The high spatial variability of estuaries poses a challenge for characterizing estuarine water quality. This problem was examined by conducting monthly high-resolution transects for several water quality variables (chlorophyll a, suspended particulate matter and salinity) in San Francisco Bay (California, U.S.A.). Using these data, six different ways of choosing station locations along a transect, in order to estimate mean conditions, were compared. In addition, 11 approaches to estimating the variance of the transect mean when stations are equally spaced were compared, and the relationship between variance of the estimated transect mean and number of stations was determined. The results provide guidelines for sampling along the axis of an estuary: (1) choose as many equally-spaced stations as practical; (2) estimate the variance of the meanyby var (y)=(1/10n2)Σnj=2(yj−yj−1)2, wherey1, . . .,ynare the measurements at thenstations; and (3) attain the desired precision by adjusting the number of stations according to var(y)α1/n2. The inverse power of 2 in the last step is a consequence of the underlying spatial correlation structure in San Francisco Bay; more studies of spatial structure at other estuaries are needed to determine the generality of this relationship.
An approximately 8.5 m thick sequence of upper Viruan (upper Middle Ordovician) shales, mudstones, and limestones in an outcrop at Kyrkbäcken near Röstånga in W‐central Skåne contains 19 K‐bentonite beds, several of which are as much as 40–67 cm thick. Thirteen of these beds are in the upper part of the Sularp Fm., four in the Skagen Fm., and two questionable beds in the Mossen Fm. Evidence from macrofossils, chitinozoans, and conodonts are used for biostratigraphic age assessment of the K‐bentonite succession. Regional comparison of the sequence with those at Kinnekulle (Kullatorp), Koängen, and Tommarp suggests that its total stratigraphie thickness is smaller than those at the two former sites but the thicknesses of several of the Kyrkbacken ash beds are greater than those in similar stratigraphic positions in the other successions. The K‐bentonites at Kyrkbacken have a similar clay mineralogy and major and trace element composition as other Ordovician K‐bentonites, and these data indicate that the parental magma was of felsic, probably rhyolitic composition. Based on amphibole geoba‐rometry, the magma chamber is interpreted to have been at a depth of 14–20 km. The relatively large number of unusually thick ash beds of Middle Ordovician age makes the easily accessible Kyrkbäcken outcrop unique not only in Baltoscandia but, as far as we are aware, also on the entire northern hemisphere, and only one comparable exposure is known in the southern hemisphere, namely in the Precordillera of northern Argentina.
","language":"English","publisher":"Taylor & Francs","doi":"10.1080/11035899709546481","issn":"11035897","usgsCitation":"Bergstrom, S., Huff, W.D., Kolata, D.R., Yost, D.A., and Hart, C.P., 1997, A unique Middle Ordovician K-bentonite bed succession at Röstånga, S. Sweden: GFF, v. 119, no. 3, p. 231-244, https://doi.org/10.1080/11035899709546481.","productDescription":"14 p.","startPage":"231","endPage":"244","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":227968,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"119","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e60be4b0c8380cd4711b","contributors":{"authors":[{"text":"Bergstrom, Stig M.","contributorId":80832,"corporation":false,"usgs":true,"family":"Bergstrom","given":"Stig M.","affiliations":[],"preferred":false,"id":383469,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Huff, Warren D.","contributorId":90228,"corporation":false,"usgs":true,"family":"Huff","given":"Warren","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":383467,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kolata, Dennis R.","contributorId":79495,"corporation":false,"usgs":false,"family":"Kolata","given":"Dennis","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":383468,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Yost, Deborah A.","contributorId":29972,"corporation":false,"usgs":true,"family":"Yost","given":"Deborah","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":383465,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hart, Charles P. cphart@usgs.gov","contributorId":2603,"corporation":false,"usgs":true,"family":"Hart","given":"Charles","email":"cphart@usgs.gov","middleInitial":"P.","affiliations":[],"preferred":true,"id":383466,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019168,"text":"70019168 - 1997 - Recognition of maximum flooding events in mixed siliciclastic-carbonate systems: Key to global chronostratigraphic correlation","interactions":[],"lastModifiedDate":"2024-01-20T00:54:19.267571","indexId":"70019168","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Recognition of maximum flooding events in mixed siliciclastic-carbonate systems: Key to global chronostratigraphic correlation","docAbstract":"The maximum flooding event within a depositional sequence is an important datum for correlation because it represents a virtually synchronous horizon. This event is typically recognized by a distinctive physical surface and/or a significant change in microfossil assemblages (relative fossil abundance peaks) in siliciclastic deposits from shoreline to continental slope environments in a passive margin setting. Recognition of maximum flooding events in mixed siliciclastic-carbonate sediments is more complicated because the entire section usually represents deposition in continental shelf environments with varying rates of biologic and carbonate productivity versus siliciclastic influx. Hence, this event cannot be consistently identified simply by relative fossil abundance peaks. Factors such as siliciclastic input, carbonate productivity, sediment accumulation rates, and paleoenvironmental conditions dramatically affect the relative abundances of microfossils. Failure to recognize these complications can lead to a sequence stratigraphic interpretation that substantially overestimates the number of depositional sequences of 1 to 10 m.y. duration.
Field experiments were conducted to test the ability of ground-penetrating radar (GPR) to measure stream-channel cross sections at high flows without the necessity of placing instruments in the water. Experiments were conducted at four U.S. Geological Survey gaging stations in southwest Washington State. With the GPR antenna suspended above the water surface from a bridge or cableway, traverses were made across stream channels to collect radar profile plots of the streambed. Subsequent measurements of water depth were made using conventional depth-measuring equipment (weight and tape) and were used to calculate radar signal velocities. Other streamflow-parameter data were collected to examine their relation to radar signal velocity and to clarity of streambed definition. These initial tests indicate that GPR is capable of producing a reasonably accurate (±20%) stream-channel profile and discharge far more quickly than conventional stream-gaging procedures, while avoiding the problems and hazards associated with placing instruments in the water.
Existing methods for dynamic calibration of tipping-bucket rain gauges (TBRs) can be time consuming and labor intensive. A new automated dynamic calibration system has been developed to calibrate TBRs with minimal effort. The system consists of a programmable pump, datalogger, digital balance, and computer. Calibration is performed in two steps: 1) pump calibration and 2) rain gauge calibration. Pump calibration ensures precise control of water flow rates delivered to the rain gauge funnel; rain gauge calibration ensures precise conversion of bucket tip times to actual rainfall rates. Calibration of the pump and one rain gauge for 10 selected pump rates typically requires about 8 h. Data files generated during rain gauge calibration are used to compute rainfall intensities and amounts from a record of bucket tip times collected in the field.
The system was tested using 5 types of commercial TBRs (15.2-, 20.3-, and 30.5-cm diameters; 0.1-, 0.2-, and 1.0-mm resolutions) and using 14 TBRs of a single type (20.3-cm diameter; 0.1-mm resolution). Ten pump rates ranging from 3 to 154 mL min−1 were used to calibrate the TBRs and represented rainfall rates between 6 and 254 mm h−1 depending on the rain gauge diameter. All pump calibration results were very linear with R2 values greater than 0.99. All rain gauges exhibited large nonlinear underestimation errors (between 5% and 29%) that decreased with increasing rain gauge resolution and increased with increasing rainfall rate, especially for rates greater than 50 mm h−1. Calibration curves of bucket tip time against the reciprocal of the true pump rate for all rain gauges also were linear with R2 values of 0.99. Calibration data for the 14 rain gauges of the same type were very similar, as indicated by slope values that were within 14% of each other and ranged from about 367 to 417 s mm h−1. The developed system can calibrate TBRs efficiently, accurately, and virtually unattended and could be modified for use with other rain gauge designs. The system is now in routine use to calibrate TBRs in a large rainfall collection network at Yucca Mountain, Nevada.
","language":"English","publisher":"American Meteorological Society","doi":"10.1175/1520-0426(1997)014%3C1513:ANMFAD%3E2.0.CO;2","issn":"07390572","usgsCitation":"Humphrey, M., Istok, J., Lee, J., Hevesi, J., and Flint, A.L., 1997, A new method for automated dynamic calibration of tipping-bucket rain gauges: Journal of Atmospheric and Oceanic Technology, v. 14, no. 6, p. 1513-1519, https://doi.org/10.1175/1520-0426(1997)014%3C1513:ANMFAD%3E2.0.CO;2.","productDescription":"7 p.","startPage":"1513","endPage":"1519","numberOfPages":"7","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":226775,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"14","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e4a7e4b0c8380cd467ea","contributors":{"authors":[{"text":"Humphrey, M.D.","contributorId":63181,"corporation":false,"usgs":true,"family":"Humphrey","given":"M.D.","email":"","affiliations":[],"preferred":false,"id":381856,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Istok, J.D.","contributorId":34165,"corporation":false,"usgs":true,"family":"Istok","given":"J.D.","affiliations":[],"preferred":false,"id":381854,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lee, J.Y.","contributorId":20061,"corporation":false,"usgs":true,"family":"Lee","given":"J.Y.","email":"","affiliations":[],"preferred":false,"id":381853,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hevesi, J.A. 0000-0003-2898-1800","orcid":"https://orcid.org/0000-0003-2898-1800","contributorId":43320,"corporation":false,"usgs":true,"family":"Hevesi","given":"J.A.","affiliations":[],"preferred":false,"id":381855,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Flint, A. L.","contributorId":102453,"corporation":false,"usgs":true,"family":"Flint","given":"A.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":381857,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019163,"text":"70019163 - 1997 - Spatial and temporal variability in nutrient concentrations in surface waters of the Chattahoochee River basin near Atlanta, Georgia, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:19:16","indexId":"70019163","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1934,"text":"IAHS-AISH Publication","active":true,"publicationSubtype":{"id":10}},"title":"Spatial and temporal variability in nutrient concentrations in surface waters of the Chattahoochee River basin near Atlanta, Georgia, USA","docAbstract":"Nutrient concentrations from the early 1970s through 1995 were evaluated at several sites along the Chattahoochee River and its tributaries near Atlanta, to determine general patterns and processes controlling nutrient concentrations in the river. A spatial analysis was conducted on data collected in 1994 and 1995 from an intensive nutrient study of the Chattahoochee River and its tributaries by the Georgia Department of Natural Resources, Environmental Protection Division. The 1994-1995 data show step increases in ammonium (NH4-N), nitrite plus nitrate (NO2 + NO3-N), and total-phosphorus (Tot-P) concentrations in the river. The step increases occur downstream of two wastewater treatment facilities (WWTFs) and Peachtree Creek, a small tributary inflow with degraded water quality draining a predominantly urban and industrial area. Median NO2 + NO3-N and Tot-P concentrations in the mainstem increase downstream of these inputs from 0.5 to 1 mg 1-1 and from 0.04 to 0.13 mg 1-1, respectively. NH4-N concentrations were typically low with 95% of the 2575 observations less than 0.2 mg 1-1 throughout the river system, except some high values (>1 mg 1-1) in some tributaries, particularly near the central part of Atlanta. High NH4-N concentrations are attributed to sewage discharge as they also are associated with high biological oxygen demand and faecal coliform bacteria concentrations. Nutrient concentrations vary temporally. An assessment of four sites, two mainstem and two tributaries, from 1970 to 1995 indicates a progressive increase and variability in NO2 + NO3-N concentrations during the period. The progressive increase in NO2 + NO3-N concentrations and their variability is similar to that reported for surface waters throughout the world and for which increased fertilizer usage has been attributed. Tot-P concentrations increase at mainstem sites through the middle to late 1980s and decrease markedly thereafter, due to improvements to WWTFs and a 1990 phosphate detergent ban. NH4-N concentrations, although less pronounced than Tot-P, display a similar decrease from the late 1980s to 1995 at the four sites. Tot-P concentration variability has increased at the tributary sites since 1993, although recent concentrations, on average, are the lowest since 1970 at each of the four sites.