Journal of Paleolimnology

, Volume 19, Issue 3, pp 365–376 | Cite as

Combining geomorphological and geodetic data to determine postglacial tilting in Manitoba

  • A. Lambert
  • T. S. James
  • L. H. Thorleifson
Article

Abstract

Estimates of postglacial rebound in central North America from Laurentide deglaciation to the present time are uncertain as a result of lack of data from the continental interior. A more precise knowledge of postglacial tilt history will assist studies of the evolution of the major lakes in Manitoba and will facilitate the engineering and environmental management of the present-day hydrological system. This paper explores the benefits of combining geomorphological data with high-precision, real-time geodetic data (GPS positioning and absolute gravity) and lake-gauge tilt data now being collected for postglacial rebound studies in Manitoba and adjacent regions in the US. Presently-available data sets representing these data types are (1) tilting of the 9.5 kyr B.P. Campbell strand line south and west of Lake Winnipeg, (2) the rate of decrease in absolute gravity values measured from 1987 to 1995 at Churchill, Manitoba, and (3) the present-day regional tilt rate derived from water-level gauges in southern Manitoba lakes. These data are compared to theoretical predictions based on the published ICE-3G loading history and on a model of Earth rheology characterized by a 1066B density and elastic structure, an upper-mantle viscosity of 10 21Pa s, a lower-mantle viscosity of 2 × 10 21Pa s, and a lithosphere thickness of 120 km (Tushingham & Peltier, 1991). All three data types show disagreement in Manitoba with ICE-3G and the ‘standard’ Earth model. ICE-4G does better but could not be investigated in any detail. The constraints on model parameters provided by the different data types were investigated by varying, one at a time, three key parameters, (1) the thickness of the lithosphere in excess of 120 km, (2) the lower mantle viscosity, and (3) the thickness of Laurentide ice over the Prairies, to obtain better fits to the data. The present data do not appear to constrain lithosphere thickness in excess of 120 km very well. While both the Campbell strand line data and the Churchill absolute gravity data are consistent with an increase in lower-mantle viscosity, the present-day, lake-gauge data are not. All three data types are consistent with a thinning of the Laurentide ice-sheet over the Prairies relative to the ICE-3G model. Simultaneous adjustment of model parameters with the advantage of anticipated new data in Manitoba and adjacent regions in the US will lead to better understanding of the trade-offs between Earth rheology and ice sheet history and hence to an improved Laurentide postglacial rebound model.

Lake Winnipeg Laurentide ice sheet postglacial rebound absolute gravimetry strand line Lake Agassiz 

