Volatile (sulphur and chlorine), major,and trace element geochemistry of mafic to intermediate tephras from the Chilean Southern Volcanic Zone (33–43°S)     

Heidi Wehrmann  Kaj Hoernle  Guillaume Jacques  Dieter Garbe-Schönberg  Kai Schumann  Julia Mahlke  Luis E. Lara 《International Journal of Earth Sciences》2014,103(7):1945-1962

Here we present the first systematic investigation of volatile geochemistry along the Southern Volcanic Zone (SVZ) of Chile. Holocene olivine-hosted melt inclusions in the most mafic tephras sampled from 16 volcanoes along the volcanic front of the SVZ between 33°S and 43°S were analysed for pre-eruptive sulphur, chlorine, and major element contents. These results are combined with trace element compositions of the host whole rocks. The highest fractionation-corrected gas contents occur in the least-degassed melt inclusions from small monogenetic cones of Los Hornitos, Cabeza de Vaca, and Apagado from both the transitional and the southern-central SVZ, reaching ~3,000 μg/g S and 1,400 μg/g Cl, while the lowest abundances of ~1,100 μg/g S and ~600 μg/g Cl were found in the central SVZ at Volcán Lonquimay, Volcán Llaima, and Volcán Villarrica. Chlorine co-varies with trace element indicators for the degree of melting and/or source enrichment, such that the lowest Cl contents are found in high-degree melts from the most depleted mantle sources. The size of the volcanic edifices correlates inversely with Cl abundances in the melt. This could reflect more extensive degassing during ascent through the complex magma plumbing systems beneath the stratovolcanoes or greater dilution during larger degrees of melting of more depleted sources, or a combination of these factors. Compared to other subduction zones, the SVZ melt inclusions exhibit Cl and S abundances in the same range as most of those from the Central American and those from the Marianas arcs.  相似文献   

Comment on the paper of Willems,P.: Multidecadal oscillatory behaviour of rainfall extremes in Europe. Published in: Climatic Change 120 (4), p. 931–944     

Svenja Fischer  Andreas Schumann 《Climatic change》2015,130(2):77-81

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Flood-plain mapping: a critical discussion of deterministic and probabilistic approaches     

Giuliano Di Baldassarre  Guy Schumann  Paul D. Bates  Jim E. Freer  Keith J. Beven 《水文科学杂志》2013,58(3):364-376

Abstract

Different methodologies for flood-plain mapping are analysed and discussed by comparing deterministic and probabilistic approaches using hydrodynamic numerical solutions. In order to facilitate the critical discussion, state-of-art techniques in the field of flood inundation modelling are applied to a specific test site (River Dee, UK). Specifically, different flood-plain maps are derived for this test site. A first map is built by applying an advanced deterministic approach: use of a fully two-dimensional finite element model (TELEMAC-2D), calibrated against a historical flood extent, to derive a 1-in-100 year flood inundation map. A second map is derived by using a probabilistic approach: use of a simple raster-based inundation model (LISFLOOD-FP) to derive an uncertain flood extent map predicting the 1-in-100 year event conditioned on the extent of the 2006 flood. The flood-plain maps are then compared and the advantages and disadvantages of the two different approaches are critically discussed.

Citation Di Baldassarre, G., Schumann, G., Bates, P. D., Freer, J. E. & Beven, K. J. (2010) Flood-plain mapping: a critical discussion of deterministic and probabilistic approaches. Hydrol. Sci. J. 55(3), 364–376.  相似文献   

A Jar for Culturing Small Pelagic Marine Organisms in Running Water during Shipboard or Laboratory Studies     

Schumann  George O.; Perkins  Herbert C. 《ICES Journal of Marine Science》1966,30(2):171-176

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Co-management and “consciousness”: Fishers’ assimilation of management principles in Chile     

Sarah Schumann 《Marine Policy》2007

Chile's new Management Area system delegates management responsibility to organizations of artisanal shell-fishers on the condition that they team with professionally trained marine biologists. A survey of participating fishers in Chile's Fourth and Fifth regions examined four social benefits predicted to result from this type of co-management: (1) improved rapport between fishers and the state, (2) greater awareness among fishers of ecology and the benefits of management, (3) cooperation between fishers and scientists, and (4) unity between fishers. A discussion analyzes the principal benefit encountered—fishers’ newfound “consciousness” of the value of management—within the context of co-management and territorial use rights.  相似文献   

Suitability of Mn‐ and Fe‐Rich Reference Materials for Microanalytical Research          下载免费PDF全文

Dorothea S. Macholdt  Klaus Peter Jochum  Stephen A. Wilson  Laura M. Otter  Brigitte Stoll  Ulrike Weis  Meinrat O. Andreae 《Geostandards and Geoanalytical Research》2016,40(4):493-504

