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Ice-thickness measurements of Taku Glacier, Alaska, U.S.A., and their relevance to its recent behavior

  • Matt Nolan (a1), Roman J. Motkya (a2), Keith Echelmeyer (a1) and Dennis C. Trabant (a3)

Abstract

Using radio-echo soundings and seismic reflections, we measured cross-sections of Taku Glacier, near Juneau, Alaska, to resolve inconsistencies in previous measurements and to understand better the glacier’s dynamics. The maximum thickness is about 1477 m and the minimum bed elevation is about 600 m below sea level, which establishes Taku Glacier as the thickest and deepest temperate glacier yet measured. Our data indicate that, during the 19th century, the terminus of Taku Glacier may have begun its rapid advance at a position where the ice bed was greater than 300 m below sea level and more than 25 km from the inland end of its submarine trough; this behavior is uncharacteristic of temperate tide-water glaciers. The glacier, which no longer calves, has eroded a sediment layer 100 m thick since 1890 at an average rate of about 3 m a−1 since 1948; this high erosion rate retards advance by entrenching the glacier into the terminal moraine. Calculations based on ice-deformation theory indicate significant basal ice motion near the terminus and high basal shear stress (140–220kPa) along much of its length. Estimated differences between ice flux and balance flux are consistent with observed thickening and positive net mass balance; these data indicate that ice volume is increasing and that further advance is likely.

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References

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Alley, R.B. 1991 Sedimentary processes may cause fluctuations of tidewater glaciers. Ann. Glaciol., 15, 119–124.
Alley, R.B, D.D. Blankenship, CR. Bentley and S.T. Rooney. 1987. Till beneath Ice Stream B. 3. Till deformation: evidence and implications. J. Geophy. Res., 92(B9), 8921–8929.
Blankenship, D.D., C.R. Bentley, S. T. Rooney and R.B. Alley. 1987. Till beneath Ice Stream Β: 1. Properties derived from seismic travel times. J. Ceophys. Res., 92, 8903–8911.
Brown, C.S., M. F. Meier and Α. Post. 1982. Calving speed of Alaska tidewater glaciers, with application to Columbia Glacier. U.S. Geol. Surv. Prof. Pap. 1258-C.
Brown, C. S., L. A. Rasmussen and M. F. Meier. 1986. Bed topography inferred from airborne radio-echo sounding of Columbia Glacier, Alaska. U.S. Geol. Surv. Prof. Pap. 1258-G.
Carlson. P. R., B.R. Molnia, A. Post, M.C Wheeler and R D. Powell. 1983. Maps showing post-neoglacial sediment thickness and bathymetry in Tarr Intel, Glacier Bay, Alaska. Washington, DC, U.S. Geological Survey. (USGS Miscellaneous Field Studies Map MF-1456.)
Clarke, T. and Κ. Echelmeyer. In press. Seismic reflection evidence for a deep subglacial trough beneath Jakobshavns Isbræ, Greenland. J. Glacial.
Echelmeyer, K.A. 1983. Response of Blue Glacier to a perturbation in ice thickness: theory and observations. (Ph.D. thesis, California Institute of Technology.)
Echelmeyer, K., T.S. Clarke and W.D. Harrison. 1991. Surficial glaciology of Jakobshavns Isbæ, West Greenland; Part I. Surface morphology. J. Glaciol., 37(127}. 368–382.
Field, W.O., Jr. 1954. Notes on the advance of Taku Glacier. Geogr. Rev 44(2), 236–239.
Gehrels, G. E. and H.C Berg. 1992. Geologic map of southeastern Alaska. Map Sheet 1–1867. Washington, DC, U.S. Geological Survey. (Miscellaneous Investigations Series.)
Hooke, R. LeB. 1981. Flow law lor polycrystalline ice in glaciers; comparison of theoretical predictions, laboratory data, and field measurements, Rev.Geophys. Spce Phys., 10(4), 664–672.
Jordan, G. F. 1962. Redistribution of sediments in Alaskan bays and inlets. Geogr. Rev., 52(4), 548–558.
Lawrence, D.B. 1950. Glacier fluctuation for six centuries in Southeastern Alaska and its relation to solar activity, Geogr. Rev., 40(2) 191–223.
Meier, M.F. and A. Post. 1987. Fast tidewater glaciers. J. Geophys. Res., 92(Β9), 9051–9058.
Mercer, J. H. 1961. The response of fiord glaciers to changes in the firn limit. J. Glaciol., 3(29), 850–858.
Miller. M.M. 1963. Taku Glacier evaluation study. Seattle, WA, Foundation for Glacier Research.
Motyka, R.J and A. Post. In press. Taku Glacier: influence of sedimentation, accumulation to total area ratio, and channel geometry on the advance of a fjord-type glacier. In Proceedings, 3rd Glacier Bay Science Symposium, 14–18 September 1995.
Motkya, R.J. and J.E. Begét. In press. Taku Glacier, Alaska: Late Holocene history of a tidewater glacier and comparison to land terminating glaciers. Arct. Alp. Res.
Nielsen, L. E. 1957. Preliminary study on the regimen and movement of the Taku Glacier, Alaska. Geol. Soc. Am. Bull., 68(2), 171–180.
Nye, J. F. 1965. The flow of a glacier in a channel of rectangular, elliptic or parabolic cross-section. J. Glacial., 5(41) . 661–690.
Paterson, W.S.B. 1981. The physics of glaciers. Second edition. Oxford, etc., Pergamoa Press.
Pelto., M. S. and M. M. Miller. 1990. Mass balance of the Taku Glacier, Alaska from 1946 to 1986. Northwest Sci., 64(3), 121–130.
Port, A 1975. Preliminary hydrology and historic terminus changes of Columbia Glacier, Alaska. U. S. Geol. Surv. Hydrol. Invest. Allai, HA-559, 3 maps.
Post, A. and R.J. Motyka. In press. Taku and LeConte Glaciers, Alaska: calving speed control of Late Holocene advances and retreats. In Nelson, F., ed. Physical geography: William O. Field Festschrift. Fairbanks, AK, University of Alaska Press.
Poulter, Τ. C, C.F. Allen and S.W. Miller. 1949. Seismic mesurements on the Taku Glacier. Stanford, CA, Stanford Research Institute.
Röthlisberger, Η. 1972. Seismic exploration in cold regions. CRREL Manner. II-A2a.
Sharp, R. P. 1988. Lining ice; understanding glaciers and glaciation. Cambridge, etc., Cambridge University Press.
Watts, R.D and D.L. Wright. 1981. System far measuring thickness of temperate and polar ice from the ground or from the air. J. Glacial., 27(97), 459–169.

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