On the basis of three sediment-based chronologies, Fritz et al. ( 1994) concluded that during the ’Little Ice Age’ (about AD 1500 to 1850), the Devils Lake Basin generally had less effective moisture (precipitation minus evaporation) and warmer temperatures than at present. In this comment, we argue that historic data indicate that runoff and effective moisture were greater than at present. The largest nineteenth-century floods (AD 1826, 1852 and 1861) were significantly greater than the twentiethcentury floods, and flooding in the Red River of the North Basin occurred more frequently from AD 1800 to 1870 than since 1870. Between AD 1776 and 1870, the ratio of wet to dry years was about 2 to 1. Mean temperatures in all seasons were cooler for 1850-70 than for 1931-60. Lake levels of Devils Lake during the first half of the nineteenth century were higher than they are today, and, even when Devils Lake was almost dry, the salinity was less than the ’diatom-inferred’ salinity values that Fritz et al. (1994) estimated for 1800 through about 1850. We acknowledge the importance of high-resolution palaeoclimatic records, but interpretation of these records must be consistent with historic information.
","language":"English","publisher":"SAGE Journals","doi":"10.1177/095968369600600413","usgsCitation":"Wiche, G.J., Lent, R.M., and Rannie, W.F., 1996, 'Little Ice Age' aridity in the North American Great Plains - a high-resolution reconstruction of salinity fluctuations from Devils Lake, North Dakota, USA: a comment on Fritz, Engstrom and Haskell: The Holocene, v. 6, no. 4, p. 489-490, https://doi.org/10.1177/095968369600600413.","productDescription":"2 p.","startPage":"489","endPage":"490","costCenters":[{"id":478,"text":"North Dakota Water Science Center","active":true,"usgs":true},{"id":34685,"text":"Dakota Water Science Center","active":true,"usgs":true}],"links":[{"id":352490,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6","issue":"4","noUsgsAuthors":false,"publicationDate":"1996-12-01","publicationStatus":"PW","scienceBaseUri":"5aff1df9e4b0da30c1bfd53e","contributors":{"authors":[{"text":"Wiche, Gregg J. gjwiche@usgs.gov","contributorId":1675,"corporation":false,"usgs":true,"family":"Wiche","given":"Gregg","email":"gjwiche@usgs.gov","middleInitial":"J.","affiliations":[{"id":478,"text":"North Dakota Water Science Center","active":true,"usgs":true}],"preferred":true,"id":730967,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lent, Robert M. rmlent@usgs.gov","contributorId":284,"corporation":false,"usgs":true,"family":"Lent","given":"Robert","email":"rmlent@usgs.gov","middleInitial":"M.","affiliations":[{"id":371,"text":"Maine Water Science Center","active":true,"usgs":true}],"preferred":true,"id":730968,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rannie, W. F.","contributorId":203306,"corporation":false,"usgs":false,"family":"Rannie","given":"W.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":730969,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":1000799,"text":"1000799 - 1996 - Otoliths reveal a diverse age structure for humper lake trout in Lake Superior","interactions":[],"lastModifiedDate":"2016-04-11T13:30:46","indexId":"1000799","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3624,"text":"Transactions of the American Fisheries Society","active":true,"publicationSubtype":{"id":10}},"title":"Otoliths reveal a diverse age structure for humper lake trout in Lake Superior","docAbstract":"Humpers are one of at least three morphological variants of wild lake trout Salvelinus namaycush that maintain self-sustaining populations in Lake Superior. In an early study, bumpers from Isle Royale were shown to have a sharply truncated age distribution that was attributed to high mortality after age 11, but we suspected that these fish were underaged. In August of 1989 and 1992 we collected spawning humper lake trout from the same area and estimated their ages using both scales and sagittal otoliths. Humpers in our sample ranged from 5 to 13 years, based on scale annuli, but counts of sagitta annuli revealed ages of 8 to 28 years. Individual discrepancies between ages from scales and sagittae varied from –2 to 20 years, but differences between scale and otolith ages did not increase with individual age. We applied the von Bertalanffy growth model to the humper length-at-age data to indirectly assess the accuracy of aging estimates. The model significantly overestimated mean asymptotic length when scale ages were used, but the mean asymptotic length estimate was more similar to observed lengths when sagitta ages were used. Our results corroborate evidence that bumpers in Lake Superior grow more slowly and mature at a smaller size than lean lake trout; however, the age composition of bumpers is more diverse than previously thought. This particular population experiences little or no exploitation; the presence of older fish provides one standard by which the success of lake trout rehabilitation programs can be evaluated and emphasizes the need for accurate aging techniques.
","language":"English","publisher":"Taylor & Francis","doi":"10.1577/1548-8659(1996)125<0844:ORADAS>2.3.CO;2","usgsCitation":"Burnham-Curtis, M.K., and Bronte, C.R., 1996, Otoliths reveal a diverse age structure for humper lake trout in Lake Superior: Transactions of the American Fisheries Society, v. 125, no. 6, p. 844-851, https://doi.org/10.1577/1548-8659(1996)125<0844:ORADAS>2.3.CO;2.","productDescription":"8 p.","startPage":"844","endPage":"851","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":133368,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"125","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4ae5e4b07f02db68a4b2","contributors":{"authors":[{"text":"Burnham-Curtis, Mary K.","contributorId":78267,"corporation":false,"usgs":true,"family":"Burnham-Curtis","given":"Mary","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":309471,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bronte, Charles R.","contributorId":83050,"corporation":false,"usgs":true,"family":"Bronte","given":"Charles","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":309472,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70178204,"text":"70178204 - 1996 - Comparison of the uptake of dioxin-like compounds by caged channel catfish and semipermeable membrane devices in the Saginaw River, Michigan","interactions":[],"lastModifiedDate":"2017-08-26T14:41:08","indexId":"70178204","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Comparison of the uptake of dioxin-like compounds by caged channel catfish and semipermeable membrane devices in the Saginaw River, Michigan","docAbstract":"Elevated concentrations of planar, halogenated hydrocarbons have been linked to reproductive problems in a variety of fish-eating birds and mammals in the Great Lakes and in particular Saginaw Bay. Currently, there are no accurate procedures to assess bioavailability of these contaminants. Polychlorinated dibenzo-p-dioxins and dibenzofurans and mono- and non-ortho-chloro-substituted biphenyls in water at the femtogram to picogram per liter range were passively concentrated in semipermeable membrane devices (SPMDs), and these data were compared to the bioconcentration in co-exposed (caged) channel catfish. Sediment-derived water concentration estimates, calculated from a steady-state partitioning model, did not correlate well to those derived from either fish or SPMDs. The use of SPMDs demonstrated the utility of in-situ passive sampling over inference of water concentrations from accumulation in biota or partitioning with sediment. Residues ac cumulated by SPMDs have been shown to be proportional to analyte water concentration, whereas this does not appear to be the case for fish tissues. The greater amounts of 3,3‘,4,4‘-tetrachlorobiphenyl and 2,3,7,8-tetrachlorodibenzofuran accumulated in SPMDs than in exposed channel catfish indicated those non-passive aspects of bioconcentration in organisms, such as biotransformation and elimination, introduced 50−500% error in the assumed degree of exposure.
