Estimation of descriptive statistics for multiply censored water quality data
Dennis R. Helsel, Timothy A. Cohn
1988, Water Resources Research (24) 1997-2004
This paper extends the work of Gilliom and Helsel (1986) on procedures for estimating descriptive statistics of water quality data that contain “less than” observations. Previously, procedures were evaluated when only one detection limit was present. Here we investigate the performance of estimators for data that have multiple detection limits....
Elastic-wave propagation and site amplification in the Salt Lake Valley, Utah, from simulated normal faulting earthquakes
H.M. Benz, R. B. Smith
1988, Bulletin of the Seismological Society of America (78) 1851-1874
The two-dimensional seismic response of the Salt Lake valley to near- and far-field earthquakes has been investigated from simulations of vertically incident plane waves and from normal-faulting earthquakes generated on the basin-bounding Wasatch fault. The response to normal faulting earthquakes was simulated using a two-dimensional finite-element method and the plane-wave...
Coastal erosion: Processes, timing and magnitudes at the bluff toe
C.H. Carter, D.E. Guy Jr.
1988, Marine Geology (84) 1-17
Five Lake Erie bluffs (one interlaminated clay and silt, three clay-rich diamicts and one shale) were surveyed at about 2-week intervals and after wind storms for up to 5 years. Erosion of the bluff toes along this low-energy coast occurred during...
The global distribution, abundance, and stability of SO2 on Io
A. S. McEwen, T. V. Johnson, D. L. Matson, L.A. Soderblom
1988, Icarus (75) 450-478
Sulfur dioxide distribution and abundances, bolometric hemispheric albedos, and passive surface temperatures on Io are modeled and mapped globally from Voyager multispectral mosaics, Earth-based spectra, and photometric descriptions. Photometric models indicate global average values for regolith porosity of 75-95% and macroscopic roughness with a mean slope angle of ~30??. Abundances...
Geochemistry of some gases in hydrothermal fluids from the southern Juan de Fuca Ridge
William C. Evans, L. D. White, J. B. Rapp
1988, Journal of Geophysical Research Solid Earth (93) 15305-15313
Five samples of hydrothermal fluids from two vent areas on the southern Juan de Fuca Ridge were analyzed for dissolved gases. Concentrations in the end-member hydrothermal fluid of H2 (270–527 μmol/kg), CH4 (82–118 μmol/kg), and CO2 (3920–4460 μmol/kg) are well above values in ambient seawater and are similar to concentrations reported for other...
Using exogenous variables in testing for monotonic trends in hydrologic time series
William M. Alley
1988, Water Resources Research (24) 1955-1961
One approach that has been used in performing a nonparametric test for monotonic trend in a hydrologic time series consists of a two-stage analysis. First, a regression equation is estimated for the variable being tested as a function of an exogenous variable. A nonparametric trend test such as...
Three decades of geochronologic studies in the New England Appalachians
R. E. Zartman
1988, Geological Society of America Bulletin (100) 1168-1180
Over the past 30 years, both isotope geochronology and plate tectonics grew from infancy into authoritative disciplines in the geological sciences. Previously, mountain systems like the Appalachians had been viewed almost entirely in the context of the classical geosyncline, implying a gradualism in stratigraphic and structural change throughout the orogen....
A tentative protocol for measurement of radon availability from the ground
A.B. Tanner
1988, Radiation Protection Dosimetry (24) 79-83
A procedure is being tested in order to determine its suitability for assessing the intrinsic ability of the ground at a particular site to supply 222Rn to a basement structure to be built on the site. Soil gas is sucked from a borehole probe through an alpha scintillation chamber and flow...
Contrasting serpentinization processes in the eastern Central Alps
D.J.M. Burkhard, J. R. O’Neil
1988, Contributions to Mineralogy and Petrology (99) 498-506
Stable isotope compositions have been determined for serpentinites from between Davos (Arosa-Platta nappe, Switzerland) and the Valmalenco (Italy). ??D and ??18O values (-120 to -60 and 6-10???, respectively) in the Arosa-Platta nappe indicate that serpentinization took place on the continent at relatively low temperatures in the presence of limited amounts...
