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241.
Luigia Di Nicola Stefan Strasky Maria Cristina Salvatore Peter W. Kubik Haino Uwe Kasper Carlo Baroni 《Quaternary Research》2009,71(1):83-149
Geomorphological and glacial geological surveys and multiple cosmogenic nuclide analyses (10Be, 26Al, and 21Ne) allowed us to reconstruct the chronology of variations prior to the last glacial maximum of the East Antarctic Ice Sheet (EAIS) and valley glaciers in the Terra Nova Bay region. Glacially scoured coastal piedmonts with round-topped mountains occur below the highest local erosional trimline. They represent relict landscape features eroded by extensive ice overriding the whole coastal area before at least 6 Ma (pre-dating the build-up of the Mt. Melbourne volcanic field). Since then, summit surfaces were continuously exposed and well preserved under polar condition with negligible erosion rates on the order of 17 cm/Ma. Complex older drifts rest on deglaciated areas above the younger late-Pleistocene glacial drift and below the previously overridden summits. The combination of stable and radionuclide isotopes documents complex exposure histories with substantial periods of burial combined with minimal erosion. The areas below rounded summits were repeatedly exposed and buried by ice from local and outlet glaciers. The exposure ages of the older drift(s) indicate multiple Pleistocene glacial cycles, which did not significantly modify the pre-existing landscape. 相似文献
242.
Giancarlo Della Ventura G. Diego Gatta Gunter J. Redhammer Fabio Bellatreccia Anja Loose Gian Carlo Parodi 《Physics and Chemistry of Minerals》2009,36(4):193-206
We relate a single-crystal FTIR (Fourier transform infrared) and neutron diffraction study of two natural cancrinites. The structural refinements show that the oxygen site of the H2O molecule lies off the triad axis. The water molecule is almost symmetric and slightly tilted from the (0001) plane. It is involved in bifurcated hydrogen bridges, with Ow···O donor–acceptor distances >2.7 Å. The FTIR spectra show two main absorptions. The first at 3,602 cm?1 is polarized for E ⊥ c and is assigned to the ν3 mode. The second, at 3,531 cm?1, is also polarized for E ⊥ c and is assigned to ν1 mode. A weak component at 4,108 cm?1 could possibly indicate the presence of additional OH groups in the structure of cancrinite. Several overlapping bands in the 1,300–1,500 cm?1 range are strongly polarized for E ⊥ c, and are assigned to the vibrations of the CO3 group. 相似文献
243.
Piero Di Carlo Giovanni Pitari Natalia De Luca Domenico Battisti 《Environmental Geology》2009,58(2):431-436
Two years of in situ radon concentration measurements in the atmospheric surface layer have been collected in a central Italy
town (L’Aquila), located in the Aterno river valley. These data have been analyzed in order to study the controlling mechanisms
of surface radon abundance; observations of coincident meteorological parameters confirmed the role of dynamics on the local
removal rate of this tracer. The relatively high negative correlation of hourly data of surface wind speed and radon activity
concentration (R = −0.54, on annual scale) suggests that dynamical removal of radon is one of the most important controlling processes of
the tracer accumulation in the atmospheric surface layer. An attempt is made to quantify the precipitation impact on radon
soil fluxes. No anticorrelation of radon and precipitation comes out from the data (R = −0.15), as in previous studies. However, since the main physical parameter affecting the ground radon release is expected
to be the soil accumulation of water, snow or ice, the emission flux has also been correlated with soil moisture; in this
way a much clearer anticorrelation is found (R = −0.54). 相似文献
244.
Alessio Rovere Stefano Bellati Valeriano Parravicini Marco Firpo Carla Morri Carlo Nike Bianchi 《Estuaries and Coasts》2009,32(2):333-339
The existence of linkages between ecological and geomorphological processes and the influence of human activities both on
the biota and on geomorphology is well known for terrestrial environments, while it has been seldom reported for submerged
ones. A survey in the Noli-Bergeggi area (NW Mediterranean Sea) has been carried out to test the hypothesis that the harvesting
of Lithophaga lithophaga has an impact not only on the hammered rock, but also on the sediments at the cliff foot. Size and roundness of pebbles have
been measured at different stations and statistical analyses have been used to test the differences between impact and control
situations. Results show a dependence of the roundness of pebbles on the date mussel harvesting, indicating a decrease both
of the roundness index and of its variability at the cliff foot in impacted sites. Conclusions stress the biogeomorphological
nature of this activity, not limited to the present location. 相似文献
245.
Alexander?Alexandrovich?KonovalenkoEmail author Igor?Savelievich?Falkovich Nikolay?Nikolaevich?Kalinichenko Alexander?Alexandrovich?Gridin Igor?Nikolaevich?Bubnov Alain?Lecacheux Carlo?Rosolen Helmut?O.?Rucker 《Experimental Astronomy》2003,16(3):149-164
An effective wide-band (10 to 60 MHz) active antenna element has been developed. The cost of one short (3 m), thin dipole with built-in amplifier and metal construction is less than 45 euro. It was shown both theoretically and experimentally that the upper limiting frequency is at least 60 MHz, the dynamic range is 90 dB/V and the share of the amplifier noise to the background antenna temperature is about 10%. The developed active dipole was tested by building a 30-element antenna array and comparing its parameters with one of the subpart of the UTR-2 radio telescope having passive dipoles of 8.6 m in length and 1.8 m in diameter. The 3C461 ionospheric scintillation spectra observed in the experiments show that the sensitivities and noise-immunities of both antennas are close. This proves the availability using of a short cheap active dipole in new generation giant radio telescopes. 相似文献
246.