","language":"English","publisher":"ACS Publications","doi":"10.1021/es960263m","usgsCitation":"Gale, R.W., Huckins, J.N., Petty, J.D., Peterman, P.H., Williams, L.L., Morse, D., Schwartz, T.R., and Tillitt, D.E., 1996, Comparison of the uptake of dioxin-like compounds by caged channel catfish and semipermeable membrane devices in the Saginaw River, Michigan: Environmental Science & Technology, v. 31, no. 1, p. 178-187, https://doi.org/10.1021/es960263m.","productDescription":"10 p.","startPage":"178","endPage":"187","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"links":[{"id":330840,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"31","issue":"1","noUsgsAuthors":false,"publicationDate":"1996-12-30","publicationStatus":"PW","scienceBaseUri":"5821a0dee4b02f1a881de982","contributors":{"authors":[{"text":"Gale, Robert W. 0000-0002-8533-141X rgale@usgs.gov","orcid":"https://orcid.org/0000-0002-8533-141X","contributorId":2808,"corporation":false,"usgs":true,"family":"Gale","given":"Robert","email":"rgale@usgs.gov","middleInitial":"W.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":653235,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Huckins, James N.","contributorId":83454,"corporation":false,"usgs":true,"family":"Huckins","given":"James","email":"","middleInitial":"N.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":false,"id":653236,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Petty, Jimmie D.","contributorId":175402,"corporation":false,"usgs":false,"family":"Petty","given":"Jimmie","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":653237,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Peterman, Paul H. ppeterman@usgs.gov","contributorId":2872,"corporation":false,"usgs":true,"family":"Peterman","given":"Paul","email":"ppeterman@usgs.gov","middleInitial":"H.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":653238,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Williams, Lisa L.","contributorId":172543,"corporation":false,"usgs":false,"family":"Williams","given":"Lisa","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":653239,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Morse, Douglas","contributorId":176716,"corporation":false,"usgs":false,"family":"Morse","given":"Douglas","email":"","affiliations":[],"preferred":false,"id":653240,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Schwartz, Ted R.","contributorId":36510,"corporation":false,"usgs":true,"family":"Schwartz","given":"Ted","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":653241,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Tillitt, Donald E. 0000-0002-8278-3955 dtillitt@usgs.gov","orcid":"https://orcid.org/0000-0002-8278-3955","contributorId":1875,"corporation":false,"usgs":true,"family":"Tillitt","given":"Donald","email":"dtillitt@usgs.gov","middleInitial":"E.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":653242,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70017775,"text":"70017775 - 1996 - Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters","interactions":[],"lastModifiedDate":"2024-08-01T13:28:57.358214","indexId":"70017775","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2317,"text":"Journal of Geophysical Research E: Planets","active":true,"publicationSubtype":{"id":10}},"title":"Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters","docAbstract":"Two independent methods, with no common assumptions, have been used to estimate the extension across the heavily deformed Tempe Terra province of the Tharsis region of Mars. One method uses measurements of normal fault scarp width with average scarp slope data for simple grabens and rifts on Mars to estimate the fault throw, which, combined with sparse fault dip data, can be used to estimate extension. Formal uncertainties in this method are only slightly greater than those in other methods, given that the total uncertainty is dominated by the likely uncertainty in the fault dip (assumed to be 60° ± 15°). Measurement of normal fault scarp widths along two N25°–50°W directed traverses across Tempe Terra both yield about 22 ± 16 km of extension (or ∼2% strain across the northern traverse and nearly 3% across the southern one). About three quarters of the extension has occurred during the two main phases of Tharsis-related deformation from Middle/Late Noachian to Early Hesperian and from Late Hesperian to Early Amazonian, with more extension closer to the center of Tharsis during the first phase. Extension across the region was also determined by measuring the elongation and elongation direction of all ancient Noachian impact craters without ejecta blankets, which predate most of the deformation. Results have been corrected for initial non circularity of craters, established from similar measurements of young (post deformation) impact craters, yielding a statistically significant mean strain of 1.96 ± 0.35% in a N38° ± 10°W direction across Tempe Terra (extension of ∼20 ± 4, comparable in magnitude and direction to the average result from the scarp measurement method). Both methods indicate an average extension for single normal fault scarps (and shortening across wrinkle ridges for the crater method) of ∼100 m. The agreement between the results of the two independent methods in overall extension and average single normal fault extension argues that the average scarp slope and fault dip data in the fault scarp width method accurately represent the actual extension across the observed structures. This conclusion supports existing geometric and kinematic models for structural features on Mars. A preliminary estimate of the total circumferential extension around Tharsis (at a radius of ∼2500 km) is roughly 60 ± 42 km; total hoop strain is about 0.4% distributed heterogeneously (Tempe Terra is the most highly strained region on Mars).
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JE02709","issn":"01480227","usgsCitation":"Golombek, M., Tanaka, K.L., and Franklin, B., 1996, Extension across Tempe Terra, Mars, from measurements of fault scarp widths and deformed craters: Journal of Geophysical Research E: Planets, v. 101, no. E11, p. 26119-26130, https://doi.org/10.1029/96JE02709.","productDescription":"12 p.","startPage":"26119","endPage":"26130","numberOfPages":"12","costCenters":[],"links":[{"id":228772,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Mars","volume":"101","issue":"E11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0e41e4b0c8380cd53384","contributors":{"authors":[{"text":"Golombek, M.P.","contributorId":52696,"corporation":false,"usgs":true,"family":"Golombek","given":"M.P.","email":"","affiliations":[],"preferred":false,"id":377535,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tanaka, K. L.","contributorId":31394,"corporation":false,"usgs":false,"family":"Tanaka","given":"K.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":377533,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Franklin, B.J.","contributorId":48358,"corporation":false,"usgs":true,"family":"Franklin","given":"B.J.","email":"","affiliations":[],"preferred":false,"id":377534,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018086,"text":"70018086 - 1996 - On the coherence of ground motion in the San Fernando valley","interactions":[],"lastModifiedDate":"2023-10-23T12:24:29.131464","indexId":"70018086","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"On the coherence of ground motion in the San Fernando valley","docAbstract":"We present an analysis of the coherence of seismic ground motion recorded on alluvial sediments in the San Fernando Valley, California. Using aftershocks of the 17 January 1994 Mw6.7 earthquake recorded at a quasi-dense array of portable stations, we analyze the coherence of three well-recorded magnitude 3.7 to 4.0 events over the frequency range 0.5 to 15 Hz and a distance range of 0.5 to 5.3 km. All stations are located at sites with broadly similar near-site geology, characterized by medium to fine-grain Quaternary alluvial sediments. On average, relatively high values of coherence are observed for distances up to 3 to 4 km and frequencies up to 2 to 3 Hz; coherence drops sharply at frequencies near and above 3 Hz. Although average coherence functions are described reasonably well by a log-linear relationship with frequency, the curves at all distances exhibit a flattening at low frequencies that is not consistent with previous observations of coherence at hardrock sites. The distance decay of coherence is also markedly less strong, with high coherence values observed over station separations corresponding to multiple wavelengths. This may reflect fundamental differences in shallow-wave propagation in the two environments, with high-frequency scattering relatively more dominant in regions of hard-rock near-surface geology. Within a sedimentary basin or valley, the site response itself generally reflects a resonance phenomenon that may tend to give rise to more uniform ground motions. However, previous studies have demonstrated the existence of pathological focusing and amplification effects within complex sedimentary basin environments such as the greater Los Angeles region; our results undoubtedly do not quantify the full range of ground-motion variability at all sites, but rather represent the level of that variability that can be expected, and quantified, for typical source/receiver paths.
Geophysical, geological, and seismicity data are combined to develop a transpressional strain model for the southern Washington Cascades region. We use this model to explain oblique fold and fault systems, transverse faults, and a linear seismic zone just west of Mt. Rainier known as the western Rainier zone. We also attempt to explain a concentration of earthquakes that connects the northwest-trending Mount St. Helens seismic zone to the north-trending western Rainier zone. Our tectonic model illustrates the pervasive effects of accretionary processes, combined with subsequent transpressive forces generated by oblique subduction, on Eocene to present crustal processes, such as seismicity and volcanism.