Teleseismic and near-field analysis of the Nahanni earthquakes in the Northwest Territories, Canada
G. L. Choy, J. Boatwright
1988, Bulletin of the Seismological Society of America (78) 1627-1652
The analysis of the Nahanni earthquakes of October 5, 1985 (MS 6.6), and December 23, 1985 (MS 6.9), will have important implications for the assessment of seismic hazards in intraplate environments. To maximize the information available to seismic engineers, broadband data recorded teleseismically are analyzed jointly with strong-motion data recorded...
Major- and minor-metal composition of three distinct solid material fractions associated with Juan de Fuca hydrothermal fluids (northeast Pacific), and calculation of dilution fluid samples
T. K. Hinkley, J. L. Seeley, M. Tatsumoto
1988, Chemical Geology (70) 235-248
Three distinct types of solid material are associated with each sample of the hydrothermal fluid that was collected from the vents of the Southern Juan de Fuca Ridge. The solid materials appear to be representative of deposits on ocean floors near mid-ocean ridges, and interpretation of the chemistry of the...
Acid neutralizing processes in an alpine watershed front range, Colorado, U.S.A.-1: Buffering capacity of dissolved organic carbon in soil solutions
Litaor M. Iggy, E.M. Thurman
1988, Applied Geochemistry (3) 645-652
Soil interstitial waters in the Green Lakes Valley, Front Range, Colorado were studied to evaluate the capacity of the soil system to buffer acid deposition. In order to determine the contribution of humic substances to the buffering capacity of a given...
Cyclic development of igneous features and their relationship to high-temperature hydrothermal features in the Henderson porphyry molybdenum deposit, Colorado
R.B. Carten, E. P. Geraghty, B.M. Walker
1988, Economic Geology (83) 266-296
The Henderson porphyry molybdenum deposit was formed by the superposition of coupled alteration and mineralization events, of varying intensity and size, that were associated with each of at least 11 intrusions. Deposition of molybdenite was accompanied by time-equivalent silicic and potassic alteration. High-temperature alteration and mineralization are spatially and temporally...
Origin of metaluminous and alkaline volcanic rocks of the Latir volcanic field, northern Rio Grande rift, New Mexico
C.M. Johnson, P. W. Lipman
1988, Contributions to Mineralogy and Petrology (100) 107-128
Volcanic rocks of the Latir volcanic field evolved in an open system by crystal fractionation, magma mixing, and crustal assimilation. Early high-SiO2 rhyolites (28.5 Ma) fractionated from intermediate compositionmagmas that did not reach the surface. Most precaldera lavas have intermediate-compositions, from olivine basaltic-andesite (53% SiO2) to quartz latite (67% SiO2)....
Measuring contemporary crustal motions; NASA’s Crustal Dynamics Project
H. V. Frey, J. M. Bosworth
1988, Earthquakes & Volcanoes (USGS) (20) 96-113
In the early and middle 1970's, two new space-based geodetic techniques became available that offered unprecedented accuracy in the measurement of distances over long baselines. As described below, Satellite Laser Ranging (SLR) and Very Long Baseline Interferometry (VLBI) provided a capability to determine in relatively short periods of time the...
The role of the Federal government in the Parkfield earthquake prediction experiment
J.R. Filson
1988, Earthquakes & Volcanoes (USGS) (20) 56-59
Earthquake prediction research in the United States us carried out under the aegis of the National Earthquake Hazards Reduction Act of 1977. One of the objectives of the act is "the implementation in all areas of high or moderate seismic risk, of a system (including personnel and procedures) for predicting...
