Impacts

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.     

Dodici anni di misure magnetiche in Italia dell'Istituto Geografico Militare

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).

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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.

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

Moto di un vortice sulla Terra e sua influenza sulla polodia

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.

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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.

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Comunicazione presentata alla 2^a. Assemblea annuale della «Società Italiana di Geofisica e Meteorologia» (Genova, 23–25 Aprile 1954).     

On a self-consistent representation of earth models,with an application to the computing of internal flattening

Most realistic Earth models published as yet have been given in tabulated form, with the noticeable exception of three simple parametric Earth models derived by Dziewonski et al. (1975). Simple interpolation in these tables may lead to inconsistencies, when we consider certain effects which depend crucially on detailed density structure. We establish algorithmic formulae, which may be used to compute all the mechanical properties of a model in an entirely consistent way, once the density as well asP— andS— wave velocities are known. We then use this formulation to integrate Clairaut’s equation in a very efficient way, and thus obtain the hydrostatic flattening to the first order in smallness at any point inside the model. For most geodynamic purposes, we may suffice with this approximation. Finally, we show the results of some calculations of hydrostatic flattening to the first and second order, using an iterative technique of solving the integral figure equations, for an Earth model consistent with all geophysical data available at present. We find that the hydrostatic flattening at the surface should be about 1/298.8, instead of 1/296.961 as quoted by Nakiboglu (1979) for essentially the same model. Moreover, from our results, we estimate the actual flattening of the coremantle boundary to be about 1/390.3.     

Genesis of massif-type anorthosites — the role of high-grade metamorphism

The genesis of massif-type anorthosites in general is discussed on the basis of data obtained on the Capivarita massif, a labradorite-type anorthosite from Southern Brazil. Massif anorthosites are thought to have originated by fractional crystallization of magmas of suitable compositions (essentially high-alumina basalt and andesite melts) that underwent extremely slow cooling under high-grade metamorphic conditions. Plagioclase is the dominant liquidus phase in the melt only over a very restricted temperature interval (10–20 °C) in which water pressure (PH₂O<P total) is maintained more or less constant at a critical value. Plagioclase accumulation by gravitational sinking is operative only under a set of critical conditions that are statistically unlikely to occur or to be maintained for any length of time. Hence, anorthosites would be relatively rare. The possible influence of the total pressure on anorthosite composition is discussed.At present, Chief Research Worker of the Brazilian CNPq.     

Simultaneous measurement and inversion of surface wave dispersion and attenuation curves

Surface wave tests are non-invasive seismic techniques that have traditionally been used to determine the shear wave velocity (i.e. shear modulus) profile of soil deposits and pavement systems. Recently, Rix et al. [J. Geotech. Geoenviron. Engng 126 (2000) 472] developed a procedure to obtain near-surface values of material damping ratio from measurements of the spatial attenuation of Rayleigh waves. To date, however, the shear wave velocity and shear damping ratio profiles have been determined separately. This practice neglects the coupling between surface wave phase velocity and attenuation that arises from material dispersion in dissipative media. This paper presents a procedure to measure and invert surface wave dispersion and attenuation data simultaneously and, thus, account for the close coupling between the two quantities. The methodology also introduces consistency between phase velocity and attenuation measurements by using the same experimental configuration for both. The new approach has been applied at a site in Memphis, TN and the results obtained are compared with independent measurements.     

Rare earth elements in the water column of Lake Vanda, McMurdo Dry Valleys, Antarctica

We present data on the composition of water from Lake Vanda, Antarctica. Vanda and other lakes in the McMurdo Dry Valleys of Antarctica are characterized by closed basins, permanent ice covers, and deep saline waters. The meromictic lakes provide model systems for the study of trace metal cycling owing to their pristine nature and the relative simplicity of their biogeochemical systems. Lake Vanda, in the Wright Valley, is supplied by a single input, the Onyx River, and has no output. Water input to the lake is balanced by sublimation of the nearly permanent ice cap that is broken only near the shoreline during the austral summer. The water column is characterized by an inverse thermal stratification of anoxic warm hypersaline water underlying cold oxic freshwater.Water collected under trace-element clean conditions was analyzed for its dissolved and total rare earth element (REE) concentrations by inductively coupled plasma mass spectrometry. Depth profiles are characterized by low dissolved REE concentrations (La, Ce, <15 pM) in surface waters that increase slightly (La, 70 pM; Ce, 20 pM) with increasing depth to ∼55 m, the limit of the fresh oxic waters. Below this depth, a sharp increase in the concentrations of strictly trivalent REE (e.g., La, 5 nM) is observed, and a submaximum in redox sensitive Ce (2.6 nM) is found at 60- to 62-m depth. At a slightly deeper depth, a sharper Ce maximum is observed with concentrations exceeding 11 nM at a 67-m depth, immediately above the anoxic zone. The aquatic concentrations of REE reported here are ∼50-fold higher than previously reported for marine oxic/anoxic boundaries and are, to our knowledge, the highest ever observed at natural oxic/anoxic interfaces. REE maxima occur within stable and warm saline waters. All REE concentrations decrease sharply in the sulfidic bottom waters. The redox-cline in Lake Vanda is dominated by diffusional processes and vertical transport of dissolved species driven by concentration gradients. Furthermore, because the ultraoligotrophic nature of the lake limits the potential for organic phases to act as metal carriers, metal oxide coatings and sulfide phases appear to largely govern the distribution of trace elements. We discuss REE cycling in relation to the roles of redox reactions and competitive scavenging onto Mn- and Fe-oxides coatings on clay sized particles in the upper oxic water column and their release by reductive dissolution near the anoxic/oxic interface.     

Tangible User Interfaces (TUIs): A Novel Paradigm for GIS

In recent years, an increasing amount of effort has gone into the design of GIS user interfaces. On the one hand, Graphical User Interfaces (GUIs) with a high degree of sophistication have replaced line‐driven commands of first‐generation GIS. On the other hand, a number of alternative approaches have been suggested, most notably those based on Virtual Environments (VEs). In this paper we discuss a novel interface for GIS, which springs from recent work carried out in the field of Tangible User Interfaces (TUIs). The philosophy behind TUIs is to allow people to interact with computers via familiar tangible objects, therefore taking advantage of the richness of the tactile world combined with the power of numerical simulations. Two experimental systems, named Illuminating Clay and SandScape, are described here and their applications to GIS are examined. Conclusions suggest that these interfaces might streamline the landscape design process and result in a more effective use of GIS, especially when distributed decision‐making and discussion with non‐experts are involved.