The Woodworth Study Area (WSA) was purchased by the U.S. Fish and Wildlife Service (FWS) during the early 1960's as a waterfowl production area. Unlike most such areas, its primary purpose was not to provide waterfowl breeding habitat directly, but instead it was dedicated for use as a research area to develop information for better management of upland and wetland habitats. This article provides some history of the area and background information about biological monitoring and research that have been conducted on the WSA. Unless otherwise stated, information included in derived from (1) or unpublished data on file at the Northern Prairie Science Center (NPSC).
This report identifies key technical issues related to hydrologic assessment of water flow in the unsaturated zone at low-level radioactive waste (LLW) disposal facilities. In addition, a methodology for incorporating these issues in the performance assessment of proposed LLW disposal facilities is identified and evaluated. The issues discussed fall into four areas:
An estimate of recharge at a LLW site is important since recharge is a principal factor in controlling the release of contaminants via the groundwater pathway. The most common methods for estimating recharge are discussed in Chapter 2. Many factors affect recharge; the natural recharge at an undisturbed site is not necessarily representative either of the recharge that will occur after the site has been disturbed or of the flow of water into a disposal facility at the site. Factors affecting recharge are discussed in Chapter 2.
At many sites engineered components are required for a LLW facility to meet performance requirements. Chapter 3 discusses the use of engineered barriers to control the flow of water in a LLW facility, with a particular emphasis on cover systems. Design options and the potential performance and degradation mechanisms of engineered components are also discussed.
Water flow in a LLW disposal facility must be evaluated before construction of the facility. In addition, hydrologic performance must be predicted over a very long time frame. For these reasons, the hydrologic evaluation relies on the use of predictive modeling. In Chapter 4, the evaluation of unsaturated water flow modeling is discussed. A checklist of items is presented to guide the evaluation. Several computer simulation codes that were used in the examples (Chapter 6) are discussed with respect to this checklist. The codes used include HELP, UNSAT-H, and VAM3DCG.
To provide a defensible estimate of water flow in a LLW disposal facility, the uncertainty associated with model predictions must be considered. Uncertainty arises because of the highly heterogeneous nature of most subsurface environments and the long time frame required in the analysis. Sources of uncertainty in hydrologic evaluation of the unsaturated zone and several approaches for analysis are discussed in Chapter 5. The methods of analysis discussed include a bounding approach, sensitivity analysis, and Monte Carlo simulation.
To illustrate the application of the discussion in Chapters 2 through 5, two examples are presented in Chapter 6. The first example is of a below ground vault located in a humid environment. The second example looks at a shallow land burial facility located in an arid environment. The examples utilize actual site-specific data and realistic facility designs. The two examples illustrate the issues unique to humid and arid sites as well as the issues common to all LLW sites. Strategies for addressing the analytical difficulties arising in any complex hydrologic evaluation of the unsaturated zone are demonstrated.
The report concludes with some final observations and recommendations.
","language":"English","publisher":"U.S. Nuclear Regulatory Comission","usgsCitation":"Meyer, P., Rockhold, M., Nichols, W., and Gee, G., 1996, Hydrologic evaluation methodology for estimating water movement through the unsaturated zone at commercial low-level radioactive waste disposal site, Report: xxii, 102 p.; Appendicies A, B, C.","productDescription":"Report: xxii, 102 p.; Appendicies A, B, C","costCenters":[{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":350760,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":350759,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6346/"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5a7040d9e4b06e28e9cae507","contributors":{"authors":[{"text":"Meyer, P.D.","contributorId":84860,"corporation":false,"usgs":false,"family":"Meyer","given":"P.D.","email":"","affiliations":[],"preferred":false,"id":726092,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rockhold, M.L.","contributorId":189624,"corporation":false,"usgs":false,"family":"Rockhold","given":"M.L.","email":"","affiliations":[],"preferred":false,"id":726093,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nichols, W.E.","contributorId":100579,"corporation":false,"usgs":false,"family":"Nichols","given":"W.E.","email":"","affiliations":[],"preferred":false,"id":726094,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gee, G.W.","contributorId":189340,"corporation":false,"usgs":false,"family":"Gee","given":"G.W.","email":"","affiliations":[],"preferred":false,"id":726095,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018750,"text":"70018750 - 1996 - Site response for urban Los Angeles using aftershocks of the Northridge earthquake","interactions":[],"lastModifiedDate":"2023-10-23T11:57:41.728477","indexId":"70018750","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Site response for urban Los Angeles using aftershocks of the Northridge earthquake","docAbstract":"Ground-motion records from aftershocks of the 1994 Northridge earthquake are used to estimate site response in the urban Los Angeles area. Over 1300 shear-wave records from 61 sources and 90 sites are used in a linear inversion for source and site-response spectra. The methodology makes no assumptions about the shape of the source spectrum. To obtain a stable unique inverse, a Q model and geometrical spreading factor are assumed. In addition, the site response at a hard-rock site is constrained to be approximately 1.0 with a kappa of 0.02. The site-response spectra compare favorably with the results of previous and on-going investigations in Los Angeles. A couple of first-order effects are lower site response in the surrounding mountains, dominated by Mesozoic and Tertiary rocks, and higher values in the San Fernando and Los Angeles Basins, containing surficial Pleistocene and Holocene alluvial deposits. Results show good correlation of high site-response spectral values with localized areas of severe damage (Interstate 10 collapse, Sherman Oaks, Northridge, Interstate 5/14 collapse). However, widespread trends in site response across the sedimentary basins are not obvious. The data suggest that site responses are lower near the southern margin of the San Fernando Valley for sources to the north, due to north-dipping sedimentary structures. But the general pattern of site response is characterized by high variability on length scales less than a kilometer. Variations of a factor of 2 in site response are observed over the length scale of 200 m and for the same surficial geologic unit. For some of the alluvial basin sites, surface-wave generation is a significant contributor to elevated site response at lower frequencies, below 2 Hz. The total damage pattern for the Northridge earthquake is influenced by strong source directivity to the north and strong local site effects. The correlation of weak-motion site-response estimates with areas of significant damage demonstrates the value of these field measurements in future urban planning and in the reduction of seismic risk in urban areas.
A 160 year record of skeletal δ13C and δ18O was examined in a specimen of the coral Solenastrea bournonigrowing in Florida Bay. Variations in the δ18O of the skeleton can be correlated to changes in salinity while changes in the δ13C reflect cycling of organic material within the Bay. Based on the correlation between salinity and skeletal δ18O, we have concluded that there has been no long term increase in salinity in this area of Florida Bay over the past 160 years. Using salinity correlations between the various basins obtained from instrumental data, we have been able to extend our interpretations to other parts of Florida Bay reaching similar conclusions. In contrast to current ideas which have focused on changes in Florida Bay water quality over the past 20-yr history of the Bay as causative in its decline, we have determined that changes in water quality in this basin were already set in motion between 1905 and 1912 by the construction of the Florida East Coast Railway from Miami to Key West. The construction of the railway resulted in the restriction of the exchange of water between the Florida reef tract and the Gulf of Mexico causing Florida Bay to become more eutrophic. Evidence of this process is observed in the sudden shift to relatively lower δ13C values coincident with railway construction. Natural events also appear to have influenced the water in the Bay. Between 1912 and 1948 frequent hurricanes had the effect of increasing exchange of water between the Bay and reef tract and removing large quantities of organic rich sediments. However, since 1948 the number of hurricanes affecting the area has decreased and the products of the oxidation of organic material have been increasingly retained within the basin promoting the initiation of eutrophic conditions.
