Buchbesprechungen     

Dr. med G. Huber-Pestalozzi  Hans Wolfgang Schäfer 《Aquatic Sciences - Research Across Boundaries》1951,13(1):192-196

Ohne Zusammenfassung  相似文献   

3a. Mons Claudianus     

H. M. E. Schürmann 《International Journal of Earth Sciences》1943,33(4-6):400-402

Ohne Zusammenfassung  相似文献   

Untersuchungen über die Mächtigkeit von Schlickschichten mit Hilfe des Echographen     

Friedrich Schüler 《Ocean Dynamics》1952,5(5-6):220-231

Zusammenfassung Es wird über eine Methode zur Feststellung von Schlickmächtigkeiten, von Bodenschichtungen in weichem Boden und zur Ermittlung des Tiefenprofils des harten Untergrundes berichtet. An Hand von Echogrammen und im Vergleich mit Bodenproben wird die Methode diskutiert.

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Investigations into the thickness of mud layers with the aid of ultra sound records

Summary A method is discussed allowing to make investigations into the thickness of mud layers and to ascertain the stratification in soft ground as well as to reveal the relief of the solid substratum of the sea bottom. The method is explained by the aid of ultra sound records which are compared with bottom samples.

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Recherches sur l'épaisseur des couches vaseuses au moyen d'enregistrements d'ondes ultrasonores

Résumé Une méthode est exposée qui permet de déterminer qualitativement l'épaisseur de couches vaseuses, d'explorer la stratification dans des fonds meubles et de découvrir le relief du substratum solide du fond de la mer. Ensuite, cette méthode est illustrée à l'aide d'enregistrements d'ondes ultrasonores qui sont comparés avec des échantillons du fond de la mer.

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Handlotungen und Echolotungen in der Seevermessung geringer Wassertiefen in strömenden Gewässern — eine kritische Betrachtung     

Friedrich Schüler 《Ocean Dynamics》1952,5(1):6-21

Zusammenfassung Vergleichslotungen zwischen Echolot und Handlot führen zu einer mathematischen Ableitung der Handlotleinen-Kurve in strömenden Gewässern. Durch Einführung von zwei Vereinfachungen — Vernachlässigung des Lotleinen-Gewichts und Annahme der Konstanz der Strömungsgeschwindigkeit nach der Tiefe — wird theoretisch die Kettenlinie, praktisch eine Parabel ermittelt. Als bestimmend für den Parameter der Kettenlinie ergeben sich das Lotgewicht und der Staudruck auf die Lotleine. Aus einem praktischen Beispiel wird der Parameter entnommen, und es werden für diese Verhältnisse die für die Tiefenwerte bis 26 m zu erwartenden Fehlmessungen des Handlotes sowie die Größe der Ablagen der Lotbirne vom Lotpunkt berechnet. Für andere Werte der Strömungsgeschwindigkeit werden die Veränderungen auf die Ausbuchtung der Lotleine ebenfalls rechnerisch bestimmt und in Kurven dargestellt. Aus diesen Kurven ergeben sich zwangsläufig die größten Tiefen, die man bei verschiedenen Strömungsgeschwindigkeiten mit dem schweren Handlot vermessen darf; sie liegen bei v=1 m/sec bei 8 m, bei v=0,7 m/sec bei 12 m und bei v=0,5 m/sec bei 20 m Wassertiefe.Praktische Beispiele der Seevermessung aus der jüngsten Zeit zeigen deutlich die Notwendigkeit, zukünftig nur noch mit dem Echolot zu vermessen.

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A comment on the applicability of hand leads and echo sounders to surveying operations in flowing shallow waters

Summary From comparisons between hand-lead soundings and echo soundings in streaming waters the divergency of the lead line from the vertical is mathematically derived. In introducing two simplifications, i. e. in neglecting the weight of the lead line and in assuming the velocity of current to be constant at all depths, the catenary curve which practically speaking is a parabola, is theoretically ascertained. The weight of the lead and the dynamic pressuro of the water (the pressure as exerted on a jet and measured by it) are found to be decisive for the parameter of the catenary-curve. The parameter is derived from a practical example and, according to the conditions of same, the errors to be expected in sounding with the hand lead at depths up to 26 m (= 79 ft) as well as the divergency of the sounding lead from the vertical are calculated. The various degrees of the lead line's divergency caused by a greater or lesser intensity of the current are likewise calculated and represented by curves. These curves necessarily indicate the maximum depths that can be sounded with sufficient accuracy with the heavy hand lead (5 kilos) at different velocities of current; the approximate values are as follows: 8 m for 1,0 m/sec, 12 m for 0,7 m/sec, 20 m for 0,5 m/sec (or: 25 ft for 2,0 knots, 37 ft for 1,5 knots, 61 ft for 1,0 knot). As a result of practical experience in recent survey operations the echo sounder should be regarded as the only reliable instrument to be used in future surveying.