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"IAHS-AISH Publication","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01447815","usgsCitation":"Peters, N., Buell, G.R., and Frick, E.A., 1997, Spatial and temporal variability in nutrient concentrations in surface waters of the Chattahoochee River basin near Atlanta, Georgia, USA: IAHS-AISH Publication, v. 243, p. 153-165.","startPage":"153","endPage":"165","numberOfPages":"13","costCenters":[],"links":[{"id":226774,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"243","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b944ee4b08c986b31a9c6","contributors":{"authors":[{"text":"Peters, N.E.","contributorId":33332,"corporation":false,"usgs":true,"family":"Peters","given":"N.E.","email":"","affiliations":[],"preferred":false,"id":381850,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Buell, G. R.","contributorId":57103,"corporation":false,"usgs":true,"family":"Buell","given":"G.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":381851,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Frick, E. A.","contributorId":61840,"corporation":false,"usgs":true,"family":"Frick","given":"E.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":381852,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019670,"text":"70019670 - 1997 - GSLIB-style programs for discriminant analysis and regionalized classification","interactions":[],"lastModifiedDate":"2013-01-21T13:14:07","indexId":"70019670","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1315,"text":"Computers & Geosciences","printIssn":"0098-3004","active":true,"publicationSubtype":{"id":10}},"title":"GSLIB-style programs for discriminant analysis and regionalized classification","docAbstract":"Discriminant analysis is a statistical technique used to predict the group membership of a set of multivariate observations, each of which is assumed to arise from one of a set of distinct classes or groups. Each group is characterized by a certain distribution in multivariate space, and group allocations are based on the similarity of each sample to each group. Assuming multivariate normality, generalized distance measures based on the squared Mahalanobis distance from each sample to each group centroid arise as the natural measure of similarity. One can allocate samples to groups either on the basis of minimum generalized distance or, equivalently, maximum posterior probability of group membership. In earth science applications samples are often associated with geographic locations. In this situation regionalized classification can be used to produce a map representing group membership throughout the sampled domain. This can be accomplished by interpolating either generalized distances or membership probabilities from sample locations to regularly spaced grid nodes and comparing resulting grids to produce a classification map. This paper presents a set of GSLIB-style FORTRAN programs for performing discriminant analysis and regionalized classification. The program disco performs discriminant analysis and the programs xmd2cls and prb2cls combine interpolated distances and probabilities, respectively, to create a grid of predicted classifications. In addition, the utility program colbind allows the user to combine selected columns from different GSLIB-style data files into one file. ?? 1997 Elsevier Science Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Computers and Geosciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/S0098-3004(97)00050-2","issn":"00983004","usgsCitation":"Bohling, G.C., 1997, GSLIB-style programs for discriminant analysis and regionalized classification: Computers & Geosciences, v. 23, no. 7, p. 739-761, https://doi.org/10.1016/S0098-3004(97)00050-2.","startPage":"739","endPage":"761","numberOfPages":"23","costCenters":[],"links":[{"id":228168,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266156,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0098-3004(97)00050-2"}],"volume":"23","issue":"7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a148fe4b0c8380cd54aa5","contributors":{"authors":[{"text":"Bohling, Geoffrey C.","contributorId":43109,"corporation":false,"usgs":false,"family":"Bohling","given":"Geoffrey","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":383509,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019160,"text":"70019160 - 1997 - The roles of time and displacement in velocity-dependent volumetric strain of fault zones","interactions":[],"lastModifiedDate":"2024-10-03T16:11:48.660896","indexId":"70019160","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"The roles of time and displacement in velocity-dependent volumetric strain of fault zones","docAbstract":"The relationship between measured friction μA and volumetric strain during frictional sliding was determined using a rate and state variable dependent friction constitutive equation, a common work balance relating friction and volume change, and two types of experimental faults: initially bare surfaces of Westerly granite and rock surfaces separated by a 1 mm layer of less than 90 μm Westerly granite gouge. The constitutive equation is the sum of a constant term representing the nominal resistance to sliding and two smaller terms: a rate dependent term representing the shear viscosity of the fault surface (direct effect), and a term which represents variations in the area of contact (evolution effect). The work balance relationship requires that μA differs from the frictional resistance that leads to shear heating by the derivative of fault normal displacement with respect shear displacement, dδn/dδs. An implication of this relationship is that the rate dependence of dδn/dδs contributes to the rate dependence of μA. Experiments show changes in sliding velocity lead to changes in both fault strength and volume. Analysis of data with the rate and state equations combined with the work balance relationship preclude the conventional interpretation of the direct effect in the rate and state variable constitutive equations. Consideration of a model bare surface fault consisting of an undeformable indentor sliding on a deformable surface reveals a serious flaw in the work balance relationship if volume change is time-dependent. For the model, at zero slip rate indentation creep under the normal load leads to time-dependent strengthening of the fault surface but, according to the work balance relationship, no work is done because compaction or dilatancy can only be induced by shearing. Additional tests on initially bare surfaces and gouges show that fault normal strain in experiments is time-dependent, consistent with the model. This time-dependent fault normal strain, which is not accounted for in the work balance relationship, explains the inconsistency between the constitutive equations and the work balance. For initially bare surface faults, all rate dependence of volume change is due to time dependence. Similar results are found for gouge. We conclude that μA reflects the frictional resistance that results in shear heating, and no correction needs to be made for the volume changes. The result that time-dependent volume changes do not contribute to μA is a general result and extends beyond these experiments, the simple indentor model and particular constitutive equations used to illustrate the principle.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JB01828","issn":"01480227","usgsCitation":"Beeler, N., and Tullis, T., 1997, The roles of time and displacement in velocity-dependent volumetric strain of fault zones: Journal of Geophysical Research B: Solid Earth, v. 102, no. B10, p. 22595-22609, https://doi.org/10.1029/97JB01828.","productDescription":"15p.","startPage":"22595","endPage":"22609","numberOfPages":"15","costCenters":[],"links":[{"id":480011,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97jb01828","text":"Publisher Index Page"},{"id":226728,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B10","noUsgsAuthors":false,"publicationDate":"1997-10-10","publicationStatus":"PW","scienceBaseUri":"505bafa9e4b08c986b324966","contributors":{"authors":[{"text":"Beeler, N.M. 0000-0002-3397-8481","orcid":"https://orcid.org/0000-0002-3397-8481","contributorId":68894,"corporation":false,"usgs":true,"family":"Beeler","given":"N.M.","affiliations":[],"preferred":false,"id":381840,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tullis, T.E.","contributorId":91252,"corporation":false,"usgs":true,"family":"Tullis","given":"T.E.","email":"","affiliations":[],"preferred":false,"id":381841,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019152,"text":"70019152 - 1997 - Permo-Carboniferous sedimentary basins related to the distribution of planetary cryptoblemes","interactions":[],"lastModifiedDate":"2012-03-12T17:19:15","indexId":"70019152","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3108,"text":"Prace - Panstwowego Instytutu Geologicznego","active":true,"publicationSubtype":{"id":10}},"title":"Permo-Carboniferous sedimentary basins related to the distribution of planetary cryptoblemes","docAbstract":"Massive/high velocity solar, galactic, and cosmic debris impacting the Earths surface may account for the enormous energy required for the formation of Permo-Carboniferous sedimentary basins and related mountain building orogenies. Analysis of satellite immagry, sea floor sonar, geophysical data, and geotectonic fabrics show a strong correlation throughout geologic time between sedimentary basin origin and planetary cryptoblemes. Cryptoblemes are subtile, multi-ringed, radial centric impact shock signatures covering the entire terrestrial surface and ocean floors, having a geometry and distribution strikingly similar to the surfaces of the lunar planetary bodies in the solar system. Investigations of Permo-Carboniferous basins show an intensely overprinted pattern of cryptoblemes coinciding with partial obliteration and elliptical compression of pre-existing basins and accompanying shock patterns. Large distorted cryptoblemes may incorporate thin skin deformation, localized sediment diagenesis, regional metamorphism, and juxtaposed exotic terrains. These data, related to basin morphogenic symmetry, suggest that large episodic impact events are the primary cause of tectonogenic features, geologic boundary formation and mass extinction episodes on the planet Earth. Plate tectonics may be only a slow moving, low energy secondary effect defined and set in motion by megacosmic accretion events. Permo-Carboniferous sediments of note are preserved or accumulated in relatively small rectangular to arcuate rift valleys and synclinal down warps, such as the Narraganset basin of Massachusetts, USA, and Paganzo basin in Argentina, S.A. These deposits and depocenters may originate from dynamic reinforcement/cancellation impact effects, as can be seen in the Basin Range of Nevada and Utah, USA. Large circular to oval sedimentary basins commonly include internal ring structures indicating post depositional subsidence and rebound adjustments with growth faulting, notable in the Illinois basin USA and Ordos basin in China. Recent impact events on the planet Jupiter, July 1994, lend increasing support towards an impact orogenic geologic paradigm on the planet Earth.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Prace - Panstwowego Instytutu Geologicznego","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"08669465","usgsCitation":"Windolph, J., 1997, Permo-Carboniferous sedimentary basins related to the distribution of planetary cryptoblemes: Prace - Panstwowego Instytutu Geologicznego, v. 157, p. 87-89.","startPage":"87","endPage":"89","numberOfPages":"3","costCenters":[],"links":[{"id":226583,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"157","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a76dce4b0c8380cd7834f","contributors":{"authors":[{"text":"Windolph, J. F. Jr.","contributorId":96256,"corporation":false,"usgs":true,"family":"Windolph","given":"J. F.","suffix":"Jr.","affiliations":[],"preferred":false,"id":381821,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019150,"text":"70019150 - 1997 - The forms of trace metals in an Illinois basin coal by x-ray absorption fine structure spectroscopy","interactions":[],"lastModifiedDate":"2012-03-12T17:19:15","indexId":"70019150","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":611,"text":"ACS Division of Fuel Chemistry, Preprints","active":true,"publicationSubtype":{"id":10}},"title":"The forms of trace metals in an Illinois basin coal by x-ray absorption fine structure spectroscopy","docAbstract":"Utilities burning Illinois coals currently do not consider trace elements in their flue gas emissions. After the US EPA completes an investigation on trace elements, however, this may change and flue gas emission standards may be established. The mode of occurrence of a trace element may determine its cleanability and Hue gas emission potential. X-ray Absorption Fine Structure (XAFS) is a spectroscopic technique that can differentiate the mode of occurrence of an element, even at the low concentrations that trace elements are found in coal. This is principally accomplished by comparing the XAFS spectra of a coal to a database of reference sample spectra. This study evaluated the technique as a potential tool to examine six trace elements in an Illinois #6 coal. For the elements As and Zn, the present database provides a definitive interpretation on their mode of occurrence. For the elements Ti, V, Cr, and Mn the database of XAFS spectra of trace elements in coal was still too limited to allow a definitive interpretation. The data obtained on these elements, however, was sufficient to rule out several of the mineralogical possibilities that have been suggested previously. The results indicate that XAFS is a promising technique for the study of trace elements in coal.