","language":"English","publisher":"Elsevier","doi":"10.1016/0031-0182(95)00078-X","usgsCitation":"Swart, P.K., Healy, G.F., Dodge, R.E., Kramer, P., Hudson, J., Halley, R., and Robblee, M.B., 1996, The stable oxygen and carbon isotopic record from a coral growing in Florida Bay: a 160 year record of climatic and anthropogenic influence: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 123, no. 1-4, p. 219-237, https://doi.org/10.1016/0031-0182(95)00078-X.","productDescription":"19 p.","startPage":"219","endPage":"237","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"links":[{"id":479099,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/0031-0182(95)00078-x","text":"Publisher Index Page"},{"id":296302,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Florida Bay","volume":"123","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5475a843e4b082506142051c","contributors":{"authors":[{"text":"Swart, Peter K.","contributorId":96832,"corporation":false,"usgs":false,"family":"Swart","given":"Peter","email":"","middleInitial":"K.","affiliations":[{"id":5112,"text":"University of Miami","active":true,"usgs":false}],"preferred":false,"id":525901,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Healy, Genevieve F.","contributorId":127608,"corporation":false,"usgs":false,"family":"Healy","given":"Genevieve","email":"","middleInitial":"F.","affiliations":[{"id":5112,"text":"University of Miami","active":true,"usgs":false}],"preferred":false,"id":525902,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dodge, Richard E.","contributorId":46628,"corporation":false,"usgs":false,"family":"Dodge","given":"Richard","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":525903,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kramer, Philip","contributorId":35911,"corporation":false,"usgs":false,"family":"Kramer","given":"Philip","affiliations":[{"id":5112,"text":"University of Miami","active":true,"usgs":false}],"preferred":false,"id":525904,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hudson, J. Harold","contributorId":54897,"corporation":false,"usgs":true,"family":"Hudson","given":"J. Harold","affiliations":[],"preferred":false,"id":525905,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Halley, Robert B.","contributorId":45692,"corporation":false,"usgs":true,"family":"Halley","given":"Robert B.","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":false,"id":525906,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Robblee, Michael B. mike_robblee@usgs.gov","contributorId":3865,"corporation":false,"usgs":true,"family":"Robblee","given":"Michael","email":"mike_robblee@usgs.gov","middleInitial":"B.","affiliations":[],"preferred":true,"id":525907,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70018433,"text":"70018433 - 1996 - Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake","interactions":[],"lastModifiedDate":"2013-01-22T15:39:21","indexId":"70018433","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake","docAbstract":"A method is presented for the simultaneous calculation of slip amplitudes and rupture times for a finite fault using a hybrid global search algorithm. The method we use combines simulated annealing with the downhill simplex method to produce a more efficient search algorithm then either of the two constituent parts. This formulation has advantages over traditional iterative or linearized approaches to the problem because it is able to escape local minima in its search through model space for the global optimum. We apply this global search method to the calculation of the rupture history for the Landers, California, earthquake. The rupture is modeled using three separate finite-fault planes to represent the three main fault segments that failed during this earthquake. Both the slip amplitude and the time of slip are calculated for a grid work of subfaults. The data used consist of digital, teleseismic P and SH body waves. Long-period, broadband, and short-period records are utilized to obtain a wideband characterization of the source. The results of the global search inversion are compared with a more traditional linear-least-squares inversion for only slip amplitudes. We use a multi-time-window linear analysis to relax the constraints on rupture time and rise time in the least-squares inversion. Both inversions produce similar slip distributions, although the linear-least-squares solution has a 10% larger moment (7.3 ?? 1026 dyne-cm compared with 6.6 ?? 1026 dyne-cm). Both inversions fit the data equally well and point out the importance of (1) using a parameterization with sufficient spatial and temporal flexibility to encompass likely complexities in the rupture process, (2) including suitable physically based constraints on the inversion to reduce instabilities in the solution, and (3) focusing on those robust rupture characteristics that rise above the details of the parameterization and data set.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(95)03108-1","issn":"00319201","usgsCitation":"Hartzell, S., and Liu, P., 1996, Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake: Physics of the Earth and Planetary Interiors, v. 95, no. 1-2, p. 79-99, https://doi.org/10.1016/0031-9201(95)03108-1.","startPage":"79","endPage":"99","numberOfPages":"21","costCenters":[],"links":[{"id":227383,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266262,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(95)03108-1"}],"volume":"95","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f302e4b0c8380cd4b547","contributors":{"authors":[{"text":"Hartzell, S.","contributorId":12603,"corporation":false,"usgs":true,"family":"Hartzell","given":"S.","email":"","affiliations":[],"preferred":false,"id":379555,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Liu, P.","contributorId":98443,"corporation":false,"usgs":true,"family":"Liu","given":"P.","email":"","affiliations":[],"preferred":false,"id":379556,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018495,"text":"70018495 - 1996 - Lithologic analysis from multispectral thermal infrared data of the alkalic rock complex at Iron Hill, Colorado","interactions":[],"lastModifiedDate":"2024-04-18T15:18:50.693012","indexId":"70018495","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1808,"text":"Geophysics","active":true,"publicationSubtype":{"id":10}},"title":"Lithologic analysis from multispectral thermal infrared data of the alkalic rock complex at Iron Hill, Colorado","docAbstract":"Airborne thermal-infrared multispectral scanner (TIMS) data of the Iron Hill carbonatite-alkalic igneous rock complex in south-central Colorado are analyzed using a new spectral emissivity ratio algorithm and confirmed by field examination using existing 1:24 000-scale geologic maps and petrographic studies. Color composite images show that the alkalic rocks could be clearly identified and that differences existed among alkalic rocks in several parts of the complex. An unsupervised classification algorithm defines four alkalic rock classes within the complex: biotitic pyroxenite, uncompahgrite, augitic pyroxenite, and fenite + nepheline syenite. Felsic rock classes defined in the surrounding country rock are an extensive class consisting of tuff, granite, and felsite, a less extensive class of granite and felsite, and quartzite. The general composition of the classes can be determined from comparisons of the TIMS spectra with laboratory spectra. Carbonatite rocks are not classified, and we attribute that to the fact that dolomite, the predominant carbonate mineral in the complex, has a spectral feature that falls between TIMS channels 5 and 6. Mineralogical variability in the fenitized granite contributed to the nonuniform pattern of the fenite-nepheline syenite class. The biotitic pyroxenite, which resulted from alteration of the pyroxenite, is spatially associated and appears to be related to narrow carbonatite dikes and sills. Results from a linear unmixing algorithm suggest that the detected spatial extent of the two mixed felsic rock classes was sensitive to the amount of vegetation cover. These results illustrate that spectral thermal infrared data can be processed to yield compositional information that can be a cost-effective tool to target mineral exploration, particularly in igneous terranes.
