Misure magnetiche in Albania     

Carlo Morelli 《Pure and Applied Geophysics》1944,6(1-2):14-22

Riassunto Il campo magnetico terrestre in Albania è stato studiato (per la prima volta) dall'Istituto Geografico Militare attraverso l'esecuzione di una rete del 1⁰ crdine (65 stazioni assolute nei tre elementiD, H edI a circa 20 Km l'una dall'altra). I risultati sono compendiati in una carta magnetica della regione, scala 1750.000, isolinee al 1942.0. Oltre a due zone molto estese di anomalie dovute a rocce eruttive del periodo eocenico nell' Albania settentrionale e sud-orientale, sono messe in evidenza altre tre importanti anomalie regionali nella regione a NE di Scutari, a SO di Kruja, a NE di Korcia ed una locale a SE di Valona. L'esame geofisico indica come probabile causa per la prima e la terza la presenza di rocce basiche a profondità non molto rilevanti (dell' ordine di qualche Km).

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Zusammenfassung Das erdmagnetische Feld in Albanien ist (zum ersten Mal) von Ital. Mil. Geogr. Institut studiert worden. Ein magnetisches Netz erster Ordnung von 65 Stationen (ungefähr 20 Km Punktabstand) inD, H undI wurde gemessen. Die Ergebnisse sind in einer Karte dargestellt, Massstab 1750.000, Isolinien am 1942,0. Ausser zwei ausgedehnten Störgebieten von Eruptivgesteinen (Eozän) in Nord-und Süd-Ost-Albanien, sind drei andere Regionalstörungen im Gebiet NO von Scutari, SW von Kruja und NW Koriza, und eine Lokalstörung SO von Valona zu erkennen. Die erste und die dritte sind wahrscheinlich den Ergussgesteinen zuzuschreiben.

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con una tavola f. t.

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Dott.Carlo Morelli, Capo della Sezione Geomagnetica dell'Istituto Geografico Militare.  相似文献   

The problem of rock assimilation by Somma-Vesuvius magma     

Carlo Savelli 《Contributions to Mineralogy and Petrology》1967,16(4):328-353

New chemical and modal analyses are presented of magmatic rocks and pyroxenes nodules from the Somma-Vesuvius volcano and of trachytes from the surrounding area. Geochemical evidence is employed in checking the generally accepted suggestion that magma composition develops from that of trachyte into phonolitic tephrite and finally into tephritic leucitite (vesuvite) by assimilation of dolomite. At the Somma stage of the volcano, phonolitic tephrites (tephritic phonolites) alone have been produced. Vesuvius lavas (tephritic leucitites) are comparatively high in K₂O, CaO, F, Cl, Mn, Cu, Sr and Ba and low in SiO₂ and Nb. The formation of vesuvites by assimilation of dolomitic sedimentary rocks, combined with gravity-separation of early-formed pyroxenes from a trachytic or tephritic magma, is improbable as shown by chemical balances between the respective igneous and sedimentary rocks.  相似文献   

Interference Testing for Atmospheric HOx Measurements by Laser-induced Fluorescence     

Xinrong Ren  Hartwig Harder  Monica Martinez  Ian C. Faloona  David Tan  Robert L. Lesher  Piero Di Carlo  James B. Simpas  William H. Brune 《Journal of Atmospheric Chemistry》2004,47(2):169-190

Accurate OH and HO₂ (collectively called HO_x) measurements by laser-induced fluorescence (LIF) may be contaminated by spurious signals from interfering atmospheric chemicals or from the instrument itself. Interference tests must be conducted to ensure that observed OH signal originates solely from ambient OH and is not due to instrument artifacts. Several tests were performed on the Penn State LIF HO_x instrument, both in the laboratory and in the field. Theseincluded measurements of the instrument's zero signal by using either zero air or perfluoropropylene to remove OH, examination of spectral interferences from naphthalene, sulfur dioxide, and formaldehyde, and tests of interferences by addition of suspected interfering atmospheric chemicals, including ozone, hydrogen peroxide, nitrous acid, formaldehyde, nitric acid, acetone, and organic peroxy radicals (RO₂). All tests lacked evidence ofsignificant interferences for measurements in the atmosphere, including highly polluted urban environments.  相似文献   

Trace elements in streambed sediments of small subtropical streams on O‘ahu, Hawai‘i: Results from the USGS NAWQA program     

Eric Heinen De Carlo  Michael S. Tomlinson  Stephen S. Anthony 《Applied Geochemistry》2005,20(12):2157-2188