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"ACS Division of Fuel Chemistry, Preprints","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"05693772","usgsCitation":"Chou, I., Bruinius, J., Lytle, J., Ruch, R., Huggins, F.E., Huffman, G., and Ho, K., 1997, The forms of trace metals in an Illinois basin coal by x-ray absorption fine structure spectroscopy: ACS Division of Fuel Chemistry, Preprints, v. 42, no. 4, p. 1113-1116.","startPage":"1113","endPage":"1116","numberOfPages":"4","costCenters":[],"links":[{"id":226540,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"42","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bac25e4b08c986b3232ce","contributors":{"authors":[{"text":"Chou, I.-M. 0000-0001-5233-6479","orcid":"https://orcid.org/0000-0001-5233-6479","contributorId":44283,"corporation":false,"usgs":true,"family":"Chou","given":"I.-M.","affiliations":[{"id":245,"text":"Eastern Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":381814,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bruinius, J.A.","contributorId":7072,"corporation":false,"usgs":true,"family":"Bruinius","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":381811,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lytle, J.M.","contributorId":82072,"corporation":false,"usgs":true,"family":"Lytle","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":381817,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ruch, R.R.","contributorId":80804,"corporation":false,"usgs":true,"family":"Ruch","given":"R.R.","email":"","affiliations":[],"preferred":false,"id":381815,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Huggins, Frank E.","contributorId":81273,"corporation":false,"usgs":true,"family":"Huggins","given":"Frank","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":381816,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Huffman, G.P.","contributorId":12232,"corporation":false,"usgs":true,"family":"Huffman","given":"G.P.","email":"","affiliations":[],"preferred":false,"id":381812,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Ho, K.K.","contributorId":30768,"corporation":false,"usgs":true,"family":"Ho","given":"K.K.","email":"","affiliations":[],"preferred":false,"id":381813,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70019146,"text":"70019146 - 1997 - Land cover mapping, fire regeneration, and scaling studies in the Canadian boreal forest with 1 km AVHRR and Landsat TM data","interactions":[],"lastModifiedDate":"2017-04-07T14:59:54","indexId":"70019146","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2316,"text":"Journal of Geophysical Research D: Atmospheres","active":true,"publicationSubtype":{"id":10}},"title":"Land cover mapping, fire regeneration, and scaling studies in the Canadian boreal forest with 1 km AVHRR and Landsat TM data","docAbstract":"A multitemporal 1 km advanced very high resolution radiometer (AVHRR) land cover analysis approach was used as the basis for regional land cover mapping, fire disturbance-regeneration, and multiresolution land cover scaling studies in the boreal forest ecosystem of central Canada. The land cover classification was developed by using regional field observations from ground and low-level aircraft transits to analyze spectral-temporal clusters that were derived from an unsupervised cluster analysis of monthly normalized difference vegetation index (NDVI) image composites (April-September 1992). Quantitative areal proportions of the major boreal forest components were determined for a 821 km ?? 619 km region, ranging from the southern grasslands-boreal forest ecotone to the northern boreal transitional forest. The boreal wetlands (mostly lowland black spruce, tamarack, mosses, fens, and bogs) occupied approximately 33% of the region, while lakes accounted for another 13%. Upland mixed coniferous-deciduous forests represented 23% of the ecosystem. A SW-NE productivity gradient across the region is manifested by three levels of tree stand density for both the boreal wetland conifer and the mixed forest classes, which are generally aligned with isopleths of regional growing degree days. Approximately 30% of the region was directly affected by fire disturbance within the preceding 30-35 years, especially in the Canadian Shield Zone where large fire-regeneration patterns contribute to the heterogeneous boreal landscape. Intercomparisons with land cover classifications derived from 30-m Landsat Thematic Mapper (TM) data provided important insights into the relative accuracy of the 1 km AVHRR land cover classification. Primarily due to the multitemporal NDVI image compositing process, the 1 km AVHRR land cover classes have an effective spatial resolution in the 3-4 km range; therefore fens, bogs, small water bodies, and small patches of dry jack pine cannot be resolved within the wet conifer mosaic. Major differences in the 1-km AVHRR and 30-m Landsat TM-derived land cover classes are most likely due to differences in the spatial resolution of the data sets. In general, the 1 km AVHRR land cover classes are vegetation mosaics consisting of mixed combinations of the Landsat classes. Detailed mapping of the global boreal forest with this approach will benefit from algorithms for cloud screening and to atmospherically correct reflectance data for both aerosol and water vapor effects. We believe that this 1 km AVHRR land cover analysis provides new and useful information for regional water, energy, carbon, and trace gases studies in BOREAS, especially given the significant spatial variability in land cover type and associated biophysical land cover parameters (e.g., albedo, leaf area index, FPAR, and surface roughness). Multiresolution land cover comparisons (30 m, 1 km, and 100 km grid cells) also illustrated how heterogeneous landscape patterns are represented in land cover maps with differing spatial scales and provided insights on the requirements and challenges for parameterizing landscape heterogeneity as part of land surface process research.","language":"English","publisher":"AGU","doi":"10.1029/97JD01220","issn":"01480227","usgsCitation":"Steyaert, L.T., Hall, F., and Loveland, T., 1997, Land cover mapping, fire regeneration, and scaling studies in the Canadian boreal forest with 1 km AVHRR and Landsat TM data: Journal of Geophysical Research D: Atmospheres, v. 102, no. 24, p. 29581-29598, https://doi.org/10.1029/97JD01220.","productDescription":"18 p.","startPage":"29581","endPage":"29598","numberOfPages":"18","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":226457,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"24","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a41a8e4b0c8380cd656b8","contributors":{"authors":[{"text":"Steyaert, L. T.","contributorId":71303,"corporation":false,"usgs":true,"family":"Steyaert","given":"L.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":381800,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hall, F.G.","contributorId":47099,"corporation":false,"usgs":true,"family":"Hall","given":"F.G.","email":"","affiliations":[],"preferred":false,"id":381799,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Loveland, Thomas R. 0000-0003-3114-6646","orcid":"https://orcid.org/0000-0003-3114-6646","contributorId":106125,"corporation":false,"usgs":true,"family":"Loveland","given":"Thomas R.","affiliations":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"preferred":false,"id":381801,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020230,"text":"70020230 - 1997 - Field-scale tests for determining mixing patterns associated with coarse-bubble air diffuser configurations, Egan Quarry, Illinois","interactions":[],"lastModifiedDate":"2018-02-06T12:21:27","indexId":"70020230","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Field-scale tests for determining mixing patterns associated with coarse-bubble air diffuser configurations, Egan Quarry, Illinois","docAbstract":"The U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers, Chicago District did field-scale tests in August-September 1996 to determine mixing patterns associated with different configurations of coarse-bubble air diffusers. The tests were done in an approximately 13-meter deep quarry near Chicago, Ill. Three-dimensional velocity, water-temperature, dissolved oxygen concentration, and specific-conductivity profiles were collected from locations between approximately 2 to 30 meters from the diffusers for two sets of five test configurations; one set for stratified and one set for destratified conditions in the quarry. The data-collection methods and instrumentation used to characterize mixing patterns and interactions of coarse-bubble diffusers were successful. An extensive data set was collected and is available to calibrate and verify aeration and stratification models, and to characterize basic features of bubble-plume interaction.","largerWorkTitle":"Proceedings, Congress of the International Association of Hydraulic Research, IAHR","conferenceTitle":"Proceedings of the 1997 27th Congress of the International Association of Hydraulic Research, IAHR. Part D","conferenceDate":"10 August 1997 through 15 August 1997","conferenceLocation":"San Francisco, CA, USA","language":"English","publisher":"ASCE","publisherLocation":"New York, NY, United States","usgsCitation":"Hornewer, N., Johnson, G., Robertson, D.M., and Hondzo, M., 1997, Field-scale tests for determining mixing patterns associated with coarse-bubble air diffuser configurations, Egan Quarry, Illinois, in Proceedings, Congress of the International Association of Hydraulic Research, IAHR, v. B pt 1, San Francisco, CA, USA, 10 August 1997 through 15 August 1997, p. 57-63.","startPage":"57","endPage":"63","numberOfPages":"7","costCenters":[],"links":[{"id":231285,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"B pt 1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0fefe4b0c8380cd53a8c","contributors":{"authors":[{"text":"Hornewer, Nancy J.","contributorId":57895,"corporation":false,"usgs":true,"family":"Hornewer","given":"Nancy J.","affiliations":[],"preferred":false,"id":385461,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnson, G.P.","contributorId":34554,"corporation":false,"usgs":true,"family":"Johnson","given":"G.P.","affiliations":[],"preferred":false,"id":385459,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Robertson, Dale M. 0000-0001-6799-0596 dzrobert@usgs.gov","orcid":"https://orcid.org/0000-0001-6799-0596","contributorId":150760,"corporation":false,"usgs":true,"family":"Robertson","given":"Dale","email":"dzrobert@usgs.gov","middleInitial":"M.","affiliations":[{"id":37947,"text":"Upper Midwest Water Science Center","active":true,"usgs":true}],"preferred":true,"id":385460,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hondzo, Miki","contributorId":11816,"corporation":false,"usgs":false,"family":"Hondzo","given":"Miki","email":"","affiliations":[{"id":12693,"text":"Department of Civil, Environmental, and Geo- Engineering and St. Anthony Falls Laboratory, Minneapolis, MN","active":true,"usgs":false}],"preferred":false,"id":385458,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019139,"text":"70019139 - 1997 - Analysis of environmental data with censored observations","interactions":[],"lastModifiedDate":"2019-02-14T06:36:53","indexId":"70019139","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Analysis of environmental data with censored observations","docAbstract":"The potential threats to humans and to terrestrial and aquatic ecosystems from environmental contamination could depend on the sum of the concentrations of different chemicals. However, direct summation of environmental data is not generally feasible because it is common for some chemical concentrations to be recorded as being below the analytical reporting limit. This creates special problems in the analysis of the data. A new model selection procedure, named forward censored regression, is introduced for selecting an appropriate model for environmental data with censored observations. The procedure is demonstrated using concentrations of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), deethylatrazine (DEA, 2-amino-4-chloro-6-isopropylamino-s-triazine), and deisopropylatrazine (DIA, 2-amino-4-chloro-6-ethylamino-s-triazine) in groundwater in the midwestern United States by using the data derived from a previous study conducted by the U.S. Geological Survey. More than 80% of the observations for each compound for this study were left censored at 0.05 μg/L. The values for censored observations of atrazine, DEA, and DIA are imputed with the selected models. The summation of atrazine residue (atrazine + DEA + DIA) can then be calculated using the combination of observed and imputed values to generate a pseudo-complete data set. The all-subsets regression procedure is applied to the pseudo-complete data to select the final model for atrazine residue. The methodology presented can be used to analyze similar cases of environmental contamination involving censored data.