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Note critique sur l'applicabilité de la sonde au plomb-poisson et celle du sondeur acoustique aux levés hydrographiques effectués en faibles profondeurs dans les eaux courantes

Résumé Les comparaisons des sondages au plomb-poisson avec ceux effectués par écho permettent d'en dériver mathématiquement la courbe formée par la ligne de sonde dans des eaux courantes. En introduisant deux simplifications, c'est à dire en négligeant le poids de la ligne et en supposant que la vitesse de courant soit constante dans toutes les profondeurs on arrive à déterminer théoriquement la chaînette qui est en effet une parabole. Le paramètre est fonction du poids du plomb-poisson et celle de la poussée sensiblement horizontale sur le fil due au frottement du liquide. On se sert d'un exemple pratique pour en dériver le paramètre, pour calculer, dans les conditions de cet exemple, les sondages faux de la sonde au plomb-poisson dont il faut tenir compte dans les profondeurs jusqu'à 26 m, et pour déterminer la déviation entre le plomb au bout de la ligne et la verticale. Les diverses variations de la courbe, que la ligne subit et qui sont causées par d'autres valeurs de la vitesse de courant sont aussi calculées et représentées à l'aide des courbes. Ces courbes indiquent forcément les profondeurs permettant encore une précision suffisante du sondage au plombpoisson lourd (5 kg) aux différentes variations de la vitesse de courant. Ces maxima sont à peu près comme suit:v=1,0 m/sec à 8 m de profondeur,v=0,7 m/sec à 12 m de profondeur,v=0,5 m/sec à 20 m de profondeur. Des exemples pratiques offerts par des récentes levés hydrographiques prouvent que le sondeur acoustique doit être considéré comme le seul instrument assurant le précis levé hydrographique.

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Das Kuselitvorkommen vom Steinberg bei Oberlinxweiler (Saar)     

N. Theobald  R. Schömer  K. Britz 《International Journal of Earth Sciences》1949,37(1):93-94

Ohne Zusammenfassung  相似文献   

The Transmission of Rayleigh Waves across an Ocean Floor with Two Surface Layers, Part II: Numerical     

Urs Hochstrasser  Robert Stoneley 《Geophysical Journal International》1937,4(S1):197-201

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Paleoenvironmental Analysis of Italian Crater Lake and Adriatic Sediments (PALICLAS)     

Brigitta Schütt 《Journal of Paleolimnology》1999,22(1):115-117

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Impact of Climate Change on Hydrological Regimes and Water Resources Management in the Rhine Basin   总被引：18，自引：2，他引：18  

H. Middelkoop  K. Daamen  D. Gellens  W. Grabs  J. C. J. Kwadijk  H. Lang  B. W. A. H. Parmet  B. Schädler  J. Schulla  K. Wilke 《Climatic change》2001,49(1-2):105-128

The International Commission for the Hydrology of the Rhine basin (CHR) hascarried out a researchproject to assess the impact of climate change on the river flow conditionsin the Rhine basin. Along abottom-up line, different detailed hydrological models with hourly and dailytime steps have beendeveloped for representative sub-catchments of the Rhine basin. Along atop-down line, a water balancemodel for the entire Rhine basin has been developed, which calculates monthlydischarges and which wastested on the scale of the major tributaries of the Rhine. Using this set ofmodels, the effects of climatechange on the discharge regime in different parts of the Rhine basin werecalculated using the results ofUKHI and XCCC GCM-experiments. All models indicate the same trends in thechanges: higher winterdischarge as a result of intensified snow-melt and increased winterprecipitation, and lower summerdischarge due to the reduced winter snow storage and an increase ofevapotranspiration. When the resultsare considered in more detail, however, several differences show up. These canfirstly be attributed todifferent physical characteristics of the studied areas, but different spatialand temporal scales used in themodelling and different representations of several hydrological processes(e.g., evapotranspiration,snow melt) are responsible for the differences found as well. Climate changecan affect various socio-economicsectors. Higher temperatures may threaten winter tourism in the lower wintersport areas. The hydrologicalchanges will increase flood risk during winter, whilst low flows during summerwill adversely affectinland navigation, and reduce water availability for agriculture and industry.Balancing the required actionsagainst economic cost and the existing uncertainties in the climate changescenarios, a policy of `no-regretand flexibility' in water management planning and design is recommended, whereanticipatory adaptivemeasures in response to climate change impacts are undertaken in combinationwith ongoing activities.  相似文献   

Determination of Mislocation Vectors to Evaluate bias at GSETT-3 primary stations     

Karl Koch  Urs Kradolfer 《Journal of Seismology》1999,3(2):139-151

Using the database provided by the Reviewed Event Bulletins (REBs) for the first 2.5 years of the Group of Scientific Experts Technical Test-3 (GSETT-3) experiment, we compiled mislocation vectors for both arrays and selected three-component stations of the primary network from the published slowness and azimuth information gained through f-k- and polarization analysis. Imposing constraints such as a minimum signal-to-noise ratio (SNR) and number of defining phases, we aim at eliminating location bias as the hypocentral parameters are taken from the REBs. Results from 14 arrays with apertures from about 1 km to more than 20 km are presented as well as from 18 three-component stations, which indicate that the mislocation vectors in many cases can improve location accuracy considerably. If these mislocation vectors are compiled to provide coverage of a sufficient portion of the slowness domain these empirical corrections can easily be applied prior to location processing. In the context of the Comprehensive Nuclear Test-Ban Treaty (CTBT), these mislocation patterns could be essential for providing accurate event location of suspicious low-magnitude events, as these location parameters will be used to pinpoint the area where to conduct an on-site inspection.  相似文献   

Influence of multiple compton scattering on the spectrum of soft diffuse gamma rays at balloon altitudes     

C. Moyano  V. Schönfelder 《Astrophysics and Space Science》1974,30(2):L17-L20

A Monte Carlo program has been developed in order to examine the influence of multiple Compton scattering in the atmosphere on the spectrum of cosmic diffuse gamma rays. It is shown that the corrections to the made to the measurements of the double-Compton gamma telescope at 2·5 gr cm^–2 rest atmosphere by Schönfelder and Lichti (1974) are lower than 4% in the energy range between 1.5 and 10 MeV.Under support of a fellowship by the Deutscher Akademischer Austauschdienst  相似文献