Water within,moving through,and shaping the Earth's surface: Introducing a special issue on water in the critical zone     

Ying Fan  Gordon Grant  Suzanne P. Anderson 《水文研究》2019,33(25):3146-3151

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Chronic and episodic acidification of streams along the Appalachian Trail corridor,eastern United States     

Douglas A. Burns  Todd C. McDonnell  Karen C. Rice  Gregory B. Lawrence  Timothy J. Sullivan 《水文研究》2020,34(7):1498-1513

Acidic atmospheric deposition has adversely affected aquatic ecosystems globally. As emissions and deposition of sulfur (S) and nitrogen (N) have declined in recent decades across North America and Europe, ecosystem recovery is evident in many surface waters. However, persistent chronic and episodic acidification remain important concerns in vulnerable regions. We evaluated acidification in 269 headwater streams during 2010–2012 along the Appalachian Trail (AT) that transits several ecoregions and is located downwind of high levels of S and N emission sources. Discharge was estimated by matching sampled streams to those of a nearby gaged stream and assuming equivalent daily mean flow percentiles. Charge balance acid-neutralizing capacity (ANC) values were adjusted to the 15th (Q15) and 85th flow percentiles (Q85) by applying the ANC/discharge slope among sample pairs collected at each stream. A site-based approach was applied to streams sampled twice or more and a second regression-based approach to streams sampled once to estimate episodic acidification magnitudes as the ANC difference from Q15 to Q85. Streams with ANC <0 μeq/L doubled from 16% to 32% as discharge increased from Q15 to Q85 according to the site-based approach. The proportion of streams with ANC <0 μeq/L at low flow and high flow decreased from north to south. Base cation dilution explained the greatest amount of episodic acidification among streams and variation in sulfate (SO₄²⁻) concentrations was a secondary explanatory variable. Episodic SO₄²⁻ patterns varied geographically with dilution dominant in northern streams underlain by soils developed in glacial sediment and increased concentrations dominant in southern streams with older, highly weathered soils. Episodic acidification increased as low-flow ANC increased, exceeding 90 μeq/L in 25% of streams. Episodic increases in ANC were the dominant pattern in streams with low-flow ANC values <30 μeq/L. Chronic and episodic acidification remain an ecological concern among AT streams. The approach developed here could be applied to estimate the magnitude and extent of chronic and episodic acidification in other regions recovering from decreasing levels of atmospheric S and N deposition.  相似文献   

EMERGING SOUTHEAST ASIA. A STUDY IN GROWTH AND STAGNATION. By Donald W. Fryer.     

A. G. Anderson 《New Zealand geographer》1971,27(2):216-218

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Direct-Drive Inertial Confinement Fusion Implosions on Omega     

S. P. Regan  T. C. Sangster  D. D. Meyerhofer  K. Anderson  R. Betti  T. R. Boehly  T. J. B. Collins  R. S. Craxton  J. A. Delettrez  R. Epstein  O. V. Gotchev  V. Yu. Glebov  V. N. Goncharov  D. R. Harding  P. A. Jaanimagi  J. P. Knauer  S. J. Loucks  L. D. Lund  J. A. Marozas  F. J. Marshall  R. L. Mccrory  P. W. Mckenty  S. F. B. Morse  P. B. Radha  W. Seka  S. Skupsky  H. Sawada  V. A. Smalyuk  J. M. Soures  C. Stoeckl  B. Yaakobi  J. A. Frenje  C. K. Li  R. D. Petrasso  F. H. SÉguin 《Astrophysics and Space Science》2005,298(1-2):227-233

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A laboratory survey of the thermal desorption of astrophysically relevant molecules     

Mark P. Collings  Mark A. Anderson  Rui Chen  John W. Dever  Serena Viti  David A. Williams  Martin R. S. McCoustra 《Monthly notices of the Royal Astronomical Society》2004,354(4):1133-1140

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Editorial     

E. W. Anderson 《GeoJournal》1997,41(2):99-100

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Modeling studies of the bioluminescence potential dynamics in a high Arctic fjord during polar night     

