interactions":[],"lastModifiedDate":"2012-03-12T17:19:36","indexId":"70014227","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1429,"text":"Earth, Moon and Planets","active":true,"publicationSubtype":{"id":10}},"title":"Basin-ring spacing on the Moon, Mercury, and Mars","docAbstract":"Radial spacing between concentric rings of impact basins that lack central peaks is statistically similar and nonrandom on the Moon, Mercury, and Mars, both inside and outside the main ring. One spacing interval, (2.0 ?? 0.3)0.5D, or an integer multiple of it, dominates most basin rings. Three analytical approaches yield similar results from 296 remapped or newly mapped rings of 67 multi-ringed basins: least-squares of rank-grouped rings, least-squares of rank and ring diameter for each basin, and averaged ratios of adjacent rings. Analysis of 106 rings of 53 two-ring basins by the first and third methods yields an integer multiple (2 ??) of 2.00.5D. There are two exceptions: (1) Rings adjacent to the main ring of multi-ring basins are consistently spaced at a slightly, but significantly, larger interval, (2.1 ?? 0.3)0.5D; (2) The 88 rings of 44 protobasins (large peak-plus-inner-ring craters) are spaced at an entirely different interval (3.3 ?? 0.6)0.5D. The statistically constant and target-invariant spacing of so many rings suggests that this characteristic may constrain formational models of impact basins on the terrestrial planets. The key elements of such a constraint include: (1) ring positions may not have been located by the same process(es) that formed ring topography; (2) ring location and emplacement of ring topography need not be coeval; (3) ring location, but not necessarily the mode of ring emplacement, reflects one process that operated at the time of impact; and (4) the process yields similarly-disposed topographic features that are spatially discrete at 20.5D intervals, or some multiple, rather than continuous. These four elements suggest that some type of wave mechanism dominates the location, but not necessarily the formation, of basin rings. The waves may be standing, rather than travelling. The ring topography itself may be emplaced at impact by this and/or other mechanisms and may reflect additional, including post-impact, influences. ?? 1987 D. Reidel Publishing Company.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earth, Moon and Planets","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Kluwer Academic Publishers","doi":"10.1007/BF00054060","issn":"01679295","usgsCitation":"Pike, R., and Spudis, P.D., 1987, Basin-ring spacing on the Moon, Mercury, and Mars: Earth, Moon and Planets, v. 39, no. 2, p. 129-194, https://doi.org/10.1007/BF00054060.","startPage":"129","endPage":"194","numberOfPages":"66","costCenters":[],"links":[{"id":205683,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00054060"},{"id":226139,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"39","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059efefe4b0c8380cd4a516","contributors":{"authors":[{"text":"Pike, R.J.","contributorId":72814,"corporation":false,"usgs":true,"family":"Pike","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":367901,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Spudis, P. D.","contributorId":58719,"corporation":false,"usgs":true,"family":"Spudis","given":"P.","email":"","middleInitial":"D.","affiliations":[{"id":12445,"text":"Lunar and Planetary Institute","active":true,"usgs":false}],"preferred":false,"id":367900,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014219,"text":"70014219 - 1987 - Some effects of quiet geomagnetic field changes upon values used for main field modeling","interactions":[],"lastModifiedDate":"2013-02-13T13:27:25","indexId":"70014219","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Some effects of quiet geomagnetic field changes upon values used for main field modeling","docAbstract":"The effects of three methods of data selection upon the assumed main field levels for geomagnetic observatory records used in main field modeling were investigated for a year of very low solar-terrestrial activity. The first method concerned the differences between the year's average of quiet day field values and the average of all values during the year. For H these differences were 2-3 gammas, for D they were -0.04 to -0.12???, for Z the differences were negligible. The second method of selection concerned the effects of the daytime internal Sq variations upon the daily mean values of field. The midnight field levels when the Sq currents were a minimum deviated from the daily mean levels by as much as 4-7 gammas in H and Z but were negligible for D. The third method of selection was designed to avoid the annual and semi-annual quiet level changes of field caused by the seasonal changes in the magnetosphere. Contributions from these changes were found to be as much as 4-7 gammas in quiet years and expected to be greater than 10 gammas in active years. Suggestions for improved methods of improved data selection in main field modeling are given. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(87)90144-0","issn":"00319201","usgsCitation":"Campbell, W., 1987, Some effects of quiet geomagnetic field changes upon values used for main field modeling: Physics of the Earth and Planetary Interiors, v. 48, no. 3-4, p. 193-199, https://doi.org/10.1016/0031-9201(87)90144-0.","startPage":"193","endPage":"199","numberOfPages":"7","costCenters":[],"links":[{"id":267335,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(87)90144-0"},{"id":226007,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b929ae4b08c986b319fe6","contributors":{"authors":[{"text":"Campbell, W.H.","contributorId":30749,"corporation":false,"usgs":true,"family":"Campbell","given":"W.H.","email":"","affiliations":[],"preferred":false,"id":367877,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014217,"text":"70014217 - 1987 - Coal deposits of the United States","interactions":[],"lastModifiedDate":"2024-02-24T01:12:26.417172","indexId":"70014217","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2033,"text":"International Journal of Coal Geology","active":true,"publicationSubtype":{"id":10}},"title":"Coal deposits of the United States","docAbstract":"The coal fields of the Unites States can be divided into six major provinces. The Appalachian and Interior Provinces contain dominantly bituminous coal in strata of Pennsylvanian age. The coal seams are relatively thin and are mined both by surface and underground methods. Sulfyur content is low to moderate in the Appalachian Province, generally high in the Interior province. The Gulf Coastal Plain Province, in Texas and neighboring states, contains lignite of Eocene age. The seams are 3–25 ft (0.9–7.5 m) thick and are minded in large open pits. The Northern Great Plains Province has lignite and subbituminous coal of Cretaceous, Paleocene and Eocene age. The coal, largely very low in sulfur, occurs in beds up to 100 ft (30 m) thick and is strip-mined. The Rocky Mountain Province contains a great variety of coal deposits in numerous separate intermontane basins. Most of it is low-sulfur subbituminous to bituminous coal iof Creatceous and early Tertiary age. The seams range from a few feet to over 100 ft (30 m) thick. Strip-mining dominates but underground mines are important in Utah and Colorado. The Pacific Coast Province, which includes Alaska, contains enormous cola resources but has seen little mining. The coal is highly diverse in physical character and geologic setting.