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References

  1. Andrews, J. T., 1982. On the reconstruction of Pleistocene ice sheets: a review. Quat. Sci. Rev. 1: 1–30.Google Scholar
  2. Blake, W. (Jr), 1975. Radiocarbon age determinations and postglacial emergence at Cape Storm, Southern Ellesmere Island, Arctic Canada. Geografiska Annaler 57: 1–71.Google Scholar
  3. Carrera, G., P. Vanicek & M. R. Craymer, 1991. The compilation of a map of recent vertical crustal movements in Canada. Department of Surveying Engineering Technical Report No. 153, University of New Brunswick, Fredericton, N.B., Canada: 106 pp.Google Scholar
  4. Clark, P. U., 1992. Surface form of the southern Laurentide Ice Sheet and its implications to ice sheet dynamics, Geol. Soc. Am. Bull. 104: 595–605.Google Scholar
  5. Dragert, H. & R. Hyndman, 1995. Continuous GPS monitoring of strain in the northern Cascadia subduction zone. Geophys. Res. Lett. 22: 755–758.Google Scholar
  6. Dyke, A. S., 1996. Preliminary paleogeographic maps of glaciated North America. Geological Survey of Canada Open File Report 3296.Google Scholar
  7. Dyke, A. S. & V. K. Prest, 1987. Paleogeography of northern North America, 18 000-5000 years ago. Geol. Survey Canada, Map 1703A, scale 1:12 500 000 (three sheets), Natural Resources Canada, 601 Booth St., Ottawa, Ont. K1A 0E8.Google Scholar
  8. Dyke, A. S., T. F. Morris & D. E. C. Green, 1991. Postglacial tectonic and sea level history of the central Canadian Arctic. Geological Survey of Canada Bulletin No. 397, Minister of Supply and Services Canada, Ottawa: 56 pp.Google Scholar
  9. Fenton, M., S. Moran, J. Teller & L. Clayton, 1983. Quaternary stratigraphy and history in the southern part of the Lake Agassiz basin. In J. T. Teller & L. Clayton (eds), Glacial Lake Agassiz: 44–74, Geol. Assoc. Canada Special Paper 26.Google Scholar
  10. Fisher, D.A., N. Reeh & K. Langley, 1985. Objective reconstructions of the LateWisconsinan Laurentide Ice Sheet and the significance of deformable beds. Geographie physique et Quaternaire 39: 229–238.Google Scholar
  11. Fisher, T. G. & D. G. Smith, 1994. Glacial Lake Agassiz: Its northwest maximum extent and outlet in Saskatchewan (Emerson Phase), Quat. Sci. Rev. 13: 845–858.Google Scholar
  12. Gilbert, F. & M. Dziewonski, 1975. An application of normal mode theory to the retrieval of structural parameters and source mechanisms from seismic spectra, Phil. Trans. r. Soc. London Ser. A, 278: 187–269.Google Scholar
  13. Heflin, M., D. Jefferson, Y. Vigue, F. Webb, J. Zumberge & D. Argus, 1994. Vertical rates determined with the Global Positioning System. EOS Transactions of the AGU, Spring AGU Abstract Supplement 75: 104.Google Scholar
  14. James, T. S. & A. S. Dyke, 1995. A high resolution geophysical model of the Laurentide glaciation from 30 000 B.P. to the present, CANQUA Meeting, June 5-7, St. John's.Google Scholar
  15. Johansson, J. M. et al. (12 colleagues), 1994. Baseline inferences for Fennoscandian rebound observations, sealevel, and tectonics (BIFROST): One year of GPS observations. EOS Transactions of the AGU, Fall AGU Abstract Supplement 75: 178.Google Scholar
  16. Johnston, W. A., 1946. Glacial Lake Agassiz, with Special Reference to the Mode of Deformation of the Beaches. Geol. Surv. Bull. No. 7, Department of Mines and Resources, Ottawa: 25 pp.Google Scholar
  17. Lambeck, K., P. Johnston, C. Smither & M. Nakada, 1996. Glacial rebound of the British Isles - III. Constraints on mantle viscosity, Geophys. J. Int. 125: 340–354.Google Scholar
  18. Mathews, W. H., 1974. Surface profiles of the Laurentide Ice Sheet in its marginal areas. J. Glaciol. 13: 37–43.Google Scholar
  19. Mitrovica, J. X., 1996. Haskell [1935] revisited, J. Geophys. Res. 101: 555–569.Google Scholar
  20. Mitrovica, J. X. & A. M. Forte, 1997. Radial profile of mantle viscosity: Results from the joint inversion of convection and postglacial rebound observables, J. Geophys. Res. 102: 2751–2769.Google Scholar
  21. Mitrovica, J. X. & W. R. Peltier, 1995. Constraints on mantle viscosity based upon the inversion of postglacial uplift data from the Hudson Bay region, Geophys. J. Int. 122: 353–377.Google Scholar
