Macroinfaunal assemblages associated with mussel and clam beds in an estuary of Southern Chile

Samples were collected from September 1990 to February 1992, at three subtidal sites of the middle reaches of the Queule River estuary, southern Chile, to analyze the spatial and temporal variability of the macroinfauna inhabiting substrata with different abundances of bivalves. In addition, water and sediment samples were obtained to study the relationships between the temporal variability in macroinfaunal abundances, physical factors and chlorophylla content. Temperature, salinity, and chlorophylla showed a rather strong seasonal variability but slight between-site differences. Sediment characteristics and bivalve abundances, by contrast, exhibited little temporal variability but large differences between sites. The macroinfauna was primarily represented by polychaetesPrionospio (Minuspio) patagonica being dominant in the three areas. Most dominant species showed similar trends of temporal variability, with maximum abundances recorded during spring and fall. The appearance of recruits was restricted to the summer with little difference among sites. Multiple regression analyses showed that the temporal variability of macroinfaunal adults and recruits, was primarily associated with variability in salinity and water temperature, respectively. Spatial variability of these organisms was also explained by variations in these factors, together with those of sediment texture and organic matter content. No evidence of interactions (significant relationships) was found between the abundances of bivalves and those of the macroinfauna, nor among macroinfaunal organisms.     

Inelastic response and design criteria of plan-wise asymmetric systems

The study of the torsional response of buildings in the inelastic range of behaviour is of great interest since the ability of structures to resist strong earthquakes mainly relies on their ductility and capacity for energy dissipation. Furthermore, an examination of the performance of structures during past earthquakes demonstrates that plan-asymmetric buildings suffered greater damage due to torsional response. The paper deals with this subject by analysing a model which idealizes a one-storey building with resisting elements oriented along two perpendicular directions. In addition to the parameters of the elastic behaviour, the inelastic system response depends on full yield capacity and plan-wise strength distribution. The influence of the criterion adopted for the design of resisting elements on local ductility demand and damage has been evaluated by parametric analysis. In particular, a comparison has been carried out between systems with equal design levels for all elements and systems with design levels dependent on the element location. For a given elastic behaviour and total capacity, the strength distributions in plan have been defined which minimize ductility demand and structural damage. Finally, based on these findings, responses from models designed according to several seismic codes have been compared.     

The contribution of geoscience to the EC survey on European historic cities

The EC Executive Commission has established a permanent survey for historic cities in Europe. The survey will evaluate the economic and social yield of architectural and archeological restoration and preservation projects, establish basic criteria for decisions regarding the preservation of buildings or their reconstruction and conversion, their being closed for research purposes or rendering them accessible to the public, and indicate the type of use most suited to the characteristics of the landmark.

One aspect of fundamental importance, to which primary consideration should be given in order to correctly evaluate the restoration project and future use, concerns the relationship between the architectural structure and its environment. Three sectors of this aspect are indicated, along with examples, with particular emphasis on geological implications.

(1) Environmental hazards: earth (erosion, earthquakes, volcanoes, subsidence etc.); water (floods, seastorms, pollution etc.); air (hurricanes, whirlwinds, pollution etc.); biological factors (deteriorated areas, infestation etc.).

(2) Causes and effects: the study of the environmental factors that have led to the construction and the typology of the architectural landmark; forecasts of the consequences for the environment of the various types of conversion of the historical landmark.

(3) Environment education: informative and educational programs for an integral knowledge of the environment in which the historical city is situated and to promote an environmental consciousness.     

Confronto fra i regimi pluviometrici di Genova e Savona

Riassunto L'esame dei giorni di ciascun anno dal 1886 al 1900 nei quali si sono avute precipitazioni apprezzabili tanto a Genova quanto a Savona (località distanti fra loro 35 km) viene istituito utilizzando l'indice di similitudineS recentemene introdotto daM. Bouët. La discussione dei risultati dimostra fra l'altro come le località marittime a ridosso di catene montuose siano più adatte a mettere in luce le variazioni nel tempo delle caratteristiche climatiche.

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Zusammenfassung Ausgehend von der Anzahl der gleichzeitigen Niederschlagstagen in Genua und Savona (Abstand 35 km) wurde der AehnlichkeitsindexS nachBouët für jedes Jahr der Periode 1886–1900 berechnet. Die Diskussion der Ergebnisse zeigt u.a., dass die maritimen Orte, die am Fusse einer Bergkette liegen, gewöhnlich besser als die kontinentalen geeignet sind die zeitlichen Veränderungen der klimatischen Verhältnisse darzustellen.

     

Sull'idrologia del Foehn

Riassunto Per alcuni casi diFöhn delle Alpi Italiane, interessanti il Piemonte e la Lombardia, sono state esaminate le variazioni dei deflussi nei giorni in cui soffiava tale vento nonchè in quelli adiacenti, trovando che di regola, quando non intervengono precipitazioni od altri fattori, ilFöhn provoca una diminuzione netta delle portate, che può raggiungere e superare il 10% e che si esplica con relativa prontezza. Si spiega tale riduzione con la forte evaporazione causata dalFöhn.

