Triton: stratospheric molecules and organic sediments     

Thompson WR  Singh SK  Khare BN  Sagan C 《Geophysical research letters》1989,16(8):981-984

Hydrocarbons and nitriles are produced in Triton's stratosphere by energetic electrons from Neptune's magnetosphere and other charged particle sources. Laboratory plasma experiments reported here show a substantial yield of molecules from low pressure flows of 10(-3) CH4 in N2 appropriate to Triton if both CH4 and N2 are saturated at the surface. An active magnetosphere similar to that of Uranus would result in a flux approximately 0.3 erg cm-2 s-1 of 0.1-1 MeV electrons in Triton's stratosphere; molecular production rates are then 10(6)-10(8) cm-2 s-1 for NH3, C2H2, HCN, and NCCN; tens of hundreds of gm cm-2 of these compounds per 10(9) yr (and lesser quantities of at least eight other molecules experimentally detected) would freeze to fine-grained white condensates in the lower stratosphere and sediment to the surface. Along with dark/colored organic haze produced in the stratosphere and other heteropolymers produced at the surface, these condensates are subjects to redistribution by aeolian processes and may appear as lag deposits and/or sediment layers. A simple eddy diffusion model indicates abundances approximately 10(19) molec cm-2 for HCN and C2H2, and > 10(17) molec cm-2 for NCCN, CH3CCH, CH2CCH2, and CH3CN in the stratosphere; these and other organic molecules will be detectable by IRIS if the stratosphere is (as expected) heated through ultraviolet and visible light absorption by the haze.  相似文献   

Eccentric geomagnetic dipole drift     

Joseph C. Cain  Dave R. Schmitz  Christopher Kluth 《Physics of the Earth and Planetary Interiors》1985,39(4):237-242

A recalculation of the rate of westward drift of the eccentric geomagnetic dipole since 1900 has confirmed its correlation with irregularities in the excess length-of-day (LOD) as originally reported by Vestine. The major changes in the LOD curve since 1900 are shown to be well correlated with the westward drift rate from a number of magnetic models covering the interval. A new Magsat model of secular variation for 1980.0 shows no increase in the drift rate which dropped by a factor of three in the interval 1965–1970.  相似文献   

Emission spectrographic estimation of gold     

K. C. Joseph 《Journal of Earth System Science》1985,94(3):279-282

A procedure for estimating minute quantities (parts per billion) of gold is described, based on dissolution of the sample in aqua regia, adsorption on activated charcoal, arcing of the charcoal ash, and measurement of the intensity of the emitted spectra.  相似文献   

Distribution of Volatile Organic Compounds in a New Jersey Coastal Plain Aquifer System     

Thomas V. Fusillo  Joseph J. Hochreiter  Jr.  Deborah Grant Lord 《Ground water》1985,23(3):354-360

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Field and Laboratory Analyses of Water from the Columbia Aquifer in Eastern Maryland     

L. Joseph Bachman 《Ground water》1984,22(4):460-467

Field and laboratory analyses of pH, alkalinity, and specific conductance from water samples collected from the Columbia aquifer on the Delmarva Peninsula in eastern Maryland were compared to determine if laboratory analyses could be used for making regional water-quality interpretations. On the basis of 170 field pH and specific conductance measurements, 165 laboratory pH and specific conductance measurements, and 86 field and 135 laboratory alkalinity measurements, a significant difference at the 0.1-percent level was found between laboratory and field analyses of pH and specific conductance. No significant difference was found between laboratory and field analyses of alkalinity. In most samples, laboratory pH was greater than field pH, laboratory specific conductance was less than field specific conductance, and laboratory alkalinity was equally likely to be less than, the same as, or greater than field alkalinity. Kruskal-Wallis tests of field and laboratory data grouped by north-south and east-west coordinates and by land use indicate that the difference between field and laboratory values is usually not enough to affect the outcome of the statistical tests. Thus, laboratory measurements of these constituents may be adequate for making certain regional water-quality interpretations, although they may result in errors if used for geochemical interpretations.  相似文献   

An Overview of Computer Technology Used in Ground Water Field Studies: Part I: Basics     

Joseph D. Ritchey  Mark A. Collins 《Ground Water Monitoring & Remediation》1984,4(1):33-38

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Geomagnetic evolution: 400 years of change on planet Earth     