Data are presented for trace element concentrations determined in the <63 μm fraction of streambed sediment samples collected at 24 sites on the island of O‘ahu, Hawai‘i. Sampling sites were classified as urban, agricultural, mixed (urban/agricultural), or forested based on their dominant land use, although the mixed land use at selected sampling sites consisted of either urban and agricultural or forested and agricultural land uses. Forest dominated sites were used as reference sites for calculating enrichment factors.Trace element concentrations were compared to concentrations from studies conducted in the conterminous United States using identical methods and to aquatic-life guidelines provided by the Canadian Council of Ministers of the Environment. A variety of elements including Pb, Cr, Cu and Zn exceeded the aquatic-life guidelines in selected samples. All of the Cr and Zn values and 16 of 24 Cu values exceeded their respective guidelines. The potential toxicity of elements exceeding guidelines, however, should be considered in the context of strong enrichments of selected trace elements attributable to source rocks in Hawai‘i, as well as in the context of the abundance of fine-grained sediment in the streambed of O‘ahu streams.Statistical methods including cluster analysis, Kruskal–Wallis non-parametric test, correlation analysis, and principal component analysis (PCA) were used to evaluate differences and elucidate relationships between trace elements and sites. Overall, trace element distributions and abundances can be correlated to three principal sources of elements. These include basaltic rocks of the volcanic edifice (Fe, Al, Ni, Co, Cr, V and Cu), carbonate/seawater derived elements (Mg, Ca, Na and Sr), and elements enriched owing to anthropogenic activity (P, Sn, Cd, Sn, Ba and Pb). Anthropogenic enrichment gradients were observed for Ba, Cd, Pb, Sn and Zn in the four streams in which sediments were collected upstream and downstream.The findings of this study are generally similar to but differ slightly from previous work on sediments and suspended particulate matter in streams, from two urban watersheds of O‘ahu, Hawai‘i. Inter-element associations in the latter were often stronger and indicated a mixture of anthropogenic, agricultural and basaltic sources of trace elements. Some elements fell into different statistical categories in the two studies, owing in part to differences in study design and the hydrogeological constraints on the respective study areas.  相似文献   

A climatic control on the accretion of meteoric and super-chondritic iridium–platinum to the Antarctic ice cap     

Paolo Gabrielli  John M.C. Plane  Claude F. Boutron  Sungmin Hong  Giulio Cozzi  Paolo Cescon  Christophe Ferrari  Paul J. Crutzen  Jean Robert Petit  Vladimir Y. Lipenkov  Carlo Barbante   《Earth and Planetary Science Letters》2006,250(3-4):459-469

Meteoric smoke particles (MSPs) form through the vaporization of meteoroids and the subsequent re-condensation of metallic species in the mesosphere. Recently, iridium and platinum enrichments have been identified in Greenland ice layers and attributed to the fallout of MSPs supplying polar latitudes with cosmic matter during the Holocene. However, the MSP fallout to Antarctica during the Earth's climatic history remains essentially unknown.

We have determined iridium and platinum in deep Antarctic ice from Dome C and Vostok dated back to 240 kyrs BP. We find high super-chondritic fluxes during warm periods and low meteoric accretion during glacial times, a pattern that is opposite to any known climatic variation in dust fallout to polar regions. The proposed explanation of this accretion regime is a weaker polar vortex during warm periods, allowing peripheral air masses enriched in volcanic iridium and platinum to penetrate inland to Antarctica. The MSP signal emerges only during cold phases and is four times lower than in the Greenland ice cap where more snow accumulates. This suggests that wet deposition is an important route of cosmic material to the Earth's surface.  相似文献   

Geotechnical characterization and rockfall simulation of a slope: a practical case study from South Tyrol (Italy)     

Joachim Schweigl  Carlo Ferretti  Ludwig Nssing 《Engineering Geology》2003,67(3-4):281-296

Rockfalls occur often along the state road SS241 Val d'Ega in the Val d'Ega Valley (South Tyrol, Italy). In order to protect the road and the traffic, stabilization works are necessary. Detailed geological and geomorphologic mapping along structural and geomechanic sections was carried out, and experimental rockfall trails were examined on the slope above the state road between km 3.550 and 3.830. Rockfall simulation, rock mass classification and an interpretation of field data, especially concerning joints, wrapped up the investigations. They helped find the specific need for stabilization work and its positioning along the slope. The stabilization works were completed on February 2002. Another important aspect concerns ongoing geotechnical investigations and stabilization works urgently realised during autumn 1999.

