Materials of the International Conference
50th Anniversary of the International Geophysical Year
and Electronic Geophysical Year

16-19 September 2007 • Suzdal, Russia

Research of the earth's interior after IGY: Projects "Geotraverse" and "Intermargins"

A. G. Rodnikov, N. A. Sergeeva, and L. P. Zabarinskaya

Geophysical Center, Russian Academy of Sciences, Moscow, Russia

Abstract

Fifty years passed since implementation of the International Geophysical Year (IGY), which went down in the history of science and in the history of humanity in general as one of the most human and noble initiatives. IGY became the ground for new scientific international projects in the sphere of Solid Earth, such as Project of the upper mantle (1961–1971), International Geodynamic Project (1971–1980), Study of electric conductivity of asthenosphere (1978–1985), International programme "Lithosphere", International Project "Geotravers" (1987–2003) and international project "InterMARGINS" ("Continental Margins", operating since 2003. Projects "Geotravers" and "InterMARGINS" were aimed at the research of the deep structure of continental margins, characterized by high seismicity, volcanism, and natural cataclysms, being dangerous for inhabitants of those areas. Active margins are also areas of recent intensive tectonic movements and hydrothermal processes, and areas of accumulation of mineral fields of different kinds. The major task of the projects was to build geodynamic models of continental margins with the purpose of studying deep structure of the Earth beneath seismically dangerous zones, volcanic structures, mineragenetic zones and sedimentary basins, and to reveal roles of deep processes, occurring in the mantle, including asthenosphere, in the formation of the major tectonic elements. Geodynamic models include geophysical fields and geological-geophysical parameters, describing structure of the crust and upper mantle. It was established that a spread of asthenospheric layer in the upper mantle is a distinctive feature of the deep structure of continental margins. Formation of the Earth crust structures is caused with processes occurring in the diapirs of the hot anomalous mantle; diapirs being stretched from asthenospheric layer. Correlation between geological structures, tectonic-magmatic activity and structure of the upper mantle is outlined. A powerful, fully revealed asthenosphere, generating magma, corresponds to tectonically active regions, such as island areas, rift structures of the marginal seas. On the surface, rifts and outflows of magmas, mainly tholeitic basalts, correspond to upheavals of the asthenosphere. Sedimentary basins of the marginal seas are different from other regions in anomalous deep structure. Their characteristic features are: localization of the asthenospheric diapir beneath sedimentary basins; rift structures or spreading centres in their basement; active volcanism in the initial stage of formation, connected with hydrothermal processes and sulphides production. Probably, asthenospheric diapirs with a partial material fusion represent channels, through which hot mantle fluids from asthenosphere penetrate into sedimentary basins. Information database of geological-geophysical parameters of the litosphere via systems of geotravereses and Database for the construction of digital models of the litosphere of the marginal and inland seas are created in the Geophysical Center of RAS. Geotravereses of the Phillippine Sea region, constructed together with the Japanese and Chinese scientists, was published in the International Geological-Geophysical Atlas of the Pacific Ocean in 2003.

Citation: A. G. Rodnikov, N. A. Sergeeva, and L. P. Zabarinskaya (2007), Research of the earth's interior after IGY: Projects "Geotraverse" and "Intermargins", in: Materials of the International Conference '50th Anniversary of the International Geophysical Year and Electronic Geophysical Year', GC RAS, Moscow, doi:10.2205/2007-IGY50conf.

© 2007 Geophysical Center RAS and authors


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