Jörn Happel, Christophe von Werdt, Mira Jovanović éds., Osteuropa kartiert – Mapping Eastern Europe

Ce recueil d’articles aborde des questions qui s’inscrivent dans l’actualité des débats scientifiques animant la recherche en géographie, cartographie et histoire : histoire de l’espace, représentation d’images spatiales du passé, émergence de la cartographie et de ses moyens de représentation de l’Europe de l’Est. Dans ces perspectives, l’espace est‑européen apparaît comme un objet d’investigation particulièrement intéressant. En effet, bien qu’étant une construction façonnée dans l’histoire..

Ground-Based Measurements of the 2014–2015 Holuhraun Volcanic Cloud (Iceland)

The 2014–2015 Bárðarbunga fissure eruption at Holuhraun in central Iceland was distinguished by the high emission of gases, in total 9.6 Mt SO2, with almost no tephra. This work collates all ground-based measurements of this extraordinary eruption cloud made under particularly challenging conditions: remote location, optically dense cloud with high SO2 column amounts, low UV intensity, frequent clouds and precipitation, an extensive and hot lava field, developing ramparts, and high-latitude winter conditions. Semi-continuous measurements of SO2 flux with three scanning DOAS instruments were augmented by car traverses along the ring-road and along the lava. The ratios of other gases/SO2 were measured by OP-FTIR, MultiGAS, and filter packs. Ratios SO2/HCl = 30–110 and SO2/HF = 30–130 show a halogen-poor eruption cloud. Scientists on-site reported extremely minor tephra production during the eruption. OPC and filter packs showed low particle concentrations similar to non-eruption cloud conditions. Three weather radars detected a droplet-rich eruption cloud. Top of eruption cloud heights of 0.3–5.5 km agl were measured with ground- and aircraft-based visual observations, web camera and NicAIR II infrared images, triangulation of scanning DOAS instruments, and the location of SO2 peaks measured by DOAS traverses. Cloud height and emission rate measurements were critical for initializing gas dispersal simulations for hazard forecasting

SDL-2000: A Language with a Formal Semantics

A new version of SDL called SDL-2000 is currently reaching maturity, and is expected to pass the standardization bodies shortly. It will offer new features as object-oriented data types, simplify and unify concepts of previous language versions and provide an alignment with UML. Due to the significant changes to SDL it was necessary to define a new formal semantics for SDL. Abstract State Machines (ASMs) have been chosen as the underlying formalism. In this paper, after introducing the new SDL language features, it is shown, how these features get an executable formal semantics using ASMs