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Summary Researches have been undertaken on the influence of the Föhn in the italian Alps, regarding the runoff-variations. The Föhn causes as a rule a decrease of the runoff, which, in absence of precipitation, can reach or exceed 10%. It can be explained by the strong evaporation during the Föhn.

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Zusammenfassung Anhand einiger Föhnfälle in den italienischen Alpen wurde der Einfluss des Föhns auf die Aenderungen der Abflussmenge untersucht. Wenn empfindliche Niederschläge oder andere Faktoren nicht vorkommen, verursacht in der Regel der Föhn eine Abnahme der Abflussmenge, die 10% erreichen oder sogar überschreiten kann. Die Erklärung ist in der starken Verdunstung während des Föhns zu suchen.

     

Le barovariographe comme appareil de sondage aérologique

Summary First, the theory of the barovariograph, the deductions from which have also been confirmed by experiments, is presented with some improvements. Then there follows a concise illustration of the various possibilities of applying the instrument for the disclosure of aerological phenomena existing over a given locality.

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Zusammenfassung Zunächst wird, mit einigen Erweiterungen, die Theorie des Barovariographen dargelegt, deren Ableitungen auch experimentell bestätigt wurden. Dann folgt eine kurze Erläuterung der verschiedenen Anwendungsmöglichkeiten des Instrumentes für die Registrierung gewisser aerologischer Erscheinungen über einem Ort.

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Riasunto Dapprima viene esposta con alcuni perfezionamenti la teoria del barovariografo, le cui deduzioni sono state confermate anche sperimentalmente. Segue una illustrazione succinta delle varie possibilità applicative dello strumento per la rilevazione dei fenomeni aerologici sovrastanti una località determinata.

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Communication présentée à l'Association Internationale de Météorologie, IXe Assemblée Générale de l'UGGI, Bruxelles, Séance du 24 Août 1951.     

SporadicE-layer ionization and sunspot cycle

Summary The correlation between the sunspot cycle and the sporadicE-layer ionization is investigated at middle latitudes. Higher mean values off ₀Es occur generally with higher sunspot numbers. Some evidence for a phase-shift between long term time-variation in sunspot numbers andf ₀Es is obtained. The solar cycle variation ofEs is somewhat larger over the Far East. Regarding the behaviour of the time-development ofEs events in diurnal variation, an interpretation is proposed.     

Applicabilita' di nuove bussole alla determinazione degli elementi angolari del campo geomagnetico

Riassunto Viene dimostrata ed illustrata l'applicabilità delle bussole Giulietti alla misura della declinazione e della inclinazione geomagnetiche; esse consentono alte precisioni e sono adatte anche al pratico impiego in campagna.

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Zusammenfassung Es wird bewiesen, dass die Kompasse von Giulietti geeignet sind um die Deklination und die Inklination des geomagnetischen Feldes zu messen. Das Verfahren gestattet eine hohe Genauigkeit zu erreichen und ist auch leicht auf dem Land anwendbar.

     

Le possibilita' minerarie della Provincia di Messina

Riassunto Premessi alcuni richiami sulle caratteristiche geologiche della Provincia di Messina, si illustrano le possibilità minerarie della regione in base specialmente alle indagini eseguite dal R. Istituto Geofisico e Geodetico di Messina. Dal relativo esame consegue l'importanza delle manifestazioni di minerali metallici con giacimenti che possono assicurare una produzione notevole—sopratutto per il rame, ma anche il piombo, antimonio, zinco, ferro, ecc.—nonostante la distribuzione complessa ed irregolare delle mineralizzazioni. In pari tempo sono segnalate altresi le sicure possibilità di un conveniente sfruttamento degli scisti bituminosi, delle ligniti, nonchè di altri materiali (fluorite, caolino,...) di cui è dotato il sottosuolo della Provincia di Messina.

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Zusammenfassung Nach der Untersuchungen des R. Istituto Geofisico e Geodetico zu Messina werden die bergbauwürdigen Lagerstätten der Messina-Provinz beschrieben und erörtet. Das geschieht unter einer allgemeinen Erwähnung der geologischen Bedingugen. Dazu lässt sich zeigen, wie die Messina-Provinz besonders reich an Erz-Lagerstätte ist, vor allem an Kupfer-Erze, weiter auch an Blei-, Antimon-, Zink-, Eisen-Erze, usw, obwohl die Verteilung einigermassen kompliziert und ungleichmässig ist. Auch die bauwürdigen Lagerstätten der anderen Materialen, wie bituminose Schiefer, Braunkohlen, usw werden erwähnt.

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Résumé Après un bref rappel des caractères géologiques de la Province de Messina, on documente les possibilités minières de la région surtout à la suite des recherches faites par l'Istituto Geofisico e Geodetico di Messina. De l'examen rélatif dérive l'importance des maniféstations en mineraux métalliques, avec gisements capables de donner une production convenable—particulièrement de cuivre, mais aussi de plomb, d'antimoine, de zinc, de fer, etc,—malgré la distribution complexe et irrégulière des minéralisations. On mentionne aussi les autres possibilités d'exploitation des gîtes de schistes bitumineuses, de lignites et d'autres matériaux.