Shulman  Igor  Cohen  Jonathan H.  Moline  Mark A.  Anderson  Stephanie  Metzger  E. Joseph  Rowley  Clark 《Ocean Dynamics》2022,72(1):37-48

Ocean Dynamics - During polar nights in January 2012 and 2017, significantly higher bioluminescence (BL) potential emissions in the upper 50&nbsp;m were observed in the fjord Rijpfjorden...  相似文献   

Geotechnical zonation and soil–structure interaction at Puerto Vallarta,México     

Escudero  Christian R.  Ramirez Gaytan  Alejandro  Zamora Camacho  Araceli  Preciado  Adolfo  Flores  Karen L.  Gomez Hernandez  Adan 《Natural Hazards》2022,110(1):247-267

Natural Hazards - We performed a seismic vulnerability assessment that involves geotechnical and building structure analysis for Puerto Vallarta, Mexico, a city located along the pacific coast....  相似文献   

Monitoring the crystallization of water-saturated granitic melts in real time using the hydrothermal diamond anvil cell     

Victoria?ManetaEmail authorView author&#;s OrcID profile  Alan?J.?Anderson 《Contributions to Mineralogy and Petrology》2018,173(10):83

Critical aspects of the crystallization dynamics of H₂O-saturated melts of a typical granitic composition as well as granitic melts enriched in lithium (8800 ppm) were investigated in real-time experiments using the hydrothermal diamond anvil cell at 480–700 °C and 220–960 MPa. Complete crystallization of the charges was achieved within 5–118 h with average crystal growth rates ranging from 3 to 41 cm/year for quartz and from 18 to 58 cm/year for alkali feldspars, demonstrating that crystals formed from a silicate melt in the presence of a coexisting aqueous phase crystallize rapidly. The combination of substantial nucleation delays, low nucleation densities, and rapid growth rates for quartz and alkali feldspars led to the formation of euhedral megacrysts of these minerals in the vicinity of clusters comprised of much smaller muscovite or α-spodumene crystals. Subsolidus replacement processes initiated during crystal–fluid interactions after the silicate melt was consumed were directly observed in the experiments. The experimental results underscore the important role of water as a medium for the transport of essential elements such as Si, Al, Na, and K from the silicate melt to the newly formed crystals, and provide important insights into the crystallization of miarolitic pegmatites.  相似文献   

The Science and Policy of the Verified Carbon Standard Methodology for Tidal Wetland and Seagrass Restoration     

Brian A. Needelman  Igino M. Emmer  Stephen Emmett-Mattox  Stephen Crooks  J. Patrick Megonigal  Doug Myers  Matthew P. J. Oreska  Karen McGlathery 《Estuaries and Coasts》2018,41(8):2159-2171

The restoration of tidal wetland and seagrass systems has the potential for significant greenhouse gas benefits, but project-level accounting procedures have not been available at an international scale. In this paper, we describe the Verified Carbon Standard Methodology for Tidal Wetland and Seagrass Restoration, which provides greenhouse gas accounting procedures for marsh, mangrove, tidal forested wetland, and seagrasses systems across a diversity of geomorphic conditions and restoration techniques. We discuss and critique the essential science and policy elements of the methodology and underlying knowledge gaps. We developed a method for estimating mineral-protected (recalcitrant) allochthonous carbon in tidal wetland systems using field-collected soils data and literature-derived default values of the recalcitrant carbon that accompanies mineral deposition. We provided default values for methane emissions from polyhaline soils but did not provide default values for freshwater, oligohaline, and mesohaline soils due to high variability of emissions in these systems. Additional topics covered are soil carbon sequestration default values, soil carbon fate following erosion, avoided losses in organic and mineral soils, nitrous oxide emissions, soil profile sampling methods, sample size, prescribed fire, additionality, and leakage. Knowledge gaps that limit the application of the methodology include the estimation of CH₄ emissions from fresh and brackish tidal wetlands, lack of validation of our approach for the estimation of recalcitrant allochthonous carbon, understanding of carbon oxidation rates following drainage of mineral tidal wetland soils, estimation of the effects of prescribed fire on soil carbon stocks, and the analysis of additionality for projects outside of the USA.  相似文献