ALBERT

Description: The IUGG Yearbook is a reference document of IUGG members, administrative officers, and Association and Union Commission officers that is updated annually and distributed free of charge. Each issue endeavors to update the contact information for hundreds of persons who are actively participating in IUGG scientific activities. Information is complied throughout the year until end December. The Yearbooks are published and posted at the IUGG webpage at the beginning of the year. The Yearbooks are printed together with the Annual Reports for the preceding year in May and mailed to National Committee for Geodesy and Geophysics, Adhering Bodies, IUGG partners, and major libraries.

Description: La traduction fait référence à la partie principale de la publication anglaise (Grünthal et al., 1998) décrivant l'Echelle Macrosismique Européenne (EMS-98). Ce texte est un extrait de la traduction française existante de la version anglaise complète (Grünthal et Levret, 2001). La partie princi-pale est constituée des pages 14 à 20 de l'original anglais et de la traduction de la version complète. Cette numérotation des pages est conservée ici.

Description: The translation refers to the core part of the European Macroseismic Scale (EMS-98) of the English original (Grünthal et al., 1998), respectively the core part reproduced here is an excerpt from the existing French translation of the English full version (Grünthal and Levret, 2001). The core part consists of pages 14 to 20 of both the English original and the translation of the full French version. This page numbering is retained here. The European Macroseismic Scale (EMS-98) is a tool for intensity assignment. The macroseismic intensity represents a classification of the severity of ground-motion shaking during an earthquake on the basis of observed effects at a given place. The EMS-98 is the most recent scale in general use. It fully considers the varying strength of buildings in the form of six vulnerability classes, five damage grades for both masonry and reinforced concrete structures, and differentiates structural and non-structural damage as well. Another diagnostic element concerns the relative frequency of observed effects with quantitative definitions of the qualitative terms “few, many, most.” EMS-98 is the only intensity scale complemented by comprehensive guidelines and background materials. They provide the basis that the EMS-98 can easily be adapted for use to the building stock anywhere in the world. The European Seismological Commission launched the development of a new scale in 1988 which should consider modern earthquake-resistant building types and engineering requirements. So the test version EMS-92 and then EMS-98 were evolved. The latter should be the basis for intensity evaluation in European countries and is also applied in many countries outside Europe. The English original of the EMS-98 was translated as full scale into French, Italian, Spanish and Chinese. Moreover, the core part or the short form is available in a total of altogether 30 languages. Such multilingual availability is important since persons, not always fluent in English, act as observers and sensors in macroseismology.

Description: Slab retreat, slab tearing and interactions of slabs are first-order drivers of the deformation of the overriding lithosphere. An independent description of the tectonic evolution of the back-arc and peripheral regions is a pre-requisite to test the proposed conceptual, analogue and numerical models of these complex dynamics in 3-D. We propose here a new series of detailed kinematics and tectonic reconstructions from 35 Ma to the Present shedding light on the driving mechanisms of back-arc rifting in the Mediterranean where several back-arc basins all started to form in the Oligocene. The step-by-step backward reconstructions lead to an initial situation 35 Ma ago with two subduction zones with opposite direction, below the AlKaPeCa block (i.e. belonging to the Alboran, Kabylies, Peloritani, Calabrian internal zones). Extension directions are quite variable and extension rates in these basins are high compared to the Africa-Eurasia convergence velocity. The highest rates are found in the Western Mediterranean, the Liguro-Provençal, Alboran and Tyrrhenian basins. These reconstructions are based on shortening rates in the peripheral mountain belts, extension rates in the basins, paleomagnetic rotations, pressure-temperature-time paths of metamorphic complexes within the internal zones of orogens, and kinematics of the large bounding plates. Results allow visualizing the interactions between the Alps, Apennines, Pyrenean-Cantabrian belt, Betic Cordillera and Rif, as well as back-arc basins. These back-arc basins formed at the emplacement of mountain belts with superimposed volcanic arcs, thus with thick, hot and weak crusts explaining the formation of metamorphic core complexes and the exhumation of large portions of lower crustal domains during rifting. They emphasize the role of transfer faults zones accommodating differential rates of retreat above slab tears and their relations with magmatism. Several transfer zones are identified, separating four different kinematic domains, the largest one being the Catalan-Balearic-Sicily Transfer Zone. Their integration in the wider Mediterranean realm and a comparison of motion paths calculated in several kinematic frameworks with mantle fabric shows that fast slab retreat was the main driver of back-arc extension in this region and that large-scale convection was a subsidiary driver for the pre-8 Ma period, though it became dominant afterward. Slab retreat and back-arc extension was mostly NW-SE until ∼ 20 Ma and the docking of the AlKaPeCa continental blocks along the northern margin of Africa induced a slab detachment that propagated eastward and westward, thus inducing a change in the direction of extension from NW-SE to E-W. Fast slab retreat between 32 and 8 Ma and induced asthenospheric flow have prevented the transmission of the horizontal compression due to Africa-Eurasia convergence from Africa to Eurasia and favored instead upper-plate extension driven by slab retreat. Once slab retreat had slowed down in the Late Miocene, this N-S compression was felt and recorded again from the High Atlas to the Paris Basin.