The dust in the atmosphere above the Mars Pathfinder landing site produced a bright, red sky that increases in redness toward the horizon at midday. There is also evidence for an absorption band in the scattered light from the sky at 860 nm. A model of the sky brightness has been developed [Markiewicz et al., this issue] and tested against Imager for Mars Pathfinder (IMP) observations of calibration targets on the lander. The resulting model has been used to quantify the total diffuse flux onto a surface parallel to the local level for several solar elevation angles and optical depths. The model shows that the diffuse illumination in shadowed areas is strongly reddened while areas illuminated directly by the Sun (and the blue forward scattering peak) see a more solar-type spectrum, in agreement with Viking and IMP observations. Quantitative corrections for the reddening in shadowed areas are demonstrated. It is shown quantitatively that the unusual appearance of the rock Yogi (the east face of which appeared relatively blue in images taken during the morning but relatively red during the afternoon) can be explained purely by the changing illumination geometry. We conclude that any spectrophotometric analysis of surfaces on Mars must take into account the diffuse flux. Specifically, the reflectances of surfaces viewed under different illumination geometries cannot be investigated for spectral diversity unless a correction has been applied which removes the influence of the reddened diffuse flux.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/98JE02556","issn":"01480227","usgsCitation":"Thomas, N., Markiewicz, W., Sablotny, R., Wuttke, M., Keller, H., Johnson, J.R., Reid, R., and Smith, R., 1999, The color of the Martian sky and its influence on the illumination of the Martian surface: Journal of Geophysical Research E: Planets, v. 104, no. E4, p. 8795-8808, https://doi.org/10.1029/98JE02556.","productDescription":"14 p.","startPage":"8795","endPage":"8808","numberOfPages":"14","costCenters":[],"links":[{"id":479630,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/98je02556","text":"Publisher Index Page"},{"id":229368,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"104","issue":"E4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505baa3ee4b08c986b32278c","contributors":{"authors":[{"text":"Thomas, N.","contributorId":72490,"corporation":false,"usgs":true,"family":"Thomas","given":"N.","email":"","affiliations":[],"preferred":false,"id":391209,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Markiewicz, W.J.","contributorId":33869,"corporation":false,"usgs":true,"family":"Markiewicz","given":"W.J.","email":"","affiliations":[],"preferred":false,"id":391206,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sablotny, R.M.","contributorId":78106,"corporation":false,"usgs":true,"family":"Sablotny","given":"R.M.","email":"","affiliations":[],"preferred":false,"id":391210,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wuttke, M.W.","contributorId":52353,"corporation":false,"usgs":true,"family":"Wuttke","given":"M.W.","email":"","affiliations":[],"preferred":false,"id":391207,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Keller, H.U.","contributorId":84526,"corporation":false,"usgs":true,"family":"Keller","given":"H.U.","email":"","affiliations":[],"preferred":false,"id":391211,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Johnson, J. R.","contributorId":69278,"corporation":false,"usgs":true,"family":"Johnson","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":391208,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Reid, R.J.","contributorId":88899,"corporation":false,"usgs":true,"family":"Reid","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":391212,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Smith, R.H.","contributorId":31932,"corporation":false,"usgs":true,"family":"Smith","given":"R.H.","email":"","affiliations":[],"preferred":false,"id":391205,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70021794,"text":"70021794 - 1999 - GIXAFS study of Fe3+ sorption and precipitation on natural quartz surfaces","interactions":[],"lastModifiedDate":"2024-05-13T16:43:41.611101","indexId":"70021794","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2473,"text":"Journal of Synchrotron Radiation","active":true,"publicationSubtype":{"id":10}},"title":"GIXAFS study of Fe3+ sorption and precipitation on natural quartz surfaces","docAbstract":"Grazing-incidence EXAFS has been used to characterize the structure of Fe3+ sorbed onto natural single crystal quartz surfaces. Fe3+ sorption at ca. 5% monolayer coverage on a natural crystal allowed to equilibrate in air resulted in formation of hematite nuclei with strong texturing on r-and m-planes. EXAFS calculations suggests that both O and Fe backscattering is necessary to yield acceptable structural models, that about 50% of the sorbed iron resides in nuclei, and that the approximate dimensions of the nuclei can be estimated via Feff 7.0 calculations of various nuclei sizes and shapes.
","language":"English","publisher":"Scripts","doi":"10.1107/s0909049599001764","issn":"09090495","usgsCitation":"Waychunas, G., Davis, J., and Reitmeyer, R., 1999, GIXAFS study of Fe3+ sorption and precipitation on natural quartz surfaces: Journal of Synchrotron Radiation, v. 6, no. 3, p. 615-617, https://doi.org/10.1107/s0909049599001764.","productDescription":"3 p.","startPage":"615","endPage":"617","numberOfPages":"3","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":479496,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1107/s0909049599001764","text":"Publisher Index Page"},{"id":229336,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6","issue":"3","noUsgsAuthors":false,"publicationDate":"1999-05-01","publicationStatus":"PW","scienceBaseUri":"505a146ce4b0c8380cd54a21","contributors":{"authors":[{"text":"Waychunas, G.","contributorId":37098,"corporation":false,"usgs":true,"family":"Waychunas","given":"G.","email":"","affiliations":[],"preferred":false,"id":391202,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Davis, J.","contributorId":41376,"corporation":false,"usgs":true,"family":"Davis","given":"J.","affiliations":[],"preferred":false,"id":391203,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Reitmeyer, R.","contributorId":87710,"corporation":false,"usgs":true,"family":"Reitmeyer","given":"R.","affiliations":[],"preferred":false,"id":391204,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021793,"text":"70021793 - 1999 - Ten years of studies on Maryland's inner Continental Margin and coastal bays","interactions":[],"lastModifiedDate":"2013-02-24T19:12:51","indexId":"70021793","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2669,"text":"Marine Georesources and Geotechnology","active":true,"publicationSubtype":{"id":10}},"title":"Ten years of studies on Maryland's inner Continental Margin and coastal bays","docAbstract":"During the past ten years of the Association of American State Geologists-Mineral Management Service Continental Margins Program, the Maryland Geological Survey investigated the sedimentological, paleontological, stratigraphical and geophysical character of Maryland's inner continental shelf. Based on seismic records and sedimentological analyses completed during the first four years, a late Quaternary stratigraphic model was developed. Five distinct stratigraphic units were identified and described on the Maryland inner shelf. These units represent late Pleistocene interglacial deposits, the oldest of which corresponds to pre-Illinoian (oxygen-isotope stages 7 and/or 9) transgressive shelf sands. Overlying the Q1 unit, the Q2 unit is a 6-meter thick mud sequence of oxygen-isotope stage 5 (128-75 ka) age. Units Q3 and Q4 representing fluvial and leading edge estuarine deposits (oxygen-isotope stages 4, 3 and 2) filled numerous paleochannels that were incised into units Q2 and Q1. Modern trailing-edge transgressive shelf shoals (Unit Q5) discontinuously cap the sequence. The 5th and 6th years studies reported on the economic minerals of surficial and cored sediments. Vibracores collected off the Maryland's shelf during previous studies were analyzed for mineral types and abundances, weight percent of general size fractions, and heavy mineral (HM) content. Mineralogic maturity indices were compiled to correlate the THM and economic heavy minerals (EHM) abundances with position offshore, sediment type, and the indices themselves. For the 7th year, the Maryland Geological Survey re-examined geophysical records and lithological data originally collected by the Army Corps of Engineers to locate and assess beach fill borrow areas for the Ocean City Beach Replenishment Project. Data from 163 vibracores and over 300 kilometers of high-resolution seismic profile records collected off Ocean City, Maryland, supported the stratigraphic model developed by MGS during the first four years of the AASG-MMS program. The Maryland coastal bays became the focus of study during the 8th and 9th years during which seismic records, cores and surficial sediment were collected in Isle of Wight and Assawoman Bays. Shallow pretransgression surface was mapped, relating the existing streams to offshore paleochannels. The tenth year study focused on developing a repository for vibracores collected on Maryland's inner continental shelf.During the past ten years of the Association of American State Geologists-Mineral Management Service Continental Margins Program, the Maryland Geological Survey investigated the sedimentological, paleontological, stratigraphical and geophysical character of Maryland's inner continental shelf. Based on seismic records and sedimentological analysis completed during the first four years, a late quaternary stratigraphic model was developed. Five distinct stratigraphic units were identified and described on the Maryland inner shelf. These units represent late Pleistocene interglacial deposits, the oldest of which corresponds to pre-Illinoian transgressive shelf sands.