","language":"English","publisher":"ACS","doi":"10.1021/es960695x","issn":"0013936X","usgsCitation":"Liu, S., Lu, J., Kolpin, D., and Meeker, W., 1997, Analysis of environmental data with censored observations: Environmental Science & Technology, v. 31, no. 12, p. 3358-3362, https://doi.org/10.1021/es960695x.","productDescription":"5 p.","startPage":"3358","endPage":"3362","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":480108,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1318&context=stat_las_pubs","text":"External Repository"},{"id":205715,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es960695x"},{"id":226364,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -81.298828125, 41.705728515237524 ], [ -80.52978515625, 41.36031866306708 ], [ -80.52978515625, 40.613952441166596 ], [ -81.49658203125, 40.195659093364654 ], [ -81.8701171875, 39.825413103424786 ], [ -82.9248046875, 39.35129035526705 ], [ -83.78173828125, 39.30029918615029 ], [ -84.83642578125, 39.14710270770074 ], [ -85.53955078125, 38.788345355085625 ], [ -85.97900390625, 38.496593518947556 ], [ -86.37451171875, 38.11727165830543 ], [ -86.66015624999999, 37.89219554724437 ], [ -86.923828125, 38.013476231041935 ], [ -87.0556640625, 37.78808138412046 ], [ -87.42919921875, 37.89219554724437 ], [ -87.890625, 37.80544394934274 ], [ -88.11035156249999, 37.579412513438385 ], [ -88.08837890625, 37.474858084971046 ], [ -88.43994140625, 37.33522435930641 ], [ -88.3740234375, 37.055177106660814 ], [ -88.72558593749999, 37.03763967977139 ], [ -88.9892578125, 37.142803443716836 ], [ -88.96728515624999, 36.932330061503144 ], [ -89.6044921875, 37.19533058280065 ], [ -89.47265625, 37.37015718405753 ], [ -89.53857421875, 37.61423141542417 ], [ -89.97802734375, 37.94419750075404 ], [ -90.41748046874999, 38.20365531807149 ], [ -91.12060546875, 38.013476231041935 ], [ -92.1533203125, 37.90953361677018 ], [ -93.01025390625, 37.96152331396616 ], [ -93.80126953124999, 37.96152331396616 ], [ -94.5703125, 38.20365531807149 ], [ -94.68017578125, 38.70265930723801 ], [ -94.921875, 39.06184913429154 ], [ -95.2734375, 39.707186656826565 ], [ -95.44921875, 39.8928799002948 ], [ -101.2060546875, 39.926588421909436 ], [ -101.42578124999999, 40.3130432088809 ], [ -101.66748046874999, 40.64730356252251 ], [ -102.0849609375, 40.979898069620155 ], [ -102.041015625, 41.27780646738183 ], [ -100.96435546875, 42.114523952464246 ], [ -100.107421875, 42.66628070564928 ], [ -99.55810546875, 42.97250158602597 ], [ -98.81103515625, 43.42100882994726 ], [ -97.119140625, 43.75522505306928 ], [ -96.591796875, 43.8186748554532 ], [ -96.65771484375, 44.512176171071054 ], [ -96.61376953125, 45.22848059584359 ], [ -96.96533203125, 45.61403741135093 ], [ -98.26171875, 45.85941212790755 ], [ -98.37158203125, 46.10370875598026 ], [ -97.71240234375, 46.13417004624326 ], [ -95.5810546875, 46.604167162931844 ], [ -95.29541015625, 46.33175800051563 ], [ -92.724609375, 45.62940492064501 ], [ -91.7578125, 45.42929873257377 ], [ -90.94482421875, 45.042478050891546 ], [ -89.9560546875, 44.762336674810996 ], [ -89.14306640625, 44.731125592643274 ], [ -88.4619140625, 44.55916341529184 ], [ -88.0224609375, 44.33956524809713 ], [ -87.5830078125, 44.15068115978091 ], [ -87.91259765625, 43.89789239125797 ], [ -88.13232421875, 43.628123412124616 ], [ -88.1982421875, 43.14909399920127 ], [ -88.1982421875, 42.293564192170095 ], [ -88.00048828124999, 41.78769700539063 ], [ -87.60498046875, 41.393294288784865 ], [ -86.72607421875, 41.50857729743935 ], [ -86.0009765625, 41.902277040963696 ], [ -85.93505859374999, 42.48830197960227 ], [ -86.1328125, 42.85985981506279 ], [ -86.484375, 43.35713822211053 ], [ -86.2646484375, 43.51668853502909 ], [ -85.62744140625, 43.51668853502909 ], [ -85.25390625, 43.43696596521823 ], [ -84.39697265625, 43.37311218382002 ], [ -83.56201171875, 43.35713822211053 ], [ -83.03466796874999, 43.35713822211053 ], [ -82.96875, 43.02071359427862 ], [ -83.1884765625, 42.81152174509788 ], [ -83.3642578125, 42.391008609205045 ], [ -83.69384765625, 41.918628865183045 ], [ -83.56201171875, 41.64007838467894 ], [ -83.25439453125, 41.64007838467894 ], [ -82.7490234375, 41.393294288784865 ], [ -82.30957031249999, 41.393294288784865 ], [ -81.84814453125, 41.492120839687786 ], [ -81.298828125, 41.705728515237524 ] ] ] } } ] }","volume":"31","issue":"12","noUsgsAuthors":false,"publicationDate":"1997-11-26","publicationStatus":"PW","scienceBaseUri":"5059eb11e4b0c8380cd48bc8","contributors":{"authors":[{"text":"Liu, S.","contributorId":93170,"corporation":false,"usgs":true,"family":"Liu","given":"S.","affiliations":[],"preferred":false,"id":381787,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lu, J.-C.","contributorId":104642,"corporation":false,"usgs":true,"family":"Lu","given":"J.-C.","email":"","affiliations":[],"preferred":false,"id":381788,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kolpin, D.W.","contributorId":87565,"corporation":false,"usgs":true,"family":"Kolpin","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":381786,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Meeker, W.Q.","contributorId":43117,"corporation":false,"usgs":true,"family":"Meeker","given":"W.Q.","email":"","affiliations":[],"preferred":false,"id":381785,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019137,"text":"70019137 - 1997 - Ophiolitic basement to the Great Valley forearc basin, California, from seismic and gravity data: Implications for crustal growth at the North American continental margin","interactions":[],"lastModifiedDate":"2020-05-05T14:21:14.37421","indexId":"70019137","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Ophiolitic basement to the Great Valley forearc basin, California, from seismic and gravity data: Implications for crustal growth at the North American continental margin","docAbstract":"The nature of the Great Valley basement, whether oceanic or continental, has long been a source of controversy. A velocity model (derived from a 200-km-long east-west reflection-refraction profile collected south of the Mendocino triple junction, northern California, in 1993), further constrained by density and magnetic models, reveals an ophiolite underlying the Great Valley (Great Valley ophiolite), which in turn is underlain by a westward extension of lower-density continental crust (Sierran affinity material). We used an integrated modeling philosophy, first modeling the seismic-refraction data to obtain a final velocity model, and then modeling the long-wavelength features of the gravity data to obtain a final density model that is constrained in the upper crust by our velocity model. The crustal section of Great Valley ophiolite is 7-8 km thick, and the Great Valley ophiolite relict oceanic Moho is at 11-16 km depth. The Great Valley ophiolite does not extend west beneath the Coast Ranges, but only as far as the western margin of the Great Valley, where the 5-7-km-thick Great Valley ophiolite mantle section dips west into the present-day mantle. There are 16-18 km of lower-density Sierran affinity material beneath the Great Valley ophiolite mantle section, such that a second, deeper, \"present-day\" continental Moho is at about 34 km depth. At mid-crustal depths, the boundary between the eastern extent of the Great Valley ophiolite and the western extent of Sierran affinity material is a near-vertical velocity and density discontinuity about 80 km east of the western margin of the Great Valley. Our model has important implications for crustal growth at the North American continental margin. We suggest that a thick ophiolite sequence was obducted onto continental material, probably during the Jurassic Nevadan orogeny, so that the Great Valley basement is oceanic crust above oceanic mantle vertically stacked above continental crust and continental mantle.","largerWorkTitle":"","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1997)109<1536:OBTTGV>2.3.CO;2","issn":"00167606","usgsCitation":"Godfrey, N.J., Beaudoin, B.C., Klemperer, S., Levander, A., Luetgert, J., Meltzer, A., Mooney, W.D., and Trehu, A., 1997, Ophiolitic basement to the Great Valley forearc basin, California, from seismic and gravity data: Implications for crustal growth at the North American continental margin: Geological Society of America Bulletin, v. 109, no. 12, p. 1536-1562, https://doi.org/10.1130/0016-7606(1997)109<1536:OBTTGV>2.3.CO;2.","productDescription":"27 p.","startPage":"1536","endPage":"1562","numberOfPages":"27","costCenters":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"links":[{"id":226319,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\"type\":\"FeatureCollection\",\"features\":[{\"type\":\"Feature\",\"geometry\":{\"type\":\"MultiPolygon\",\"coordinates\":[[[[-122.421439,37.869969],[-122.41847,37.852721],[-122.434403,37.852434],[-122.446316,37.861046],[-122.430958,37.872242],[-122.421439,37.869969]]],[[[-122.3785,37.826505],[-122.377879,37.830648],[-122.369941,37.832137],[-122.358779,37.814278],[-122.362661,37.807577],[-122.372422,37.811301],[-122.3785,37.826505]]],[[[-120.248484,33.999329],[-120.230001,34.010136],[-120.19578,34.004284],[-120.167306,34.008219],[-120.147647,34.024831],[-120.140362,34.025974],[-120.115058,34.019866],[-120.090182,34.019806],[-120.073609,34.024477],[-120.057637,34.03734],[-120.043259,34.035806],[-120.050382,34.013331],[-120.046575,34.000002],[-120.011123,33.979894],[-119.978876,33.983081],[-119.979913,33.969623],[-119.97026,33.944359],[-120.017715,33.936366],[-120.048611,33.915775],[-120.098601,33.907853],[-120.121817,33.895712],[-120.168974,33.91909],[-120.224461,33.989059],[-120.248484,33.999329]]],[[[-119.789798,34.05726],[-119.755521,34.056716],[-119.712576,34.043265],[-119.686507,34.019805],[-119.637742,34.013178],[-119.612226,34.021256],[-119.604287,34.031561],[-119.608798,34.035245],[-119.59324,34.049625],[-119.5667,34.053452],[-119.52064,34.034262],[-119.542449,34.021082],[-119.547072,34.005469],[-119.560464,33.99553],[-119.575636,33.996009],[-119.596877,33.988611],[-119.662825,33.985889],[-119.721206,33.959583],[-119.742966,33.963877],[-119.758141,33.959212],[-119.842748