Two natural lignins, one from a gymnosperm wood the other from angiosperm wood, were examined by conventional solid-state and dipolar dephasing 13C nuclear magnetic resonance (NMR) techniques. The results obtained from both techniques show that the structure of natural lignins is consistent with models of softwood and hardwood lignin. The dipolar dephasing NMR data provide a measure of the degree of substitution on aromatic rings which is consistent with the models.
","language":"English","publisher":"Elsevier","doi":"10.1016/0146-6380(87)90049-0","usgsCitation":"Hatcher, P.G., 1987, Chemical structural studies of natural lignin by dipolar dephasing solid-state 13C nuclear magnetic resonance: Organic Geochemistry, v. 11, no. 1, p. 31-39, https://doi.org/10.1016/0146-6380(87)90049-0.","productDescription":"9 p.","startPage":"31","endPage":"39","costCenters":[],"links":[{"id":225881,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Virginia, 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\"}}]}","volume":"11","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f596e4b0c8380cd4c2d4","contributors":{"authors":[{"text":"Hatcher, Patrick G.","contributorId":93625,"corporation":false,"usgs":true,"family":"Hatcher","given":"Patrick","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":367870,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014212,"text":"70014212 - 1987 - Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina","interactions":[],"lastModifiedDate":"2023-11-15T16:40:43.85911","indexId":"70014212","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1761,"text":"Geoexploration","active":true,"publicationSubtype":{"id":10}},"title":"Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina","docAbstract":"Sixty-two Schlumberger electrical soundings were made in the Durham Triassic basin in an effort to determine basin structural geometry, depth of the sedimentary layers, and spatial distribution of individual rock facies. A digital computer program was used to invert the sounding curves of apparent resistivity versus distance to apparent resistivity versus depth. The apparent-resistivity-versus-depth data from the computer-modeling program were used to construct a geoelectric model of the basin that is believed to accurately represent the subsurface geology of the basin. The largest depth to basement in the basin along a resistivity profile (geoelectric section) was determined to be 1,800 m. A resistivity decrease was observed on certain soundings from depths of 100 to 1,000 m; below a 1,000-m depth, apparent resistivity increased to the bottom of the basin. Resistivity values for basement rocks were greater than 1,000 ohm-m and less than 350 ohm-m for the sedimentary layers in the basin. The data suggest that the basin contains a system of step faults near its eastern boundary.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7142(87)90012-3","usgsCitation":"Brown, C.E., 1987, Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina: Geoexploration, v. 24, no. 6, p. 429-440, https://doi.org/10.1016/0016-7142(87)90012-3.","productDescription":"12 p.","startPage":"429","endPage":"440","numberOfPages":"12","costCenters":[],"links":[{"id":225880,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"North Carolina","otherGeospatial":"Durham basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -80.11054032257658,\n 34.81424858901997\n ],\n [\n -78.71952572597303,\n 35.63369969562967\n ],\n [\n -78.29487040818577,\n 36.369481295510155\n ],\n [\n -78.80312574155963,\n 36.15648733554863\n ],\n [\n -79.43844490827757,\n 35.6255443614009\n ],\n [\n -80.1172332811392,\n 35.01166900462569\n ],\n [\n -80.28442253553915,\n 34.81424671856449\n ],\n [\n -80.11054032257658,\n 34.81424858901997\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"24","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5bd4e4b0c8380cd6f828","contributors":{"authors":[{"text":"Brown, C. Erwin","contributorId":96261,"corporation":false,"usgs":true,"family":"Brown","given":"C.","email":"","middleInitial":"Erwin","affiliations":[],"preferred":false,"id":367869,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014207,"text":"70014207 - 1987 - Sedimentation across the central California oxygen minimum zone: an alternative coastal upwelling sequence","interactions":[],"lastModifiedDate":"2024-05-20T23:21:01.592141","indexId":"70014207","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2450,"text":"Journal of Sedimentary Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Sedimentation across the central California oxygen minimum zone: an alternative coastal upwelling sequence","docAbstract":"Distribution, abundance, and diversity of terrigenous, authigenous, and biogenous material provide evidence of the effect of bottom currents and oxygen minimum zone (OMZ) on continental slope sedimentation offshore central California. Box core samples and bottom photographs collected across the oxygen minimum zone of the coastal upwelling system were analyzed for lithologic and biologic trends. Three major OMZ facies are identified, along the upper and lower edges of the OMZ and one at its core. The upper boundary (525 m) of the central California OMZ (< 0.5 ml/liter O 2 ) is characterized by glauconitic gravelly sands relatively depleted in detrital silicates and enriched in carbonate and total organic carbon (TOC). These upper-boundary sands also have a maximum macrofauna density and a high abundance of foraminiferal fragments (> 80% of total forams) with Cassidulina the dominant benthic foraminifer. With increasing water depth, decreasing current speed, and dissolved oxygen content toward the core of the OMZ (750 m), grain size, glauconite, carbonate, TOC, and foraminiferal fragments all decrease as the abundance of mica and detrital silicates increase. The greatest number of genera of benthic foraminifera occurs at the core of the OMZ where their relative concentration is at a minimum and Bolivina is the dominant genus. No heavily calcified macrofauna were found at the core of the OMZ; however, near-surface sediments are highly bioturbated. As the lower boundary (1,025 m) of the OMZ is approached, grain size and abundance of detrital silicates continue to decrease as glauconite disappears. Concomitantly, the relative abundance of mica, carbonate, TOC, siliceous microfauna, benthic foraminifers, and foram fragments increase. The benthic foraminifer population consists largely (> 40%) of Globobulimina and Praeglobobulimina . The lower edge of the OMZ is highlighted by a distinct peak of fecal pellets (25% of sand-size material). Lithofacies and biofacies associated with the OMZ are controlled by an interplay of oceanic circulation, dissolved oxygen concentrations, and possibly by increased biological activity within the OMZ edge environment and slight changes in the slope gradient. Recognition of key lithofacies and biofacies trends may prove to be powerful paleoenvironmental/paleoceanographic indicators and may be useful in identifying ancient zones of upwelling analogous to the modern central California system where phosphorites, organic-rich shales, and/or chert are absent.