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Georesources and Geotechnology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Taylor & Francis Ltd","publisherLocation":"London, United Kingdom","doi":"10.1080/106411999273792","issn":"1064119X","usgsCitation":"Kerhin, R., Conkwright, R., and Wells, D., 1999, Ten years of studies on Maryland's inner Continental Margin and coastal bays: Marine Georesources and Geotechnology, v. 17, no. 2-3, p. 127-137, https://doi.org/10.1080/106411999273792.","startPage":"127","endPage":"137","numberOfPages":"11","costCenters":[],"links":[{"id":229335,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":268185,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1080/106411999273792"}],"volume":"17","issue":"2-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba539e4b08c986b3208d3","contributors":{"authors":[{"text":"Kerhin, R.T.","contributorId":38189,"corporation":false,"usgs":true,"family":"Kerhin","given":"R.T.","email":"","affiliations":[],"preferred":false,"id":391200,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Conkwright, R.","contributorId":69717,"corporation":false,"usgs":true,"family":"Conkwright","given":"R.","email":"","affiliations":[],"preferred":false,"id":391201,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wells, D.","contributorId":35893,"corporation":false,"usgs":true,"family":"Wells","given":"D.","affiliations":[],"preferred":false,"id":391199,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021789,"text":"70021789 - 1999 - Trace elements in coal: Environmental and health significance","interactions":[],"lastModifiedDate":"2023-08-28T15:40:45.180832","indexId":"70021789","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1024,"text":"Biological Trace Element Research","active":true,"publicationSubtype":{"id":10}},"title":"Trace elements in coal: Environmental and health significance","docAbstract":"Trace elements can have profound adverse effects on the health of people burning coal in homes or living near coal deposits, coal mines, and coal-burning power plants. Trace elements such as arsenic emitted from coal-burning power plants in Europe and Asia have been shown to cause severe health problems. Perhaps the most widespread health problems are caused by domestic coal combustion in developing countries where millions of people suffer from fluorosis and thousands from arsenism. Better knowledge of coal quality characteristics may help to reduce some of these health problems. For example, information on concentrations and distributions of potentially toxic elements in coal may help delineate areas of a coal deposit to be avoided. Information on the modes of occurrence of these elements and the textural relations of the minerals in coal may help to predict the behavior of the potentially toxic trace metals during coal cleaning, combustion, weathering, and leaching.
","language":"English","publisher":"Springer","doi":"10.1007/BF02784420","usgsCitation":"Finkelman, R.B., 1999, Trace elements in coal: Environmental and health significance: Biological Trace Element Research, v. 67, no. 3, p. 197-204, https://doi.org/10.1007/BF02784420.","productDescription":"8 p.","startPage":"197","endPage":"204","numberOfPages":"8","costCenters":[],"links":[{"id":229265,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"67","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb64ee4b08c986b326bb9","contributors":{"authors":[{"text":"Finkelman, Robert B.","contributorId":85951,"corporation":false,"usgs":true,"family":"Finkelman","given":"Robert","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":391187,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70021786,"text":"70021786 - 1999 - William Maclure's Wernerian Appalachians","interactions":[],"lastModifiedDate":"2012-03-12T17:19:37","indexId":"70021786","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3443,"text":"Southeastern Geology","active":true,"publicationSubtype":{"id":10}},"title":"William Maclure's Wernerian Appalachians","docAbstract":"William Maclure (1763-1840), a geologist of Scottish ancestry, was also a man of many other talents and interests including educator, philanthropist, world traveler, prolific writer, patron of science, businessman, bibliophile, and social reformer. He produced the first American printing of a geological map of the United States in 1809 and followed this with four other editions identified as 1811, 1817A, 1817B, and 1817C. All were well received and reproduced by others at least 15 times, as recently as 1989. Maclure has been called 'Father of American Geology,' a title he rightly deserves, primarily for these maps, but also for the first cross sections through the Appalachians, many other geological articles, and substantial donations of specimens, books, and funds to many learned institutions, including the Academy of Natural Sciences of Philadelphia. Maclure's delineation of Appalachian geology followed Werner's geognostic classification of strata using Primary, Transition, Secondary, and Alluvial, but with modifications and considerable doubt concerning their Neptunian origin. He added 'Rock Salt' on his 1809 map as a line on the western edge of the Appalachians and 'Old Red Sand Stone' on the 1811 map for the basins later identified as Triassic. In his later articles, Maclure noted several times that 'trap' or basalt was an igneous rock and not an aqueous precipitate. He further stated that the Secondary and Transition strata are aggregates from the disintegration of the older Primitive rocks. He came to the conclusion near the end of his life that organic remains indicate '...that nature began with the most simple, and gradually proceeded to the more complicated and perfect.'.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Southeastern Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00383678","usgsCitation":"Lessing, P., 1999, William Maclure's Wernerian Appalachians: Southeastern Geology, v. 38, no. 3, p. 117-134.","startPage":"117","endPage":"134","numberOfPages":"18","costCenters":[],"links":[{"id":229226,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"38","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bd10ee4b08c986b32f1e2","contributors":{"authors":[{"text":"Lessing, P.","contributorId":90038,"corporation":false,"usgs":true,"family":"Lessing","given":"P.","affiliations":[],"preferred":false,"id":391179,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70021785,"text":"70021785 - 1999 - Northern San Andreas fault near Shelter Cove, California","interactions":[],"lastModifiedDate":"2023-12-20T00:39:35.30422","indexId":"70021785","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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":"Northern San Andreas fault near Shelter Cove, California","docAbstract":"The location of the San Andreas fault in the Shelter Cove area of northern California has been the subject of long-standing debate within the geological community. Although surface ruptures were reported near Shelter Cove in 1906, several subsequent workers questioned whether these ruptures represented true fault slip or shaking-related, gravity-driven deformation. This study, involving geologic and geomorphic mapping, historical research, and excavation across the 1906 rupture zone, concludes that the surface ruptures reported in 1906 were the result of strike-slip faulting, and that a significant Quaternary fault is located onshore near Shelter Cove. Geomorphic arguments suggest that the Holocene slip rate of this fault is greater than about 14 mm/yr, indicating that it plays an important role within the modern plate-boundary system. The onshore trace of the fault zone is well expressed as far north as Telegraph Hill; north of Telegraph Hill, its location is less well-constrained, but we propose that a splay of the fault may continue onshore northward for at least 9 km to the vicinity of Saddle Mountain.
