SECOND INTERNATIONAL SYMPOSIUM: GEODYNAMICS OF THE ALPS-ADRIA AREA BY MEANS OF TERRESTRIAL AND SATELLITE METHODS

Last autumn the beautiful city of Dubrovnik became a meeting point of the international geodetic community again. It was after a long interruption lasting almost exactly 9 years. In 1989 the participants of the First International Symposium on Gravity Field Determination and GPS-Positioning in the Alps-Adria Area left the Dubrovnik Inter-University Centre, the venue of the symposium, with a believe that they will reconvene at the same place in four years. However, the reality and the difficult time in this area prepared another development.

                             Only last year the reconstructed Inter-University Centre of Dubrovnik became the venue of the Second International Symposium: Geodynamics of the Alps-Adria Area by means of Terrestrial and Satellite Methods which was held here between September 28 and October 2, 1998. The symposium was sponsored by the International Association of Geodesy and it also had a generous local support. In total 43 interesting papers were presented by scientists coming from 9 different countries to the audience of over 70 participants. The meeting was organized by Prof. K. Èoliæ (as the local organizer, University of Zagreb) and Prof. H. Moritz (as the international co-organizer).

                             At the opening session a number of addresses was presented by local and international representatives. Then the participants of the symposium heard a very interesting lecture by K. Èoliæ and H. Moritz on Rudjer Boškoviæ (1711-1787), a native of Dubrovnik and a remarkable figure in the history of modern European science who also made considerable contributions to geodesy and geophysics.

                             The symposium itself was subdivided into 10 session: 3 sessions were devoted to Geodynamics and chaired subsequently by H. Seeger, G. Rossi and C. Marchesini. Then G. Schmitt chaired a session on Geoid, F. Vodopivec a session on GPS, P. Holota a session on Positioning and Gravity, P. Pesec chaired a session on CERGOP, E. Groten a session on the Theory and finally two session devoted to practical works were chaired by A. Zeman and K. Kaniuth.

                             The first session on Geodynamics started with a paper by Hussein A. Abd-Elmotaal who discussed inverse Vening Meinesz Moho depths for the Eastern Alps. Then Z. Altiner et al. presented a talk on crustal deformations in the Adriatic sea area as inferred on the basis of GPS observations. Subsequently, E. Groten and St. Leinen treated deformation monitoring around a large viaduct close to Istambul using GPS and levelling. Finally, F. Vodopivec and D. Kogoj discussed the geodynamics in Slovenia and A. Zeman approached a problem of estimating vertical dynamics on the territory of former Austro-Hungarian empire on the bases of results of historical levellings.

                             The second session on Geodynamics was opened by A. Caporali who in his talk attacked a problem of constraining the rheology of continental lithosphere near Orogens with the use of Bouguer gravity anomalies. The programme of the session continued with a paper by D. Miškoviæ on problems of national reference frame and geodynamic investigations in Slovenia. Then B. Richter et al. discussed absolute gravity measurements in Croatia approached as a standardized base net for geodynamic, height and gravity studies. Finally, G. Schmitt and C. Marchesini informed about geodetic activities with respect to geokinematics in Friuli and the Eastern Alps.

                             At the last session on Geodynamics E. Prelogiæ et al. treated recent tectonic movements and earthquakes in Croatia and then G. Rossi and M. Zadro discussed geodynamic processes at the northern boundary of Adria plate, especially strain-tilt measurements and modelling. The session was closed with a paper by P. Vyskoèil (presented in absentia by H. Moritz) on the map of vertical movements of Dinaridies Eastern Alps, Pannonian Basin and the Bohemian Massif.

                             As already mentioned, together with geodynamics oriented sessions there were also sessions on closely related topics in Dubrovnik.

                             The paper by H. Abd-Elmotaal et al. stared the Geoid session. The talk was devoted to the influence of implementing the seismic Moho depths in geoid computation. K. Arsov and H. Sünkel approached the problem of influence of the resolution of DEM in gravity reduction. They used fractal models of the topography for their analyses. E. Groten and K. Seitz discussed a detailed geoid of Germany based on EGM96. N. Kühtreiber presented a recent geoid computation for Audtria and N. Kühtreiber et al. then concluded the session with results of a geoid computation for the central part of the Alps-Adria area.

                             At the GPS session A. Caporali devoted his talk to an analysis of a GPS network along the Alpine Arc. K. Kaniuth and Stuber attacked the problem of accuracy and reliability of height estimates in regional GPS networks. H. Seeger et al. contributed with results of a re-computation of the EUREF GPS campaigns in Croatia and Slovenia. Finally, M. Marjanoviæ and Lj. Rašiæ discussed the results of the EUREF 1997 GPS campaign in Croatia.

