Atmospheric mercury near Salmon Falls Creek Reservoir in southern Idaho     

Michael L. Abbott  Che-Jen Lin  Peter Martian  Jeffrey J. Einerson 《Applied Geochemistry》2008

Gaseous elemental mercury (GEM) and reactive gaseous mercury (RGM) were measured over 2-week seasonal field campaigns near Salmon Falls Creek Reservoir in south-central Idaho from the summer of 2005 through the fall of 2006 and over the entire summer of 2006 using automated Tekran Hg analyzers. GEM, RGM, and particulate Hg (HgP) were also measured at a secondary site 90 km to the west in southwestern Idaho during the summer of 2006. The study was performed to characterize Hg air concentrations in the southern Idaho area for the first time, estimate Hg dry deposition rates, and investigate the source of observed elevated concentrations. High seasonal variability was observed with the highest GEM (1.91 ± 0.9 ng m⁻³) and RGM (8.1 ± 5.6 pg m⁻³) concentrations occurring in the summer and lower values in the winter (1.32 ± 0.3 ng m⁻³, 3.2 ± 2.9 pg m⁻³ for GEM, RGM, respectively). The summer-average HgP concentrations were generally below detection limit (0.6 ± 1 pg m⁻³). Seasonally averaged deposition velocities calculated using a resistance model were 0.034 ± 0.032, 0.043 ± 0.040, 0.00084 ± 0.0017 and 0.00036 ± 0.0011 cm s⁻¹ for GEM (spring, summer, fall and winter, respectively) and 0.50 ± 0.39, 0.40 ± 0.31, 0.51 ± 0.43 and 0.76 ± 0.57 cm s⁻¹ for RGM. The total annual RGM + GEM dry deposition estimate was calculated to be 11.9 ± 3.3 μg m⁻², or about 2/3 of the total (wet + dry) deposition estimate for the area. Periodic elevated short-term GEM (2.2–12 ng m⁻³) and RGM (50–150 pg m⁻³) events were observed primarily during the warm seasons. Back-trajectory modeling and PSCF analysis indicate predominant source directions to the SE (western Utah, northeastern Nevada) and SW (north-central Nevada) with fewer inputs from the NW (southeastern Oregon and southwestern Idaho).  相似文献   

The passivation of calcite by acid mine water. Column experiments with ferric sulfate and ferric chloride solutions at pH 2   总被引：2，自引：1，他引：1  

Josep M. Soler  Marco Boi  Jos Luis Mogolln  Jordi Cama  Carlos Ayora  Peter S. Nico  Nobumichi Tamura  Martin Kunz 《Applied Geochemistry》2008,23(12):3579-3588

Column experiments, simulating the behavior of passive treatment systems for acid mine drainage, have been performed. Acid solutions (HCl or H₂SO₄, pH 2), with initial concentrations of Fe(III) ranging from 250 to 1500 mg L⁻¹, were injected into column reactors packed with calcite grains at a constant flow rate. The composition of the solutions was monitored during the experiments. At the end of the experiments (passivation of the columns), the composition and structure of the solids were measured. The dissolution of calcite in the columns caused an increase in pH and the release of Ca into the solution, leading to the precipitation of gypsum and Fe–oxyhydroxysulfates (Fe(III)–SO₄–H⁺ solutions) or Fe–oxyhydroxychlorides (Fe(III)–Cl–H⁺ solutions). The columns worked as an efficient barrier for some time, increasing the pH of the circulating solutions from 2 to 6–7 and removing its metal content. However, after some time (several weeks, depending on the conditions), the columns became chemically inert. The results showed that passivation time increased with decreasing anion and metal content of the solutions. Gypsum was the phase responsible for the passivation of calcite in the experiments with Fe(III)–SO₄–H⁺ solutions. Schwertmannite and goethite appeared as the Fe(III) secondary phases in those experiments. Akaganeite was the phase responsible for the passivation of the system in the experiments with Fe(III)–Cl–H⁺ solutions.  相似文献   

Millennium-long recession of limestone facades in London     

Peter Brimblecombe  Carlota M. Grossi 《Environmental Geology》2008,56(3-4):463-471