,33.97034],[-119.873358,33.980375],[-119.884896,34.008814],[-119.876329,34.032087],[-119.916216,34.058351],[-119.923337,34.069361],[-119.919155,34.07728],[-119.912857,34.077508],[-119.857304,34.071298],[-119.825865,34.059794],[-119.818742,34.052997],[-119.789798,34.05726]]],[[[-120.46258,34.042627],[-120.440248,34.036918],[-120.415287,34.05496],[-120.403613,34.050442],[-120.390906,34.051994],[-120.368813,34.06778],[-120.370176,34.074907],[-120.362251,34.073056],[-120.354982,34.059256],[-120.36029,34.05582],[-120.358608,34.050235],[-120.346946,34.046576],[-120.331161,34.049097],[-120.302122,34.023574],[-120.317052,34.018837],[-120.347706,34.020114],[-120.35793,34.015029],[-120.409368,34.032198],[-120.427408,34.025425],[-120.454134,34.028081],[-120.465329,34.038448],[-120.46258,34.042627]]],[[[-118.524531,32.895488],[-118.535823,32.90628],[-118.551134,32.945155],[-118.573522,32.969183],[-118.586928,33.008281],[-118.596037,33.015357],[-118.606559,33.01469],[-118.605534,33.030999],[-118.594033,33.035951],[-118.57516,33.033961],[-118.569013,33.029151],[-118.559171,33.006291],[-118.540069,32.980933],[-118.496811,32.933847],[-118.369984,32.839273],[-118.353504,32.821962],[-118.356541,32.817311],[-118.379968,32.824545],[-118.394565,32.823978],[-118.425634,32.800595],[-118.44492,32.820593],[-118.496298,32.851572],[-118.507193,32.876264],[-118.524531,32.895488]]],[[[-118.500212,33.449592],[-118.477646,33.448392],[-118.445812,33.428907],[-118.423576,33.427258],[-118.382037,33.409883],[-118.370323,33.409285],[-118.365094,33.388374],[-118.310213,33.335795],[-118.303174,33.320264],[-118.305084,33.310323],[-118.325244,33.299075],[-118.374768,33.320065],[-118.440047,33.318638],[-118.465368,33.326056],[-118.48877,33.356649],[-118.478465,33.38632],[-118.48875,33.419826],[-118.515914,33.422417],[-118.52323,33.430733],[-118.53738,33.434608],[-118.563442,33.434381],[-118.60403,33.47654],[-118.54453,33.474119],[-118.500212,33.449592]]],[[[-119.543842,33.280329],[-119.528141,33.284929],[-119.465717,33.259239],[-119.429559,33.228167],[-119.444269,33.21919],[-119.476029,33.21552],[-119.545872,33.233406],[-119.564971,33.24744],[-119.578942,33.278628],[-119.562042,33.271129],[-119.543842,33.280329]]],[[[-122.289533,42.007764],[-121.035195,41.993323],[-120.001058,41.995139],[-119.995926,40.499901],[-120.005743,39.228664],[-120.001014,38.999574],[-119.333423,38.538328],[-118.714312,38.102185],[-117.875927,37.497267],[-117.244917,37.030244],[-116.488233,36.459097],[-115.852908,35.96966],[-115.102881,35.379371],[-114.633013,35.002085],[-114.629015,34.986148],[-114.634953,34.958918],[-114.629753,34.938684],[-114.635176,34.875003],[-114.623939,34.859738],[-114.586842,34.835672],[-114.57101,34.794294],[-114.552682,34.766871],[-114.516619,34.736745],[-114.470477,34.711368],[-114.452628,34.668546],[-114.451753,34.654321],[-114.441465,34.64253],[-114.438739,34.621455],[-114.424202,34.610453],[-114.429747,34.591734],[-114.422382,34.580711],[-114.405228,34.569637],[-114.380838,34.529724],[-114.378124,34.507288],[-114.386699,34.457911],[-114.375789,34.447798],[-114.335372,34.450038],[-114.32613,34.437251],[-114.294836,34.421389],[-114.286802,34.40534],[-114.264317,34.401329],[-114.226107,34.365916],[-114.199482,34.361373],[-114.176909,34.349306],[-114.157206,34.317862],[-114.138282,34.30323],[-114.134768,34.268965],[-114.139055,34.259538],[-114.159697,34.258242],[-114.223384,34.205136],[-114.229715,34.186928],[-114.254141,34.173831],[-114.287294,34.170529],[-114.320777,34.138635],[-114.353031,34.133121],[-114.366521,34.118575],[-114.390565,34.110084],[-114.411681,34.110031],[-114.43338,34.088413],[-114.43934,34.057893],[-114.434949,34.037784],[-114.438266,34.022609],[-114.46283,34.008421],[-114.46117,33.994687],[-114.499883,33.961789],[-114.522002,33.955623],[-114.535478,33.934651],[-114.533679,33.926072],[-114.508558,33.906098],[-114.518555,33.889847],[-114.50434,33.876882],[-114.503017,33.867998],[-114.514673,33.858638],[-114.52453,33.858477],[-114.529597,33.848063],[-114.520465,33.827778],[-114.527161,33.816191],[-114.504863,33.760465],[-114.504483,33.750998],[-114.512348,33.734214],[-114.496565,33.719155],[-114.494197,33.707922],[-114.495719,33.698454],[-114.523959,33.685879],[-114.531523,33.675108],[-114.525201,33.661583],[-114.530244,33.65014],[-114.526947,33.637534],[-114.529662,33.622794],[-114.524813,33.611351],[-114.540617,33.591412],[-114.5403,33.580615],[-114.524391,33.553683],[-114.558898,33.531819],[-114.560552,33.518272],[-114.569533,33.509219],[-114.591554,33.499443],[-114.622918,33.456561],[-114.627125,33.433554],[-114.635183,33.422726],[-114.652828,33.412922],[-114.687953,33.417944],[-114.701732,33.408388],[-114.725535,33.404056],[-114.708408,33.384147],[-114.698035,33.352442],[-114.707962,33.323421],[-114.731223,33.302434],[-114.723259,33.288079],[-114.684363,33.276025],[-114.672401,33.26047],[-114.689421,33.24525],[-114.674479,33.225504],[-114.678749,33.203448],[-114.675831,33.18152],[-114.679359,33.159519],[-114.703682,33.113769],[-114.706488,33.08816],[-114.68902,33.084036],[-114.686991,33.070969],[-114.674296,33.057171],[-114.673659,33.041897],[-114.662317,33.032671],[-114.64598,33.048903],[-114.618788,33.027202],[-114.589778,33.026228],[-114.575161,33.036542],[-114.52013,33.029984],[-114.502871,33.011153],[-114.492938,32.971781],[-114.476156,32.975168],[-114.467664,32.966861],[-114.469113,32.952673],[-114.48074,32.937027],[-114.47664,32.923628],[-114.462929,32.907944],[-114.468971,32.845155],[-114.494116,32.823288],[-114.510217,32.816417],[-114.530755,32.793485],[-114.532432,32.776923],[-114.526856,32.757094],[-114.539093,32.756949],[-114.539224,32.749812],[-114.564447,32.749554],[-114.564508,32.742298],[-114.581736,32.742321],[-114.581784,32.734946],[-114.612697,32.734516],[-114.618373,32.728245],[-114.688779,32.737675],[-114.701918,32.745548],[-114.719633,32.718763],[-116.04662,32.623353],[-117.124862,32.534156],[-117.136664,32.618754],[-117.168866,32.671952],[-117.196767,32.688851],[-117.213068,32.687751],[-117.236239,32.671353],[-117.246069,32.669352],[-117.25757,32.72605],[-117.25257,32.752949],[-117.25497,32.786948],[-117.26107,32.803148],[-117.280971,32.822247],[-117.28217,32.839547],[-117.27387,32.851447],[-117.26497,32.848947],[-117.25617,32.859447],[-117.25167,32.874346],[-117.25447,32.900146],[-117.28077,33.012343],[-117.315278,33.093504],[-117.328359,33.121842],[-117.362572,33.168437],[-117.469794,33.296417],[-117.50565,33.334063],[-117.547693,33.365491],[-117.59588,33.386629],[-117.607905,33.406317],[-117.645582,33.440728],[-117.684584,33.461927],[-117.691984,33.456627],[-117.715349,33.460556],[-117.726486,33.483427],[-117.784888,33.541525],[-117.814188,33.552224],[-117.840289,33.573523],[-117.87679,33.592322],[-117.927091,33.605521],[-117.940591,33.620021],[-118.000593,33.654319],[-118.029694,33.676418],[-118.088896,33.729817],[-118.132698,33.753217],[-118.180831,33.763072],[-118.187701,33.749218],[-118.181367,33.717367],[-118.207476,33.716905],[-118.258687,33.703741],[-118.317205,33.712818],[-118.360505,33.736817],[-118.385006,33.741417],[-118.396606,33.735917],[-118.411211,33.741985],[-118.428407,33.774715],[-118.405007,33.800215],[-118.394376,33.804289],[-118.392107,33.840915],[-118.460611,33.969111],[-118.482729,33.995912],[-118.519514,34.027509],[-118.543115,34.038508],[-118.569235,34.04164],[-118.609652,34.036424],[-118.668358,34.038887],[-118.706215,34.029383],[-118.744952,34.032103],[-118.783433,34.021543],[-118.805114,34.001239],[-118.854653,34.034215],[-118.928048,34.045847],[-118.938081,34.043383],[-119.004644,34.066231],[-119.037494,34.083111],[-119.088536,34.09831],[-119.109784,34.094566],[-119.130169,34.100102],[-119.18864,34.139005],[-119.216441,34.146105],[-119.257043,34.213304],[-119.278644,34.266902],[-119.290945,34.274902],[-119.313034,34.275689],[-119.337475,34.290576],[-119.370356,34.319486],[-119.388249,34.317398],[-119.42777,34.353016],[-119.461036,34.374064],[-119.536957,34.395495],[-119.559459,34.413395],[-119.616862,34.420995],[-119.638864,34.415696],[-119.671866,34.416096],[-119.688167,34.412497],[-119.684666,34.408297],[-119.709067,34.395397],[-119.729369,34.395897],[-119.794771,34.417597],[-119.835771,34.415796],[-119.853771,34.407996],[-119.873971,34.408795],[-119.925227,34.433931],[-119.956433,34.435288],[-120.008077,34.460447],[-120.038828,34.463434],[-120.088591,34.460208],[-120.141165,34.473405],[-120.25777,34.467451],[-120.295051,34.470623],[-120.341369,34.458789],[-120.471376,34.447846],[-120.47661,34.475131],[-120.511421,34.522953],[-120.581293,34.556959],[-120.622575,34.554017],[-120.637805,34.56622],[-120.645739,34.581035],[-120.640244,34.604406],[-120.60197,34.692095],[-120.60045,34.70464],[-120.614852,34.730709],[-120.62632,34.738072],[-120.637415,34.755895],[-120.616296,34.816308],[-120.610266,34.85818],[-120.616325,34.866739],[-120.639283,34.880413],[-120.647328,34.901133],[-120.670835,34.904115],[-120.63999,35.002963],[-120.629931,35.061515],[-120.630957,35.101941],[-120.644311,35.139616],[-120.651134,35.147768],[-120.662475,35.153357],[-120.675074,35.153061],[-120.698906,35.171192],[-120.714185,35.175998],[-120.74887,35.177795],[-120.754823,35.174701],[-120.756086,35.160459],[-120.760492,35.15971],[-120.778998,35.168897],[-120.786076,35.177666],[-120.856047,35.206487],[-120.89679,35.247877],[-120.862684,35.346776],[-120.866099,35.393045],[-120.884757,35.430196],[-120.907937,35.449069],[-120.946546,35.446715],[-120.969436,35.460197],[-121.003359,35.46071],[-121.101595,35.548814],[-121.126027,35.593058],[-121.143561,35.606046],[-121.166712,35.635399],[-121.251034,35.656641],[-121.284973,35.674109],[-121.289794,35.689428],[-121.314632,35.71331],[-121.315786,35.75252],[-121.332449,35.783106],[-121.388053,35.823483],[-121.413146,35.855316],[-121.439584,35.86695],[-121.462264,35.885618],[-121.461227,35.896906],[-121.472435,35.91989],[-121.4862,35.970348],[-121.503112,36.000299],[-121.531876,36.014368],[-121.574602,36.025156],[-121.590395,36.050363],[-121.592853,36.065062],[-121.606845,36.072065],[-121.618672,36.087767],[-121.629634,36.114452],[-121.680145,36.165818],[-121.717176,36.195146],[-121.779851,36.227407],[-121.797059,36