Normal alkanes (n-C13![\"single](\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/sbnd.gif\")
n-C36), isoprenoid hydrocarbons (i-C15, i-C16, i-C18, i-C19, and i-C20) triterpanes (C27C32), and (C27C29) are present in low concentrations offshore Antarctica in near-surface, Quaternary sediment of the Wilkes Land continental margin and of the western Ross Sea. The distributions of these hydrocarbons are interpreted relative to possible sources and processes. The hydrocarbons appear to be mixtures of primary and recycled material from marine and terrigenous sources. The n-alkanes are most abundant and are characterized by two distinct populations, one of probable marine origin and the other likely from terrigenous, vascular plant sources. Because the continent of Antarctica today is devoid of higher plants, the plant-derived hydrocarbons in these offshore sediments probably came from wind-blown material and recycled Antarctic sediment that contains land-plant remains from an earlier period of time. Isoprenoid hydrocarbons are partially recycled and mainly of marine origin; the dominance of pristane over phytane suggests oxic paleoenvironmental conditions. Both modern and ancient triterpanes and steranes are present, and the distribution of these indicates a mixture of primary and recycled bacterial, algal, and possible higher-plant materials. Although the sampled sediments were deposited during the Quaternary, they apparently contain a significant component of hydrocarbons of pre-Quaternary age.
","language":"English","publisher":"Elsevier","doi":"10.1016/0146-6380(87)90040-4","usgsCitation":"Kvenvolden, K.A., Rapp, J., Golan-Bac, M., and Hostettler, F.D., 1987, Multiple sources of alkanes in Quaternary oceanic sediment of Antarctica: Organic Geochemistry, v. 11, no. 4, p. 291-302, https://doi.org/10.1016/0146-6380(87)90040-4.","productDescription":"12 p.","startPage":"291","endPage":"302","costCenters":[],"links":[{"id":225690,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Antarctica","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n 160.97363351207912,\n -73.17043004224713\n ],\n [\n 160.97363351207912,\n -78.3166029074892\n ],\n [\n 181.77303555738786,\n -78.3166029074892\n ],\n [\n 181.77303555738786,\n -73.17043004224713\n ],\n [\n 160.97363351207912,\n -73.17043004224713\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"11","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a607ce4b0c8380cd714be","contributors":{"authors":[{"text":"Kvenvolden, Keith A. kkvenvolden@usgs.gov","contributorId":3384,"corporation":false,"usgs":true,"family":"Kvenvolden","given":"Keith","email":"kkvenvolden@usgs.gov","middleInitial":"A.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":367823,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rapp, John B.","contributorId":32028,"corporation":false,"usgs":true,"family":"Rapp","given":"John B.","affiliations":[],"preferred":false,"id":367822,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Golan-Bac, Margaret","contributorId":19169,"corporation":false,"usgs":true,"family":"Golan-Bac","given":"Margaret","email":"","affiliations":[],"preferred":false,"id":367824,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hostettler, Frances D. fdhostet@usgs.gov","contributorId":3383,"corporation":false,"usgs":true,"family":"Hostettler","given":"Frances","email":"fdhostet@usgs.gov","middleInitial":"D.","affiliations":[],"preferred":true,"id":367825,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70014184,"text":"70014184 - 1987 - Chalcopyrite disease in sphalerite: pathology and epidemiology.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:29","indexId":"70014184","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":738,"text":"American Mineralogist","active":true,"publicationSubtype":{"id":10}},"title":"Chalcopyrite disease in sphalerite: pathology and epidemiology.","docAbstract":"This descriptive paper identifies three widely occurring textures designated as 'watermelon', 'dusting' and 'bimodal' that characterize the replacement of original Fe-bearing sphalerite by an aggregate of chalcopyrite and low-Fe sphalerite as an integral part of the mineralization process. Replacement probably predominates over alternative modes of origin for small chalcopyrite blebs in sphalerite from most vein and sea-floor massive sulphide deposits that formed in the 200-400oC temperature range and that have not been subsequently subjected to higher T. Sphalerite from the epithermal Ag-Pb-Zn deposit at Creede, Colorado, displays a rich variety of features (\"bead chains') that are primary crystal dislocations decorated by exsolved chalcopyrite.-J.A.Z.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Mineralogist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"0003004X","usgsCitation":"Barton, P.B., and Bethke, P.M., 1987, Chalcopyrite disease in sphalerite: pathology and epidemiology.: American Mineralogist, v. 72, no. 5-6, p. 451-467.","startPage":"451","endPage":"467","numberOfPages":"17","costCenters":[],"links":[{"id":225557,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"72","issue":"5-6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f3f9e4b0c8380cd4ba6c","contributors":{"authors":[{"text":"Barton, P. B. Jr.","contributorId":23683,"corporation":false,"usgs":true,"family":"Barton","given":"P.","suffix":"Jr.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":367804,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bethke, P. M.","contributorId":32921,"corporation":false,"usgs":true,"family":"Bethke","given":"P.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":367805,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014180,"text":"70014180 - 1987 - Evaluation of the 1985-1990 IGRF secular variation candidates","interactions":[],"lastModifiedDate":"2013-02-13T13:23:58","indexId":"70014180","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of the 1985-1990 IGRF secular variation candidates","docAbstract":"The IGRF secular variation model for 1985-1990 was adopted by the International Association of Geomagnetism and Aeronomy at its Prague meeting in August 1985 as an average of the three candidate models submitted to the committee. We compared the three models at epoch 1985.0 against each other and against a new model based on observatory data available as of July 1, 1985. These comparisons showed that one of the three candidate models disagreed more with the other two and our model, especially in the eastern Pacific. None of the candidate models was seen to respond to a change in the secular variation of the vertical component that appears to have taken place most strongly in the western Pacific area since 1982. The lack of satellite data was seen to be a significant handicap towards prediction of the field change over most of the Earth's surface, especially the southern oceans. Maximum errors of any model are estimated to be of the order of 80 nT a-1. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(87)90161-0","issn":"00319201","usgsCitation":"Cain, J., and Kluth, C., 1987, Evaluation of the 1985-1990 IGRF secular variation candidates: Physics of the Earth and Planetary Interiors, v. 48, no. 3-4, p. 362-378, https://doi.org/10.1016/0031-9201(87)90161-0.","startPage":"362","endPage":"378","numberOfPages":"17","costCenters":[],"links":[{"id":267332,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(87)90161-0"},{"id":225429,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0ccfe4b0c8380cd52ce6","contributors":{"authors":[{"text":"Cain, J.C.","contributorId":68457,"corporation":false,"usgs":true,"family":"Cain","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":367792,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kluth, C.","contributorId":60390,"corporation":false,"usgs":true,"family":"Kluth","given":"C.","email":"","affiliations":[],"preferred":false,"id":367791,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014179,"text":"70014179 - 1987 - A model of geomagnetic secular variation for 1980-1983","interactions":[],"lastModifiedDate":"2013-02-13T13:22:26","indexId":"70014179","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"A model of geomagnetic secular variation for 1980-1983","docAbstract":"We developed an updated model of the secular variation of the main geomagnetic field during 1980 through 1983 based on annual mean values for that interval from 148 worldwide magnetic observatories. The model consists of a series of 80 spherical harmonics, up to and including those of degree and order 8. We used it to form a proposal for the 1985 revision of the International Geomagnetic Reference Field (IGRF). Comparison of the new model, whose mean epoch is approximately 1982.0, with the Provisional Geomagnetic Reference Field for 1975-1980 (PGRF 1975), indicates that the moment of the centered-dipole part of the geomagnetic field is now decreasing faster than it was 5 years ago. The rate (in field units) indicated by PGRF 1975 was about -25 nT a-1, while for the new model it is -28 nT a-1. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(87)90155-5","issn":"00319201","usgsCitation":"Peddie, N., and Zunde, A., 1987, A model of geomagnetic secular variation for 1980-1983: Physics of the Earth and Planetary Interiors, v. 48, no. 3-4, p. 324-329, https://doi.org/10.1016/0031-9201(87)90155-5.","startPage":"324","endPage":"329","numberOfPages":"6","costCenters":[],"links":[{"id":267331,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(87)90155-5"},{"id":225428,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e47fe4b0c8380cd46681","contributors":{"authors":[{"text":"Peddie, N.W.","contributorId":75911,"corporation":false,"usgs":true,"family":"Peddie","given":"N.W.","affiliations":[],"preferred":false,"id":367790,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Zunde, A.K.","contributorId":21946,"corporation":false,"usgs":true,"family":"Zunde","given":"A.K.","affiliations":[],"preferred":false,"id":367789,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014178,"text":"70014178 - 1987 - Generation of liquid water on Mars through the melting of a dusty snowpack","interactions":[],"lastModifiedDate":"2024-02-15T23:38:45.714936","indexId":"70014178","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1963,"text":"Icarus","active":true,"publicationSubtype":{"id":10}},"title":"Generation of liquid water on Mars through the melting of a dusty snowpack","docAbstract":"The possibility that snowmelt could have provided liquid water for valley network formation early in the history of Mars is investigated using an optical-thermal model developed for dusty snowpacks at temperate latitudes. The heating of the postulated snow is assumed to be driven primarily by the absorption of solar radiation during clear sky conditions. Radiative heating rates are predicted as a function of depth and shown to be sensitive to the dust concentration and the size of the ice grains while the thermal conductivity is controlled by temperature, atmospheric pressure, and bulk density. Rates of metamorphism indicate that fresh fine-grained snow on Mars would evolve into moderately coarse snow during a single summer season. Results from global climate models are used to constrain the mean-annual surface temperatures for snow and the atmospheric exchange terms in the surface energy balance. Mean-annual temperatures within Martian snowpacks fail to reach the melting point for all atmospheric pressures below 1000 mbar despite a predicted temperature enhancement beneath the surface of the snowpacks. When seasonal and diurnal variations in the incident solar flux are included in the model, melting occurs at midday during the summer for a wide range of snow types and atmospheric pressures if the dust levels in the snow exceed 100 ppmw (parts per million by weight). The optimum dust concentration appears to be about 1000 ppmw. With this dust load, melting can occur in the upper few centimeters of a dense coarse-grained snow at atmospheric pressures as low as 7 mbar. Snowpack thickness and the thermal conductivity of the underlying substrate determine whether the generated snow-melt can penetrate to the snowpack base, survive basal ice formation, and subsequently become available for runoff. Under favorable conditions, liquid water becomes available for runoff at atmospheric pressures as low as 30 to 100 mbar if the substrate is composed of regolith, as is expected in the ancient cratered terrain of Mars.
","language":"English","publisher":"Elsevier","doi":"10.1016/0019-1035(87)90123-0","issn":"00191035","usgsCitation":"Clow, G., 1987, Generation of liquid water on Mars through the melting of a dusty snowpack: Icarus, v. 72, no. 1, p. 95-127, https://doi.org/10.1016/0019-1035(87)90123-0.","productDescription":"33 p.","startPage":"95","endPage":"127","numberOfPages":"33","costCenters":[],"links":[{"id":225427,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"72","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a1554e4b0c8380cd54d70","contributors":{"authors":[{"text":"Clow, G.D.","contributorId":46112,"corporation":false,"usgs":true,"family":"Clow","given":"G.D.","email":"","affiliations":[],"preferred":false,"id":367788,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014170,"text":"70014170 - 1987 - Rainfall, ground-water flow, and seasonal movement at Minor Creek landslide, northwestern California: Physical interpretation of empirical relations","interactions":[],"lastModifiedDate":"2023-12-28T01:17:57.379043","indexId":"70014170","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1786,"text":"Geological Society of America Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Rainfall, ground-water flow, and seasonal movement at Minor Creek landslide, northwestern California: Physical interpretation of empirical relations","docAbstract":"Simple ground-water flow analyses can clarify complex empirical relations between rainfall and landslide motion. Here we present detailed data on rainfall, ground-water flow, and repetitive seasonal motion that occurred from 1982 to 1985 at Minor Creek landslide in northwestern California, and we interpret these data in the context of physically based theories. We find that landslide motion is closely regulated by the direction and magnitude of near-surface hydraulic gradients and by waves of pore pressure caused by intermittent rainfall.
Diffusive propagation of pore-pressure waves accompanies downward ground-water flow along nearly vertical hydraulic gradients that exist in most of the landslide. Field data combined with a pore-pressure diffusion analysis show that single rainstorms typically produce short-period waves that attenuate before reaching the landslide base. In contrast, seasonal rainfall cycles produce long-period waves that modify basal pore pressures, but only after time lags that range from weeks to months. Such tune lags can depend on antecedent moisture storage and can explain variable delays between the onset of the wet season and seasonal landslide motion.