","language":"English","publisher":"Society of Exploration Geophysicists","doi":"10.1190/1.1443998","issn":"00168033","usgsCitation":"Watson, K., Rowan, L.C., Bowers, T.L., Anton-Pacheco, C., Gumiel, P., and Miller, S., 1996, Lithologic analysis from multispectral thermal infrared data of the alkalic rock complex at Iron Hill, Colorado: Geophysics, v. 61, no. 3, p. 706-721, https://doi.org/10.1190/1.1443998.","productDescription":"16 p.","startPage":"706","endPage":"721","numberOfPages":"16","costCenters":[],"links":[{"id":227118,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"61","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4841e4b0c8380cd67d27","contributors":{"authors":[{"text":"Watson, K.","contributorId":39123,"corporation":false,"usgs":true,"family":"Watson","given":"K.","email":"","affiliations":[],"preferred":false,"id":379815,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rowan, L. C.","contributorId":40584,"corporation":false,"usgs":true,"family":"Rowan","given":"L.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":379816,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bowers, T. L.","contributorId":62647,"corporation":false,"usgs":true,"family":"Bowers","given":"T.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":379818,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Anton-Pacheco, C.","contributorId":20485,"corporation":false,"usgs":true,"family":"Anton-Pacheco","given":"C.","email":"","affiliations":[],"preferred":false,"id":379814,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Gumiel, P.","contributorId":49939,"corporation":false,"usgs":true,"family":"Gumiel","given":"P.","affiliations":[],"preferred":false,"id":379817,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Miller, S.H.","contributorId":8857,"corporation":false,"usgs":true,"family":"Miller","given":"S.H.","email":"","affiliations":[],"preferred":false,"id":379813,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70018502,"text":"70018502 - 1996 - A geochemical study of macerals from a Miocene lignite and an Eocene bituminous coal, Indonesia","interactions":[],"lastModifiedDate":"2012-03-12T17:19:25","indexId":"70018502","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2958,"text":"Organic Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"A geochemical study of macerals from a Miocene lignite and an Eocene bituminous coal, Indonesia","docAbstract":"Optical and chemical studies of maceral concentrates from a Miocene lignite and an Eocene high-volatile bituminous C coal from southeastern Kalimantan, Indonesia were undertaken using pyro-Lysis, optical, electron microprobe and FTIR techniques Pyrolysis products of vitrinite from bituminous coal were dominated by straight-chain aliphatics and phenols. The huminite of the Miocene lignite produced mostly phenolic compounds upon pyrolysis. Differences in the pyrolysis products between the huminite and vitrinite samples reflect both maturation related and paleobotanical differences. An undefined aliphatic source and/or bacterial biomass were the likely contributors of n-alkyl moieties to the vitrinite. The resinite fraction in the lignite yielded dammar-derived pyrolysis products, as well as aliphatics and phenols as the products of admixed huminite and other liptinites. The optically defined resinite-rich fraction of the bituminous coal from Kalimantan produced abundant n-aliphatic moieties upon pyrolysis, but only two major resin markers (cadalene and 1,6-dimethylnaphthalene). This phenomenon is likely due to the fact that Eocene resins were not dammar-related. Data from the electron microprobe and Fourier transform infrared spectrometry strongly support the results obtained by Py GC MS and microscopy.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Organic Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0146-6380(96)00038-1","issn":"01466380","usgsCitation":"Stankiewicz, B., Kruge, M., and Mastalerz, M., 1996, A geochemical study of macerals from a Miocene lignite and an Eocene bituminous coal, Indonesia: Organic Geochemistry, v. 24, no. 5, p. 531-545, https://doi.org/10.1016/0146-6380(96)00038-1.","startPage":"531","endPage":"545","numberOfPages":"15","costCenters":[],"links":[{"id":205879,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0146-6380(96)00038-1"},{"id":227253,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e3f7e4b0c8380cd46317","contributors":{"authors":[{"text":"Stankiewicz, B.A.","contributorId":83676,"corporation":false,"usgs":true,"family":"Stankiewicz","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":379843,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kruge, M.A.","contributorId":55579,"corporation":false,"usgs":true,"family":"Kruge","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":379841,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mastalerz, Maria","contributorId":78065,"corporation":false,"usgs":true,"family":"Mastalerz","given":"Maria","affiliations":[],"preferred":false,"id":379842,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018458,"text":"70018458 - 1996 - Granular-flow rheology: Role of shear-rate number in transition regime","interactions":[],"lastModifiedDate":"2024-04-22T14:34:25.295441","indexId":"70018458","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2252,"text":"Journal of Engineering Mechanics","active":true,"publicationSubtype":{"id":10}},"title":"Granular-flow rheology: Role of shear-rate number in transition regime","docAbstract":"This paper examines the rationale behind the semiempirical formulation of a generalized viscoplastic fluid (GVF) model in the light of the Reiner-Rivlin constitutive theory and the viscoplastic theory, thereby identifying the parameters that control the rheology of granular flow. The shear-rate number ( N ) proves to be among the most significant parameters identified from the GVF model. As N → 0 and N →∞, the GVF model can reduce asymptotically to the theoretical stress versus shear-rate relations in the macroviscous and grain-inertia regimes, respectively, where the grain concentration ( C ) also plays a major role in the rheology of granular flow. Using available data obtained from the rotating-cylinder experiments of neutrally buoyant solid spheres dispersing in an interstitial fluid, the shear stress for granular flow in transition between the two regimes proves dependent on N and C in addition to some material constants, such as the coefficient of restitution. The insufficiency of data on rotating-cylinder experiments cannot presently allow the GVF model to predict how a granular flow may behave in the entire range of N ; however, the analyzed data provide an insight on the interrelation among the relevant dimensionless parameters.
","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)0733-9399(1996)122:5(469)","issn":"07339399","usgsCitation":"Chen, C., and Ling, C.#., 1996, Granular-flow rheology: Role of shear-rate number in transition regime: Journal of Engineering Mechanics, v. 122, no. 5, p. 469-479, https://doi.org/10.1061/(ASCE)0733-9399(1996)122:5(469).","productDescription":"11 p.","startPage":"469","endPage":"479","numberOfPages":"11","costCenters":[],"links":[{"id":227116,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"122","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a29c7e4b0c8380cd5ac1a","contributors":{"authors":[{"text":"Chen, Chiu-Lan","contributorId":100979,"corporation":false,"usgs":true,"family":"Chen","given":"Chiu-Lan","email":"","affiliations":[],"preferred":false,"id":379660,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ling, C. #NAME?","contributorId":14133,"corporation":false,"usgs":true,"family":"Ling","given":"C.","email":"","middleInitial":"#NAME?","affiliations":[],"preferred":false,"id":379659,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018455,"text":"70018455 - 1996 - The southern Whidbey Island fault: An active structure in the Puget Lowland, Washington","interactions":[],"lastModifiedDate":"2023-12-22T12:24:37.200255","indexId":"70018455","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"The southern Whidbey Island fault: An active structure in the Puget Lowland, Washington","docAbstract":"Information from seismic-reflection profiles, outcrops, boreholes, and potential field surveys is used to interpret the structure and history of the southern Whidbey Island fault in the Puget Lowland of western Washington. This northwest-trending fault comprises a broad (as wide as 6–11 km), steep, northeast-dipping zone that includes several splays with inferred strike-slip, reverse, and thrust displacement. Transpressional deformation along the southern Whidbey Island fault is indicated by along-strike variations in structural style and geometry, positive flower structure, local unconformities, out-of-plane displacements, and juxtaposition of correlative sedimentary units with different histories.
The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. The Cascade block to the northeast is floored by diverse assemblages of pre-Tertiary rocks; the Coast Range block to the southwest is floored by lower Eocene marine basaltic rocks of the Crescent Formation. The fault probably originated during the early Eocene as a dextral strike-slip fault along the eastern side of a continental-margin rift. Bending of the fault and transpressional deformation began during the late middle Eocene and continues to the present. Oblique convergence and clockwise rotation along the continental margin are the inferred driving forces for ongoing deformation.