Manganese‐ and iron‐rich materials are of major geoscientific and economic interest, many of which contain microscopic features that provide valuable information. To obtain accurate results, a homogeneous microanalytical reference material for calibration is needed. Several researchers have used the Mn‐ and Fe‐rich RMs, JMn‐1, NOD‐A‐1, NOD‐P‐1 and FeMn‐1, for this purpose; therefore, they were tested in this study to determine their suitability for microanalysis. Their homogeneity was investigated by laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) with two different types of lasers (nano‐ and femtosecond), with spot and line scan analyses and with different operating parameters, such as spot size, pulse repetition rate and fluence. As the established manganese nodule RMs revealed inhomogeneities for picogram to microgram test portions, we also investigated the new synthetic Fe‐ and Mn‐rich RM, FeMnOx‐1. FeMnOx‐1 was found to be homogeneous for large (ø 40 μm: 2% RSD repeatability) and small (ø 8–10 μm: 10% RSD repeatability) spot sizes. This homogeneity is in the range of the homogeneous NIST SRM 610 and GSE‐1G reference glasses. Furthermore, FeMnOx‐1 revealed a large‐scale homogeneity within uncertainties of a few per cent, using test portions in the ng range, when measuring four individual mounts of this material.  相似文献   

Tonminerale in normalsedimenten,hydrothermal beeinflu\ten sedimenten und Erzschlämmen des Roten Meeres     

Prof. Dr. Werner Schneider  Dr. Dieter Schumann Dipl.-Miner. 《International Journal of Earth Sciences》1979,68(2):631-648

From 14 deeps and other regions of the Red Sea totally 226 samples from 28 cores recovered during the VALDIVIA cruises (1971, 1972) were investigated according to their clay mineral content (<2μm resp. < 6.3 μm) after carbonate dissolution. Three facies groups are to distinguish:

1. normal sediments: dominance of chlorite, kaolinite, illite, small amounts of smectite and sepiolite. Two palygorskite types are present only in a few samples.
2. normal sediments with hydrothermal influence: clay mineral paragenesis similar like that of normal sediments; but increase of smectite and presence of goethite in each sample; partly small contents of talc.
3. heavy metal deposits: dominance of iron-bearing smectite, partly with amorphous components resp. pure ore mineral assemblages with authigenic silicates (talc, quartz, opal, chrysotile, sepiolite, palygorskite, chlorite).

Crystallinity of the clay and ore minerals is independent from sedimentary overburden. Sepiolite shows in small amounts a wide distribution; palygorskite₂ (d₁₁₀=11.3 Å) yields locally an increased concentration in the range of pteropod layers cemented by aragonite. The environment of ore deposits is characterized by iron-bearing smectite besides the ore minerals.  相似文献   

Frequency of fronts in the Northern Hemisphere     

T. E. W. Schumann  M. P. van Rooy 《Meteorology and Atmospheric Physics》1951,4(1):87-97

Summary It is pointed out that there are two distinct ways of defining the frequency of the occurence of fronts. Tables and charts are presented showing frontal frequency during winter and summer for the greater part of the Northern Hemisphere, the values being based on daily synoptic charts for a period of ten years.The variation of average frequency of fronts with latitude is illustrated graphically, and it is shown to have a significant relation with the average temperature and pressure gradients.

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Zusammenfassung Es wird gezeigt, daß es zwei verschiedene Arten gibt, die Häufigkeit des Vorkommens von Fronten zu definieren. Es werden Tabellen und Karten mitgeteilt, die die Häufigkeit von Fronten während des Winters und Sommers für den größeren Teil der nördlichen Halbkugel zeigen; diese Werte gründen sich auf tägliche synoptische Karten über eine Periode von zehn Jahren. Die Änderung der mittleren Häufigkeit von Fronten mit der Breite wird graphisch dargestellt, und es wird gezeigt, daß eine eindeutige Beziehung zu dem mittleren Temperatur- und dem mittleren Druckgradienten besteht.

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Résumé On montre qu'il y a deux façons de définir la fréquence d'apparition des fronts. Des tables et des cartes illustrent la fréquence des fronts pendant l'hiver et l'été pour la plus grande partie de l'hémisphère nord; ces valeurs résultent de cartes synoptiques journalières s'étendant sur une période de dix ans. La variation des fréquences moyennes des fronts en fonction de la latitude est représentée graphiquement. Il existe une relation nette avec les gradients moyens de température et de pression.

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With 5 Figures.  相似文献   

Nachweis von Nickel in der Phosphorsalzperle     

Dr. H. Schumann 《Contributions to Mineralogy and Petrology》1949,1(5-6):689-689

Ohne Zusammenfassung  相似文献   

The use of maximum entropy to increase the informational content of hydrological networks by additional gauges     

Svenja Fischer  Philipp Bühler  Uwe Büttner  Andreas Schumann 《水文科学杂志》2020,65(13):2274-2285

ABSTRACT

The optimization and extension of existing gauging networks are a challenging task, which can be done under consideration of many different aspects. One possibility is to maximize the obtained information on regional hydrological characteristics by new gauges compared to existing ones. For this, information theory approaches are most suitable. Here, the principle of maximum entropy is applied to calculate the probability of non-similarity of catchments to determine locations of new gauges according to the catchment characteristics that are most relevant for the hydrological conditions. The realization in an interactive application, provided online, makes use easy for practitioners and scientists. Goodness-of-fit measures are applied to investigate the explanatory power of the model and the contribution of each characteristic to the model, which gives information on the most influential properties of the catchment. The relevance of the proposed approach is proven by comparing hydrological signatures between similar and non-similar catchment.  相似文献