Historical data on the temperature and precipitation data for London has been combined with output from the Hadley Model to estimate the climate of London for the period 1100–2100 CE. This has been converted to other parameters such as freeze–thaw frequency and snowfall relevant to the weathering of stone facades. The pollutant concentrations have been estimated for the same period, with the historical values taken from single box modelling and future values from changes likely given current policy within the metropolis. These values are used in the Lipfert model to show that the recession from karst weathering dominates across the period, while the contributions of sulphur deposition seem notable only across a shorter period 1700–2000 CE. Observations of the late seventeenth century suggest London architects witnessed a notable increase in the recession rate and attributed “fretting quality” to “smoaks of the sea-coal”. The recession rates measured in the late twentieth century lend some support to the estimates from the Lipfert model. The recession looks to increase only slightly, and frost shattering will decrease while salt weathering is likely to increase.  相似文献   

Flexural isostatic response of the Alps to increased Quaternary erosion recorded by foreland basin remnants,SE France     

Jean‐Daniel Champagnac  Peter Van Der Beek  Gaël Diraison  Samuel Dauphin 《地学学报》2008,20(3):213-220

We test the hypothesis that flexural isostatic compensation of the mass removed by enhanced Quaternary erosion is responsible for uplift of the Western European Alps and their forelands. We use two well‐preserved and well‐dated (1.8 Ma) abandonment surfaces of foreland basin remnants in SE France (the Chambaran and Valensole plateaux) as passive benchmarks for tilting of the foreland. Estimating their initial slope from morphometric scaling relationships, we determine bulk post‐depositional tilting of 0.5–0.8% for these surfaces. The calculated isostatic response of the Alpine lithosphere to erosional unloading, using the method recently proposed by Champagnac et al. [Geology 35 (2007) 195–198] , yields a predicted tilting of 0.3–0.4% in the considered areas, explaining approximately half of the determined post‐depositional tilting. Such long‐term deformation being insensitive to cyclic loading/unloading because of glaciations, we suspect the other half to be related to as yet undetermined long‐wavelength and long‐lived tectonic process(es).  相似文献   

The delay between solar activity and density changes in the upper atmosphere     

Peter W. Blum 《Planetary and Space Science》1968,16(12):1427-1440

Since 1958 it is known that there exists a response time of the upper atmosphere to changes in solar activity. This response time is best described as the lag between the 27-day variation of solar decimeter flux and the observed density changes of the upper atmosphere. Roemer obtained as a mean observational value for this lag 1.0 ± 0.12 days. Volland's simplified version of the Harris-Priester model of the upper atmosphere is used to calculate the delay which can be expected from theory. Only the effect of solar EUV radiation is taken into account. A possible influence of the corpuscular component of the solar radiation is not included in our estimate.

The calculations are carried out for the Harris-Priester model with solar activity index and a variation of . The resulting delay is 0.6 days. The calculated amplitude of the variations of the diurnal average temperatures during the solar 27-days cycle is in very good agreement with Jacchia's empirical formula.  相似文献   

Buchbesprechungen     

F. Steinhauser  W. Mörikofer  J. Drimmel  Peter Steinhauser 《Meteorology and Atmospheric Physics》1965,15(2):251-264

Ohne Zusammenfassung  相似文献   

THE ATLANTIC CITY ORE MINE: A STUDY IN ECONOMIC GEOGRAPHY     

Peter F. Mason 《The Professional geographer》1966,18(5):280-282

  相似文献   

GEOGRAPHIC NOTEBOOK: POLYNESIAN MIGRATION: THE NEW WAVE     

Peter  Pirie 《New Zealand geographer》1966,22(2):182-185

  相似文献   

GEOGRAPHIC NOTEBOOK: THE TURN-ROUND OF SHIPPING IN NEW ZEALAND SAVING THE SECOND MILLION     

Peter J.  Rimmer 《New Zealand geographer》1966,22(1):94-95

  相似文献   

A sonic well log of the basement complex of the Walvis Ridge     

Philip D. Rabinowitz  Peter E. Borella 《Geo-Marine Letters》1983,3(1):1-7

A sonic well log was obtained within the basement complex of the Walvis Ridge during Deep Sea Drilling Project Leg 74. The top of the basement complex is characterized by smooth acoustic reflectors. The rocks recovered within the basement complex consist of basalts with intercalated sediments. According to the log ～-50% of the upper 75 m of basement are igneous rocks and the other 50% sedimentary. Sonobuoy results indicate that the ratio of sediments to basalt increases with depth for an additional 225 m until a typical oceanic velocity structure is observed. Paleontological results suggest that the processes forming this upper 300 m of the basement complex was accomplished within a short time interval.  相似文献