This paper is a practical approach in solving rockfall problems along public roads. It should be considered as a workbook for university personnel and also for professional geologists.  相似文献   

A detailed palaeointensity and inclination record from drill core SOH1 on Hawaii   总被引：1，自引：0，他引：1  

Nicholas Teanby  Carlo LajDavid Gubbins  Malcolm Pringle 《Physics of the Earth and Planetary Interiors》2002,131(2):101-140

A new record of absolute palaeointensity was obtained from drill core Scientific Observation Hole 1 (SOH1) on Kilauea volcano, Hawaii. Kilauea’s high eruption rate resulted in a relatively continuous record and stratigraphic constraints preserved the chronological order. Three hundred and sixty samples were studied with the Thellier-Thellier technique, which gave 195 successful palaeointensity and 271 successful inclination determinations. Three geomagnetic excursions were observed, which exhibited intensity reductions of about 50%. Initial age control from K-Ar and Ar/Ar dating only constrained the total age between 20 and 120 ka. The final age model was obtained by stretching the SOH1 record relative to other Hawaiian palaeomagnetic data. This gave an age range of 0-45 ka for the flows and identified the excursions as the Hilina Pali, Mono Lake and Laschamp events. The SOH1 record of the Hilina Pali event is the most detailed ever, incorporating data from around 40 flows. This age model suggests that Kilauea had a burst of activity at the SOH1 site around 20 ka. All available data was combined to form a composite record of palaeointensity and inclination on Hawaii for 0-45 ka.  相似文献   

The physical environment of Kongsfjorden–Krossfjorden, an Arctic fjord system in Svalbard     

Harald Svendsen  Agnieszka Beszczynska-Møller  Jon Ove Hagen  Bernard Lefauconnier  Vigdis Tverberg  Sebastian Gerland  Jon Børre Ørbøk  Kai Bischof  Carlo Papucci  Marek Zajaczkowski  Roberto Azzolini  Oddbjørn Bruland  Christian Wiencke  Jan-Gunnar Winther  Winfried Dallmann 《Polar research》2002,21(1):133-166

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30-year response to damming of a Mediterranean river in California,USA     

Fernando Magdaleno  Carlo Donadio  G. Mathias Kondolf 《自然地理学》2018,39(3):197-215

Dry Creek is a major tributary of the Russian River in Northern California (USA) that has experienced hydrologic and morphologic alterations after the closure of Warm Springs Dam in 1983. Our objective is to present a detailed diagnosis of the modification of the creek’s flow and sediment regimes, and interpret the alterations regarding the ecomorphologic evolution previously observed in the creek. Statistical analysis of the river’s flow and sediment series indicates that dam operation has had significant impacts on the magnitude and frequency of occurrence of the highest floods, and the magnitude, variability, and duration of low and very low flows. Similarly, sediment concentration and discharge have also experienced major alterations. Loss of habitat complexity for native flora and fauna (especially endangered salmonids), channel incision, and vegetation encroachment are some of the negative trends found for the creek over the last 30 years, since river regulation began. We discuss the present dynamics of the river and propose, on that basis, the improvement of its hydromorphic functioning as part of future large-scale restoration initiatives.  相似文献   

A class-oriented mechanical approach for seismic damage assessment of RC buildings subjected to the 2009 L’Aquila earthquake     

Carlo Del Gaudio  Paolo Ricci  Gerardo Mario Verderame 《Bulletin of Earthquake Engineering》2018,16(10):4581-4605

The simplified mechanical method POST (PushOver on Shear Type models) for seismic vulnerability assessment of RC buildings is used in this study to derive damage scenarios for a database of 7597 RC buildings subjected to the 2009 L’Aquila earthquake. POST allows the evaluation of fragility curves through the determination of the non-linear static response of RC buildings in closed form, assuming the hypothesis of shear type behaviour, and considering the influence of infill panels both in the derivation of structural response and in assessment of building damage, which is defined according to the European Macroseismic Scale EMS-98. The aim of the present study is to provide a much more significant and reliable validation of the methodology, thanks to a much wider database compared to previous studies, and based on a different application of the methodology, i.e. at building class-level instead of single building-level. To this aim, the main geometrical-typological characteristics of the analysed buildings (number of storeys, age of construction, building area) have been statistically characterized based on data collected from post-earthquake AeDES survey forms, considering both the variability of each single parameter and the correlation that exists between one parameter and the other. This also allows to analyse the effectiveness of the adopted analytical procedure in predicting the general trends of observed damage with these parameters, showing a good agreement between observed and predicted trends. The overall predicted damage scenarios are compared with the corresponding observed ones, collected from AeDES survey forms, highlighting, again, a good agreement. Finally, the assumed mechanical interpretation of damage classification of EMS-98 is validated through the comparison between the distributions of damage to vertical structures and infill panels and the corresponding observed post-earthquake damage data.  相似文献