.234211],[-121.813734,36.234235],[-121.826425,36.24186],[-121.851967,36.277831],[-121.874797,36.289064],[-121.888491,36.30281],[-121.894714,36.317806],[-121.892917,36.340428],[-121.905446,36.358269],[-121.903195,36.393603],[-121.914378,36.404344],[-121.91474,36.42589],[-121.9416,36.485602],[-121.938763,36.506423],[-121.944666,36.521861],[-121.925937,36.525173],[-121.932508,36.559935],[-121.942533,36.566435],[-121.957335,36.564482],[-121.978592,36.580488],[-121.970427,36.582754],[-121.941666,36.618059],[-121.93643,36.636746],[-121.923866,36.634559],[-121.890164,36.609259],[-121.889064,36.601759],[-121.860604,36.611136],[-121.831995,36.644856],[-121.814462,36.682858],[-121.807062,36.714157],[-121.805643,36.750239],[-121.788278,36.803994],[-121.809363,36.848654],[-121.862266,36.931552],[-121.894667,36.961851],[-121.930069,36.97815],[-121.95167,36.97145],[-121.972771,36.954151],[-122.012373,36.96455],[-122.023373,36.96215],[-122.027174,36.95115],[-122.050122,36.948523],[-122.105976,36.955951],[-122.155078,36.98085],[-122.20618,37.013949],[-122.252181,37.059448],[-122.284882,37.101747],[-122.306139,37.116383],[-122.337071,37.117382],[-122.337833,37.135936],[-122.359791,37.155574],[-122.367085,37.172817],[-122.390599,37.182988],[-122.405073,37.195791],[-122.407181,37.219465],[-122.419113,37.24147],[-122.411686,37.265844],[-122.40085,37.359225],[-122.423286,37.392542],[-122.443687,37.435941],[-122.452087,37.48054],[-122.472388,37.50054],[-122.493789,37.492341],[-122.499289,37.495341],[-122.516689,37.52134],[-122.519533,37.537302],[-122.513688,37.552239],[-122.517187,37.590637],[-122.501386,37.599637],[-122.494085,37.644035],[-122.496784,37.686433],[-122.514483,37.780829],[-122.50531,37.788312],[-122.485783,37.790629],[-122.478083,37.810828],[-122.463793,37.804653],[-122.407452,37.811441],[-122.398139,37.80563],[-122.385323,37.790724],[-122.375854,37.734979],[-122.356784,37.729505],[-122.361749,37.71501],[-122.370411,37.717572],[-122.391374,37.708331],[-122.387626,37.67906],[-122.374291,37.662206],[-122.3756,37.652389],[-122.387381,37.648462],[-122.386072,37.637662],[-122.35531,37.615736],[-122.358583,37.611155],[-122.373309,37.613773],[-122.378545,37.605592],[-122.360219,37.592501],[-122.317676,37.590865],[-122.305895,37.575484],[-122.262698,37.572866],[-122.214264,37.538505],[-122.196593,37.537196],[-122.194957,37.522469],[-122.168449,37.504143],[-122.155686,37.501198],[-122.140142,37.507907],[-122.127706,37.500053],[-122.111344,37.50758],[-122.111998,37.528851],[-122.147014,37.588411],[-122.145378,37.600846],[-122.152905,37.640771],[-122.163049,37.667933],[-122.246826,37.72193],[-122.257953,37.739601],[-122.257134,37.745001],[-122.242638,37.753744],[-122.253753,37.761218],[-122.293996,37.770416],[-122.330963,37.786035],[-122.33555,37.799538],[-122.333711,37.809797],[-122.323567,37.823214],[-122.303931,37.830087],[-122.301313,37.847758],[-122.310477,37.873938],[-122.309986,37.892755],[-122.32373,37.905845],[-122.33453,37.908791],[-122.35711,37.908791],[-122.367582,37.903882],[-122.385908,37.908136],[-122.39049,37.922535],[-122.413725,37.937262],[-122.430087,37.963115],[-122.415361,37.963115],[-122.399832,37.956009],[-122.367582,37.978168],[-122.361905,37.989991],[-122.367909,38.01253],[-122.340093,38.003694],[-122.321112,38.012857],[-122.300823,38.010893],[-122.283478,38.022674],[-122.262861,38.0446],[-122.273006,38.07438],[-122.314567,38.115287],[-122.366273,38.141467],[-122.39638,38.149976],[-122.403514,38.150624],[-122.409798,38.136231],[-122.439577,38.116923],[-122.454958,38.118887],[-122.489974,38.112014],[-122.483757,38.071762],[-122.499465,38.032165],[-122.497828,38.019402],[-122.481466,38.007621],[-122.462812,38.003367],[-122.452995,37.996167],[-122.448413,37.984713],[-122.456595,37.978823],[-122.471975,37.981768],[-122.488665,37.966714],[-122.487684,37.948716],[-122.479175,37.941516],[-122.48572,37.937589],[-122.499465,37.939225],[-122.503064,37.928753],[-122.478193,37.918608],[-122.471975,37.910427],[-122.472303,37.902573],[-122.458558,37.894064],[-122.448413,37.89341],[-122.438268,37.880974],[-122.45005,37.871157],[-122.462158,37.868866],[-122.480811,37.873448],[-122.479151,37.825428],[-122.505383,37.822128],[-122.548986,37.836227],[-122.561487,37.851827],[-122.584289,37.859227],[-122.60129,37.875126],[-122.656519,37.904519],[-122.682171,37.90645],[-122.70264,37.89382],[-122.727297,37.904626],[-122.736898,37.925825],[-122.766138,37.938004],[-122.783244,37.951334],[-122.797405,37.976657],[-122.821383,37.996735],[-122.856573,38.016717],[-122.882114,38.025273],[-122.939711,38.031908],[-122.956811,38.02872],[-122.981776,38.009119],[-122.97439,37.992429],[-123.024066,37.994878],[-123.011533,38.003438],[-122.99242,38.041758],[-122.960889,38.112962],[-122.949074,38.15406],[-122.953629,38.17567],[-122.965408,38.187113],[-122.968112,38.202428],[-122.993959,38.237602],[-122.968569,38.242879],[-122.967203,38.250691],[-122.977082,38.267902],[-122.986319,38.273164],[-123.002911,38.295708],[-123.024333,38.310573],[-123.038742,38.313576],[-123.051061,38.310693],[-123.053504,38.299385],[-123.063671,38.302178],[-123.074684,38.322574],[-123.068437,38.33521],[-123.068265,38.359865],[-123.128825,38.450418],[-123.202277,38.494314],[-123.249797,38.511045],[-123.287156,38.540223],[-123.331899,38.565542],[-123.343338,38.590008],[-123.371876,38.607235],[-123.398166,38.647044],[-123.441774,38.699744],[-123.461291,38.717001],[-123.514784,38.741966],[-123.541837,38.776764],[-123.579856,38.802835],[-123.58638,38.802857],[-123.605317,38.822765],[-123.647387,38.845472],[-123.659846,38.872529],[-123.71054,38.91323],[-123.725367,38.917438],[-123.726315,38.936367],[-123.738886,38.95412],[-123.729053,38.956667],[-123.711149,38.977316],[-123.6969,39.004401],[-123.690095,39.031157],[-123.693969,39.057363],[-123.713392,39.108422],[-123.721505,39.125327],[-123.737913,39.143442],[-123.742221,39.164885],[-123.765891,39.193657],[-123.774998,39.212083],[-123.777368,39.237214],[-123.787893,39.264327],[-123.803848,39.278771],[-123.803081,39.291747],[-123.811387,39.312825],[-123.808772,39.324368],[-123.822085,39.343857],[-123.826306,39.36871],[-123.81469,39.446538],[-123.766475,39.552803],[-123.787417,39.604552],[-123.782322,39.621486],[-123.792659,39.684122],[-123.808208,39.710715],[-123.829545,39.723071],[-123.838089,39.752409],[-123.839797,39.795637],[-123.851714,39.832041],[-123.907664,39.863028],[-123.930047,39.909697],[-123.954952,39.922373],[-123.980031,39.962458],[-124.035904,40.013319],[-124.056408,40.024305],[-124.068908,40.021307],[-124.079983,40.029773],[-124.080709,40.06611],[-124.110549,40.103765],[-124.187874,40.130542],[-124.214895,40.160902],[-124.296497,40.208816],[-124.320912,40.226617],[-124.327691,40.23737],[-124.34307,40.243979],[-124.363414,40.260974],[-124.363634,40.276212],[-124.347853,40.314634],[-124.362796,40.350046],[-124.365357,40.374855],[-124.373599,40.392923],[-124.391496,40.407047],[-124.409591,40.438076],[-124.38494,40.48982],[-124.383224,40.499852],[-124.387023,40.504954],[-124.382816,40.519],[-124.329404,40.61643],[-124.158322,40.876069],[-124.137066,40.925732],[-124.118147,40.989263],[-124.112165,41.028173],[-124.125448,41.048504],[-124.138217,41.054342],[-124.153622,41.05355],[-124.154513,41.087159],[-124.160556,41.099011],[-124.159065,41.121957],[-124.165414,41.129822],[-124.158539,41.143021],[-124.149674,41.140845],[-124.1438,41.144686],[-124.106986,41.229678],[-124.072294,41.374844],[-124.063076,41.439579],[-124.066057,41.470258],[-124.081427,41.511228],[-124.081987,41.547761],[-124.092404,41.553615],[-124.101123,41.569192],[-124.097385,41.585251],[-124.100961,41.602499],[-124.114413,41.616768],[-124.120225,41.640354],[-124.135552,41.657307],[-124.147412,41.717955],[-124.164716,41.740126],[-124.17739,41.745756],[-124.194953,41.736778],[-124.23972,41.7708],[-124.248704,41.771459],[-124.255994,41.783014],[-124.245027,41.7923],[-124.230678,41.818681],[-124.208439,41.888192],[-124.203402,41.940964],[-124.204948,41.983441],[-124.211605,41.99846],[-123.656998,41.995137],[-123.624554,41.999837],[-123.347562,41.999108],[-123.145959,42.009247],[-123.045254,42.003049],[-122.893961,42.002605],[-122.289533,42.007764]]]]},\"properties\":{\"name\":\"California\",\"nation\":\"USA \"}}]}","volume":"109","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6eaae4b0c8380cd7574b","contributors":{"authors":[{"text":"Godfrey, N. J.","contributorId":12866,"corporation":false,"usgs":true,"family":"Godfrey","given":"N.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":381776,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Beaudoin, B. C.","contributorId":17629,"corporation":false,"usgs":true,"family":"Beaudoin","given":"B.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":381777,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Klemperer, S.L.","contributorId":52734,"corporation":false,"usgs":true,"family":"Klemperer","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":381780,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Levander, A.","contributorId":91248,"corporation":false,"usgs":true,"family":"Levander","given":"A.","affiliations":[],"preferred":false,"id":381782,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Luetgert, J.","contributorId":92807,"corporation":false,"usgs":true,"family":"Luetgert","given":"J.","email":"","affiliations":[],"preferred":false,"id":381783,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Meltzer, A.","contributorId":55692,"corporation":false,"usgs":true,"family":"Meltzer","given":"A.","email":"","affiliations":[],"preferred":false,"id":381781,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Mooney, Walter D. 0000-0002-5310-3631 mooney@usgs.gov","orcid":"https://orcid.org/0000-0002-5310-3631","contributorId":3194,"corporation":false,"usgs":true,"family":"Mooney","given":"Walter","email":"mooney@usgs.gov","middleInitial":"D.