Evidence for Quaternary movement on the southern Whidbey Island fault includes (1) offset and disrupted upper Quaternary strata imaged on seismic-reflection profiles; (2) borehole data that suggests as much as 420 m of structural relief on the Tertiary-Quaternary boundary in the fault zone; (3) several meters of displacement along exposed faults in upper Quaternary sediments; (4) late Quaternary folds with limb dips of as much as ≈9°; (5) large-scale liquefaction features in upper Quaternary sediments within the fault zone; and (6) minor historical seismicity. The southern Whidbey Island fault should be considered capable of generating large earthquakes (Ms ≥7) and represents a potential seismic hazard to residents of the Puget Lowland.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1996)108<0334:TSWIFA>2.3.CO;2","issn":"00167606","usgsCitation":"Johnson, S.Y., Potter, C., Armentrout, J., Miller, J.J., Finn, C.A., and Weaver, C., 1996, The southern Whidbey Island fault: An active structure in the Puget Lowland, Washington: Geological Society of America Bulletin, v. 108, no. 3, p. 334-354, https://doi.org/10.1130/0016-7606(1996)108<0334:TSWIFA>2.3.CO;2.","productDescription":"21 p.","startPage":"334","endPage":"354","costCenters":[],"links":[{"id":227029,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Washington","otherGeospatial":"Southern Whidbey Island Fault","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -123.06525828676914,\n 48.43268440330638\n ],\n [\n -123.06525828676914,\n 47.816407388473664\n ],\n [\n -122.18715952639644,\n 47.816407388473664\n ],\n [\n -122.18715952639644,\n 48.43268440330638\n ],\n [\n -123.06525828676914,\n 48.43268440330638\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"108","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb053e4b08c986b324dae","contributors":{"authors":[{"text":"Johnson, S. Y.","contributorId":48572,"corporation":false,"usgs":true,"family":"Johnson","given":"S.","email":"","middleInitial":"Y.","affiliations":[],"preferred":false,"id":379647,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Potter, C. J. 0000-0002-2300-6670","orcid":"https://orcid.org/0000-0002-2300-6670","contributorId":89925,"corporation":false,"usgs":true,"family":"Potter","given":"C. J.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":379651,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Armentrout, J.M.","contributorId":16176,"corporation":false,"usgs":true,"family":"Armentrout","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":379646,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Miller, J. J.","contributorId":54588,"corporation":false,"usgs":true,"family":"Miller","given":"J.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":379648,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Finn, Carol A. 0000-0002-6178-0405 cfinn@usgs.gov","orcid":"https://orcid.org/0000-0002-6178-0405","contributorId":1326,"corporation":false,"usgs":true,"family":"Finn","given":"Carol","email":"cfinn@usgs.gov","middleInitial":"A.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":true,"id":379650,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Weaver, C.S.","contributorId":57874,"corporation":false,"usgs":true,"family":"Weaver","given":"C.S.","email":"","affiliations":[],"preferred":false,"id":379649,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70018512,"text":"70018512 - 1996 - Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion","interactions":[],"lastModifiedDate":"2018-01-08T12:53:45","indexId":"70018512","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion","docAbstract":"Much of our knowledge of the worldwide distribution of submarine gas hydrates comes from seismic observations of Bottom Simulating Reflectors (BSRs). Full waveform inversion has proven to be a reliable technique for studying the fine structure of BSRs using the compressional wave velocity. We applied a non-linear full waveform inversion technique to a BSR at a location offshore Peru. We first determined the large-scale features of seismic velocity variations using a statistical inversion technique to maximise coherent energy along travel-time curves. These velocities were used for a starting velocity model for the full waveform inversion, which yielded a detailed velocity/depth model in the vicinity of the BSR. We found that the data are best fit by a model in which the BSR consists of a thin, low-velocity layer. The compressional wave velocity drops from 2.15 km/s down to an average of 1.70 km/s in an 18m thick interval, with a minimum velocity of 1.62 km/s in a 6 m interval. The resulting compressional wave velocity was used to estimate gas content in the sediments. Our results suggest that the low velocity layer is a 6-18 m thick zone containing a few percent of free gas in the pore space. The presence of the BSR coincides with a region of vertical uplift. Therefore, we suggest that gas at this BSR is formed by a dissociation of hydrates at the base of the hydrate stability zone due to uplift and subsequently a decrease in pressure.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earth and Planetary Science Letters","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0012-821X(95)00242-5","issn":"0012821X","usgsCitation":"Pecher, I., Minshull, T., Singh, S., and von Huene, R.E., 1996, Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion: Earth and Planetary Science Letters, v. 139, no. 3-4, p. 459-469, https://doi.org/10.1016/0012-821X(95)00242-5.","startPage":"459","endPage":"469","numberOfPages":"11","costCenters":[],"links":[{"id":227388,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205907,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0012-821X(95)00242-5"}],"volume":"139","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc1fce4b08c986b32a87c","contributors":{"authors":[{"text":"Pecher, I.A.","contributorId":14011,"corporation":false,"usgs":true,"family":"Pecher","given":"I.A.","email":"","affiliations":[],"preferred":false,"id":379877,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Minshull, T.A.","contributorId":75815,"corporation":false,"usgs":true,"family":"Minshull","given":"T.A.","email":"","affiliations":[],"preferred":false,"id":379879,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Singh, S.C.","contributorId":106380,"corporation":false,"usgs":true,"family":"Singh","given":"S.C.","email":"","affiliations":[],"preferred":false,"id":379880,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"von Huene, Roland E. 0000-0003-1301-3866 rvonhuene@usgs.gov","orcid":"https://orcid.org/0000-0003-1301-3866","contributorId":191070,"corporation":false,"usgs":true,"family":"von Huene","given":"Roland","email":"rvonhuene@usgs.gov","middleInitial":"E.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true},{"id":7065,"text":"USGS emeritus","active":true,"usgs":false}],"preferred":false,"id":379878,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018445,"text":"70018445 - 1996 - Uranium-series disequilibrium, sedimentation, diatom frustules, and paleoclimate change in Lake Baikal","interactions":[],"lastModifiedDate":"2023-12-09T00:46:15.253825","indexId":"70018445","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Uranium-series disequilibrium, sedimentation, diatom frustules, and paleoclimate change in Lake Baikal","docAbstract":"The large volume of water, approximately one-fifth of the total surface fresh water on the planet, contained in Lake Baikal in southeastern Siberia is distinguished by having a relatively high concentration of uranium (ca. 2 nM), and, together with the surface sediments, an unusually high234U238U alpha activity ratio of 1.95. About 80% of the input of uranium to the lake, with a234U238U ratio of 2.0, comes from the Selenga River. Profiles of uranium, as well as the extent of isotopic disequilibrium in a 9 m sediment core collected on Academic Ridge, generally show high values during interglacial periods corresponding to high diatom frustule numbers (DiFr) and biogenic silica (BSi) data that have been reported elsewhere. During glacial periods (low DiFr and BSi), uranium progeny (234U and230Th) were in secular equilibrium with low concentrations of their parent238U. Radionuclide distributions were interpreted in terms of a quantitative model allowing for adsorption of riverine inputs of uranium onto two classes of sedimenting particles with differing238U232Th ratios and uranium progeny in secular equilibrium. If the234U238U activity ratio of adsorbed uranium has remained constant, mean sedimentation rates can be independently estimated as 3.6 ± 0.6 and 3.7 ± 0.9 cm · kyr−1 for the decay of234U and in-growth of230Th, respectively. These rates are consistent with a mean rate of 3.76 cm · kyr−1, calculated by optimization of the correspondence between adsorbed238U and δ18O in dated oceanic sediments. The adsorbed uranium apparently tracks variable river flow during interglacials and is drastically reduced during periods of glaciation. Evidently, uranium has not been significantly redistributed within Baikal sediments over at least the past 250 kyr and is a unique, biologically non-essential, tracer for climate-sensitive processes, which provide their own internal geochronometers, potentially useful for ages up to 1 Myr BP.
