The research aims of the Bayerisches Geoinstitut are centred primarily on investigations of the structure, composition and dynamics of the Earth's interior. The approach to such studies involves experiments at high pressures and temperatures to determine the stability and the physical and chemical properties of Earth materials (minerals, melts and fluids) at depth in the Earth. As the results presented in this Annual Report demonstrate, considerable progress has been achieved during 1998. A variety of studies of (Mg,Fe)SiO3 silicate perovskite, the most abundant mineral in the Earth, are particularly noteworthy. Because the lower mantle (660-2900 km depth range) consists predominantly of this mineral, its properties largely control processes in the Earth's interior. It has recently been shown, through studies at the Bayerisches Geoinstitut, that the presence of minor elements, such as aluminium, have a very large effect on the physical and chemical properties of silicate perovskite. The aim of a variety of current projects described in this report is to quantify these effects and thereby to understand better the nature of the Earth's lower mantle.
The third Professorship (Experimental Geophysics) at the Bayerisches Geoinstitut was filled on 1/1/98 by Stephen Mackwell. His aim is to strengthen and further develop rheological studies of Earth materials at high pressure and temperature. The current understanding of the rheology of the Earth's mantle is poor, even though this property controls the large-scale solid-state mantle convection that is responsible for plate tectonics, earthquakes and volcanic eruptions. Two approaches are currently being developed at the Bayerisches Geoinstitut in this field: (1) High-precision, high-strain deformation experiments at low pressures (up to 0.5 GPa) and (2) multianvil deformation experiments up to pressures of 16 GPa or more (equivalent to a depth of 500 km in the Earth). A combination of these approaches is likely to be particularly effective in increasing our understanding of mantle rheology.
Many of the studies reported below have important practical applications, related for example to climate change. The studies of the solubility of water in high-pressure mantle minerals have implications for the recycling of water between the surface and the deep interior of the Earth and for the occurrence of volcanism during geological time. Understanding the behaviour of halogens in magmatic systems is critical for understanding degassing during volcanic eruptions and resulting climate changes.
Since it was founded in 1986, the Bayerisches Geoinstitut has become a centre for high-pressure research both within Europe and world-wide. This success is due, in part, to our Visiting Scientists' Programme that provides the means of attracting young research scientists from outside of Europe as postdoctoral research scientists for periods up to several years. Funding the institute as a "Large Scale Facility" by the European Union (since 1994) has enabled numerous scientists from other EU states to visit and use the experimental facilities. In terms of training young research scientists, developing scientific collaborations in Europe and publishing high-quality scientific results, this programme, together with our participation in several EU "Research Networks", has been outstandingly successful. Finally, within Germany, generous support by the German Science Foundation and the Alexander-von-Humboldt Foundation has played an important role in the pursuit of high-quality research.
Explaining the purposes of basic research to the general public is becoming increasingly important these days as more emphasis is directed towards applied research. During 1998, such public relation activities at the Bayerisches Geoinstitut have been expanded significantly. Such activities culminated towards the end of 1998 with a "Pressereise", organised by the German Science Foundation, that involved about fifteen journalists visiting the institute to participate in a programme consisting of scientific presentations and laboratory visits. This event led to excellent coverage of the activities of the institute in national newspapers and journals.
As in previous years, and also on behalf of my colleagues, I would like
to thank the Free State of Bavaria as represented by the Staatsministerium
für Wissenschaft, Forschung und Kunst as well as the Kommission
für Geowissenschaftliche Hochdruckforschung for their continuing
support and strong commitment to the Bayerisches Geoinstitut. We also gratefully
acknowledge generous support from external funding agencies, in particular
the Alexander von Humboldt Foundation, the European Union,
and the German Science Foundation, which have also contributed greatly
to the development and success of the Institute.
|Bayreuth, January 1999||
David C. Rubie