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Basal icequakes during changing subglacial water pressures beneath Gornergletscher, Switzerland

  • Fabian Walter (a1), Nicholas Deichmann (a2) and Martin Funk (a1)
Abstract

Using dense networks of three-component seismometers installed in direct contact with the ice, the seismic activity of Gornergletscher, Switzerland, was investigated during the summers of 2004 and 2006, as subglacial water pressures varied drastically. These pressure variations are due to the diurnal cycle of meltwater input as well as the subglacial drainage of Gornersee, a nearby marginal ice-dammed lake. Up to several thousand seismic signals per day were recorded. Whereas most icequakes are due to surface crevasse openings, about 200 events have been reliably located close to the glacier bed. These basal events tend to occur in clusters and have signals with impulsive first arrivals. At the same time, basal water pressures and ice-surface velocities were measured to capture the impact of the lake drainage on the subglacial hydrological system and the ice-flow dynamics. Contrary to our expectations, we did not observe an increase of basal icequake activity as the lake emptied, thereby raising the subglacial water pressures close to the flotation level for several days. In fact, the basal icequakes were usually recorded during the morning hours, when the basal water pressure was either low or decreasing. During the high-pressure period caused by the drainage of the lake, no basal icequakes were observed. Furthermore, GPS measurements showed that the glacier surface was lowering during the basal seismic activity. These observations lead us to conclude that such icequakes are connected to the diurnal variation in glacier sliding across the glacier bed.