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":true,"id":381779,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Trehu, A.","contributorId":28372,"corporation":false,"usgs":false,"family":"Trehu","given":"A.","email":"","affiliations":[],"preferred":false,"id":381778,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70019128,"text":"70019128 - 1997 - Correlated errors in geodetic time series: Implications for time-dependent deformation","interactions":[],"lastModifiedDate":"2024-09-30T14:12:43.368976","indexId":"70019128","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Correlated errors in geodetic time series: Implications for time-dependent deformation","docAbstract":"Analysis of frequent trilateration observations from the two-color electronic distance measuring networks in California demonstrate that the noise power spectra are dominated by white noise at higher frequencies and power law behavior at lower frequencies. In contrast, Earth scientists typically have assumed that only white noise is present in a geodetic time series, since a combination of infrequent measurements and low precision usually preclude identifying the time-correlated signature in such data. After removing a linear trend from the two-color data, it becomes evident that there are primarily two recognizable types of time-correlated noise present in the residuals. The first type is a seasonal variation in displacement which is probably a result of measuring to shallow surface monuments installed in clayey soil which responds to seasonally occurring rainfall; this noise is significant only for a small fraction of the sites analyzed. The second type of correlated noise becomes evident only after spectral analysis of line length changes and shows a functional relation at long periods between power and frequency of 1/ƒα, where ƒ is frequency and α≈2. With α=2, this type of correlated noise is termed random-walk noise, and its source is mainly thought to be small random motions of geodetic monuments with respect to the Earth's crust, though other sources are possible. Because the line length changes in the two-color networks are measured at irregular intervals, power spectral techniques cannot reliably estimate the level of 1/ƒα noise. Rather, we also use here a maximum likelihood estimation technique which assumes that there are only two sources of noise in the residual time series (white noise and random-walk noise) and estimates the amount of each. From this analysis we find that the random-walk noise level averages about 1.3 mm/√yr and that our estimates of the white noise component confirm theoretical limitations of the measurement technique. In addition, the seasonal noise can be as large as 3 mm in amplitude but typically is less than 0.5 mm. Because of the presence of random-walk noise in these time series, modeling and interpretation of the geodetic data must account for this source of error. By way of example we show that estimating the time-varying strain tensor (a form of spatial averaging) from geodetic data having both random-walk and white noise error components results in seemingly significant variations in the rate of strain accumulation; spatial averaging does reduce the size of both noise components but not their relative influence on the resulting strain accumulation model.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB02945","issn":"01480227","usgsCitation":"Langbein, J., and Johnson, H., 1997, Correlated errors in geodetic time series: Implications for time-dependent deformation: Journal of Geophysical Research B: Solid Earth, v. 102, no. B1, p. 591-603, https://doi.org/10.1029/96JB02945.","productDescription":"13 p.","startPage":"591","endPage":"603","numberOfPages":"13","costCenters":[],"links":[{"id":480067,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb02945","text":"Publisher Index Page"},{"id":226907,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B1","noUsgsAuthors":false,"publicationDate":"1997-01-10","publicationStatus":"PW","scienceBaseUri":"5059fc21e4b0c8380cd4e12e","contributors":{"authors":[{"text":"Langbein, J.","contributorId":16990,"corporation":false,"usgs":true,"family":"Langbein","given":"J.","affiliations":[],"preferred":false,"id":381753,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Johnson, H.","contributorId":61163,"corporation":false,"usgs":true,"family":"Johnson","given":"H.","affiliations":[],"preferred":false,"id":381754,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019674,"text":"70019674 - 1997 - Moss and soil contributions to the annual net carbon flux of a maturing boreal forest","interactions":[],"lastModifiedDate":"2024-05-02T15:30:17.017669","indexId":"70019674","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2316,"text":"Journal of Geophysical Research D: Atmospheres","active":true,"publicationSubtype":{"id":10}},"title":"Moss and soil contributions to the annual net carbon flux of a maturing boreal forest","docAbstract":"We used input and decomposition data from 14C studies of soils to determine rates of vertical accumulation of moss combined with carbon storage inventories on a sequence of burns to model how carbon accumulates in soils and moss after a stand-killing fire. We used soil drainage—moss associations and soil drainage maps of the old black spruce (OBS) site at the BOREAS northern study area (NSA) to areally weight the contributions of each moderately well drained, feathermoss areas; poorly drained sphagnum—feathermoss areas; and very poorly drained brown moss areas to the carbon storage and flux at the OBS NSA site. On this very old (117 years) complex of black spruce, sphagnum bog veneer, and fen systems we conclude that these systems are likely sequestering 0.01–0.03 kg C m−2 yr−1 at OBS-NSA today. Soil drainage in boreal forests near Thompson, Manitoba, controls carbon storage and flux by controlling moss input and decomposition rates and by controlling through fire the amount and quality of carbon left after burning. On poorly drained soils rich in sphagnum moss, net accumulation and long-term storage of carbon is higher than on better drained soils colonized by feathermosses. The carbon flux of these contrasting ecosystems is best characterized by soil drainage class and stand age, where stands recently burned are net sources of CO2, and maturing stands become increasingly stronger sinks of atmospheric CO2. This approach to measuring carbon storage and flux presents a method of scaling to larger areas using soil drainage, moss cover, and stand age information.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JD02237","issn":"01480227","usgsCitation":"Harden, J., O’Neill, K.P., Trumbore, S., Veldhuis, H., and Stocks, B., 1997, Moss and soil contributions to the annual net carbon flux of a maturing boreal forest: Journal of Geophysical Research D: Atmospheres, v. 102, no. 24, p. 28805-28816, https://doi.org/10.1029/97JD02237.","productDescription":"12 p.","startPage":"28805","endPage":"28816","numberOfPages":"12","costCenters":[],"links":[{"id":480021,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97jd02237","text":"Publisher Index Page"},{"id":228202,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"24","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5e88e4b0c8380cd70ade","contributors":{"authors":[{"text":"Harden, J.W. 0000-0002-6570-8259","orcid":"https://orcid.org/0000-0002-6570-8259","contributorId":38585,"corporation":false,"usgs":true,"family":"Harden","given":"J.W.","affiliations":[],"preferred":false,"id":383517,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"O’Neill, K. P.","contributorId":104935,"corporation":false,"usgs":true,"family":"O’Neill","given":"K.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":383521,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Trumbore, S.E.","contributorId":57879,"corporation":false,"usgs":true,"family":"Trumbore","given":"S.E.","email":"","affiliations":[],"preferred":false,"id":383518,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Veldhuis, H.","contributorId":64410,"corporation":false,"usgs":true,"family":"Veldhuis","given":"H.","affiliations":[],"preferred":false,"id":383519,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Stocks, B.J.","contributorId":78894,"corporation":false,"usgs":true,"family":"Stocks","given":"B.J.","email":"","affiliations":[],"preferred":false,"id":383520,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019505,"text":"70019505 - 1997 - Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem","interactions":[],"lastModifiedDate":"2018-05-20T11:50:44","indexId":"70019505","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2603,"text":"Landscape and Urban Planning","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem","title":"Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem","docAbstract":"The California clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing causes remains unclear. The rail is one of the key targets of emerging plans to conserve and restore tidal marshlands. Reduction of tidal marsh habitat, estimated at 85–95%, has been the major historical cause of rail decline. Increased predation intensity may be the more important present problem, because habitat fragmentation and alteration coupled with the invasion of the red fox have made the remaining populations more vulnerable to predators. Population viability analysis shows that adult survivorship is the key demographic variable; reversals in population fate occur over a narrow range of ecologically realistic values. Analysis of habitat requirements and population dynamics of the clapper rail in the San Francisco Estuary shows that decreased within-marsh habitat quality, particularly reduction of tidal flows and alteration of drainage, is an important barrier to population recovery. Management and restoration activities should emphasize the development of well-channelized high tidal marsh, because this is the key requirement of rail habitat. Developing effective restoration programs depends upon having information that field research will not provide. The effect of spatial pattern of reserves requires accurate estimation of the effects of prédation and inter-marsh movement, both of which are practically impossible to measure adequately. It will be necessary to develop and use simulation models that can be applied to geographic data to accomplish this task.