This paper describes our photogrammetric analysis of the Imager for Mars Pathfinder data, part of a broader program of mapping the Mars Pathfinder landing site in support of geoscience investigations. This analysis, carried out primarily with a commercial digital photogrammetric system, supported by our in‐house Integrated Software for Imagers and Spectrometers (ISIS), consists of three steps: (1) geometric control: simultaneous solution for refined estimates of camera positions and pointing plus three‐dimensional (3‐D) coordinates of ∼103 features sitewide, based on the measured image coordinates of those features; (2) topographic modeling: identification of ∼3×105 closely spaced points in the images and calculation (based on camera parameters from step 1) of their 3‐D coordinates, yielding digital terrain models (DTMs); and (3) geometric manipulation of the data: combination of the DTMs from different stereo pairs into a sitewide model, and reprojection of image data to remove parallax between the different spectral filters in the two cameras and to provide an undistorted planimetric view of the site. These processes are described in detail and example products are shown. Plans for combining the photogrammetrically derived topographic data with spectrophotometry are also described. These include photometric modeling using surface orientations from the DTM to study surface microtextures and improve the accuracy of spectral measurements, and photoclinometry to refine the DTM to single‐pixel resolution where photometric properties are sufficiently uniform. Finally, the inclusion of rover images in a joint photogrammetric analysis with IMP images is described. This challenging task will provide coverage of areas hidden to the IMP, but accurate ranging of distant features can be achieved only if the lander is also visible in the rover image used.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research E: Planets","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Geophysical Union","publisherLocation":"Washington, D.C.","doi":"10.1029/1998JE900012","issn":"01480227","usgsCitation":"Kirk, R.L., Howington-Kraus, E., Hare, T.M., Dorrer, E., Cook, D., Becker, K.J., Thompson, K., Redding, B., Blue, J., Galuszka, D., Lee, E., Gaddis, L.R., Johnson, J.R., Soderblom, L.A., Ward, A.W., Smith, P.H., and Britt, D., 1999, Digital photogrammetric analysis of the IMP camera images: Mapping the Mars Pathfinder landing site in three dimensions: Journal of Geophysical Research E: Planets, v. 104, no. E4, p. 8869-8887, https://doi.org/10.1029/1998JE900012.","productDescription":"19 p.","startPage":"8869","endPage":"8887","numberOfPages":"19","costCenters":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"links":[{"id":479464,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/1998je900012","text":"Publisher Index Page"},{"id":229116,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"104","issue":"E4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a017de4b0c8380cd4fc14","contributors":{"authors":[{"text":"Kirk, Randolph L. 0000-0003-0842-9226 rkirk@usgs.gov","orcid":"https://orcid.org/0000-0003-0842-9226","contributorId":2765,"corporation":false,"usgs":true,"family":"Kirk","given":"Randolph","email":"rkirk@usgs.gov","middleInitial":"L.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391156,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Howington-Kraus, Elpitha 0000-0001-5787-6554 ahowington@usgs.gov","orcid":"https://orcid.org/0000-0001-5787-6554","contributorId":2815,"corporation":false,"usgs":true,"family":"Howington-Kraus","given":"Elpitha","email":"ahowington@usgs.gov","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391147,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hare, Trent M. 0000-0001-8842-389X thare@usgs.gov","orcid":"https://orcid.org/0000-0001-8842-389X","contributorId":3188,"corporation":false,"usgs":true,"family":"Hare","given":"Trent","email":"thare@usgs.gov","middleInitial":"M.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391146,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dorrer, E.","contributorId":68056,"corporation":false,"usgs":true,"family":"Dorrer","given":"E.","affiliations":[],"preferred":false,"id":391150,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cook, D.","contributorId":61774,"corporation":false,"usgs":true,"family":"Cook","given":"D.","email":"","affiliations":[],"preferred":false,"id":391149,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Becker, Kris J. 0000-0003-1971-5957 kbecker@usgs.gov","orcid":"https://orcid.org/0000-0003-1971-5957","contributorId":2910,"corporation":false,"usgs":true,"family":"Becker","given":"Kris","email":"kbecker@usgs.gov","middleInitial":"J.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391157,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Thompson, K.","contributorId":104445,"corporation":false,"usgs":false,"family":"Thompson","given":"K.","affiliations":[],"preferred":false,"id":391158,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Redding, B.","contributorId":25720,"corporation":false,"usgs":true,"family":"Redding","given":"B.","email":"","affiliations":[],"preferred":false,"id":391145,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Blue, J.","contributorId":53111,"corporation":false,"usgs":true,"family":"Blue","given":"J.","email":"","affiliations":[],"preferred":false,"id":391148,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Galuszka, D.","contributorId":85739,"corporation":false,"usgs":true,"family":"Galuszka","given":"D.","email":"","affiliations":[],"preferred":false,"id":391153,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Lee, E.M.","contributorId":17005,"corporation":false,"usgs":true,"family":"Lee","given":"E.M.","email":"","affiliations":[],"preferred":false,"id":391144,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Gaddis, Lisa R. 0000-0001-9953-5483 lgaddis@usgs.gov","orcid":"https://orcid.org/0000-0001-9953-5483","contributorId":2817,"corporation":false,"usgs":true,"family":"Gaddis","given":"Lisa","email":"lgaddis@usgs.gov","middleInitial":"R.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391154,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Johnson, J. R.","contributorId":69278,"corporation":false,"usgs":true,"family":"Johnson","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":391151,"contributorType":{"id":1,"text":"Authors"},"rank":13},{"text":"Soderblom, Laurence A. 0000-0002-0917-853X lsoderblom@usgs.gov","orcid":"https://orcid.org/0000-0002-0917-853X","contributorId":2721,"corporation":false,"usgs":true,"family":"Soderblom","given":"Laurence","email":"lsoderblom@usgs.gov","middleInitial":"A.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391142,"contributorType":{"id":1,"text":"Authors"},"rank":14},{"text":"Ward, A. W.","contributorId":8129,"corporation":false,"usgs":true,"family":"Ward","given":"A.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":391143,"contributorType":{"id":1,"text":"Authors"},"rank":15},{"text":"Smith, P. H.","contributorId":94058,"corporation":false,"usgs":false,"family":"Smith","given":"P.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":391155,"contributorType":{"id":1,"text":"Authors"},"rank":16},{"text":"Britt, D.T.","contributorId":72150,"corporation":false,"usgs":true,"family":"Britt","given":"D.T.","email":"","affiliations":[],"preferred":false,"id":391152,"contributorType":{"id":1,"text":"Authors"},"rank":17}]}} ,{"id":70021774,"text":"70021774 - 1999 - Analysis of pumping tests: Significance of well diameter, partial penetration, and noise","interactions":[],"lastModifiedDate":"2024-05-23T11:24:18.930528","indexId":"70021774","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"Analysis of pumping tests: Significance of well diameter, partial penetration, and noise","docAbstract":"The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezometers located at distances greater than the initial saturated thickness of the aquifer.
","language":"English","publisher":"American Water Resources Association","doi":"10.1111/j.1752-1688.1999.tb03594.x","issn":"1093474X","usgsCitation":"Heidari, M., Ghiassi, K., and Mehnert, E., 1999, Analysis of pumping tests: Significance of well diameter, partial penetration, and noise: Journal of the American Water Resources Association, v. 35, no. 2, p. 333-347, https://doi.org/10.1111/j.1752-1688.1999.tb03594.x.","productDescription":"15 p.","startPage":"333","endPage":"347","numberOfPages":"15","costCenters":[],"links":[{"id":229595,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-06-08","publicationStatus":"PW","scienceBaseUri":"5059eb29e4b0c8380cd48c6a","contributors":{"authors":[{"text":"Heidari, M.","contributorId":26430,"corporation":false,"usgs":true,"family":"Heidari","given":"M.","email":"","affiliations":[],"preferred":false,"id":391101,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ghiassi, K.","contributorId":46247,"corporation":false,"usgs":true,"family":"Ghiassi","given":"K.","email":"","affiliations":[],"preferred":false,"id":391102,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mehnert, E.","contributorId":64830,"corporation":false,"usgs":true,"family":"Mehnert","given":"E.","email":"","affiliations":[],"preferred":false,"id":391103,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021771,"text":"70021771 - 1999 - Foreshock occurrence before large earthquakes","interactions":[],"lastModifiedDate":"2024-07-17T15:23:52.102772","indexId":"70021771","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Foreshock occurrence before large earthquakes","docAbstract":"Rates of foreshock occurrence involving shallow M ≥ 6 and M ≥ 7 mainshocks and M ≥ 5 foreshocks were measured in two worldwide catalogs over ∼20-year intervals. The overall rates observed are similar to ones measured in previous worldwide and regional studies when they are normalized for the ranges of magnitude difference they each span. The observed worldwide rates were compared to a generic model of earthquake clustering based on patterns of small and moderate aftershocks in California. The aftershock model was extended to the case of moderate foreshocks preceding large mainshocks. Overall, the observed worldwide foreshock rates exceed the extended California generic model by a factor of ∼2. Significant differences in foreshock rate were found among subsets of earthquakes defined by their focal mechanism and tectonic region, with the rate before thrust events higher and the rate before strike-slip events lower than the worldwide average. Among the thrust events, a large majority, composed of events located in shallow subduction zones, had a high foreshock rate, while a minority, located in continental thrust belts, had a low rate. These differences may explain why previous surveys have found low foreshock rates among thrust events in California (especially southern California), while the worldwide observations suggests the opposite: California, lacking an active subduction zone in most of its territory, and including a region of mountain-building thrusts in the south, reflects the low rate apparently typical for continental thrusts, while the worldwide observations, dominated by shallow subduction zone events, are foreshock-rich. If this is so, then the California generic model may significantly underestimate the conditional probability for a very large (M ≥ 8) earthquake following a potential (M ≥ 7) foreshock in Cascadia. The magnitude differences among the identified foreshock-mainshock pairs in the Harvard catalog are consistent with a uniform distribution over the range of observation.