The geochemical transport of cyanazine and its metabolite cyanazine amide (CAM) was compared to atrazine and its metabolite deethylatrazine (DEA) at three sites in the Mississippi River basin during 1992 and six sites during 1993. The floods of 1993 caused an uninterrupted exponential decline in herbicide concentrations; whereas, in 1992 herbicide concentrations varied mostly in response to two discrete discharge pulses in the spring and midsummer and were stable during an extended period of summer low-flow. Concentration half-lives calculated from the 1993 data for atrazine were approximately twice those of cyanazine at all sites. The half-life for atrazine and cyanazine was shortest, 22 and 14 days, respectively at the Mississippi River at Clinton, Ill. -- the farthest upstream site -- and longest, 42 and 22 days, respectively, at the Baton Rouge, La. site -- the farthest downstream site. The concentration of CAM exceeded the concentration of DEA through September at all sites where the mean ratio of atrazine-to-cyanazine (ACR) was less than 4.0. The ratio of CAM-to-cyanazine (CAMCR) increased from 0.2 to more than 1.0 and the ratio of DEA-to-atrazine (DAR) increased from less than 0.1 to 0.3 from application in May through early to mid- July. Temporal changes in the CAMCR were used to identify pre- and post-application \"slugs\" of water transported along the reaches of the Mississippi River.
","language":"English","publisher":"ACS Publications","doi":"10.1021/bk-1996-0630.ch021","usgsCitation":"Meyer, M.T., Thurman, E., and Goolsby, D.A., 1996, Cyanazine, atrazine, and their metabolites as geochemical indicators of contaminant transport in the Mississippi River: ACS Symposium Series, v. 630, p. 288-302, https://doi.org/10.1021/bk-1996-0630.ch021.","productDescription":"15 p.","startPage":"288","endPage":"302","numberOfPages":"15","costCenters":[],"links":[{"id":227095,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee","city":"Baton Rouge, Clinton","otherGeospatial":"Mississippi River basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -88.60423401044336,\n 39.863641898142305\n ],\n [\n -92.710604915468,\n 39.863641898142305\n ],\n [\n -92.710604915468,\n 30.147065506425733\n ],\n [\n -88.60423401044336,\n 30.147065506425733\n ],\n [\n -88.60423401044336,\n 39.863641898142305\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"630","noUsgsAuthors":false,"publicationDate":"2009-07-23","publicationStatus":"PW","scienceBaseUri":"5059fd1ee4b0c8380cd4e63b","contributors":{"authors":[{"text":"Meyer, M. T.","contributorId":92279,"corporation":false,"usgs":true,"family":"Meyer","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":378673,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thurman, E.M.","contributorId":102864,"corporation":false,"usgs":true,"family":"Thurman","given":"E.M.","affiliations":[],"preferred":false,"id":378674,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Goolsby, D. A.","contributorId":50508,"corporation":false,"usgs":true,"family":"Goolsby","given":"D.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":378672,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018718,"text":"70018718 - 1996 - Distribution of nitrate and orthophosphate in selected streams in Central Nebraska","interactions":[],"lastModifiedDate":"2013-02-19T10:41:49","indexId":"70018718","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3718,"text":"Water Resources Bulletin","printIssn":"0043-1370","active":true,"publicationSubtype":{"id":10}},"title":"Distribution of nitrate and orthophosphate in selected streams in Central Nebraska","docAbstract":"The Central Nebraska Basins is one of 60 study units in the National Water-Quality Assessment Program of the U.S. Geological Survey. The study unit includes the Platte River and two major tributaries, the Loup and Elkhorn Rivers. Agriculture is the predominant land use in the study unit, with only eight urbanized communities exceeding a population of 10,000. Water samples were collected from selected streams in the study unit during 1993- 1995. The data were used to assess the distribution of nitrogen compounds and phosphorus in the streams and to relate the concentrations of these constituents to environmental settings. This article focuses on dissolved nitrate and orthophosphate. Dissolved nitrate concentrations were highest (90th percentiles were less than 7.0 milligrams per liter as nitrogen) in areas with extensive cropland and pasture, where chemical fertilizers are intensively applied. Synoptic measurements conducted in March and August 1994 indicate that relatively little residual fertilizer, as nitrate, applied during a single crop-growing season enters streams. Dissolved nitrate concentrations showed a seasonal pattern, being highest during winter months and lowest during the late spring and summer. Dissolved orthophosphate concentrations tended to be low across the study unit, 90 percent of all analyses did not exceed 1.7 milligrams per liter as phosphorus.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Water Resources Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Wiley","doi":"10.1111/j.1752-1688.1996.tb03494.x","issn":"00431370","usgsCitation":"Boyd, R., 1996, Distribution of nitrate and orthophosphate in selected streams in Central Nebraska: Water Resources Bulletin, v. 32, no. 6, p. 1247-1257, https://doi.org/10.1111/j.1752-1688.1996.tb03494.x.","startPage":"1247","endPage":"1257","numberOfPages":"11","costCenters":[],"links":[{"id":227267,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":267668,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1752-1688.1996.tb03494.x"}],"volume":"32","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-06-08","publicationStatus":"PW","scienceBaseUri":"505a02e8e4b0c8380cd5025e","contributors":{"authors":[{"text":"Boyd, R.A.","contributorId":19590,"corporation":false,"usgs":true,"family":"Boyd","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":380544,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018144,"text":"70018144 - 1996 - Global distribution of plant-extractable water capacity of soil","interactions":[],"lastModifiedDate":"2024-02-02T17:52:55.847937","indexId":"70018144","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2032,"text":"International Journal of Climatology","active":true,"publicationSubtype":{"id":10}},"title":"Global distribution of plant-extractable water capacity of soil","docAbstract":"Plant-extractable water capacity of soil is the amount of water that can be extracted from the soil to fulfill evapotranspiration demands. It is often assumed to be spatially invariant in large-scale computations of the soil-water balance. Empirical evidence, however, suggests that this assumption is incorrect. In this paper, we estimate the global distribution of the plant-extractable water capacity of soil.
A representative soil profile, characterized by horizon (layer) particle size data and thickness, was created for each soil unit mapped by FAO (Food and Agriculture Organization of the United Nations)/Unesco. Soil organic matter was estimated empirically from climate data. Plant rooting depths and ground coverages were obtained from a vegetation characteristic data set. At each 0.5°×0.5° grid cell where vegetation is present, unit available water capacity (cm water per cm soil) was estimated from the sand, clay, and organic content of each profile horizon, and integrated over horizon thickness. Summation of the integrated values over the lesser of profile depth and root depth produced an estimate of the plant-extractable water capacity of soil.
The global average of the estimated plant-extractable water capacities of soil is 8ċ6cm (Greenland, Antarctica and bare soil areas excluded). Estimates are less than 5, 10 and 15 cm—over approximately 30, 60, and 89 per cent of the area, respectively. Estimates reflect the combined effects of soil texture, soil organic content, and plant root depth or profile depth. The most influential and uncertain parameter is the depth over which the plant- extractable water capacity of soil is computed, which is usually limited by root depth. Soil texture exerts a lesser, but still substantial, influence. Organic content, except where concentrations are very high, has relatively little effect.
