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本文通过调查黄龙风景区水体的环境地质特征与微生物群落结构及多样性,并与黄石公园对比分析,探讨了两种特殊地理环境下的微生物群落结构和多样性及其对钙华沉积的影响.结果表明:黄龙沟泉水属于地下冷泉,且景区内覆盖着大量植被,水体中有大量藻类和细菌;黄石公园猛犸象温泉区泉水属于地下热泉,植被覆盖率很低,泉水中微生物多为嗜热菌,藻...  相似文献   

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The combined geothermal discharge from over 10,000 features in Yellowstone National Park (YNP) can be can be estimated from the Cl flux in the Madison, Yellowstone, Falls, and Snake Rivers. Over the last 30 years, the Cl flux in YNP Rivers has been calculated using discharge measurements and Cl concentrations determined in discrete water samples and it has been determined that approximately 12% of the Cl flux exiting YNP is from the Snake River. The relationship between electrical conductivity and concentrations of Cl and other geothermal solutes was quantified at a monitoring site located downstream from the thermal inputs in the Snake River. Beginning in 2012, continuous (15 min) electrical conductivity measurements have been made at the monitoring site. Combining continuous electrical conductivity and discharge data, the Cl and other geothermal solute fluxes were determined. The 2013–2015 Cl fluxes (5.3–5.8 kt/yr) determined using electrical conductivity are comparable to historical data. In addition, synoptic water samples and discharge data were obtained from sites along the Snake River under low-flow conditions of September 2014. The synoptic water study extended 17 km upstream from the monitoring site. Surface inflows were sampled to identify sources and to quantify solute loading. The Lewis River was the primary source of Cl, Na, K, Cl, SiO2, Rb, and As loads (50–80%) in the Snake River. The largest source of SO4 was from the upper Snake River (50%). Most of the Ca and Mg (50–55%) originate from the Snake Hot Springs. Chloride, Ca, Mg, Na, K, SiO2, F, HCO3, SO4, B, Li, Rb, and As behave conservatively in the Snake River, and therefore correlate well with conductivity (R2 ≥ 0.97).  相似文献   

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Chemical analyses of 21 water samples from the Firehole and Gibbon Rivers, which combine to form the Madison River, gave arsenic and fluoride values above the Environmental Protection Agency Interim Primary Drinking Water maximum contaminant levels (0.05 mg/l arsenic and 2.0 mg/l fluoride). On 18 October, 1975, during a period of moderate flow (16,600 l/s), the Madison River at West Yellowstone contained 0.23 mg/l arsenic and 6.2 mg/l fluoride. Below Hebgen Lake the Madison River during periods of high flow (56,000 liter/s at West Yellowstone and 708,000 liter/s below Hebgen Lake) would contain 0.05 mg/l arsenic at both stations and 1.5 and 4.0 mg/l fluoride at West Yellowstone and below Hebgen Lake, respectively. The strong correlations of arsenic and fluoride with other chemical constituents of the river water at the sampling sites demonstrate the conservative nature of each element after it reaches the Madison River system. Calculations indicate that water from three sampling sites is above saturation with respect to fluorite.  相似文献   

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大地震导致的同震及震后效应,对于分析不同地震之间的相互影响及区域地震危险性等有着重要的作用.文中开发了模拟地震同震及震后效应的三维黏弹性有限元程序,通过计算走滑断层震例(概念性模型)引起的同震及震后效应,并与解析/半解析解进行对比,验证了程序的可靠性.同时基于概念性模型,分析了不同介质参数对同震及震后的地表变形的影响....  相似文献   

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The Mw 9.3 Sumatra earthquake of December 26, 2004 caused extensive coseismic displacements globally, measurements of which were made essentially using modern geodetic techniques. This earthquake induced considerable perturbation in stress distribution as far as ∼8000 km away from the epicenteral region, which is tending to relax to its normal rates as seen from postseismic transient deformation. The monitoring of crustal displacements from strategically located sites using GPS provides coseismic as well as postseismic deformation that facilitates the understanding of the fault geometry, elastic thickness, postseismic relaxation mechanisms, rheology and earthquake recurrence time interval.We investigated coseismic and postseismic GPS derived displacements in Indian region together with the GPS data collected from Andaman and Sumatra region. It is found that while EW displacements are significantly large in peninsular India, those in the region to the north of Central India Tectonic Zone (CITZ) are relatively small. We could delineate the postseismic transients from position time series and interpreted them in terms of viscoelastic relaxation. It is inferred that the postseismic deformation is characterized by a power-law viscoelastic flow in the mantle. In Indian peninsula region, the timescale parameter of the exponential decay (τ = 250 days) would require an extremely low viscosity for the upper mantle. Relying on the prevailing coseismic and postseismic displacement fields, the present study also reflects upon the contemporary litho-tectonics of the Indian sub-continent.  相似文献   

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