Limit-equilibrium analysis shows that when seasonal pressure waves reach the landslide base, they establish a critical distribution of effective stress that delicately triggers landslide motion. The critical effective-stress balance is extremely sensitive to the direction and magnitude of hydraulic gradients.
Although pervasively downward gradients instigate seasonal motion, we infer from theory and limited data that ground water also may circulate locally in near-surface cells. The circulation can further reduce the landslide's frictional strength, particularly in areas of nearly horizontal ground-water flow that occur beneath steep faces of hummocks. Hummocky topography that results from slope instability may therefore cause ground-water flow that perpetuates instability.
Diffusive propagation of pore-pressure waves accompanies downward ground-water flow along nearly vertical hydraulic gradients that exist in most of the landslide. Field data combined with a pore-pressure diffusion analysis show that single rainstorms typically produce short-period waves that attenuate before reaching the landslide base. In contrast, seasonal rainfall cycles produce long-period waves that modify basal pore pressures, but only after time lags that range from weeks to months. Such tune lags can depend on antecedent moisture storage and can explain variable delays between the onset of the wet season and seasonal landslide motion.
Limit-equilibrium analysis shows that when seasonal pressure waves reach the landslide base, they establish a critical distribution of effective stress that delicately triggers landslide motion. The critical effective-stress balance is extremely sensitive to the direction and magnitude of hydraulic gradients.
Although pervasively downward gradients instigate seasonal motion, we infer from theory and limited data that ground water also may circulate locally in near-surface cells. The circulation can further reduce the landslide's frictional strength, particularly in areas of nearly horizontal ground-water flow that occur beneath steep faces of hummocks. Hummocky topography that results from slope instability may therefore cause ground-water flow that perpetuates instability.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1987)99%3C579:RGFASM%3E2.0.CO;2","usgsCitation":"Iverson, R., and Major, J., 1987, Rainfall, ground-water flow, and seasonal movement at Minor Creek landslide, northwestern California: Physical interpretation of empirical relations: Geological Society of America Bulletin, v. 99, no. 4, p. 579-594, https://doi.org/10.1130/0016-7606(1987)99%3C579:RGFASM%3E2.0.CO;2.","productDescription":"16 p.","startPage":"579","endPage":"594","numberOfPages":"16","costCenters":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"links":[{"id":225299,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Minor Creek landslide","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -123.87496948242186,\n 40.90793419432049\n ],\n [\n -123.72270584106445,\n 40.90793419432049\n ],\n [\n -123.72270584106445,\n 41.010345626044106\n ],\n [\n -123.87496948242186,\n 41.010345626044106\n ],\n [\n -123.87496948242186,\n 40.90793419432049\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"99","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a946ee4b0c8380cd813dd","contributors":{"authors":[{"text":"Iverson, R.M. 0000-0002-7369-3819","orcid":"https://orcid.org/0000-0002-7369-3819","contributorId":16435,"corporation":false,"usgs":true,"family":"Iverson","given":"R.M.","affiliations":[],"preferred":false,"id":367768,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Major, J. J. 0000-0003-2449-4466","orcid":"https://orcid.org/0000-0003-2449-4466","contributorId":29461,"corporation":false,"usgs":true,"family":"Major","given":"J. J.","affiliations":[{"id":157,"text":"Cascades Volcano Observatory","active":false,"usgs":true}],"preferred":true,"id":367769,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014168,"text":"70014168 - 1987 - Transport of reacting solutes subject to a moving dissolution boundary: Numerical methods and solutions","interactions":[],"lastModifiedDate":"2020-01-18T09:41:14","indexId":"70014168","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Transport of reacting solutes subject to a moving dissolution boundary: Numerical methods and solutions","docAbstract":"A moving boundary problem which arises during transport with precipitation-dissolution reactions is solved by three different numerical methods. Two of these methods (one explicit and one implicit) are based on an integral formulation of mass balance and lead to an approximation of a weak solution. These methods are compared to a front-tracking scheme. Although the two approaches are conceptually different, the numerical solutions showed good agreement. As the ratio of dispersion to convection decreases, the methods based on the integral formulation become computationally more efficient. Specific reactions were modeled to examine the dependence of the system on the physical and chemical parameters. Although the water flow rate does not explicitly appear in the equation for the velocity of the moving boundary, the speed of the boundary depends more on the flux rate than on the dispersion coefficient. The discontinuity in the gradient of the solute concentration profile at the boundary increases with convection and with the initial concentration of the mineral. Our implicit method is extended to allow participation of the solutes in complexation reactions as well as the precipitation-dissolution reaction. This extension is easily made and does not change the basic method.