","language":"English","publisher":"Royal Meteorological Society","doi":"10.1002/(SICI)1097-0088(199608)16:8<841::AID-JOC60>3.0.CO;2-8","issn":"08998418","usgsCitation":"Dunne, K., and Willmott, C., 1996, Global distribution of plant-extractable water capacity of soil: International Journal of Climatology, v. 16, no. 8, p. 841-859, https://doi.org/10.1002/(SICI)1097-0088(199608)16:8<841::AID-JOC60>3.0.CO;2-8.","productDescription":"19 p.","startPage":"841","endPage":"859","numberOfPages":"19","costCenters":[],"links":[{"id":227142,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2944e4b0c8380cd5a7e7","contributors":{"authors":[{"text":"Dunne, K.A.","contributorId":18920,"corporation":false,"usgs":true,"family":"Dunne","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":378678,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Willmott, C.J.","contributorId":99315,"corporation":false,"usgs":true,"family":"Willmott","given":"C.J.","email":"","affiliations":[],"preferred":false,"id":378679,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018600,"text":"70018600 - 1996 - Experimental investigation and modeling of uranium (VI) transport under variable chemical conditions","interactions":[],"lastModifiedDate":"2019-02-20T08:50:46","indexId":"70018600","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Experimental investigation and modeling of uranium (VI) transport under variable chemical conditions","docAbstract":"The transport of adsorbing and complexing metal ions in porous media was investigated with a series of batch and column experiments and with reactive solute transport modeling. Pulses of solutions containing U(VI) were pumped through columns filled with quartz grains, and the breakthrough of U(VI) was studied as a function of variable solution composition (pH, total U(VI) concentration, total fluoride concentration, and pH-buffering capacity). Decreasing pH and the formation of nonadsorbing aqueous complexes with fluoride increased U(VI) mobility. A transport simulation with surface complexation model (SCM) parameters estimated from batch experiments was able to predict U(VI) retardation in the column experiments within 30%. SCM parameters were also estimated directly from transport data, using the results of three column experiments collected at different pH and U(VI) pulse concentrations. SCM formulations of varying complexity (multiple surface types and reaction stoichiometries) were tested to examine the trade-off between model simplicity and goodness of fit to breakthrough. A two-site model (weak- and strong-binding sites) with three surface complexation reactions fit these transport data well. With this reaction set the model was able to predict (1) the effects of fluoride complexation on U(VI) retardation at two different pH values and (2) the effects of temporal variability of pH on U(VI) transport caused by low pH buffering. The results illustrate the utility of the SCM approach in modeling the transport of adsorbing inorganic solutes under variable chemical conditions.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/95WR02815","usgsCitation":"Kohler, M., Curtis, G., Kent, D., and Davis, J., 1996, Experimental investigation and modeling of uranium (VI) transport under variable chemical conditions: Water Resources Research, v. 32, no. 12, p. 3539-3551, https://doi.org/10.1029/95WR02815.","productDescription":"13 p.","startPage":"3539","endPage":"3551","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227432,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0dd4e4b0c8380cd531f4","contributors":{"authors":[{"text":"Kohler, M.","contributorId":32694,"corporation":false,"usgs":true,"family":"Kohler","given":"M.","affiliations":[],"preferred":false,"id":380188,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Curtis, G.P.","contributorId":65619,"corporation":false,"usgs":true,"family":"Curtis","given":"G.P.","email":"","affiliations":[],"preferred":false,"id":380189,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kent, D.B.","contributorId":16588,"corporation":false,"usgs":true,"family":"Kent","given":"D.B.","email":"","affiliations":[],"preferred":false,"id":380187,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Davis, J.A.","contributorId":71694,"corporation":false,"usgs":true,"family":"Davis","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":380190,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70018603,"text":"70018603 - 1996 - Identification of groundwater parameters at Columbus, Mississippi, using a 3D inverse flow and transport model","interactions":[],"lastModifiedDate":"2012-03-12T17:19:25","indexId":"70018603","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","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":"Identification of groundwater parameters at Columbus, Mississippi, using a 3D inverse flow and transport model","docAbstract":"An extensive amount of data including hydraulic heads, hydraulic conductivities and concentrations of several solutes from controlled injections have been collected during the MADE 1 and MADE 2 experiments at a heterogeneous site near Columbus, Mississippi. In this paper the use of three-dimensional inverse groundwater models including simultaneous estimation of flow and transport parameters is proposed to help identify the dominant characteristics at the site. Simulations show that using a hydraulic conductivity distribution obtained from 2187 borehole flowmeter tests directly in the model produces poor matches to the measured hydraulic heads and tritium concentrations. Alternatively, time averaged hydraulic head maps are used to define zones of constant hydraulic conductivity to be estimated. Preliminary simulations suggest that in the case of conservative transport many, but not all, of the major plume characteristics can be explained by large-scale heterogeneity in recharge and hydraulic conductivity.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"IAHS-AISH Publication","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01447815","usgsCitation":"Barlebo, H., Rosbjerg, D., and Hill, M.C., 1996, Identification of groundwater parameters at Columbus, Mississippi, using a 3D inverse flow and transport model: IAHS-AISH Publication, v. 237, p. 189-208.","startPage":"189","endPage":"208","numberOfPages":"20","costCenters":[],"links":[{"id":227481,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"237","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3829e4b0c8380cd6147f","contributors":{"authors":[{"text":"Barlebo, H.C.","contributorId":90484,"corporation":false,"usgs":true,"family":"Barlebo","given":"H.C.","email":"","affiliations":[],"preferred":false,"id":380198,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rosbjerg, D.","contributorId":108266,"corporation":false,"usgs":true,"family":"Rosbjerg","given":"D.","affiliations":[],"preferred":false,"id":380199,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hill, M. C.","contributorId":48993,"corporation":false,"usgs":true,"family":"Hill","given":"M.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":380197,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70018574,"text":"70018574 - 1996 - Estimation of the potential for atrazine transport in a silt loam soil","interactions":[],"lastModifiedDate":"2023-02-03T16:57:00.061972","indexId":"70018574","displayToPublicDate":"1996-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":612,"text":"ACS Symposium Series","active":true,"publicationSubtype":{"id":10}},"title":"Estimation of the potential for atrazine transport in a silt loam soil","docAbstract":"The transport potential of the herbicide atrazine (2-chloro-4-ethyl-6-isopropyl-s-triazine) through a 1-meter-thick root zone of corn (Zea mays L.) in a silty-loam soil in Kansas was estimated for a 22-year period (1972-93) using the one-dimensional water-flow and solute-transport model LEACHM. Results demonstrate that, for this soil, atrazine transport is directly related to the amount and timing of rain that follows spring applications of atrazine. Two other critical transport factors were important in wet years — [1] variability in atrazine application rate, and [2] atrazine degradation rates below the root zone. Results demonstrate that the coincidence of heavy rain soon after atrazine application can cause herbicide to move below the rooting zone into depths at which biodegradation rates are assumed to be low but are often unknown. Atrazine that reaches below the rooting zone and persists in the underlying soil can subsequently be transported into ground water as soil water drains, typically after the growing season. A frequency analysis of atrazine concentrations in subsurface drainage, combined with field data, demonstrates the relative importance of critical transport factors and confirms a need for definitive estimates of atrazine-degradation rates below the root zone. The analysis indicates that periodic leaching of atrazine can be expected for this soil when rainfall that exceeds 20 cm/mo coincides with atrazine presence in soil.
","language":"English","publisher":"ACS Publications","doi":"10.1021/bk-1996-0630.ch009","usgsCitation":"Eckhardt, D.A., and Wagenet, R.J., 1996, Estimation of the potential for atrazine transport in a silt loam soil: ACS Symposium Series, v. 630, p. 101-116, https://doi.org/10.1021/bk-1996-0630.ch009.","productDescription":"16 p.","startPage":"101","endPage":"116","numberOfPages":"16","costCenters":[],"links":[{"id":226996,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"630","noUsgsAuthors":false,"publicationDate":"2009-07-23","publicationStatus":"PW","scienceBaseUri":"505a0bb5e4b0c8380cd52837","contributors":{"authors":[{"text":"Eckhardt, D. A. V.","contributorId":31127,"corporation":false,"usgs":true,"family":"Eckhardt","given":"D.","email":"","middleInitial":"A. V.","affiliations":[],"preferred":false,"id":380090,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wagenet, R. J.","contributorId":55584,"corporation":false,"usgs":true,"family":"Wagenet","given":"R.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":380091,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}