  22. Neilsen, E., E. M. Gryba & M. C. Wilson, 1984. Bison remains from a Lake Agassiz spit complex in the Swan River valley, Manitoba: Depositional environment and paleoecological implications, Can. J. Earth Sci. 21: 829–842.Google Scholar
  23. Niebauer, T. M., G. S. Sasagawa, J. E. Faller, R. Hilt & F. Klopping, 1995. A new generation of absolute gravimeters. Metrologia 32: 159–180.Google Scholar
  24. Peltier, W. R., 1984. The thickness of the continental lithosphere, J. Geophys. Res. 89: 11303–11316.Google Scholar
  25. Peltier, W. R., 1986. Deglaciation induced vertical motion of the North American continent and transient lower mantle rheology, J. Geophys. Res. 91: 9099–9123.Google Scholar
  26. Peltier, W. R., 1994. Ice age paleotopography. Science 265: 195–201.Google Scholar
  27. Peltier, W. R., 1985. The Lageos constraint on deepmantle viscosity: Results from a new normal mode method for the inversion of viscoelastic relaxation spectra, J. Geophys. Res. 90: 9411–9421.Google Scholar
  28. Peltier, W. R., 1996. Mantle viscosity and iceage ice sheet topography. Science 273: 1359–1364.Google Scholar
  29. Shilts, W.W., 1980. Flow patterns in the central North American ice sheet. Nature 286: 213–218.Google Scholar
  30. Sjoberg, L. E., P. Vanicek & M. Kwimbere, 1990. Estimates of present rates of land and geoid uplift in eastern North America. Manuscripta geodetica 15: 261–272.Google Scholar
  31. Smith, D. G. & T. G. Fisher, 1993. Glacial Lake Agassiz: The northwestern outlet and paleoflood. Geology 21: 9–12.Google Scholar
  32. Tackman, G., 1997. Postglacial Tilting and Lake Level Change in Southern Manitoba, Ph.D. thesis, University of Utah, Salt Lake City.Google Scholar
  33. Tackman, G. & D. Currey, 1996. Paleoshoreline and lake gauge evidence for post Lake Agassiz regional tilting in Manitoba. In B. J. Todd, C. F. M. Lewis & H. L. Thorleifson (eds), Lake Winnipeg Project: Cruise Report and Scientific Results, Geol. Surv. Can. Open File 3113: 421–433.Google Scholar
  34. Tackman, G. E., D. R. Currey & T. S. James, 1998. Paleoshoreline evidence for postglacial tilting in southern Manitoba. J. Paleolimnol. 19: 343–363.Google Scholar
  35. Teller, J. T., 1989. Importance of the Rossendale Site in establishing a deglacial chronology along the southwestern margin of the Laurentide Ice Sheet. Quat. Res. 32: 12–23.Google Scholar
  36. Teller, J. T. & L. H. Thorleifson, 1983. The Lake AgassizLake Superior Connection. In J. T. Teller & L. Clayton (eds), Glacial Lake Agassiz, Geolog. Assoc. Can. Special Paper 26: 261–290.Google Scholar
  37. Tushingham, A. M. & W. R. Peltier, 1991. ICE3G: A new global model of late Pleistocene deglaciation based upon geophysical predictions of postglacial relative sea level change. J. Geophys. Res. 96: 4497–4523.Google Scholar
  38. Tushingham, A. M. & W. R. Peltier, 1992. Validation of the ICE3G model of WurmWisconsin deglaciation using a global data base of relative sea level histories, J. Geophys. Res. 97: 3285–3304.Google Scholar
  39. Tushingham, A. M., 1992. Observations of postglacial uplift at Churchill, Manitoba. Can. J. Earth Sci. 29: 2418–2425.Google Scholar
  40. Walcott, R. I., 1972. Late Quaternary vertical movements in North America: Quantitative evidence of glacioisostatic rebound. Rev. Geophys. Space Phys. 10: 849–884.Google Scholar
  41. Warrick, R. & J. Oerlemans, 1990. Sea level rise. In J. T. Houghton, G. J. Jenkins & J. J. Ephraums (eds), Climate Change: The IPCC Scientific Assessment, 260–280, Cambridge University Press, New York.Google Scholar
  42. Wolf, D., 1985. An improved estimate of lithospheric thickness based on a reinterpretation of tilt data form Pleistocene Lake Algonquin, Can. J. Earth Sci. 22: 768–773.Google Scholar

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • A. Lambert
    • 1
  • T. S. James
    • 1
  • L. H. Thorleifson
    • 2
  1. 1.GSC-Pacific, Geological Survey of CanadaSidneyCanada
  2. 2.Terrain Sciences DivisionGeological Survey of CanadaOttawaCanada

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