","language":"English","publisher":"Elsevier","doi":"10.1016/S0169-2046(97)00036-4","usgsCitation":"Foin, T.C., Garcia, E.J., Gill, R., Culberson, S.D., and Collins, J.N., 1997, Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem: Landscape and Urban Planning, v. 38, no. 3-4, p. 229-243, https://doi.org/10.1016/S0169-2046(97)00036-4.","productDescription":"15 p.","startPage":"229","endPage":"243","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":226433,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"38","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a349e4b0e8fec6cdb7ff","contributors":{"authors":[{"text":"Foin, Theodore C.","contributorId":174646,"corporation":false,"usgs":false,"family":"Foin","given":"Theodore","email":"","middleInitial":"C.","affiliations":[{"id":13461,"text":"U.C. Davis","active":true,"usgs":false}],"preferred":false,"id":382997,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Garcia, E. Jacqueline","contributorId":174039,"corporation":false,"usgs":false,"family":"Garcia","given":"E.","email":"","middleInitial":"Jacqueline","affiliations":[{"id":12711,"text":"UC Davis","active":true,"usgs":false}],"preferred":false,"id":382993,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gill, Robert E. Jr. 0000-0002-6385-4500 rgill@usgs.gov","orcid":"https://orcid.org/0000-0002-6385-4500","contributorId":171747,"corporation":false,"usgs":true,"family":"Gill","given":"Robert E.","suffix":"Jr.","email":"rgill@usgs.gov","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":382994,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Culberson, Steven D.","contributorId":82166,"corporation":false,"usgs":true,"family":"Culberson","given":"Steven","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":382996,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Collins, Joshua N.","contributorId":150531,"corporation":false,"usgs":false,"family":"Collins","given":"Joshua","email":"","middleInitial":"N.","affiliations":[{"id":12703,"text":"San Francisco Estuary Institute","active":true,"usgs":false}],"preferred":false,"id":382995,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019114,"text":"70019114 - 1997 - Use of inexpensive pressure transducers for measuring water levels in wells","interactions":[],"lastModifiedDate":"2019-09-16T12:51:20","indexId":"70019114","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3751,"text":"Wetlands Ecology and Management","active":true,"publicationSubtype":{"id":10}},"title":"Use of inexpensive pressure transducers for measuring water levels in wells","docAbstract":"Frequent measurement of below ground water levels at multiple locations is an important component of many wetland ecosystem studies. These measurements, however, are usually time consuming, labor intensive, and expensive. This paper describes a water-level sensor that is inexpensive and easy to construct. The sensor is placed below the expected low water level in a shallow well and, when connected to a datalogger, uses a pressure transducer to detect groundwater or surface water elevations. Details of pressure transducer theory, sensor construction, calibration, and examples of field installations are presented. Although the transducers must be individually calibrated, the sensors have a linear response to changing water levels (r2 ≈ .999). Measurement errors resulting from temperature fluctuations are shown to be about 4 cm over a 35°C temperature range, but are minimal when the sensors are installed in groundwater wells where temperatures are less variable. Greater accuracy may be obtained by incorporating water temperature data into the initial calibration (0.14 cm error over a 35C temperature range). Examples of the utility of these sensors in studies of groundwater/surface water interactions and the effects of water level fluctuations on tree growth are provided.
","language":"English","publisher":"Springer","doi":"10.1023/A:1008203625917","issn":"09234861","usgsCitation":"Keeland, B.D., Dowd, J., and Hardegree, W., 1997, Use of inexpensive pressure transducers for measuring water levels in wells: Wetlands Ecology and Management, v. 5, no. 2, p. 121-129, https://doi.org/10.1023/A:1008203625917.","productDescription":"9 p.","startPage":"121","endPage":"129","numberOfPages":"9","costCenters":[{"id":455,"text":"National Wetlands Research Center","active":true,"usgs":true}],"links":[{"id":226725,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"5","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbf2ce4b08c986b3299d4","contributors":{"authors":[{"text":"Keeland, B. D.","contributorId":45275,"corporation":false,"usgs":true,"family":"Keeland","given":"B.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":381711,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dowd, J.F.","contributorId":47926,"corporation":false,"usgs":true,"family":"Dowd","given":"J.F.","email":"","affiliations":[],"preferred":false,"id":381712,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hardegree, W.S.","contributorId":70125,"corporation":false,"usgs":true,"family":"Hardegree","given":"W.S.","email":"","affiliations":[],"preferred":false,"id":381713,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019113,"text":"70019113 - 1997 - Permeability and porosity of the Illinois UPH 3 drillhole granite and a comparison with other deep drillhole rocks","interactions":[],"lastModifiedDate":"2024-09-30T13:48:18.000108","indexId":"70019113","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Permeability and porosity of the Illinois UPH 3 drillhole granite and a comparison with other deep drillhole rocks","docAbstract":"Permeability, porosity, and volumetric strain measurements were conducted on granite cores obtained at depths of 0.7 to 1.6 km from the Illinois UPH 3 drillhole at effective confining pressures from 5 to 100 MPa. Initial permeabilities were in the range of 10-17 to 10-19 m2 and dropped rapidly with applied pressure to values between 10-20 and 10-24 m2 at 100 MPa, typical of other deep granite core samples. These values are several decades lower than equivalent weathered surface granites at comparable effective confining pressures, where weathering products in cracks and pores inhibit crack closure with applied pressure. Permeabilities of the Illinois cores were inversely related to sample depth, suggesting that stress relief and thermal microfractures induced during core retrieval dominated the fluid flow. Thus these samples provide an upper bound on in situ matrix permeability values. A comparison of core permeability from UPH 3 and other deep drillholes shows that stress relief damage can often dominate laboratory permeability measurements. We conclude that it may be difficult to make meaningful estimates of in situ permeability based on either borehole samples (possible damage during retrieval) or surface-derived analogs (altered by weathering). Volumetric strain determined from porosity measurements was compared with differential strain analysis (DSA) data reported by other investigators on samples from the same depths in the drillhole. Our strain measurements (0.002 to 0.005 at 100 MPa) were nearly twice as large as the DSA values, probably because of the crack-enhancing effects of fluids present in our samples that are absent in the dry DSA cores, as well as other time-dependent deformation effects. This difference in observed strain magnitudes between the two measurement methods may be an important consideration if strain and/or porosity data from deep core samples are used in models of stress, fluid circulation, and excess fluid pressure generation in the midcrust.","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB03178","issn":"01480227","usgsCitation":"Morrow, C., and Lockner, D., 1997, Permeability and porosity of the Illinois UPH 3 drillhole granite and a comparison with other deep drillhole rocks: Journal of Geophysical Research B: Solid Earth, v. 102, no. B2, p. 3067-3075, https://doi.org/10.1029/96JB03178.","productDescription":"9 p.","startPage":"3067","endPage":"3075","numberOfPages":"9","costCenters":[],"links":[{"id":479963,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb03178","text":"Publisher Index Page"},{"id":226680,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B2","noUsgsAuthors":false,"publicationDate":"1997-02-10","publicationStatus":"PW","scienceBaseUri":"505a76ace4b0c8380cd78253","contributors":{"authors":[{"text":"Morrow, C.A.","contributorId":99977,"corporation":false,"usgs":true,"family":"Morrow","given":"C.A.","email":"","affiliations":[],"preferred":false,"id":381710,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lockner, D.A. 0000-0001-8630-6833","orcid":"https://orcid.org/0000-0001-8630-6833","contributorId":85603,"corporation":false,"usgs":true,"family":"Lockner","given":"D.A.","affiliations":[],"preferred":false,"id":381709,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019111,"text":"70019111 - 1997 - Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas","interactions":[],"lastModifiedDate":"2019-09-16T12:57:00","indexId":"70019111","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas","title":"Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas","docAbstract":"Caddo Lake, situated on the border of northeast Texas and northwest Louisiana, USA is a medium-sized lake dominated by stands of baldcypress (Taxodiwn distichum). A study of tree growth was initiated at Caddo Lake to address concerns about the health of the baldcypress ecosystem. The lake has been subjected to several dramatic water-level changes over the past 200 years, including water-level stabilization following dam construction in 1914. To assess the long-term growth trends of baldcypress trees and determine if a recent growth decline is occurring at Caddo Lake, increment cores were taken from 52 trees. The cores were crossdated and rings between the years 1900 and 1992 measured to the nearest 0.01 mm. Most cores were characterized by high variation in year-to-year growth. Although increasing growth rates were observed at most locations, trees from two backwater areas of the lake had recent growth rates lower than their long-term average. Growth amounts at these two sites were, however, within the historic range of variation. No recruitment was observed. From these data, we can conclude that the historic, extreme changes in hydrologic regime and the current stabilized water levels have not resulted in an overall decline in baldcypress growth at Caddo Lake.","language":"English","publisher":"Springer","doi":"10.1007/BF03161522","issn":"02775212","usgsCitation":"Keeland, B.D., and Young, P., 1997, Long-term growth trends of baldcypress (Taxodium distichum (L.) rich.) at Caddo Lake, Texas: Wetlands, v. 17, no. 4, p. 559-566, https://doi.org/10.1007/BF03161522.","productDescription":"8 p.","startPage":"559","endPage":"566","numberOfPages":"8","costCenters":[{"id":455,"text":"National Wetlands Research Center","active":true,"usgs":true}],"links":[{"id":226678,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Texas","otherGeospatial":"Caddo Lake","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -94.37667846679688,\n 32.64110949213927\n ],\n [\n -94.04571533203125,\n 32.64110949213927\n ],\n [\n -94.04571533203125,\n 32.895732015669815\n ],\n [\n -94.37667846679688,\n 32.895732015669815\n ],\n [\n -94.37667846679688,\n 32.64110949213927\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"17","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4993e4b0c8380cd68720","contributors":{"authors":[{"text":"Keeland, B. D.","contributorId":45275,"corporation":false,"usgs":true,"family":"Keeland","given":"B.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":381705,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Young, P.J.","contributorId":79636,"corporation":false,"usgs":true,"family":"Young","given":"P.J.","email":"","affiliations":[],"preferred":false,"id":381706,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019110,"text":"70019110 - 1997 - Kinetics of the coesite to quartz transformation","interactions":[],"lastModifiedDate":"2023-12-08T12:27:47.187901","indexId":"70019110","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","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":"Kinetics of the coesite to quartz transformation","docAbstract":"The survival of coesite in ultrahigh-pressure (UHP) rocks has important implications for the exhumation of subducted crustal rocks. We have conducted experiments to study the mechanism and rate of the coesite→quartz transformation using polycrystalline coesite aggregates, fabricated by devitrifying silica glass cylinders containing 2850 H/106 Si at 1000°C and 3.6 GPa for 24 h. Conditions were adjusted following synthesis to transform the samples at 700–1000°C at pressures 190–410 MPa below the quartz–coesite equilibrium boundary. Reaction proceeds via grain-boundary nucleation and interface-controlled growth, with characteristic reaction textures remarkably similar to those seen in natural UHP rocks. We infer that the experimental reaction mechanism is identical to that in nature, a prerequisite for reliable extrapolation of the rate data. Growth rates obtained by direct measurement differ by up to two orders of magnitude from those estimated by fitting a rate equation to the transformation–time data. Fitting the rates to Turnbull's equation for growth therefore yields two distinct sets of parameters with similar activation energies (242 or 269 kJ/mol) but significantly different pre-exponential constants. Extrapolation based on either set of growth rates suggests that coesite should not be preserved on geologic time scales if it reaches the quartz stability field at temperatures above 375–400°C. The survival of coesite has previously been linked to its inclusion in strong phases, such as garnet, that can sustain a high internal pressure during decompression. Other factors that may play a crucial role in preservation are low fluid availability — possibly even less than that of our nominally “dry” experiments — and the development of transformation stress, which inhibits nucleation and growth. These issues are discussed in the context of our experiments as well as recent observations from natural rocks.