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/WR023i008p01561","usgsCitation":"Willis, C., and Rubin, J., 1987, Transport of reacting solutes subject to a moving dissolution boundary: Numerical methods and solutions: Water Resources Research, v. 23, no. 8, p. 1561-1574, https://doi.org/10.1029/WR023i008p01561.","productDescription":"14 p.","startPage":"1561","endPage":"1574","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":225297,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"23","issue":"8","noUsgsAuthors":false,"publicationDate":"2010-07-09","publicationStatus":"PW","scienceBaseUri":"505ba391e4b08c986b31fd6f","contributors":{"authors":[{"text":"Willis, Catherine","contributorId":42489,"corporation":false,"usgs":true,"family":"Willis","given":"Catherine","email":"","affiliations":[],"preferred":false,"id":367765,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rubin, Jacob","contributorId":23918,"corporation":false,"usgs":true,"family":"Rubin","given":"Jacob","email":"","affiliations":[],"preferred":false,"id":367764,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014167,"text":"70014167 - 1987 - Moment tensor solutions estimated using optimal filter theory for 51 selected earthquakes, 1980-1984","interactions":[],"lastModifiedDate":"2013-02-13T13:20:21","indexId":"70014167","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Moment tensor solutions estimated using optimal filter theory for 51 selected earthquakes, 1980-1984","docAbstract":"The 51 global events that occurred from January 1980 to March 1984, which were chosen by the convenors of the Symposium on Seismological Theory and Practice, have been analyzed using a moment tensor inversion algorithm (Sipkin). Many of the events were routinely analyzed as part of the National Earthquake Information Center's (NEIC) efforts to publish moment tensor and first-motion fault-plane solutions for all moderate- to large-sized (mb>5.7) earthquakes. In routine use only long-period P-waves are used and the source-time function is constrained to be a step-function at the source (??-function in the far-field). Four of the events were of special interest, and long-period P, SH-wave solutions were obtained. For three of these events, an unconstrained inversion was performed. The resulting time-dependent solutions indicated that, for many cases, departures of the solutions from pure double-couples are caused by source complexity that has not been adequately modeled. These solutions also indicate that source complexity of moderate-sized events can be determined from long-period data. Finally, for one of the events of special interest, an inversion of the broadband P-waveforms was also performed, demonstrating the potential for using broadband waveform data in inversion procedures. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(87)90068-9","issn":"00319201","usgsCitation":"Sipkin, S., 1987, Moment tensor solutions estimated using optimal filter theory for 51 selected earthquakes, 1980-1984: Physics of the Earth and Planetary Interiors, v. 47, no. C, p. 67-79, https://doi.org/10.1016/0031-9201(87)90068-9.","startPage":"67","endPage":"79","numberOfPages":"13","costCenters":[],"links":[{"id":267329,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(87)90068-9"},{"id":225237,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"47","issue":"C","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5d3ae4b0c8380cd70242","contributors":{"authors":[{"text":"Sipkin, S.A.","contributorId":9399,"corporation":false,"usgs":true,"family":"Sipkin","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":367763,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014158,"text":"70014158 - 1987 - On regional geomagnetic charts","interactions":[],"lastModifiedDate":"2024-04-25T00:10:46.479375","indexId":"70014158","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2310,"text":"Journal of Geomagnetism & Geoelectricity","active":true,"publicationSubtype":{"id":10}},"title":"On regional geomagnetic charts","docAbstract":"When regional geomagnetic charts for areas roughly the size of the United States were compiled by hand, some large local anomalies were displayed in the isomagnetic lines. Since the late nineteen sixties, when the compilation of charts using computers and mathematical models was started, most of the details available in the hand drawn regional charts have been lost. One exception to this is the Canadian magnetic declination chart for 1980. This chart was constructed using a 180 degree spherical harmonic model. It managed to show considerable detail, but even more detail might be useful. Suggestions are made about how more detail might be displayed in regional charts when adequate data are available.
","language":"English","publisher":"J-STAGE","doi":"10.5636/jgg.39.723","usgsCitation":"Alldredge, L., 1987, On regional geomagnetic charts: Journal of Geomagnetism & Geoelectricity, v. 39, no. 12, p. 723-738, https://doi.org/10.5636/jgg.39.723.","productDescription":"16 p.","startPage":"723","endPage":"738","numberOfPages":"16","costCenters":[],"links":[{"id":480535,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.5636/jgg.39.723","text":"Publisher Index Page"},{"id":226072,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"39","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6da8e4b0c8380cd7525e","contributors":{"authors":[{"text":"Alldredge, L.R.","contributorId":53457,"corporation":false,"usgs":true,"family":"Alldredge","given":"L.R.","email":"","affiliations":[],"preferred":false,"id":367745,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014155,"text":"70014155 - 1987 - Evaluation of the stability of gas hydrates in Northern Alaska","interactions":[],"lastModifiedDate":"2023-09-21T15:26:40.006371","indexId":"70014155","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1264,"text":"Cold Regions Science and Technology","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of the stability of gas hydrates in Northern Alaska","docAbstract":"The factors which control the distribution of in situ gas hydrate deposits in colder regions such as Northern Alaska include; mean annual surface temperatures (MAST), geothermal gradients above and below the base of permafrost, subsurface pressures, gas composition, pore-fluid salinity and the soil condition. Currently existing data on the above parameters for the forty-six wells located in Northern Alaska were critically examined and used in calculations of depths and thicknesses of gas hydrate stability zones. To illustrate the effect of gas hydrate stability zones, calculations were done for a variable gas composition using the thermodynamic model of Holder and John (1982). The hydrostatic pressure gradient of 9.84 kPa/m (0.435 lbf/in2ft), the salinity of 10 parts per thousand (ppt) and the coarse-grained soil conditions were assumed. An error analysis was performed for the above parameters and the effect of these parameters on hydrate stability zone calculations were determined.
After projecting the hydrate stability zones for the forty-six wells, well logs were used to identify and to obtain values for the depth and thickness of hydrate zones. Of the forty-six wells, only ten wells showed definite evidence of the presence of gas hydrates.
