Crustal structure of the Lomonosov Ridge and the Fram and Makarov Basins near the North Pole
Tóm tắt
Reversed refraction surveys were conducted along and across the Lomonosov Ridge as part of the 1979 Lomonosov Ridge Experiment. Interpretation of the strike profiles indicates a 5‐km‐thick upper crustal layer with a velocity of 4.7 km/s overlying a 15‐ to 20‐km‐thick layer of 6.6 km/s material. An upper mantle velocity of 8.3 km/s is indicated by a few pn arrivals. High‐amplitude reflection events recorded from this boundary can be successfully modeled by a transition zone of rapidly changing velocity over a depth interval of 5 km. Ray trace modeling of the dip profiles suggests a root structure extending to about 28‐km depth flanked by crust thinning to a depth near 13 km beneath the Makarov Basin and a more gradual thinning to near 16 km beneath the Fram Basin. The similarity between the crust of the Lomonosov Ridge and that beneath the Barents and Kara seas supports the suggestion that the ridge is a slice rifted from the Baltic Shelf.
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Tài liệu tham khảo
Berckhemer J. B.Baier H.Bartelsen A.Behle H.Burkhardt H.Bebrande J.Makris H.Miller R.Vees Deep seismic soundings in the Afar region and on the highland of Ethiopia. Afar depression of Ethiopia Sci. RepA.Pilger A.Rosler 14 89–107Inter‐union Commission on Geodynamics Bad Bergzabern 1975.
Bolt B. A., 1982, Reinterpretation by ray tracing of a transverse refraction seismic profile through the California Sierra Nevada, I, Bull. Seismol. Soc. Am., 72, 889, 10.1785/BSSA0720030889
Chapman C. H., 1978, A new method for computing synthetic seismograms, Geophys. J. R. Astron. Soc., 53, 409
Coles R. The lorex magnetic gradient and total field experiment Earth Phys. Branch 1979 Geomag. rep 1–20 1980.
Demenitskaya R. M., 1968, The characteristic features of the structure, morphology and sedimentary cover of the central part of the Lomonosov Ridge based on seismic data, Geophys. Methods Explor. Appl. Arct., 5, 33
Demenitskaya R. M., 1964, Structure of the Earth's Crust Under the Arctic, 114
Gakkel' Y. Y., 1954, The submarine Lomonosov Range, Vokrug Sveta, 11, 4
Gakkel' Y. Y., 1958, Evidence of recent submarine volcanism on the Lomonosov Ridge, Priroda Moscow, 4, 87
Judge A. A.Taylor Heat flow in Arctic regions (abstractProgram of Abstracts of the 21st General Assembly MeetingInternational Association of Seismologists and Physicists of the Earth's InteriorLondon OntarioJuly 1981.
Leontiev O. K., 1963, A Short Course in Marine Geology
Ostrekin M. Y., 1954, Recent study and exploration of the central Arctic, Priroda Moscow, 12, 3
Whittall K. P., 1979, A simple, efficient method for the calculation of travel times and ray paths in laterally inhomogeneous media, J. Can. Soc. Explor. Geophys., 15, 21