The seasonal growth of ice in the Antarctic     

Ed Sobey 《Journal of Oceanography》1975,31(6):235-242

Composite pictures of the areal extent of Antarctic sea ice derived from satellite photographs, show that the growth and the rate of growth of the pack ice compare favorably to the values previously estimated on other bases. Anomalous growth patterns are found in the Weddell Sea. Possible causes of this anomaly include surface and subsurface advection of ice crystals. The rate of retrogradation of the pack ice is found to exceed the rate of progradation.  相似文献   

GPS Spoken Here     

Charlie Heimach  Ed Scholz 《GPS Solutions》1995,1(2):90-90

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Book review     

Martin A. Buzas  Michael Ed. Hohn  John H. Schuenemeyer 《Mathematical Geosciences》1986,18(2):257-262

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A generalized principal components model in petrology     

Michael Ed. Hohn 《Lithos》1979,12(4):317-324

Principal components analysis of elemental distributions among minerals elucidate chemical, thermal, and equilibrium effects. Previous approaches in applying this multivariate statistical method to petrologic data are united into a single model, so-called three-mode principal components analysis. The major advantage of the model lies in the separate analysis of each of the three modes: element, mineral, and sample. The three sets of principal components are related through a “core matrix”. The model accommodates the ordination of pair-wise combination of the modes, such as samples and minerals in visualization of multidimensional tie-lines. Because of its generality, the model permits great flexibility in the study of petrologic data.  相似文献   

Remediation of floating,open water oil spills: Comparative efficacy of commercially available polypropylene sorbent booms     

Ed L. Schrader 《Environmental Geology》1991,17(2):157-166

Several complex methods of remediation are applied to open water oil spills. Sorbing the liquid hydrocarbons with polypropylene booms is an effective and less complex means of treating such events. There are, however, a variety of commercially available booms which display different performances in sorbing different viscosity hydrocarbons. There is no acceptable A.S.T.M. protocol to evaluate these booms for performance efficiency in various weather and hydrocarbon viscosity scenarios. The current paper proposes such a protocol and evaluates the most commonly used sorbent products with the new test procedures. Nine specific performance criteria, based on actual field applications, are demonstrated.  相似文献   

Subduction factory processes beneath the Guguan cross-chain, Mariana Arc: no role for sediments, are serpentinites important?   总被引：1，自引：0，他引：1  

Robert J. Stern  Ed Kohut  Sherman H. Bloomer  Matthew Leybourne  Matthew Fouch  Jeff Vervoort 《Contributions to Mineralogy and Petrology》2006,151(2):202-221

We need to understand chemical recycling at convergent margins and how chemical interactions between subducted slab and the overlying mantle wedge affect mantle evolution and magmagenesis. This requires distinguishing contributions from recycled individual subducted components as well as those contributed by the mantle. We do this by examining magmatic products generated at different depths above a subduction zone, in an intra-oceanic arc setting. The Guguan cross-chain in the intra-oceanic Mariana arc overlies subducted Jurassic Pacific plate lithosphere at depths of ~125--230 km and erupts mostly basalt. Basalts from rear-arc volcanoes are more primitive than those from the magmatic front, in spite of being derived by lower degrees of melting of less-depleted mantle. Rear-arc magmas also show higher temperatures and pressures of equilibration. Coexisting mineral compositions become more MORB- or OIB-like with increasing height above the subduction zone. Trace element and isotopic variations indicate that the subduction component in cross-chain lavas diminishes with increasing depth to the subduction zone, except for water contents. There is little support for the idea that melting beneath the Mariana Trough back-arc basin depleted the source region of arc magmas, but melting to form rear-arc volcanoes may have depleted the source of magmatic front volcanoes. Enrichments in rear-arc lavas were not caused by sediment melting; the data instead favor an OIB-type mantle that has been modestly affected by subduction zone fluids. Our most important conclusion is that sediment fluids or melts are not responsible for the K--h relationship and other cross-chain chemical and isotopic variations. We speculate that an increasing role for supercritical fluids released from serpentinites interacting with modestly enriched mantle might be responsible for cross-chain geochemical and isotopic variations. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.  相似文献   

Microséismes et Séismes précédant l’éruption du Nyamuragira-Kitzimbanyi (Afrique Centrale) 1958     

Ed. Berg  Th. Janssen 《Bulletin of Volcanology》1960,23(1):63-68

An analysis is made of microseismic and seismic activity for a period of about 3 months prior to the 1958 eruption in the Virunga Volcanoes, Western Rift Valley of Central Africa. It is believed that it would have been possible to predict the eruption some 30 h before, on the basis of two series of small earthquakes preceeding the 2 outbrakes by some 50 h, and presenting an exponential decay of the total number of shocks.  相似文献   

Sub‐Permil Interlaboratory Consistency for Solution‐Based Boron Isotope Analyses on Marine Carbonates     