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1998JB900089","issn":"01480227","usgsCitation":"Reasenberg, P., 1999, Foreshock occurrence before large earthquakes: Journal of Geophysical Research B: Solid Earth, v. 104, no. B3, p. 4755-4768, https://doi.org/10.1029/1998JB900089.","productDescription":"14 p.","startPage":"4755","endPage":"4768","numberOfPages":"14","costCenters":[],"links":[{"id":229560,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","issue":"B3","noUsgsAuthors":false,"publicationDate":"1999-03-10","publicationStatus":"PW","scienceBaseUri":"505a1322e4b0c8380cd54535","contributors":{"authors":[{"text":"Reasenberg, P.A.","contributorId":19959,"corporation":false,"usgs":true,"family":"Reasenberg","given":"P.A.","email":"","affiliations":[],"preferred":false,"id":391092,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70021770,"text":"70021770 - 1999 - Geodetic estimates of fault slip rates in the San Francisco Bay area","interactions":[],"lastModifiedDate":"2024-07-17T15:25:27.312028","indexId":"70021770","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Geodetic estimates of fault slip rates in the San Francisco Bay area","docAbstract":"Bourne et al. [1998] have suggested that the interseismic velocity profile at the surface across a transform plate boundary is a replica of the secular velocity profile at depth in the plastosphere. On the other hand, in the viscoelastic coupling model the shape of the interseismic surface velocity profile is a consequence of plastosphere relaxation following the previous rupture of the faults that make up the plate boundary and is not directly related to the secular flow in the plastosphere. The two models appear to be incompatible. If the plate boundary is composed of several subparallel faults and the interseismic surface velocity profile across the boundary known, each model predicts the secular slip rates on the faults which make up the boundary. As suggested by Bourne et al., the models can then be tested by comparing the predicted secular slip rates to those estimated from long-term offsets inferred from geology. Here we apply that test to the secular slip rates predicted for the principal faults (San Andreas, San Gregorio, Hayward, Calaveras, Rodgers Creek, Green Valley and Greenville faults) in the San Andreas fault system in the San Francisco Bay area. The estimates from the two models generally agree with one another and to a lesser extent with the geologic estimate. Because the viscoelastic coupling model has been equally successful in estimating secular slip rates on the various fault strands at a diffuse plate boundary, the success of the model of Bourne et at. [1998] in doing the same thing should not be taken as proof that the interseismic velocity profile across the plate boundary at the surface is a replica of the velocity profile at depth in the plastosphere.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/1998JB900108","issn":"01480227","usgsCitation":"Savage, J., Svarc, J.L., and Prescott, W., 1999, Geodetic estimates of fault slip rates in the San Francisco Bay area: Journal of Geophysical Research B: Solid Earth, v. 104, no. B3, p. 4995-5002, https://doi.org/10.1029/1998JB900108.","productDescription":"8 p.","startPage":"4995","endPage":"5002","numberOfPages":"8","costCenters":[],"links":[{"id":229523,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","issue":"B3","noUsgsAuthors":false,"publicationDate":"1999-03-10","publicationStatus":"PW","scienceBaseUri":"505a173be4b0c8380cd55435","contributors":{"authors":[{"text":"Savage, J.C. 0000-0002-5114-7673","orcid":"https://orcid.org/0000-0002-5114-7673","contributorId":102876,"corporation":false,"usgs":true,"family":"Savage","given":"J.C.","affiliations":[],"preferred":false,"id":391091,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Svarc, J. L.","contributorId":75995,"corporation":false,"usgs":true,"family":"Svarc","given":"J.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":391089,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Prescott, W.H.","contributorId":96337,"corporation":false,"usgs":true,"family":"Prescott","given":"W.H.","email":"","affiliations":[],"preferred":false,"id":391090,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021766,"text":"70021766 - 1999 - Aeolian features and processes at the Mars Pathfinder landing site","interactions":[],"lastModifiedDate":"2018-12-04T10:50:35","indexId":"70021766","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2317,"text":"Journal of Geophysical Research E: Planets","active":true,"publicationSubtype":{"id":10}},"title":"Aeolian features and processes at the Mars Pathfinder landing site","docAbstract":"The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-size aggregates of finer grains, the discovery of ventifact flutes cut in rocks strongly suggests that at least some of the grains are crystalline, rather than aggregates. Excluding the ventifacts, the orientations of the wind-related features correlate well with the orientations of bright wind steaks seen on Viking Orbiter images in the general area. They also correlate with wind direction predictions from the NASA-Ames General Circulation Model (GCM) which show that the strongest winds in the area occur in the northern hemisphere winter and are directed toward 209°.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research E: Planets","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Geophysical Union","publisherLocation":"Washington, D.C.","doi":"10.1029/98JE02553","issn":"01480227","usgsCitation":"Greeley, R., Kraft, M., Sullivan, R., Wilson, G., Bridges, N., Herkenhoff, K.E., Kuzmin, R.O., Malin, M., and Ward, W., 1999, Aeolian features and processes at the Mars Pathfinder landing site: Journal of Geophysical Research E: Planets, v. 104, no. E4, p. 8573-8584, https://doi.org/10.1029/98JE02553.","productDescription":"12 p.","startPage":"8573","endPage":"8584","numberOfPages":"12","costCenters":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"links":[{"id":479543,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/98je02553","text":"Publisher Index Page"},{"id":229484,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"104","issue":"E4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e70ee4b0c8380cd47811","contributors":{"authors":[{"text":"Greeley, Ronald","contributorId":20833,"corporation":false,"usgs":true,"family":"Greeley","given":"Ronald","email":"","affiliations":[],"preferred":false,"id":391065,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kraft, Michael","contributorId":78899,"corporation":false,"usgs":true,"family":"Kraft","given":"Michael","email":"","affiliations":[],"preferred":false,"id":391070,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sullivan, Robert","contributorId":70102,"corporation":false,"usgs":true,"family":"Sullivan","given":"Robert","affiliations":[],"preferred":false,"id":391069,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wilson, Gregory","contributorId":84938,"corporation":false,"usgs":true,"family":"Wilson","given":"Gregory","email":"","affiliations":[],"preferred":false,"id":391071,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bridges, Nathan","contributorId":55168,"corporation":false,"usgs":false,"family":"Bridges","given":"Nathan","affiliations":[{"id":7166,"text":"Johns Hopkins University Applied Physics Laboratory","active":true,"usgs":false}],"preferred":false,"id":391068,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Herkenhoff, Kenneth E. 0000-0002-3153-6663 kherkenhoff@usgs.gov","orcid":"https://orcid.org/0000-0002-3153-6663","contributorId":2275,"corporation":false,"usgs":true,"family":"Herkenhoff","given":"Kenneth","email":"kherkenhoff@usgs.gov","middleInitial":"E.