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References
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Aki, K. and Richards, P.G.. 1980. Quantitative seismology: theory and methods. San Francisco, W.H. Freeman and Co.
Anandakrishnan, S. and Alley, R.B.. 1994. Ice Stream C, Antarctica, sticky spots detected by microearthquake monitoring. Ann. Glaciol., 20, 183186.
Anandakrishnan, S. and Bentley, C.R.. 1993. Micro-earthquakes beneath Ice Streams B and C, West Antarctica: observations and implications. J. Glaciol., 39(133), 455462.
Aschwanden, A. 1992. Gletscherbeben: untersuchungen am Gornergletscher 1979. (Diplomarbeit thesis, VAW/ETH Zürich.)
Björnsson, H. 2002. Subglacial lakes and jökulhlaups in Iceland. Global Planet. Change, 35(3–4), 255271.
Clarke, G.K.C. 2003. Hydraulics of subglacial outburst floods: new insights from the Spring–Hutter formulation. J. Glaciol., 49(165), 299313.
Danesi, S., Bannister, S. and Morelli, A.. 2007. Repeating earthquakes from rupture of an asperity under an Antarctic outlet glacier. Earth Planet. Sci. Lett., 253(1–2), 151158.
Deichmann, N., Ansorge, J., Scherbaum, F., Aschwanden, A., Bernardi, F. and Gudmundsson, G.H.. 2000. Evidence for deep icequakes in an Alpine glacier. Ann. Glaciol., 31, 8590.
Gischig, V. 2007. Seismic investigations on Gornergletscher. (Diplomarbeit thesis, VAW/ETH Zürich.)
Haeberli, W. 1983. Frequency and characteristics of glacier floods in the Swiss Alps. Ann. Glaciol., 4, 8590.
Huss, M. 2005. Gornergletscher: Gletscherseeausbrüche und Massenbilanzabschätzungen. (Diplomarbeit thesis, VAW/ETH Zürich.)
Huss, M., Bauder, A., Werder, M., Funk, M. and Hock, R.. 2007. Glacier-dammed lake outburst events of Gornersee, Switzerland. J. Glaciol., 53(181), 189200.
Iken, A. 1981. The effect of the subglacial water pressure on the sliding velocity of a glacier in an idealized numerical model. J. Glaciol., 27(97), 407421.
Lee, W.H.K. and Steward, S.W.. 1981. Principles and applications in microearthquake networks. New York, Academic Press. (Advances in Geophysics 2.)
Métaxian, J.-P., Araujo, S., Mora, M. and Lesage, P.. 2003. Seismicity related to the glacier of Cotopaxi Volcano, Ecuador. Geophys. Res. Lett., 30(9), 1483. (10.1029/2002GL016773.)
Neave, K.G. and Savage, J.C.. 1970. Icequakes on the Athabasca Glacier. J. Geophys. Res., 75(8), 13511362.
Nye, J.F. 1976. Water flow in glaciers: jökulhlaups, tunnels and veins. J. Glaciol., 17(76), 181207.
O’Neel, S. and Pfeffer, W.T.. 2007. Source mechanics for monochromatic icequakes produced during iceberg calving at Columbia Glacier, AK. Geophys. Res. Lett., 34(22), L22502. (10.1029/2007GL031370.)
O’Neel, S., Marshall, H.P., McNamara, D.E. and Pfeffer, W.T.. 2007. Seismic detection and analysis of icequakes at Columbia Glacier, Alaska. J. Geophys. Res., 112(F3), F03S23. (10.1029/2006JF000595.)
Paterson, W.S.B. 1994. The physics of glaciers. Third edition. Oxford, etc., Elsevier.
Raymond, M., Wegmann, M. and Funk, M.. 2003. Inventar gefährlicher Gletscher in der Schweiz. Mitt. VAW/ETH 182.
Richardson, S.D. and Reynolds, J.M.. 2000. An overview of glacial hazards in the Himalayas. Quat. Int., 65/66(1), 3147.
Roberts, M.J. 2005. Jökulhlaups: a reassessment of floodwater flow through glaciers. Rev. Geophys., 43(1), RG1002. (10.1029/2003RG000147.)
Roberts, M.J., Russell, A.J., Tweed, F.S. and Knudsen, O.. 2000. Ice fracturing during jökulhlaups: implications for englacial floodwater routing and outlet development. Earth Surf. Process. Landf., 25(13), 14291446.
Smith, A.M. 2006. Microearthquakes and subglacial conditions. Geophys. Res. Lett., 33(24), L24501. (10.1029/2006GL028207.)
Spring, U. and Hutter, K.. 1981. Numerical studies of jökulhlaups. Cold Reg. Sci. Technol., 4(3), 227244.
Stuart, G., Murray, T., Brisbourne, A., Styles, P. and Toon, S.. 2005. Seismic emissions from a surging glacier: Bakaninbreen, Svalbard. Ann. Glaciol., 42, 151157.
Sugiyama, S. and Gudmundsson, G.H.. 2003. Diurnal variations in vertical strain observed in a temperate valley glacier. Geophys. Res. Lett., 30(2), 1090. (10.1029/2002GL016160.)
Sugiyama, S. and Gudmundsson, G.H.. 2004. Short-term variations in glacier flow controlled by subglacial water pressure at Lauteraargletscher, Bernese Alps, Switzerland. J. Glaciol., 50(170), 353362.
Sugiyama, S., Bauder, A., Weiss, P. and Funk, M.. 2007. Reversal of ice motion during the outburst of a glacier-dammed lake on Gornergletscher, Switzerland. J. Glaciol. 53(181), 172180.
Van der Veen, C.J. 1998a. Fracture mechanics approach to penetration of surface crevasses on glaciers. Cold Reg. Sci. Technol., 27(1), 3147.
Van der Veen, C.J. 1998b. Fracture mechanics approach to penetration of bottom crevasses on glaciers. Cold Reg. Sci. Technol., 27(3), 213223.
Van der Veen, C.J. 2007. Fracture propagation as means of rapidly transferring surface meltwater to the base of glaciers. Geophys. Res. Lett., 34(1), L01501. (10.1029/2006GL028385.)
Weaver, C.S. and Malone, S.D.. 1979. Seismic evidence for discrete glacier motion at the rock–ice interface. J. Glaciol., 23(89), 171184.
Weiss, P. 2005. Gletscherdynamik vor und nach der Entleerung des Gornersees im Sommer 2004. (Diplomarbeit thesis, VAW/ETH Zürich.)
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Journal of Glaciology
  • ISSN: 0022-1430
  • EISSN: 1727-5652
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