Marcus Gutjahr  Louise Bordier  Eric Douville  Jesse Farmer  Gavin L. Foster  Ed C. Hathorne  Brbel Hnisch  Damien Lemarchand  Pascale Louvat  Malcolm McCulloch  Johanna Noireaux  Nicola Pallavicini  James W. B. Rae  Ilia Rodushkin  Philippe Roux  Joseph A. Stewart  Franois Thil  Chen‐Feng You 《Geostandards and Geoanalytical Research》2021,45(1):59-75

Boron isotopes in marine carbonates are increasingly used to reconstruct seawater pH and atmospheric pCO₂ through Earth’s history. While isotope ratio measurements from individual laboratories are often of high quality, it is important that records generated in different laboratories can equally be compared. Within this Boron Isotope Intercomparison Project (BIIP), we characterised the boron isotopic composition (commonly expressed in δ¹¹B) of two marine carbonates: Geological Survey of Japan carbonate reference materials JCp‐1 (coral Porites) and JCt‐1 (giant clam Tridacna gigas). Our study has three foci: (a) to assess the extent to which oxidative pre‐treatment, aimed at removing organic material from carbonate, can influence the resulting δ¹¹B; (b) to determine to what degree the chosen analytical approach may affect the resultant δ¹¹B; and (c) to provide well‐constrained consensus δ¹¹B values for JCp‐1 and JCt‐1. The resultant robust mean and associated robust standard deviation (s*) for un‐oxidised JCp‐1 is 24.36 ± 0.45‰ (2s*), compared with 24.25 ± 0.22‰ (2s*) for the same oxidised material. For un‐oxidised JCt‐1, respective compositions are 16.39 ± 0.60‰ (2s*; un‐oxidised) and 16.24 ± 0.38‰ (2s*; oxidised). The consistency between laboratories is generally better if carbonate powders were oxidatively cleaned prior to purification and measurement.  相似文献   

Discriminating sources of PCB contamination in fish on the coastal shelf off San Diego, California (USA)     

Ed Parnell P  Groce AK  Stebbins TD  Dayton PK 《Marine pollution bulletin》2008,56(12):1992-2002

Management of coastal ecosystems necessitates the evaluation of pollutant loading based on adequate source discrimination. Monitoring of sediments and fish on the shelf off San Diego has shown that some areas on the shelf are contaminated with polychlorinated biphenyls (PCBs). Here, we present an analysis of PCB contamination in fish on the shelf off San Diego designed to discriminate possible sources. The analysis was complicated by the variability of species available for analysis across the shelf, variable affinities of PCBs among species, and non-detects in the data. We utilized survival regression analysis to account for these complications. We also examined spatial patterns of PCBs in bay and offshore sediments and reviewed more than 20 years of influent and effluent data for local wastewater treatment facilities. We conclude that most PCB contamination in shelf sediments and fish is due to the ongoing practice of dumping contaminated sediments dredged from San Diego Bay.  相似文献   

The XMM Cluster Survey: forecasting cosmological and cluster scaling-relation parameter constraints     

Martin Sahlén  Pedro T. P. Viana  rew R. Liddle  A. Kathy Romer  Michael Davidson  Mark Hosmer  Ed Lloyd-Davies  Kivanc Sabirli  Chris A. Collins  Peter E. Freeman  Matt Hilton  Ben Hoyle  Scott T. Kay  Robert G. Mann  Nicola Mehrtens  Christopher J. Miller  Robert C. Nichol  S. Adam Stanford  Michael J. West  † 《Monthly notices of the Royal Astronomical Society》2009,397(2):577-607

We forecast the constraints on the values of  σ₈, Ω_m  and cluster scaling-relation parameters which we expect to obtain from the XMM Cluster Survey (XCS). We assume a flat Λ cold dark matter Universe and perform a Monte Carlo Markov Chain analysis of the evolution of the number density of galaxy clusters that takes into account a detailed simulated selection function. Comparing our current observed number of clusters shows good agreement with predictions. We determine the expected degradation of the constraints as a result of self-calibrating the luminosity–temperature relation (with scatter), including temperature measurement errors, and relying on photometric methods for the estimation of galaxy cluster redshifts. We examine the effects of systematic errors in scaling relation and measurement error assumptions. Using only  ( T , z )  self-calibration, we expect to measure Ω_m to ±0.03 (and  Ω_Λ  to the same accuracy assuming flatness), and σ₈ to ±0.05, also constraining the normalization and slope of the luminosity–temperature relation to ±6 and ±13 per cent (at 1σ), respectively, in the process. Self-calibration fails to jointly constrain the scatter and redshift evolution of the luminosity–temperature relation significantly. Additional archival and/or follow-up data will improve on this. We do not expect measurement errors or imperfect knowledge of their distribution to degrade constraints significantly. Scaling-relation systematics can easily lead to cosmological constraints 2σ or more away from the fiducial model. Our treatment is the first exact treatment to this level of detail, and introduces a new 'smoothed ML' (Maximum Likelihood) estimate of expected constraints.  相似文献