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":true,"id":391067,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Kuzmin, Ruslan O.","contributorId":31059,"corporation":false,"usgs":true,"family":"Kuzmin","given":"Ruslan","email":"","middleInitial":"O.","affiliations":[],"preferred":false,"id":391066,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Malin, Michael","contributorId":88112,"corporation":false,"usgs":true,"family":"Malin","given":"Michael","affiliations":[],"preferred":false,"id":391072,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Ward, Wes","contributorId":103815,"corporation":false,"usgs":true,"family":"Ward","given":"Wes","email":"","affiliations":[],"preferred":false,"id":391073,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":70021765,"text":"70021765 - 1999 - Observations at the Mars Pathfinder site: Do they provide \"unequivocal\" evidence of catastrophic flooding?","interactions":[],"lastModifiedDate":"2024-07-31T15:25:51.055562","indexId":"70021765","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2317,"text":"Journal of Geophysical Research E: Planets","active":true,"publicationSubtype":{"id":10}},"title":"Observations at the Mars Pathfinder site: Do they provide \"unequivocal\" evidence of catastrophic flooding?","docAbstract":"After Mars Pathfinder landed at the mouth of Ares Valus, a large channel that drains into the Chryse Planitia basin, the mission reports unanimously supported the interpretation that the lander site is the locus of catastrophic flooding by noting that all aspects of the scene are consistent with this interpretation. However, alternatives cannot be ruled out by any site observations, as all aspects of the scene are equally consistent with other interpretations of origin, namely, ice and mass-flow processes subsequently modified by wind erosion. The authors discuss alternative explanations for the geologic history of the channel based on a regional view of the circum-Chryse channels from Viking images (our best broad-scale information to date) and the local view from the recent Pathfinder landing site. Mega-indicators of channel origin, the regional geomorphology, geology, and planetary climatic conditions, taken together suggest some combination of flood, mass flow, glacial, and eolian processes. The macro-indicators of channel origin (sedimentologic) are also not indicative of one process of emplacement, either as single criteria or taken cumulatively. Finally, the micro-indicators of channel origin (geochemical and mineralogic composition) do not provide very tight constraints on the deposits' possible origins other than that water was in some way involved.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/98JE02083","issn":"01480227","usgsCitation":"Chapman, M.G., and Kargel, J., 1999, Observations at the Mars Pathfinder site: Do they provide \"unequivocal\" evidence of catastrophic flooding?: Journal of Geophysical Research E: Planets, v. 104, no. E4, p. 8671-8678, https://doi.org/10.1029/98JE02083.","productDescription":"8 p.","startPage":"8671","endPage":"8678","numberOfPages":"8","costCenters":[],"links":[{"id":479544,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/98je02083","text":"Publisher Index Page"},{"id":229445,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"104","issue":"E4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6a72e4b0c8380cd74186","contributors":{"authors":[{"text":"Chapman, M. G.","contributorId":105737,"corporation":false,"usgs":true,"family":"Chapman","given":"M.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":391064,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kargel, J.S.","contributorId":88096,"corporation":false,"usgs":true,"family":"Kargel","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":391063,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70021763,"text":"70021763 - 1999 - Modeling the effects of nutria (Myocastor coypus) on wetland loss","interactions":[],"lastModifiedDate":"2019-10-24T10:30:55","indexId":"70021763","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Modeling the effects of nutria (Myocastor coypus) on wetland loss","title":"Modeling the effects of nutria (Myocastor coypus) on wetland loss","docAbstract":"We created a model to study the process in which nutria (Myocastor coypus) feeding activities lead to erosion and loss of marsh area. This model ties together data on nutria population dynamics and feeding behavior from the literature with data from field studies on the phenology of Scirpus americanus and Spartina patens conducted in the Barataria Basin, Louisiana, USA in 1992. The complete model consists of three linked models: a model of nutria population dynamics (nutria model), a model of the annual marsh biomass cycle of Scirpus americanus and Spartina patens (biomass model), and a plant-biomass density-dependent marsh area model (area model). When all three models are linked together, they form the 'nutria-biomass-area model.' Analysis of the models indicated the following. (1) The high population densities and low survivorship rates as reported in the literature are incompatible. (2) the nutria model is sensitive to adult and juvenile survivorship and, to a lesser extent, young born per female. It is not particularly sensitive to gestation periods, impregnation rates, or time to maturity. (3) The marsh area model is not sensitive to the marsh loss equation nor to the density at which loss of marsh area begins but is sensitive to the amount of biomass destroyed per nutria. (4) Nutria numbers do not significantly decrease in the nutria-biomass-area model until the total marsh area approaches zero because marsh loss occurs only during winter when marsh biomass is at its annual low.
","language":"English","publisher":"Springer","doi":"10.1007/BF03161750","issn":"02775212","usgsCitation":"Carter, J., Foote, A., and Johnson-Randall, L., 1999, Modeling the effects of nutria (Myocastor coypus) on wetland loss: Wetlands, v. 19, no. 1, p. 209-219, https://doi.org/10.1007/BF03161750.","productDescription":"11 p.","startPage":"209","endPage":"219","numberOfPages":"11","costCenters":[{"id":455,"text":"National Wetlands Research Center","active":true,"usgs":true}],"links":[{"id":229443,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Louisiana","otherGeospatial":"Barataria Basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -90.604248046875,\n 29.084976575985912\n ],\n [\n -89.5330810546875,\n 29.084976575985912\n ],\n [\n -89.5330810546875,\n 29.76914573606667\n ],\n [\n -90.604248046875,\n 29.76914573606667\n ],\n [\n -90.604248046875,\n 29.084976575985912\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"19","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5c42e4b0c8380cd6fb47","contributors":{"authors":[{"text":"Carter, J. 0000-0003-0110-0284 carterj@usgs.gov","orcid":"https://orcid.org/0000-0003-0110-0284","contributorId":81839,"corporation":false,"usgs":true,"family":"Carter","given":"J.","email":"carterj@usgs.gov","affiliations":[{"id":455,"text":"National Wetlands Research Center","active":true,"usgs":true}],"preferred":true,"id":391060,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Foote, A.L.","contributorId":66435,"corporation":false,"usgs":true,"family":"Foote","given":"A.L.","email":"","affiliations":[],"preferred":false,"id":391059,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Johnson-Randall, L. A. 0000-0003-0100-994X","orcid":"https://orcid.org/0000-0003-0100-994X","contributorId":28029,"corporation":false,"usgs":true,"family":"Johnson-Randall","given":"L. A.","affiliations":[],"preferred":false,"id":391058,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021762,"text":"70021762 - 1999 - Post audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system","interactions":[],"lastModifiedDate":"2024-03-07T00:57:58.622153","indexId":"70021762","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3825,"text":"Groundwater","active":true,"publicationSubtype":{"id":10}},"title":"Post audit of a numerical prediction of wellfield drawdown in a semiconfined aquifer system","docAbstract":"A numerical ground water flow model was created in 1978 and revised in 1981 to predict the drawdown effects of a proposed municipal wellfield permitted to withdraw 30 million gallons per day (mgd; 1.1 × 105 m3/day) of water from the semiconfined Floridan Aquifer system. The predictions are based on the assumption that water levels in the semiconfined Floridan Aquifer reach a long-term, steady-state condition within a few days of initiation of pumping. Using this assumption, a 75 day simulation without water table recharge, pumping at the maximum permitted rates, was considered to represent a worst-case condition and the greatest drawdowns that could be experienced during wellfield operation. This method of predicting wellfield effects was accepted by the permitting agency.
For this post audit, observed drawdowns were derived by taking the difference between pre-pumping and post-pumping potentiometric surface levels. Comparison of predicted and observed drawdowns suggests that actual drawdown over a 12 year period exceeds predicted drawdown by a factor of two or more. Analysis of the source of error in the 1981 predictions suggests that the values used for transmissivity, storativity. specific yield, and leakance are reasonable at the wellfield scale. Simulation using actual 1980–1992 pumping rates improves the agreement between predicted and observed drawdowns. The principal source of error is the assumption that water levels in a semiconfined aquifer achieve a steady-state condition after a few days or weeks of pumping. Simulations using a version of the 1981 model modified to include recharge and evapotranspiration suggest that it can take hundreds of days or several years for water levels in the linked Surficial and Floridan Aquifers to reach an apparent steady-state condition, and that slow declines in levels continue for years after the initiation of pumping. While the 1981 “impact” model can be used for reasonably predicting short-term, wellfield-scale effects of pumping, using a 75 day long simulation without recharge to predict the long-term behavior of the wellfield was an inappropriate application, resulting in significant underprediction of wellfield effects.
Basement modules located in southern Minnesota have been the site of continuous radon and environmental measurements during heating seasons since 1993. Concentrations of radon within the basement modules ranged from 70 Bq.m-3 to over 4000 Bq.m-3 between November to April during the three measurement periods. In the soil gas for the same times, concentrations of radon ranged between 25,000 and 70,000 Bq.m-3. Levels of radon within the basement modules changed by factors of five or more within 24 h, in concert with pressure gradients of 4 to 20 Pa that developed between the basement modules and their surroundings. Diffusion is identified as the principal method by which radon is transferred into and out of the basement modules, and appears to be relatively independent of insulating materials and vapour retarders. The variability of radon and correlations with differential pressure gradients may be related to air currents in the block walls and soil that interrupt radon diffusing inward. This yields a net decrease of radon in the basement modules by decay and outward diffusion. Levels of radon within the basement modules increase when the pressure differential is zero and air flow ceases, allowing diffusion gradients to be re-established. Radon levels in both the soil and the basement modules then increase until an equilibrium is achieved.