The 18.7 ka phreatomagmatic flank eruption on Etna (Italy): relationship between eruptive activity and sedimentary basement setting 总被引:1,自引:0,他引:1
This paper documents a phreatomagmatic flank eruption that occurred 18 700 ± 100 a BP , on the lower north-eastern slope of Etna during the Ellittico volcano activity, which produced fall and surge deposits. This type of eruption is connected to a sedimentary basement ridge at Etna. The interaction between the rising magma and the shallow groundwater hosted in the volcanic pile overlying the impermeable sediments resulted in phreatomagmatic instead of strombolian activity. Three eruptive phases are distinguished based on field and analytical data: (i) an explosive phreatomagmatic opening, (ii) a main phase producing coarse lithic-rich fallout and a strombolian deposit, and (iii) the final pulsating surge-forming phase. The discovery of this phreatomagmatic flank eruption, which occurred at lower altitude, raises important issues for previous hazard assessments at Etna. 相似文献
247.
Christoph Schlumpf Claudia Pahl-Wostl Andreas Schönborn Carlo C. Jaeger Dieter Imboden 《Climatic change》2001,51(2):199-241
Participatory Integrated Assessement (IA) methods complement analytical methods like IA-modeling in their explicit inclusion of stakeholders and decision-makers in the assessment. Integrated Assessment is perceived as a process of social learning involving scientists, stakeholders, policymakers and the society at large. We introduce a new approach to provide expert knowledge for participatory integrated assessments of regional climate change: `Interactive Citizen's Information Tools' (ICITs). ICITs provide citizens with expert knowledge about causes of climate change, potential impacts, and policy options to address anthropogenic climate change. In this paper we discuss the development and application of IMPACTS in IA-focus groups in Switzerland. IMPACTS is based on user-friendly hypermedia technologies and allows citizens to get informed on a broad range of potential climate change impacts – with an emphasison prevailing uncertainties. IA-focus groups are deliberative group discussions that make use of computer tools to support the discussion and assessment. The goal of IA-focus groups is to elicit how informed citizens judge the risks of anthropogenic climate change. Experiences with IMPACTS showed that the combination of focus groups with ICITs is a feasible and promising approach for a participatory IA of regional climate change, in particular, and of complex environmental issues, in general. 相似文献
248.
249.
Carlo Morelli 《Pure and Applied Geophysics》1944,6(1-2):23-36
Riassunto Si riferisce sul contributo portato dall'Istituto Geografico Militare alla conoscenza del campo magnetico terrestre in Italia ed altre regioni (Libia, Albania, Etiopia). Si forniscono particolari sulle carte magnetiche d'Italia e sulle carte delle isogone per la Libia, Albania, Dalmazia, Mediterraneo, Austria, Svizzera costruite dall'I.G.M. Per lo studio della geologia profonda in Italia sono state preparate anche le carte delle anomalie magnetiche (declinazione e componente orizzontale) e gravimetriche (secondo Faye e secondo Bouguer).
Dott.Carlo Morelli, Capo della Sezione Geomagnetica dell'Istituto Geografico Militare. 相似文献
Zusammenfassung Der Verfasser behandelt den Beitrag des ital. Geogr. Mil. Instituts zur Erkenntniss des erdmagnetischen Feldes in Italien und anderen Gegenden. Einzelheiten werden über die magnetischen Karten von Italien gegeben und die Deklinationskarten für Libien, Albanien, Dalmatien, Mittelmeer, Schweiz und Ostmark, usw. erwähnt. Für Italien sind auch die Karten der magnetischen (D und H) und gravimetrischen (Faye und Bouguer) Isanomalen konstruiert worden.
Dott.Carlo Morelli, Capo della Sezione Geomagnetica dell'Istituto Geografico Militare. 相似文献
250.
Dr. Carlo Bernasconi 《Pure and Applied Geophysics》1954,28(1):190-198
Riassunto Si suppone la Terra avvolta da un velo di un fluido perfetto incomprimibile messo in rotazione da un vortice doppio puntiforme. Si calcola l'energia cinetica totale della Terra e del fluido in funzione degli angoli di Eulero , , , che esprimono il moto della Terra rispetto a una terna inerziale, e degli angoli 0, 0 esprimenti il moto del vortice rispetto alla Terra. Si determinano i predetti angoli in funzione del tempo mediante le equazioni di Lagrange; risulta che il moto del vortice è caratterizzato da 0= const.,
e che la sua influenza sulla polodia è trascurabile.
Comunicazione presentata alla 2a. Assemblea annuale della «Società Italiana di Geofisica e Meteorologia» (Genova, 23–25 Aprile 1954). 相似文献
Summary Supposing the Earth sorrounded by a veil of an incompressible perfect fluid rotationally moved by a point shaped double vortex, the Author calculates the total kinetic energy of the system as a function of the Eulerian angles , , which expres the Earth motion referred to an inertial tern, and of the angles 0, 0 for the vortex motion referred to the Earth. He determines the above said angles as temporal functions by means of the equations of Lagrange. It results that the vortex motion is determined by 0= const., and that its influence on the rate of rotation of the Earth is negligeable.
Comunicazione presentata alla 2a. Assemblea annuale della «Società Italiana di Geofisica e Meteorologia» (Genova, 23–25 Aprile 1954). 相似文献