","language":"English","publisher":"Elsevier","doi":"10.1016/0165-232X(87)90026-7","usgsCitation":"Kamath, A., Godbole, S.P., Ostermann, R.D., and Collett, T.S., 1987, Evaluation of the stability of gas hydrates in Northern Alaska: Cold Regions Science and Technology, v. 14, no. 2, p. 107-119, https://doi.org/10.1016/0165-232X(87)90026-7.","productDescription":"13 p.","startPage":"107","endPage":"119","numberOfPages":"13","costCenters":[],"links":[{"id":226069,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -162.35348507096748,\n 71.50417315803796\n ],\n [\n -163.3677789577233,\n 68.05690107968127\n ],\n [\n -145.36017551548042,\n 68.05690107968127\n ],\n [\n -145.36017551548042,\n 70.97000817935472\n ],\n [\n -162.35348507096748,\n 71.50417315803796\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"14","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0cf3e4b0c8380cd52d6c","contributors":{"authors":[{"text":"Kamath, A.","contributorId":41154,"corporation":false,"usgs":false,"family":"Kamath","given":"A.","email":"","affiliations":[],"preferred":false,"id":367734,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Godbole, S. P.","contributorId":23285,"corporation":false,"usgs":false,"family":"Godbole","given":"S.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":367733,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ostermann, R. D.","contributorId":42367,"corporation":false,"usgs":false,"family":"Ostermann","given":"R.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":367735,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Collett, T. S. 0000-0002-7598-4708","orcid":"https://orcid.org/0000-0002-7598-4708","contributorId":86342,"corporation":false,"usgs":true,"family":"Collett","given":"T.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":367736,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70014151,"text":"70014151 - 1987 - EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:36","indexId":"70014151","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2696,"text":"Materials Performance","active":true,"publicationSubtype":{"id":10}},"title":"EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.","docAbstract":"Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were not washed by precipitation. The gas-solid reaction of SO//2 with calcite was selected for detailed consideration. It appears from the model that under arid conditions, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO//2 concentration once the surface has been saturated with gypsum. Under wet conditions, surface sulfation and weight loss are probably dominated by mechanisms involving wet stone. However, if the rain events are frequent and delimited by periods of dryness, the quantity of gypsum produced by a gas-solid reaction mechanism should correlate with both the frequency of rain events and the atmospheric SO//2 level.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Materials Performance","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00941492","usgsCitation":"Mossotti, V.G., Lindsay, J.R., and Hochella, M.F., 1987, EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.: Materials Performance, v. 26, no. 11, p. 47-52.","startPage":"47","endPage":"52","numberOfPages":"6","costCenters":[],"links":[{"id":225941,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0456e4b0c8380cd508fb","contributors":{"authors":[{"text":"Mossotti, Victor G. mossotti@usgs.gov","contributorId":3494,"corporation":false,"usgs":true,"family":"Mossotti","given":"Victor","email":"mossotti@usgs.gov","middleInitial":"G.","affiliations":[],"preferred":true,"id":367723,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lindsay, James R.","contributorId":19714,"corporation":false,"usgs":true,"family":"Lindsay","given":"James","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":367725,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hochella, Michael F. Jr.","contributorId":16172,"corporation":false,"usgs":true,"family":"Hochella","given":"Michael","suffix":"Jr.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":367724,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70015325,"text":"70015325 - 1987 - 15N/14N variations in Cretaceous Atlantic sedimentary sequences: Implication for past changes in marine nitrogen biogeochemistry","interactions":[],"lastModifiedDate":"2023-12-09T15:58:03.148097","indexId":"70015325","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"15N/14N variations in Cretaceous Atlantic sedimentary sequences: Implication for past changes in marine nitrogen biogeochemistry","docAbstract":"At two locations in the Atlantic Ocean (DSDP Sites 367 and 530) early to middle Cretaceous organic-carbon-rich beds (“black shales”) were found to have significantly lower δ15N values (lower15N/14N ratios) than adjacent organic-carbon-poor beds (white limestones or green claystones). While these lithologies are of marine origin, the black strata in particular have °15N values that are significantly lower than those previously found in the marine sediment record and most contemporary marine nitrogen pools. In contrast, black, organic-carbon-rich beds at a third site (DSDP Site 603) contain predominantly terrestrial organic matter and have C- and N-isotopic compositions similar to organic matter of modern terrestrial origin.
The recurring15N depletion in the marine-derived Cretaceous sequences prove that the nitrogen they contain is the end result of an episodic and atypical biogeochemistry. Existing isotopic and other data indicate that the low15N relative abundance is the consequence of pelagic rather than post-depositional processes. Reduced ocean circulation, increased denitrification, and, hence, reduced euphotic zone nitrate availability may have led to Cretaceous phytoplankton assemblages that were periodically dominated by N2-fixing blue-green algae, a possible source of this sediment15N-depletion. Lack of parallel isotopic shifts in Cretaceous terrestrially-derived nitrogen (Site 603) argues that the above change in nitrogen cycling during this period did not extend beyond the marine environment.
","language":"English","publisher":"Elsevier","doi":"10.1016/0012-821X(87)90201-9","issn":"0012821X","usgsCitation":"Rau, G., Arthur, M., and Dean, W., 1987, 15N/14N variations in Cretaceous Atlantic sedimentary sequences: Implication for past changes in marine nitrogen biogeochemistry: Earth and Planetary Science Letters, v. 82, no. 3-4, p. 269-279, https://doi.org/10.1016/0012-821X(87)90201-9.","productDescription":"11 p.","startPage":"269","endPage":"279","numberOfPages":"11","costCenters":[],"links":[{"id":223870,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"82","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e228e4b0c8380cd459e1","contributors":{"authors":[{"text":"Rau, G.H.","contributorId":18112,"corporation":false,"usgs":true,"family":"Rau","given":"G.H.","email":"","affiliations":[],"preferred":false,"id":370649,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Arthur, M.A.","contributorId":24791,"corporation":false,"usgs":true,"family":"Arthur","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":370650,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dean, W.E.","contributorId":97099,"corporation":false,"usgs":true,"family":"Dean","given":"W.E.","email":"","affiliations":[],"preferred":false,"id":370651,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70014150,"text":"70014150 - 1987 - Compositional evidence regarding the origins of rims on Semarkona chondrules","interactions":[],"lastModifiedDate":"2024-04-03T16:02:23.697188","indexId":"70014150","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Compositional evidence regarding the origins of rims on Semarkona chondrules","docAbstract":"The compositions of the interiors and abraded surfaces of 7 chondrules from Semarkona (LL3.0) were measured by neutron activation analysis. For nonvolatile elements, the lithophile and siderophile element abundance patterns in the surfaces are generally similar to those in the corresponding interiors. Siderophile and chalcophile concentrations are much higher in the surfaces, whereas lithophile concentrations are similar in both fractions. Most of the similarities in lithophile patterns and some of the similarities in siderophile patterns between surfaces and interiors may reflect incomplete separation of the fractions in the laboratory, but for 3 or 4 chondrules the siderophile resemblance is inherent, implying that the surface and interior metal formed from a single precursor assemblage. Metal and sulfide-rich chondrule rims probably formed when droplets of these phases that migrated to the chondrule surface during melting were reheated and incorporated into matrix-like material that had accreted onto the surface. The moderately-volatile to volatile elements K, As and Zn tend to be enriched in the surfaces compared with other elements of similar mineral affinity; both enrichments and depletions are observed for other moderately volatile elements. A small fraction of chondrules experienced fractional evaporation while they were molten.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(87)90373-5","issn":"00167037","usgsCitation":"Grossman, J.N., and Wasson, J.T., 1987, Compositional evidence regarding the origins of rims on Semarkona chondrules: Geochimica et Cosmochimica Acta, v. 51, no. 11, p. 3003-3011, https://doi.org/10.1016/0016-7037(87)90373-5.","productDescription":"9 p.","startPage":"3003","endPage":"3011","numberOfPages":"9","costCenters":[],"links":[{"id":225940,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"51","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f937e4b0c8380cd4d4d8","contributors":{"authors":[{"text":"Grossman, J. N.","contributorId":41840,"corporation":false,"usgs":true,"family":"Grossman","given":"J.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":367721,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wasson, J. T.","contributorId":99269,"corporation":false,"usgs":false,"family":"Wasson","given":"J.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":367722,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70015311,"text":"70015311 - 1987 - Phytoplankton productivity in relation to light intensity: A simple equation","interactions":[],"lastModifiedDate":"2023-10-12T00:18:10.023544","indexId":"70015311","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1587,"text":"Estuarine, Coastal and Shelf Science","active":true,"publicationSubtype":{"id":10}},"title":"Phytoplankton productivity in relation to light intensity: A simple equation","docAbstract":"A simple exponential equation is used to describe photosynthetic rate as a function of light intensity for a variety of unicellular algae and higher plants where photosynthesis is proportional to (1-e−β1). The parameter β (=Ik−1\">=Ik−1) is derived by a simultaneous curve-fitting method, where I is incident quantum-flux density. The exponential equation is tested against a wide range of data and is found to adequately describe P vs. I curves. The errors associated with photosynthetic parameters are calculated. A simplified statistical model (Poisson) of photon capture provides a biophysical basis for the equation and for its ability to fit a range of light intensities. The exponential equation provides a non-subjective simultaneous curve fitting estimate for photosynthetic efficiency (a) which is less ambiguous than subjective methods: subjective methods assume that a linear region of the P vs. I curve is readily identifiable. Photosynthetic parameters β and a are used widely in aquatic studies to define photosynthesis at low quantum flux. These parameters are particularly important in estuarine environments where high suspended-material concentrations and high diffuse-light extinction coefficients are commonly encountered.