","language":"English","publisher":"Oxford Academic","doi":"10.1093/oxfordjournals.rpd.a032604","issn":"01448420","usgsCitation":"Lively, R., and Goldberg, L., 1999, Diffusion of radon through concrete block walls: A significant source of indoor radon: Radiation Protection Dosimetry, v. 82, no. 1, p. 31-42, https://doi.org/10.1093/oxfordjournals.rpd.a032604.","productDescription":"12 p.","startPage":"31","endPage":"42","numberOfPages":"12","costCenters":[],"links":[{"id":229404,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"82","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0110e4b0c8380cd4faa7","contributors":{"authors":[{"text":"Lively, R.S.","contributorId":70927,"corporation":false,"usgs":true,"family":"Lively","given":"R.S.","email":"","affiliations":[],"preferred":false,"id":391048,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Goldberg, L.F.","contributorId":73364,"corporation":false,"usgs":true,"family":"Goldberg","given":"L.F.","email":"","affiliations":[],"preferred":false,"id":391049,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70021759,"text":"70021759 - 1999 - Assessing groundwater vulnerability to agrichemical contamination in the Midwest US","interactions":[],"lastModifiedDate":"2018-12-19T10:13:09","indexId":"70021759","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3724,"text":"Water Science and Technology","active":true,"publicationSubtype":{"id":10}},"title":"Assessing groundwater vulnerability to agrichemical contamination in the Midwest US","docAbstract":"Agrichemicals (herbicides and nitrate) are significant sources of diffuse pollution to groundwater. Indirect methods are needed to assess the potential for groundwater contamination by diffuse sources because groundwater monitoring is too costly to adequately define the geographic extent of contamination at a regional or national scale. This paper presents examples of the application of statistical, overlay and index, and process-based modeling methods for groundwater vulnerability assessments to a variety of data from the Midwest U.S. The principles for vulnerability assessment include both intrinsic (pedologic, climatologic, and hydrogeologic factors) and specific (contaminant and other anthropogenic factors) vulnerability of a location. Statistical methods use the frequency of contaminant occurrence, contaminant concentration, or contamination probability as a response variable. Statistical assessments are useful for defining the relations among explanatory and response variables whether they define intrinsic or specific vulnerability. Multivariate statistical analyses are useful for ranking variables critical to estimating water quality responses of interest. Overlay and index methods involve intersecting maps of intrinsic and specific vulnerability properties and indexing the variables by applying appropriate weights. Deterministic models use process-based equations to simulate contaminant transport and are distinguished from the other methods in their potential to predict contaminant transport in both space and time. An example of a one-dimensional leaching model linked to a geographic information system (GIS) to define a regional metamodel for contamination in the Midwest is included.
","language":"English","publisher":"IWA","doi":"10.1016/S0273-1223(99)00042-6","issn":"02731223","usgsCitation":"Burkart, M.R., Kolpin, D., and James, D., 1999, Assessing groundwater vulnerability to agrichemical contamination in the Midwest US: Water Science and Technology, v. 39, no. 3, p. 103-112, https://doi.org/10.1016/S0273-1223(99)00042-6.","productDescription":"10 p.","startPage":"103","endPage":"112","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":351,"text":"Iowa Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":229403,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206315,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0273-1223(99)00042-6"}],"country":"United States","volume":"39","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059edd6e4b0c8380cd49a39","contributors":{"authors":[{"text":"Burkart, M. R.","contributorId":42190,"corporation":false,"usgs":true,"family":"Burkart","given":"M.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":391046,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kolpin, D.W.","contributorId":87565,"corporation":false,"usgs":true,"family":"Kolpin","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":391047,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"James, D.E.","contributorId":22927,"corporation":false,"usgs":true,"family":"James","given":"D.E.","email":"","affiliations":[],"preferred":false,"id":391045,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021758,"text":"70021758 - 1999 - Mesoproterozoic rapakivi granites of the Rondonia Tin Province, southwestern border of the Amazonian craton, Brazil-I. Reconnaissance U-Pb geochronology and regional implications","interactions":[],"lastModifiedDate":"2012-03-12T17:19:41","indexId":"70021758","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3112,"text":"Precambrian Research","active":true,"publicationSubtype":{"id":10}},"title":"Mesoproterozoic rapakivi granites of the Rondonia Tin Province, southwestern border of the Amazonian craton, Brazil-I. Reconnaissance U-Pb geochronology and regional implications","docAbstract":"Rapakivi granites and associated mafic and ultramafic rocks in the Rondonia Tin Province, southwestern Amazonian craton, Brazil were emplaced during six discrete episodes of magmatism between ca 1600 and 970 Ma. The seven rapakivi granite suites emplaced at this time were the Serra da Providencia Intrusive Suite (U-Pb ages between 1606 and 1532 Ma); Santo Antonio Intrusive Suite (U-Pb age 1406 Ma); Teotonio Intrusive Suite (U-Pb age 1387 Ma); Alto Candeias Intrusive Suite (U-Pb ages between 1346 and 1338 Ma); Sao Lourenco-Caripunas Intrusive Suite (U-Pb ages between 1314 and 1309 Ma); Santa Clara Intrusive Suite (U-Pb ages between 1082 and 1074 Ma); and Younger Granites of Rondonia (U-Pb ages between 998 and 974 Ma). The Serra da Providencia Intrusive Suite intruded the Paleoproterozoic (1.80 to 1.70 Ga) Rio Negro-Juruena crust whereas the other suites were emplaced into the 1.50 to 1.30 Ga Rondonia-San Ignacio crust. Their intrusion was contemporaneous with orogenic activity in other parts of the southwestern Amazonian craton, except for the oldest, Serra da Providencia Intrusive Suite. Orogenic events coeval with emplacement of the Serra da Providencia Intrusive Suite are not clearly recognized in the region. The Santo Antonio, Teotonio, Alto Candeias and Sao Lourenco-Caripunas Intrusive Suites are interpreted to represent extensional anorogenic magmatism associated with the terminal stages of the Rondonian-San Ignacio orogeny. At least the Sao Lourenco-Caripunas rapakivi granites and coeval intra-continental rift sedimentary rocks may, in contrast, represent the products of extensional tectonics and rifting preceding the Sunsas/Aguapei orogeny (1.25 to 1.0 Ga). The two youngest rapakivi suites, the Santa Clara Intrusive Suite and Younger Granites of Rondonia, seemingly represent inboard magmatism in the Rondonian-San Ignacio Province during a younger episode of reworking in the Rio Negro-Juruena Province during the waning stages of the collisional 1.1 to 1.0 Ga Sunsas/Aguapei orogeny. The six intra-plate rapakivi granite episodes in the southwestern part of the Amazonian craton form three broad periods of anorogenic magmatism that have age-correlative events composed of similar rocks and geologic environments in eastern Laurentia and Baltica, although the exact timing of magmatism appears slightly different. Recognition of lithologic and chronological correlations between various cratons provide important constraints to models explaining the interplay between rapakivi granite magmatism and deep crustal evolution of an early Mesoproterozoic supercontinent. They are, furthermore, important to plate tectonic models for the assembly, dispersal and reassembly of Amazonia, Laurentia and Baltica in the Mesoproterozoic and Neoproterozoic.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Precambrian Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0301-9268(98)00126-0","issn":"03019268","usgsCitation":"Bettencourt, J.S., Tosdal, R., Leite, W., and Payolla, B., 1999, Mesoproterozoic rapakivi granites of the Rondonia Tin Province, southwestern border of the Amazonian craton, Brazil-I. Reconnaissance U-Pb geochronology and regional implications: Precambrian Research, v. 95, no. 1-2, p. 41-67, https://doi.org/10.1016/S0301-9268(98)00126-0.","startPage":"41","endPage":"67","numberOfPages":"27","costCenters":[],"links":[{"id":206309,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0301-9268(98)00126-0"},{"id":229367,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5446e4b0c8380cd6cf2b","contributors":{"authors":[{"text":"Bettencourt, Jorge S.","contributorId":97269,"corporation":false,"usgs":true,"family":"Bettencourt","given":"Jorge","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":391044,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tosdal, R. M.","contributorId":54982,"corporation":false,"usgs":true,"family":"Tosdal","given":"R. M.","affiliations":[],"preferred":false,"id":391043,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Leite, W.B. Jr.","contributorId":28763,"corporation":false,"usgs":true,"family":"Leite","given":"W.B.