R. Thompson 《Physics of the Earth and Planetary Interiors》1984,36(1):61-77

Spherical harmonic coefficients of the geomagnetic field, calculated from historical observations of declination, inclination and intensity, and from archaeomagnetic inclination results, have been used to produce a film of geomagnetic change since 1600 A.D. The non-dipole geomagnetic field is found to be constantly changing: no fixed or standing non-dipole features are observed. Non-dipole foci are seen to have lifetimes of a few hundred years. The westward drift, which was an important feature of the 18th and early 19th century geomagnetic field, was less pronounced in the 17th century. The growth, evolution, decay and replacement of non-dipole foci, but not their movement are found to have been the major features producing century-long secular directional magnetic variation. Most of the low degree and order spherical harmonic coefficients have changed significantly over the last few hundred years. In particular the change in sign of the axisymmetric quadrupole around 1837 A.D. is noted. Sustained, century-long, intensity changes, however, appear to have been dominated by variations in the intensity of the centred dipole, rather than by non-dipole field fluctuations.  相似文献   

Arsenic and antimony in geothermal waters of Yellowstone National Park,Wyoming, USA     

Robert E. Stauffer  John M. Thompson 《Geochimica et cosmochimica acta》1984,48(12):2547-2561

A total of 268 thermal spring samples were analyzed for total soluble As using reduced molybdenum-blue; 27 of these samples were also analyzed for total Sb using flame atomic absorption spectrometry. At Yellowstone the $\text{Cl}\text{As}$ atomic ratio is nearly constant among neutral-alkaline springs with Cl > 100 mg L^?1, and within restricted geographic areas, indicating no differential effects of adiabatic vs. conductive cooling on arsenic. The $\text{Cl}\text{As}$ ratio increases with silica and decreases with decreasing $\text{Cl}\text{ΣCO}{}_3$; the latter relationship is best exemplified for springs along the extensively sampled SE-NW trend within the Lone Star-Upper-Midway Basin region. The relationship between $\text{Cl}\text{As}$ and $\text{Cl}\text{ΣCO}{}_3$ at Yellowstone suggests a possible rock leaching rather than magmatic origin for much of the Park's total As flux. Condensed vapor springs are low in both As and Cl. Very high $\text{Cl}\text{As}$ ratios ( > 1000) are associated exclusively with highly diluted (Cl < 100 mg L^?1) mixed springs in the Norris and Shoshone Basins and in the Upper White Creek and Firehole Lake areas of Lower Basin. The high ratios are associated with acidity and/or oxygen and iron; they indicate precipitation of As following massive dilution of the Asbearing high-Cl parent water.Yellowstone Sb ranged from 0.009 at Mammoth to 0.166 mg L^?1 at Joseph's Coat Spring. Within basins, the $\text{Cl}\text{Sb}$ ratio increases as the $\text{Cl}\text{ΣCO}{}_3$ ratio decreases, in marked contrast to As. Mixed springs also have elevated $\text{Cl}\text{Sb}$ ratios. White (1967) and Weissberg (1969) previously reported stibnite (Sb₂S₃), but not orpiment (As₂S₃), precipitating in the near surface zone of alkaline geothermal systems.  相似文献   

Dispatches from the Basalt Front. I. Experiments     

R.N. Thompson 《Proceedings of the Geologists' Association. Geologists' Association》1984,95(3):249-262

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Comparative growth of juvenile white sturgeon and striped bass: Effects of temperature and hypoxia   总被引：1，自引：0，他引：1  

Joseph J. Cech  Stephen J. Mitchell  Trent E. Wragg 《Estuaries and Coasts》1984,7(1):12-18

The influences of temperature and environmental hypoxia on the growth rates of two California anadromous fishes, white sturgeon (Acipenser transmontanus) and striped bass (Morone saxatilis) were examined. Fish (0.5–0.6 g initial weight) were fedad libitum rations ofArtemia in flow-through aquaria regulated for temperature (15, 20, and 25°C) and oxygen tension (130 and 90 torr P_{o 2}). Growth of sturgeon was significantly greater at 20 °C compared with 15 °C, but there was no difference between 20 and 25 °C. Striped bass growth increased with each 5° increment of temeprature elevation to 3.2% body weight per d at 25 °C, the fastest growth rate measured. The temperature of maximum growth reflected the temperature of the native estuarine rearing area. Environmental hypoxia (90 torr P_{o 2}) reduced growth of sturgeon within each temperature level, whereas striped bass growth was reduced by hypoxia only at the upper two temperatures. Sturgeon were much more active in the growth chambers than striped bass. Sturgeon activity increased with each 5 °C temperature increase under normoxia and hypoxia, except at 25 °C (hypoxia) where activity was insignificantly different from that at 20 °C (hypoxia).  相似文献