NOAA-10 AVHRR thermal-infrared image of the Colorado Rocky Mountains
Kevin P. Gallo, Bruce K. Quirk, Joy J. Hood
1988, Photogrammetric Engineering and Remote Sensing (54) 777
This month we demonstrate an example of the use of thermal infrared imagery to produce a relatively sharp surrogate shaded-relief image. The image shows one aspect of the drama and usefulness of calibrated thermal imagery that (because of compatible projection and pixel size) can be easily combined with other spectral...
Testing for individual variation in breeding success
Scott A. Hatch
1988, The Auk (105) 193-194
I measured the breeding success of Northern Fulmars (Fulmarus glacialis) in 6 consecutive years at a colony in the Semidi Islands, western Gulf of Alaska (56°N, 156°W). I tabulated the frequency distribution of the number of years successful for a sample of 224 nest sites at which breeding occurred in...
Hydraulic conductivity of a sandy soil at low water content after compaction by various methods
John R. Nimmo, Katherine C. Akstin
1988, Soil Science Society of America Journal (52) 303-310
To investigate the degree to which compaction of a sandy soil influences its unsaturated hydraulic conductivity K, samples of Oakley sand (now in the Delhi series; mixed, thermic, Typic Xeropsamments) were packed to various densities and K was measured by the steady-state centrifuge method. The air-dry, machine packing was followed...
Integrating spatial and frequency information in the search for kuroko deposits of the Hokuroku District, Japan
Donald A. Singer, Ryoichi Kouda
1988, Economic Geology (83) 18-29
A new method (FINDER) that uses the area of influence and Bayesian statistics to aid in selection of target areas on the basis of one or more variables and multiple observations was tested with drill hole data. A previously defined bimodal distribution of Na 2 O with the low sodium group confined...
Sedimentology of the Argo and Gascoyne abyssal plains, NW Australia: Report on Ocean Drilling Program Leg 123 (Sept. 1–Nov. 1, 1988)
Jurgen Thurow
1988, Carbonates and Evaporites (3) 201-212
Ocean Drilling Program Leg 123 drilled two sites in the Indian Ocean in order to study the rifting and early spreading of one of the world’s oldest ocean basins.Site 765 was drilled in 5714 meters of water on the Argo Abyssal Plain northwest of Australia. The sedimentary succession...
Observed oil and gas field size distributions: A consequence of the discovery process and prices of oil and gas
L.J. Drew, E. D. Attanasi, J.H. Schuenemeyer
1988, Mathematical Geology (20) 939-953
If observed oil and gas field size distributions are obtained by random samplings, the fitted distributions should approximate that of the parent population of oil and gas fields. However, empirical evidence strongly suggests that larger fields tend to be discovered earlier in the discovery process than they would be by...
Climate and ephemeral-stream processes: Twentieth-century geomorphology and alluvial stratigraphy of the Little Colorado River, Arizona
Richard Hereford
1988, GSA Bulletin (95) 654-668
During the first 40 years of the twentieth century, erosion was the dominant geomorphic process affecting the morphology of the Little Colorado River channel. The discharge regimen was one of frequent large floods and high annual discharge that created a wide sandy channel free of vegetation. In the 1940s and...
A detailed chronology of the most recent eruption period at Mount Hood, Oregon
Kenneth A. Cameron, P. T. Pringle
1987, Geological Society of America Bulletin (99) 845-851
The most recent eruptive period of Mount Hood volcano, the Old Maid eruptive period, was characterized by volcano-hydrologic events (hydrologic events initiated by volcanic activity) which resulted in extensive lahar inundation in the White, Sandy, and Zigzag River drainages and produced a lithic pyroclastic flow which traveled at least 9...
Chemical and biological status of lakes and streams in the upper midwest: assessment of acidic deposition effects
J.G. Wiener, J.M. Eilers
1987, Lake and Reservoir Management (3) 365-378
Many lakes in three areas in the Upper Midwest - northeastern Minnesota, northern Wisconsin, and the Upper Peninsula of Michigan - have low acid neutralizing capacity (ANC) and may be susceptible to change by acidic deposition. Northcentral Wisconsin and the Upper Peninsula of Michigan together contain about 150-300 acidic lakes...