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":391042,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Payolla, B.L.","contributorId":7441,"corporation":false,"usgs":true,"family":"Payolla","given":"B.L.","email":"","affiliations":[],"preferred":false,"id":391041,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70021534,"text":"70021534 - 1999 - Tectonics of Atlantic Canada","interactions":[],"lastModifiedDate":"2012-03-12T17:19:40","indexId":"70021534","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1813,"text":"Geoscience Canada","active":true,"publicationSubtype":{"id":10}},"title":"Tectonics of Atlantic Canada","docAbstract":"The tectonic history of Atlantic Canada is summarized according to a model of multiple ocean opening-closing cycles. The modern North Atlantic Ocean is in the opening phase of its cycle. It was preceded by an early Paleozoic lapetus Ocean whose cycle led to formation of the Appalachian Orogen. lapetus was preceded by the Neoproterozoic Uranus Ocean whose cycle led to formation of the Grenville Orogen. The phenomenon of coincident, or almost coincident orogens and modern continental margins that relate to repeated ocean opening-closing cycles is called the Accordion Effect. An understanding of the North Atlantic Ocean and its continental margins provides insights into the nature of lapetus and the evolution of the Appalachian Orogen. Likewise, an understanding of lapetus and the Appalachian Orogen raises questions about Uranus and the development of the Grenville Orogen. Modern tectonic patterns in the North Atlantic may have been determined by events that began before 1000 m.y.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geoscience Canada","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03150941","usgsCitation":"Williams, H., Dehler, S., Grant, A., and Oakey, G., 1999, Tectonics of Atlantic Canada: Geoscience Canada, v. 26, no. 2, p. 51-70.","startPage":"51","endPage":"70","numberOfPages":"20","costCenters":[],"links":[{"id":229246,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba489e4b08c986b3203fd","contributors":{"authors":[{"text":"Williams, H.","contributorId":51486,"corporation":false,"usgs":true,"family":"Williams","given":"H.","affiliations":[],"preferred":false,"id":390224,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dehler, S.A.","contributorId":64413,"corporation":false,"usgs":true,"family":"Dehler","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":390225,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Grant, A.C.","contributorId":21307,"corporation":false,"usgs":true,"family":"Grant","given":"A.C.","email":"","affiliations":[],"preferred":false,"id":390223,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Oakey, G.N.","contributorId":84103,"corporation":false,"usgs":true,"family":"Oakey","given":"G.N.","affiliations":[],"preferred":false,"id":390226,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70021533,"text":"70021533 - 1999 - A goodness-of-fit test for capture-recapture model Mt under closure","interactions":[],"lastModifiedDate":"2023-09-14T18:22:40.222924","indexId":"70021533","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1039,"text":"Biometrics","active":true,"publicationSubtype":{"id":10}},"displayTitle":"A goodness-of-fit test for capture-recapture model Mt under closure","title":"A goodness-of-fit test for capture-recapture model Mt under closure","docAbstract":"A new, fully efficient goodness-of-fit test for the time-specific closed-population capture-recapture model Mt is presented. This test is based on the residual distribution of the capture history data given the maximum likelihood parameter estimates under model Mt, is partitioned into informative components, and is based on chi-square statistics. Comparison of this test with Leslie's test (Leslie, 1958, Journal of Animal Ecology, 27, 84–86) for model Mt, using Monte Carlo simulations, shows the new test generally outperforms Leslie's test. The new test is frequently computable when Leslie's test is not, has Type I error rates that are closer to nominal error rates than Leslie's test, and is sensitive to behavioral variation and heterogeneity in capture Probabilities. Leslie's test is not sensitive to behavioral variation in capture probabilities but, when computable, has greater power to detect heterogeneity than the new test.
","language":"English","publisher":"Wiley","doi":"10.1111/j.0006-341X.1999.00366.x","issn":"0006341X","usgsCitation":"Stanley, T., and Burnham, K., 1999, A goodness-of-fit test for capture-recapture model Mt under closure: Biometrics, v. 55, no. 2, p. 366-375, https://doi.org/10.1111/j.0006-341X.1999.00366.x.","productDescription":"10 p.","startPage":"366","endPage":"375","costCenters":[],"links":[{"id":479589,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.0006-341x.1999.00366.x","text":"Publisher Index Page"},{"id":229245,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"55","issue":"2","noUsgsAuthors":false,"publicationDate":"2004-05-26","publicationStatus":"PW","scienceBaseUri":"5059e40be4b0c8380cd46396","contributors":{"authors":[{"text":"Stanley, T.R.","contributorId":61379,"corporation":false,"usgs":true,"family":"Stanley","given":"T.R.","affiliations":[],"preferred":false,"id":390221,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burnham, K.P.","contributorId":63760,"corporation":false,"usgs":true,"family":"Burnham","given":"K.P.","email":"","affiliations":[],"preferred":false,"id":390222,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70021530,"text":"70021530 - 1999 - Antarctic glacial history from numerical models and continental margin sediments","interactions":[],"lastModifiedDate":"2012-03-12T17:19:41","indexId":"70021530","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2996,"text":"Palaeogeography, Palaeoclimatology, Palaeoecology","printIssn":"0031-0182","active":true,"publicationSubtype":{"id":10}},"title":"Antarctic glacial history from numerical models and continental margin sediments","docAbstract":"The climate record of glacially transported sediments in prograded wedges around the Antarctic outer continental shelf, and their derivatives in continental rise drifts, may be combined to produce an Antarctic ice sheet history, using numerical models of ice sheet response to temperature and sea-level change. Examination of published models suggests several preliminary conclusions about ice sheet history. The ice sheet's present high sensitivity to sea-level change at short (orbital) periods was developed gradually as its size increased, replacing a declining sensitivity to temperature. Models suggest that the ice sheet grew abruptly to 40% (or possibly more) of its present size at the Eocene-Oligocene boundary, mainly as a result of its own temperature sensitivity. A large but more gradual middle Miocene change was externally driven, probably by development of the Antarctic Circumpolar Current (ACC) and Polar Front, provided that a few million years' delay can be explained. The Oligocene ice sheet varied considerably in size and areal extent, but the late Miocene ice sheet was more stable, though significantly warmer than today's. This difference probably relates to the confining effect of the Antarctic continental margin. Present-day numerical models of ice sheet development are sufficient to guide current sampling plans, but sea-ice formation, polar wander, basal topography and ice streaming can be identified as factors meriting additional modelling effort in the future.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Palaeogeography, Palaeoclimatology, Palaeoecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0031-0182(98)00224-7","issn":"00310182","usgsCitation":"Barker, P., Barrett, P.J., Cooper, A.K., and Huybrechts, P., 1999, Antarctic glacial history from numerical models and continental margin sediments: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 150, no. 3-4, p. 247-267, https://doi.org/10.1016/S0031-0182(98)00224-7.","startPage":"247","endPage":"267","numberOfPages":"21","costCenters":[],"links":[{"id":479529,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://epic.awi.de/id/eprint/3665/1/Bar1999b.pdf","text":"External Repository"},{"id":229173,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206230,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0031-0182(98)00224-7"}],"volume":"150","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ec51e4b0c8380cd491c7","contributors":{"authors":[{"text":"Barker, P.F.","contributorId":72954,"corporation":false,"usgs":true,"family":"Barker","given":"P.F.","email":"","affiliations":[],"preferred":false,"id":390209,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Barrett, P. J.","contributorId":96347,"corporation":false,"usgs":false,"family":"Barrett","given":"P.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":390210,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cooper, A. K.","contributorId":50149,"corporation":false,"usgs":true,"family":"Cooper","given":"A.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":390207,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Huybrechts, P.","contributorId":64412,"corporation":false,"usgs":true,"family":"Huybrechts","given":"P.","email":"","affiliations":[],"preferred":false,"id":390208,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70021529,"text":"70021529 - 1999 - Applications and issues of GIS as tool for civil engineering modeling","interactions":[],"lastModifiedDate":"2012-03-12T17:19:40","indexId":"70021529","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2230,"text":"Journal of Computing in Civil Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Applications and issues of GIS as tool for civil engineering modeling","docAbstract":"A tool that has proliferated within civil engineering in recent years is geographic information systems (GIS). The goal of a tool is to supplement ability and knowledge that already exists, not to serve as a replacement for that which is lacking. To secure the benefits and avoid misuse of a burgeoning tool, engineers must understand the limitations, alternatives, and context of the tool. The common benefits of using GIS as a supplement to engineering modeling are summarized. Several brief case studies of GIS modeling applications are taken from popular civil engineering literature to demonstrate the wide use and varied implementation of GIS across the discipline. Drawing from the case studies, limitations regarding traditional GIS data models find the implementation of civil engineering models within current GIS are identified and countered by discussing the direction of the next generation of GIS. The paper concludes by highlighting the potential for the misuse of GIS in the context of engineering modeling and suggests that this potential can be reduced through education and awareness. The goal of this paper is to promote awareness of the issues related to GIS-based modeling and to assist in the formulation of questions regarding the application of current GIS. The technology has experienced much publicity of late, with many engineers being perhaps too excited about the usefulness of current GIS. An undoubtedly beneficial side effect of this, however, is that engineers are becoming more aware of GIS and, hopefully, the associated subtleties. Civil engineers must stay informed of GIS issues and progress, but more importantly, civil engineers must inform the GIS community to direct the technology development optimally.