                             Also the Gravity was discussed at a separate session. Here J. Flury brought an information on a local gravity filed determination in the Estergebirge. E. Gueguen and C. Doglioni discussed the geodynamic evolution of the Appeninic subduction. R. Marjanoviæ-Kavanagh contributed with experiences with a new digital tiltmeter and G. and G.K. Walach presented a Bouguer gravity map of Styria.

                             The session on CERGOP was opened by D. Miškoviæ et al. They presented results of the GPS-measurements in the Bovec-Tolmin earthquake region. H. Düller and P. Pesec contributed with information on the Austrian permanent GPS-network. P. Pesec then summarized the current status of the Austrian IDNDR project (Crustal dynamics of the Adriatic microplate and the adjacent East-Alpine area). Finally, J. Šimek discussed possible topics for the international cooperation within CEI/CERGOP on the background of current European project.

                             Within theory oriented session the audience heard a contribution by P. Holota on Galerkin's method in the determination of the disturbing potential. Then an analysis of a straight line equation by M. Lapaine and new concepts of boundary value problems of physical geodesy after GPS presented by H. Moritz.

                             Finally, two working sessions were devoted to practical works. Here K. Èoliæ et al. contributed with two talks: on the survey of the Plitvice-lakes (the phenomenon in the Karst of the Dinaric Alps with satellite and terrestrial measurements) and on the 3-D geodynamic network of broader area of the city of Zagreb. Then Z. Kapoviæ et al. presented results of the geodynamic research of the historical center in the city of Dubrovnik with precise geometric levelling. Subsequently M. Plazibat approached linear transformation between old and new national networks by means of finite elements and M. Solariæ discussed a visibility analysis of GPS satellites in Central Europe.

                             At the closing session (chaired by B. Gajèeta) the participants adopted a number of important resolutions. They are as follows:

Resolution 1 - The Symposium,

recognizing the need of a regular exchange of ideas and research results in the field of the ‘tectonic scenario’ in the wider Alps-Adriatic region and

having in mind the hospitality of the Croatian colleagues,

recommends regular meetings in a four years cycle in the city of Dubrovnik, with one intermediate meeting at a different place between two of these symposia.

Resolution 2 - The Symposium,

recognizing the need of further research concerning the ‘tectonic scenario’ in the wider Alps-Adriatic region and of studies concerning earthquake disaster prevention in this region,

recommends the establishment of a corresponding Special Study Group in Section V ‘Geodynamics’ of IAG, with due relation to CERGOP.

Resolution 3 - The Symposium,

considering that the area of the Plitvice Lakes is not only a National Heritage under the patronage of UNESCO (No. 148), but also very important for different reasons such as Dinaric Karst geology, effect of tourism etc. and

considering that important geodetic and geodynamical studies have already been performed by the Geodetic Faculty of Zagreb University,

recommends that this area be declared an International Geodynamic Test Area in which all relevant geodetic methods are to be applied.

Resolution 4 - The Symposium,

recognizing the need of permanent GPS stations and

considering the existence of such stations e.g. in Croatia and Slovenia.

recommends the establishment of at least one permanent GPS station on the territory of Bosnia and Herzegovina.

Resolution 5 - The Symposium,

recognizing the great and successful efforts of Prof. Èoliæ and Prof. Moritz and their staff in preparing and organizing this symposium and

appreciating the importance of the topics under consideration for applied and theoretical surveying, geodesy, geodynamics and related practical activities by universities and state organizations in and around the Alpine-Adriatic Area up to the Panonnian Basin,

expresses its sincere thanks for the wonderful days in the beautiful city of Dubrovnik, which is under the patronage of UNESCO (No. 149), and in the stimulating environment of IUC in free Croatia.

The scientific programme of the symposium was enriched by the presentation of the book by H. Horitz: Science, Mind and the Universe (U. Wichmann Vlg., Heidelberg, 1995) and its translation into Croatian. On this occasion an introductory lecture was held by Acad. N. Trinajstiæ who gave an interesting outline of philosophy and discussed its contemporary trends.

                             The participants of the symposium spent nice and well organized time together and during an interesting excursion had a possibility to learn more about the marvelous city of Dubrobnik and its beautiful surrounding. The symposium was a clear success. The Proceedings will be published by the Geodetic Survey of Croatia.

                                                                                                        P. Holota

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