","language":"English","publisher":"Elsevier","doi":"10.1016/0272-7714(87)90154-5","issn":"02727714","usgsCitation":"Peterson, D.H., Perry, M., Bencala, K., and Talbot, M., 1987, Phytoplankton productivity in relation to light intensity: A simple equation: Estuarine, Coastal and Shelf Science, v. 24, no. 6, p. 813-832, https://doi.org/10.1016/0272-7714(87)90154-5.","productDescription":"20 p.","startPage":"813","endPage":"832","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":223596,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7b3be4b0c8380cd7931e","contributors":{"authors":[{"text":"Peterson, D. H.","contributorId":92229,"corporation":false,"usgs":true,"family":"Peterson","given":"D.","middleInitial":"H.","affiliations":[],"preferred":false,"id":370607,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Perry, M.J.","contributorId":105175,"corporation":false,"usgs":true,"family":"Perry","given":"M.J.","email":"","affiliations":[],"preferred":false,"id":370608,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bencala, K.E.","contributorId":105312,"corporation":false,"usgs":true,"family":"Bencala","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":370609,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Talbot, M.C.","contributorId":22202,"corporation":false,"usgs":true,"family":"Talbot","given":"M.C.","email":"","affiliations":[],"preferred":false,"id":370606,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70015310,"text":"70015310 - 1987 - Man-induced gradient adjustment of the South Fork Forked Deer River, west Tennessee","interactions":[],"lastModifiedDate":"2012-03-12T17:18:58","indexId":"70015310","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1540,"text":"Environmental Geology and Water Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Man-induced gradient adjustment of the South Fork Forked Deer River, west Tennessee","docAbstract":"Channel modifications from 1968 to 1969 on the South Fork Forked Deer River in western Tennessee have caused upstream degradation, downstream aggradation, and bank failures along the altered channels, adjacent reaches, and tributaries. The result of these adjustments is a general decrease in gradient as the channel attempts to absorb the imposed increase in energy conditions created by channelization. Headward degradation at a rate of approximately 2.57 km/yr on the South Fork Forked Deer River caused from 1.52 m to about 3.14 m of incision over a 13.5 km reach from 1969 to 1981. As a consequence of substantially increased sediment supply, approximately 2.13 m of aggradation was induced downstream of this reach during the same period. This accumulation represents a 60% recovery of bed level at the downstream site since the completion of channel work in 1969. Gradient adjustment with time is described by exponential decay functions. The length of time required for adjustment to some new quasi-equilibrium condition is computed by these decay functions and is about 20 years from the completion of channel work. Adjusted slopes are less than predisturbed values, probably because straightened channels dissipate less energy by friction, allowing more energy for sediment transport. An equivalent sediment load, therefore, can be transported at a considerably gentler slope. The predisturbed slope exceeds the adjusted slope by an order of magnitude on the downstream reach of the South Fork Forked Deer River. ?? 1987 Springer-Verlag New York Inc.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Geology and Water Sciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Springer-Verlag","doi":"10.1007/BF02449942","issn":"00990094","usgsCitation":"Simon, A., and Robbins, C.H., 1987, Man-induced gradient adjustment of the South Fork Forked Deer River, west Tennessee: Environmental Geology and Water Sciences, v. 9, no. 2, p. 109-118, https://doi.org/10.1007/BF02449942.","startPage":"109","endPage":"118","numberOfPages":"10","costCenters":[],"links":[{"id":205389,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF02449942"},{"id":223595,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"9","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4c5de4b0c8380cd69bd8","contributors":{"authors":[{"text":"Simon, A.","contributorId":43501,"corporation":false,"usgs":true,"family":"Simon","given":"A.","email":"","affiliations":[],"preferred":false,"id":370604,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Robbins, C. H.","contributorId":54210,"corporation":false,"usgs":true,"family":"Robbins","given":"C.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":370605,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70015308,"text":"70015308 - 1987 - A study of metal ion adsorption at low suspended-solid concentrations","interactions":[],"lastModifiedDate":"2020-01-17T17:30:52","indexId":"70015308","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1587,"text":"Estuarine, Coastal and Shelf Science","active":true,"publicationSubtype":{"id":10}},"title":"A study of metal ion adsorption at low suspended-solid concentrations","docAbstract":"A procedure for conducting adsorption studies at low suspended solid concentrations in natural waters (<50 mg l−1) is described. Methodological complications previously associated with such experiments have been overcome. Adsorption of zinc ion onto synthetic colloidal titania (TiO2) was studied as a function of pH, supporting electrolyte (NaCl) concentration (0·1-0·002 m) and particle concentration (2–50 mg l−1). The lack of success of the Davis Leckie site bonding model in describing Zn(II) adsorption emphasizes the need for further studies of adsorption at low suspended-solid concentrations.