Objects in mirror are closer than they appear: Reflections on Seeing the State (S. Corbridge, G. Williams, M. Srivastava, and R. Véron)     

Paul Robbins  Jennifer L. Rice 《Geoforum》2007,38(4):608-610

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Miscellaneous information     

James R. Rice  Mary Hubbard  Andrea Borgia  G?ran Ekstr?m  S. J. Gibowicz  et al. 《Bulletin of Volcanology》1990,52(Z1):81-91

Miscellaneous information  相似文献   

Oil-generating coals of the San Juan Basin, New Mexico and Colorado, U.S.A.     

J.L. Clayton  D.D. Rice  G.E. Michael 《Organic Geochemistry》1991,17(6)

Coal beds of the Upper Cretaceous Fruitland Formation in the San Juan Basin of northwestern New Mexico and southwestern Colorado have significant liquid hydrocarbon generation potential as indicated by typical Rock-Eval Hydrogen Indexes in the range of 200–400 mg hydrocarbon/g organic carbon (type II and III organic matter). Small, non-commercial quantities of oil have been produced from the coal beds at several locations. The oils are characterized by high pristane/phytane (ca 4) and pristane/n-C₁₇ ratios (ca 1.2), abundant C₂₁₊ alkanes in the C₁₀₊ fraction with a slight predominance of odd carbon-numbered n-alkanes, abundant branched-chain alkanes in the C₁₅₊ region, and a predominance of methylcyclohexane in the C₄----C₁₀ fraction. The oils are indigenous to the Fruitland Formation coals and probably migrated at thermal maturities corresponding to vitrinite reflectance values in the range 0.7–0.8%. Although the oils found to date are not present in commercial amounts, these findings illustrate the potential of some coals to generate and expel oil under conditions of moderate thermal heating.  相似文献   

The mechanism of the Mt. St. Helens eruption and speculations regarding Soret effects in planetary dynamics     

Alan Rice 《Surveys in Geophysics》1985,7(4):303-384

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Hydrocarbon contamination in sediments from urban stormwater runoff     

Robert C. Brown  Richard H. Pierce  Stanley A. Rice 《Marine pollution bulletin》1985,16(6):236-240

This investigation showed that urban stormwater runoff provides a significant amount of petrogenic material to receiving waters and sediments. A characteristic hydrocarbon ‘fingerprint’ for sediments and particulate matter in the Hillsborough Reservoir, Hillsborough River and upper Hillsborough Bay was provided. Determination of source material for petroleum contamination in stormwater runoff and river sediment indicated that crankcase oil was a primary contributor to sediment hydrocarbon contamination. A comparison of sediment hydrocarbons with hydrocarbons from stormwater runoff showed that the most probable source of crankcase oil-like petrochemicals found in sediment was the stormwater runoff.A comparison of hydrocarbon composition in suspended particulate matter with that of accumulated bottom sediments in the reservoir, river and bay, during a non-storm period and rising tide showed no resuspension and upriver transport of petroleum contaminated bay sediment. No special influence of the bay upon the lower river was observed relative to hydrocarbon tracers, indicating that most contaminated sediment transport was downriver during storm events. Additional studies should be performed over various tidal cycles and storm events incorporating sediment cores, sediment grain size analysis and hydrocarbon characterization at more closely spaced stations near the river mouth to address adequately the question of specific hydrocarbon pollution sources, rate of petroleum influx and persistence of petrochemical contaminants in the sediment.  相似文献   

Recognition of environmentally caused variations in radon time series     

M. H. Shapiro  A. Rice  M. H. Mendenhall  J. D. Melvin  T. A. Tombrello 《Pure and Applied Geophysics》1984,122(2-4):309-326

Four techniques (pattern recognition, Fourier transformation, cross-correlation, and multiple linear regression) have been used to recognize nontectonic environmental factors affecting groundwater radon data collected by the Caltech automated geochemical network. Several factors, including air temperature, rainfall, water level, carbon dioxide concentration in the water, and barometric pressure, were found to correlate with radon level at some stations in the network. For example, approximately 60% of the variance in radon signal at one site studied (Pacoima) could be accounted for by nontectonic influences. However, it was not possible to correlate all the observed changes in radon concentration with nontectonic environmental variables. Some of the observed radon anomalies did appear to be related to either regional changes in tectonic strain or some individual earthquakes. A model is developed to account for spike-like increases in radon caused by carbon dioxide emission.  相似文献   

