Strike and dip of crustal boundaries — A method and its application

Summary If for a point on the earth's surface, the apparent (moveout) seismic velocities have been determined for a number of profiles in different directions, a possibility is offered to calculate true strike and dip of crustal boundaries. In the present paper the theory is developed, partly for a sloping Mohorovii discontinuity only, partly for sloping Conrad and Mohorovii discontinuities with parallel strikes. The theory for the sloping Mohorovii discontinuity is applied to field measurements at a place about 30 km west of Uppsala performed in June 1969. With a crustalP-wave velocity of 6.3 km/sec, a good fit to the observations is obtained for aPn-velocity of 8.55 km/sec and a downdip of Moho of 7.2° in the direction S 3.8° E. These numerical values are not the most important output of this paper. On the other hand, the testing of the method appears far more important, and also that improvements can be suggested in the experimental procedure in future applications of this method.     

Das bewegliche Luftvolumen des Erdbodens

Zusammenfassung Das für die Bodenatmung wesentliche, bewegliche Luftvolumen wird in Abhängigkeit von der Tiefe aus der Absorption von Druckwellen im Boden abgeleitet. Zur Prüfung werden periodische Druckwellen künstlich erzeugt und in verschiedenen Erdbodentiefen gemessen und registriert.

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Summary The volume of moving air, which is essential for the respiration of the soil, has been calculated with the dependency on depth from absorption of pressure waves in the soil. The results have been controlled by experiments with artificial periodic pressure waves which are measured and registered at different depths in the soil.

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Résumé Le volume d'air mouvant qui est d'importance essentielle pour la respiration du sol, est déduit de l'absorption d'ondes de pression dans le sol et de leur dépendance de la profondeur. Pour vérifier la théorie, l'auteur produit des ondes de pression artificielles et périodiques qui sont ensuite mesurées et enregistrées à diverses profondeurs.

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Mit 5 Textabbildungen.

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Die Arbeit wurde mit Unterstützung des Bundesministeriums für Ernährung, Landwirtschaft und Forsten und der Karlsruher Hochschulvereinigung durchgeführt.     

Wavelet analysis of the standard map: Structure and scaling

Wavelet analysis is applied to distributions of points generated by iterating the standard map. The initial condition is chosen so that the points fill the largest chaotic region. When the standard map parameterk=1.3, the distribution of points contains many voids corresponding to islands in the chaotic region. The wavelet transform is dominated by contributions from these islands. Fork=10 the chaos fills phase space and no structure is apparent; the wavelet transform reveals statistical fluctuations in the distribution of points.     

Nature and origin of ground ice,Sandhills Moraine,southwest Banks Island,Western Canadian Arctic

The Sandhills Moraine is a Late Wisconsinan lateral moraine complex on southwest Banks Island. The occurrence of ice-ablation landforms, ground ice slumps, kettle lakes and catastrophic lake drainage in winter suggests the presence of substantial bodies of massive ground ice. The distinctive hummocky topography of the Sandhills Moraine is thought to reflect partial melt-out of this ice. Stratigraphic observations indicate that the ice is overlain irregularly and unconformably by glacigenic sediments, notably pebbly clay (till) and/or sandy gravels (outwash), while the ice itself possesses numerous and variable mineral inclusions, faults and foliations. Petrofabric analyses indicate a strongly preferred orientation to the ice crystals. It is suggested that these characteristics are best explained if the ground ice is interpreted as relict glacier ice.     

Iron(VI) Seems an Unlikely Explanation for Viking Labeled Release Results

Tsapin et al. (2000, Icarus147, 68-78) propose the strong oxidant ferrate(VI) to explain the Viking Labeled Release Mars life detection results. However, their data do not support that theory. Further, sensitive IR searches for oxidants on Mars found none, and Viking produced physical evidence against an oxidizing surface. Finally, Tsapin et al. (2000, Icarus147, 68-78) report no precautions to prevent microbial contamination from confounding their results.     

The relationships between tropical Atlantic sea level variability and major climate indices

Relationships were examined between variability in tropical Atlantic sea level and major climate indices with the use of TOPEX/POSEIDON altimeter and island tide gauge data with the aim of learning more about the external influences on the variability of the tropical Atlantic ocean. Possible important connections were found between indices related to the El Niño–Southern Oscillation (ENSO) and the sea levels in all three tropical regions (north, equatorial, and south), although the existence of only one major ENSO event within the decade of available altimetry means that a more complete investigation of the ENSO-dependence of Atlantic sea level changes has to await for the compilation of longer data sets. An additional link was found with the Indian Ocean Dipole (IOD) in the equatorial region, this perhaps surprising observation is probably an artifact of the similarity between IOD and ENSO time series in the 1990s. No evidence was obtained for significant correlations between tropical Atlantic sea level and North Atlantic Oscillation or Antarctic Oscillation Index. The most intriguing relationship observed was between the Quasi-Biennial Oscillation and sea level in a band centered approximately on 10°S. A plausible explanation for the relationship is lacking, but possibilities for further research are suggested.     

The impact of the parking situation in shopping centres on store choice behaviour

The article discusses the effects of changing the parking situation in the surrounding of shopping centres on consumers store choice behaviour. To get insight into these effects a hierarchical logit model of parking lot and store choice behaviour is estimated and validated. The research is based on before-and-after data of supermarket visitors collected in a major regional shopping centre in a suburban area in The Netherlands. The model is estimated using the before data. At the level of the supermarkets the estimated hierarchical logit model performs very well. The model is less accurate at the level of parking lots but still performs satisfactory. Significant attributes are a constant representing the characteristics of the supermarket, the distance between supermarket and parking lot, the number of parking spaces per parking lot, the location of the parking lot vis-à-vis the origin of the consumer, and the availability of supermarket trolley facilities at the parking lot. Validating the model by reproducing the after data yields less satisfactory results. Especially the model does not perform very well on predicting parking lot choice. This revised version was published online in July 2006 with corrections to the Cover Date.     

A general mixing equation with applications to Icelandic basalts

The mixing equation applied by Vollmer [1] to Pb and Sr isotope ratios is shown to be a general equation applicable to consideration of element and isotope ratios. The mixing equation is hyperbolic and has the form:Ax + Bxy + Cy + D = 0where the coefficients are dependent on the type of plot considered: i.e. ratio-ratio, ratio-element, or element-element. Careful use of this equation permits testing whether mixing is a viable process, places constraints on end member compositions, allows distinction between mixing of sources and mixing of magmas, and should allow distinction between recent mixing and long-term evolution of sources.The available chemical data for postglacial basalts from Iceland and along the Reykjanes Ridge are not consistent with either mixing of magmas or simple mixing of an enriched ocean island source with a depleted ocean ridge source. If the available analyses for basalts are representative of the source regions, the data are consistent with at least two models neither of which can be properly tested with the available data.(1) There are two separate mixing trends: one beneath Iceland with the alkali basalt source and a depleted Iceland source as end members; the second along the Reykjanes Ridge with a heterogeneous ocean ridge basalt source and a source similar to that for intermediate basalts on Iceland as end members. The depleted Iceland source and the depleted ocean ridge source are not the same.(2) The chemistry of the basalts is not determined by mixing. Instead the basalts are derived from a multiplicity of sources with a similar history which have been isolated for hundreds of millions of years.