Abstract
The phenomenon of glacial isostatic adjustment provides uniquely useful information concerning the nature of the planetary mantle. Not only can the observational data be invoked to constrain mantle viscosity but they also provide important clues as to the extent to which the radial profile of mantle density is near adiabatic. Both of these pieces of information are important for the construction of models of the mantle convection process. In this paper I focus on the manner in which the free air gravity anomalies in both Canada and Fennoscandia serve to constrain these two aspects of the radial viscoelastic structure. The results demonstrate the way in which the different horizontal scales of the rebound in these two regions map into differences in the range of depths to which the response is sensitive. A particularly important result concerns the apparent requirement, based upon the free air anomaly over the Canadian Shield, that the seismic horizon at 670 km depth behaves non-adiabatically on the timescale of postglacial rebound.
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References
Balling, N., 1980. ‘The land uplift in Fennoscandia, gravity field anomalies and isostasy’. I. Earth Rheoloay, Isostasy, and Eustasy. N.A. Mörner ed. pp. 297–321. New York, Wiley, 599 pp.
Cathles, L.M., 1975. The Viscosity of the Earth’s Mantle. Princeton, Princeton U. Press.
Clark, J.A., Farrell, W.E., and Peltier, W.R., 1978. Global changes in postglacial sea level: a numerical calculation. Quat. Res., 9, 265–287.
Dziewonski, A.M. and Anderson, D.L., 1981. Preliminary reference earth model. Phys. Earth Planet. Int., 25, 297–356.
Ekman, Martin, 1987. Postglacial uplift of the crust in Fennoscandia and some related phenomena. International Association of Geodesy, IUGG General Assembly, Vancouver, Preprint.
Forte, A.M., and Peltier, W.R., 1987. Plate tectonics and aspherical earth structure: the importance of poloidal toroidal coupling. J. Geophys. Res., 92, 3645–3679.
Hager, B.H., 1984. Subducted slabs and the geoid: constraints on mantle rheology and flow. J. Geophys. Res., 89, 6003–6015.
Lerch, F.J., Klosko, S.M., Laubscher, R.E. Wagner, C.A., 1979. Gravity model improvement using GEOS 3 (GEM 9 and 10). i. Geophys. Res., 84, 3897–3916.
Mitrovica, J.X., and Peltier, W.R., 1988. Pleistocene deglaciation and the global gravity field. J.G.R., submitted.
O’Connell, R.J., 1976. The effects of mantle phase changes on postglacial rebound. J. Geophys. Res., 81, 971–974.
Peltier, W.R., 1974. The impulse response of a Maxwell earth. Rev. Geophys. Space Phys., 12, 649–669.
Peltier, W.R., 1976. Glacial isostatic adjustment II. The inverse problem. Geophys. J.R. astr. Soc., 46, 669–706.
Peltier, W.R., 1981. Ice age geodynamics. Ann. Rev. Earth Planet. Sci., 9, 199–225.
Peltier, W.R., 1982. Dynamics of the ice age earth. Advances in Geophysics, 24, 1–146.
Peltier, W.R., 1983. Constraint on deep mantle viscosity from LAGEOS acceleration data. Nature, 304, 434–436.
Peltier, W.R., 1985. Mantle convection and viscoelasticity. Ann. Rev. Fluid Mech.. 17, 561–608.
Peltier, W.R., 1986. Deglaciation induced vertical motion of the North American continent and transient lower mantle rheology. J. Geophys. Res., 91, 9099–9123.
Peltier, W.R., 1987. Glacial isostasy, mantle viscosity, and Pleistocene climatic change, in DNAG vol. K-3, North America and Adjacent Oceans During the Last Deglaciation, pp. 155–182. The Geological Society of America, Denver.
Peltier, W.R., 1988. Global sea level and earth rotation. Science, 240, 895–901.
Peltier, W.R., and Andrews, J.T., 1976. Glacial isostatic adjustment I. The forward problem. Geophys. J. Roy, astron. Soc., 46, 605–646.
Peltier, W.R., Farrell, W.E., and Clark, J.A., 1978. Glacial isostasy and relative sea level: a global finite element model. Tectonophysics, 50m 81–110.
Peltier, W.R. and Wu, Patrick, 1982. Mantle phase transitions and the free air gravity anomalies over Fennoscandia and Laurentia. Geophys. Res. Lett., 9, 731–734.
Takehashi, Eiichi, and Ito, Eiji, 1988. Constitution and chemical evolution of the earth’s mantle: implications from high pressure experiments. Abstract for the first SEDI Symposium, Blaines Spain, June 1988.
Tushingham, A.M., and Peltier, W.R., 1988. A new global model of late Pleistocene deglaciation. J. Geophys. Res., submitted.
Walcott, R.I., 1970. Isostatic response to loading of the Crust in Canada. Can. J. Earth Sci., 7, 716–727.
Wu, Patrick, and Peltier, W.R., 1983. Glacial isostatic adjustment and the free air gravity anomaly as a constraint on deep mantle viscosity. Geophys. J.R. astr. Soc., 74, 377–450.
Wu, Patrick, and Peltier, W.R., 1984. Pleistocene deglaciation and the Earth’s rotation: a new analysis. Geophys. J.R. astron. Soc, 76, 753–791.
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© 1989 Kluwer Academic Publishers
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Peltier, W.R. (1989). Glacial Isostasy in Laurentia and Fennoscandia: New Results for the Anomalous Gravitational Field. In: Earthquakes at North-Atlantic Passive Margins: Neotectonics and Postglacial Rebound. NATO ASI Series, vol 266. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-2311-9_7
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DOI: https://doi.org/10.1007/978-94-009-2311-9_7
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