Hydraulic Properties of Stony Vadose Zonesa     

Herman Bouwer  R. C. Rice 《Ground water》1984,22(6):696-705

Hydraulic properties of saturated and unsaturated stony soils were studied on a 3.35 m long column, 1.24 m in diameter, filled with alternating sand and boulder layers. The boulders averaged 6.2 × 15 × 20 cm in size and were laid down on their flat side. Tensiometers and a neutron probe access tube were placed in the column for measuring pressure heads and water contents, respectively. Saturated conditions were obtained by ponding the column. The resulting hydraulic conductivity K was 5.1 m/day. This value could also be calculated from the measured K for the sand alone on separate samples, using a simple equation that takes into account the void ratio of the sand alone and that of the boulder-sand mixture. Unsaturated K was determined by applying water at less than ponded infiltration rates. Resulting relations between the unsaturated K and water content or negative pressure head could also be estimated from the relation between unsaturated K and pressure head for the sand alone and the calculated saturated K of the boulder-sand mixture. The method of Millington and Quirk for calculating the relation between unsaturated K and water content also gave reasonable results. The dispersivity of the boulder-sand column was 18 times that of the sand alone. Pore velocity was accurately estimated as the Darcy velocity divided by the volumetric water content. Hydraulic properties of stony vadose zones are difficult to determine. This work shows that they can be estimated from K relations measured in the laboratory on samples of the soil between the rocks. Knowledge of hydraulic properties of vadose zones is important in predicting movement of water and pollutants to the underlying ground water.  相似文献   

Rollover in volcanic crater lakes: a possible cause for Lake Nyos type disasters     

A. Rice   《Journal of Volcanology and Geothermal Research》2000,97(1-4)

Seemingly stably stratified fluids, that is a heavier layer of fluid underlying an upper layer of lighter fluid, can overturn if there is a heat flux through the system. Such events are termed “rollover” in the engineering literature (occurring for instance in liquid natural gas tanks). They take place as well in lakes and ponds. In all such cases, the stratification starts off with the heavier, more dense fluid underlying lighter. Convection driven mixing at the stratification interface (due to the heat flux) as well as other processes serves to minimize with time the stabilizing density differences, which may eventually cause the stratification to invert. If gas has been contained under pressure in the lower layer, this gas may explosively vent from the fluid as it suddenly rises to the top such as occurs in liquid natural gas tanks where rollover is a hazard. These processes are quantifiable and are applied here to various scenarios that might refer to volcanic crater lakes whose lower layers are charged with volatiles. Provided herein are some examples of calculated conditions and calculated time of evolution leading to rollover with attendant release of gases from supersaturated ascending fluids. These calculations suggest rollover could occur in volcanic lakes. The August 1986 gas release at Lake Nyos is employed as an example. These estimates were made taking note that water is commonly supersaturated in CO₂  相似文献   

Constant Drawdown Aquifer Tests: An Alternative to Traditional Constant Rate Tests     

John B. Rice Jr.  CPG 《Ground Water Monitoring & Remediation》1998,18(2):76-78

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Paleolakes on Mars     

Robert A. Wharton Jr.  Jamison M. Crosby  Christopher P. McKay  James W. Rice Jr. 《Journal of Paleolimnology》1995,13(3):267-283

Observational evidence such as outflow channels and valley networks suggest that in the past there was flowing water on Mars. The images of fluvial features on Mars logically suggest that there must exist downstream locations in which the water pooled and the sediment load deposited (i.e. lakes). Sediments and morphological features associated with the martian paleolakes are believed to occur in Valles Marineris, and several large basins including Amazonis, Chryse and Elysium planitia. As Mars became progressively colder over geological time, any lakes on its surface would have become seasonally, and eventually perennially ice-covered. We know from polar lakes on Earth that ice-covered lakes can persist even when the mean annual temperature falls below freezing. Thus, the most recent lacustrine sediments on Mars were probably deposited in ice-covered lakes. While life outside of the Earth's atmosphere has yet to be observed, there is a general consensus among exobiologists that the search for extraterrestrial life should be based upon liquid water. The inference that there was liquid water on Mars during an earlier epoch is the primary motivation for considering the possibility of life during this time. It would be of enormous interest from both an exobiological and paleolimnological perspective to discover lakes or the evidence of former lakes on another planet such as Mars. Limnology would then become an interplanetary science.  相似文献