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Computing in Civil Engineering","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"ASCE","publisherLocation":"Reston, VA, United States","doi":"10.1061/(ASCE)0887-3801(1999)13:3(144)","issn":"08873801","usgsCitation":"Miles, S., and Ho, C., 1999, Applications and issues of GIS as tool for civil engineering modeling: Journal of Computing in Civil Engineering, v. 13, no. 3, p. 144-152, https://doi.org/10.1061/(ASCE)0887-3801(1999)13:3(144).","startPage":"144","endPage":"152","numberOfPages":"9","costCenters":[],"links":[{"id":229172,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":206229,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/(ASCE)0887-3801(1999)13:3(144)"}],"volume":"13","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ecc2e4b0c8380cd4947c","contributors":{"authors":[{"text":"Miles, S.B.","contributorId":68908,"corporation":false,"usgs":true,"family":"Miles","given":"S.B.","email":"","affiliations":[],"preferred":false,"id":390206,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ho, C.L.","contributorId":49544,"corporation":false,"usgs":true,"family":"Ho","given":"C.L.","email":"","affiliations":[],"preferred":false,"id":390205,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70021528,"text":"70021528 - 1999 - Moment tensor solutions estimated using optimal filter theory: Global seismicity, 1997","interactions":[],"lastModifiedDate":"2012-03-12T17:19:57","indexId":"70021528","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","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: Global seismicity, 1997","docAbstract":"Moment tensor solutions, estimated using optimal filter theory, are listed for 218 moderate-to-large size earthquakes that occurred during 1997.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0031-9201(99)00061-8","issn":"00319201","usgsCitation":"Sipkin, S., Bufe, C., and Zirbes, M., 1999, Moment tensor solutions estimated using optimal filter theory: Global seismicity, 1997: Physics of the Earth and Planetary Interiors, v. 114, no. 3-4, p. 109-117, https://doi.org/10.1016/S0031-9201(99)00061-8.","startPage":"109","endPage":"117","numberOfPages":"9","costCenters":[],"links":[{"id":206217,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0031-9201(99)00061-8"},{"id":229138,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"114","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5d3be4b0c8380cd7024b","contributors":{"authors":[{"text":"Sipkin, S.A.","contributorId":9399,"corporation":false,"usgs":true,"family":"Sipkin","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":390202,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bufe, C. G.","contributorId":79443,"corporation":false,"usgs":true,"family":"Bufe","given":"C. G.","affiliations":[],"preferred":false,"id":390204,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Zirbes, M.D.","contributorId":27620,"corporation":false,"usgs":true,"family":"Zirbes","given":"M.D.","email":"","affiliations":[],"preferred":false,"id":390203,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70021524,"text":"70021524 - 1999 - Prediction of episodic acidification in North-eastern USA: An empirical/mechanistic approach","interactions":[],"lastModifiedDate":"2012-03-12T17:19:58","indexId":"70021524","displayToPublicDate":"1999-01-01T00:00:00","publicationYear":"1999","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Prediction of episodic acidification in North-eastern USA: An empirical/mechanistic approach","docAbstract":"Observations from the US Environmental Protection Agency's Episodic Response Project (ERP) in the North-eastern United States are used to develop an empirical/mechanistic scheme for prediction of the minimum values of acid neutralizing capacity (ANC) during episodes. An acidification episode is defined as a hydrological event during which ANC decreases. The pre-episode ANC is used to index the antecedent condition, and the stream flow increase reflects how much the relative contributions of sources of waters change during the episode. As much as 92% of the total variation in the minimum ANC in individual catchments can be explained (with levels of explanation >70% for nine of the 13 streams) by a multiple linear regression model that includes pre-episode ANC and change in discharge as independent variable. The predictive scheme is demonstrated to be regionally robust, with the regional variance explained ranging from 77 to 83%. The scheme is not successful for each ERP stream, and reasons are suggested for the individual failures. The potential for applying the predictive scheme to other watersheds is demonstrated by testing the model with data from the Panola Mountain Research Watershed in the South-eastern United States, where the variance explained by the model was 74%. The model can also be utilized to assess 'chemically new' and 'chemically old' water sources during acidification episodes.Observations from the US Environmental Protection Agency's Episodic Response Project (ERP) in the Northeastern United States are used to develop an empirical/mechanistic scheme for prediction of the minimum values of acid neutralizing capacity (ANC) during episodes. An acidification episode is defined as a hydrological event during which ANC decreases. The pre-episode ANC is used to index the antecedent condition, and the stream flow increase reflects how much the relative contributions of sources of waters change during the episode. As much as 92% of the total variation in the minimum ANC in individual catchments can be explained (with levels of explanation >70% for nine of the 13 streams) by a multiple linear regression model that includes pre-episode ANC and change in discharge as independent variables. The predictive scheme is demonstrated to be regionally robust, with the regional variance explained ranging from 77 to 83%. The scheme is not successful for each ERP stream, and reasons are suggested for the individual failures. The potential for applying the predictive scheme to other watersheds is demonstrated by testing the model with data from the Panola Mountain Research Watershed in the South-eastern United States, where the variance explained by the model was 74%. The model can also be utilized to assess `chemically new' and `chemically old' water sources during acidification episodes.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrological Processes","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"John Wiley & Sons Ltd","publisherLocation":"Chichester, United Kingdom","doi":"10.1002/(SICI)1099-1085(19990615)13:8<1181::AID-HYP767>3.0.CO;2-9","issn":"08856087","usgsCitation":"Davies, T., Tranter, M., Wigington, P., Eshleman, K., Peters, N., Van Sickle, J., DeWalle, D.R., and Murdoch, P., 1999, Prediction of episodic acidification in North-eastern USA: An empirical/mechanistic approach: Hydrological Processes, v. 13, no. 8, p. 1181-1195, https://doi.org/10.1002/(SICI)1099-1085(19990615)13:8<1181::AID-HYP767>3.0.CO;2-9.","startPage":"1181","endPage":"1195","numberOfPages":"15","costCenters":[],"links":[{"id":206201,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/(SICI)1099-1085(19990615)13:8<1181::AID-HYP767>3.0.CO;2-9"},{"id":229100,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"13","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a81ede4b0c8380cd7b7e2","contributors":{"authors":[{"text":"Davies, T.D.","contributorId":86513,"corporation":false,"usgs":true,"family":"Davies","given":"T.D.","email":"","affiliations":[],"preferred":false,"id":390193,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tranter, M.","contributorId":22525,"corporation":false,"usgs":true,"family":"Tranter","given":"M.","email":"","affiliations":[],"preferred":false,"id":390188,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wigington, P.J. Jr.","contributorId":96433,"corporation":false,"usgs":true,"family":"Wigington","given":"P.J.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":390194,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Eshleman, K.N.","contributorId":12632,"corporation":false,"usgs":true,"family":"Eshleman","given":"K.N.","email":"","affiliations":[],"preferred":false,"id":390187,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Peters, N.E.","contributorId":33332,"corporation":false,"usgs":true,"family":"Peters","given":"N.E.","email":"","affiliations":[],"preferred":false,"id":390190,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Van Sickle, J.","contributorId":79252,"corporation":false,"usgs":true,"family":"Van Sickle","given":"J.","email":"","affiliations":[],"preferred":false,"id":390192,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"DeWalle, David R.","contributorId":23291,"corporation":false,"usgs":true,"family":"DeWalle","given":"David","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":390189,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Murdoch, Peter S.","contributorId":73547,"corporation":false,"usgs":true,"family":"Murdoch","given":"Peter S.","affiliations":[],"preferred":false,"id":390191,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ]}