The Cryosphere Discussions www.the-cryosphere-discuss.net 1994-0432 1994-0440 3 1 2009 10.5194/tcd-3-1-2009 http://www.the-cryosphere-discuss.net/3/1/2009/ http://www.the-cryosphere-discuss.net/3/1/2009/tcd-3-1-2009.html http://www.the-cryosphere-discuss.net/3/1/2009/tcd-3-1-2009.pdf 1 31 2009-01-19 A full-Stokes ice flow model for the vicinity of Dome Fuji, Antarctica, with induced anisotropy and fabric evolution H. Seddik hakime@lowtem.hokudai.ac.jp R. Greve T. Zwinger L. Placidi Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan CSC – IT Center for Science Ltd., P.O. Box 405, 02101 Espoo, Finland Department of Structural and Geotechnical Engineering, "Sapienza" University of Rome, Via Eudossiana 18, 00184 Rome, Italy A three-dimensional, thermo-mechanically coupled ice flow model with induced aniso-tropy has been applied to a ~200×200 km domain around the Dome Fuji drill site, Antarctica. The model ("Elmer/Ice") is based on the open-source multi-physics package Elmer (<a href="http://www.csc.fi/elmer/"target="_blank">http://www.csc.fi/elmer/</a>) and solves the full-Stokes equations. Flow-induced anisotropy in ice is accounted for by an implementation of the Continuum-mechanical, Anisotropic Flow model, based on an anisotropic Flow Enhancement factor ("CAFFE model"). Steady-state simulations for present-day climate conditions are conducted. The main findings are: (i) the flow regime at Dome Fuji is a complex superposition of vertical compression, horizontal extension and bed-parallel shear; (ii) for a geothermal heat flux of 60 mW m−2 the basal temperature at Dome Fuji reaches the pressure melting point and the basal melting rate is ~1 mm a−1; (iii) the fabric shows a weak single maximum at Dome Fuji, which increases the age of the ice compared to an isotropic scenario; (iv) as a consequence of spatially variable basal melting conditions, and contrary to intuition, the basal age is smaller where the ice is thicker and larger where the ice is thinner. The latter result is of great relevance for the consideration of a future drill site in the area. Chung, D H. and Kwon, T H.: Invariant-based optimal fitting closure approximation for the numerical prediction of flow-induced fiber orientation, J. Rheol., 46, 169–194, 2002. Fujita, S., Maeno, H., Uratsuka, S., Furukawa, T., Mae, S., Fujii, Y., and Watanabe, O.: Nature of radio-echo layering in the Antarctic ice sheet detected by a~two-frequency experiment, J. Geophys. Res., 104, 13 013–13 024, 1999. Gillet-Chaulet, F.: Modélisation de l'écoulement de la glace polaire anisotrope et premières applications au forage de Dôme~C, Doctoral thesis, Joseph Fourier University, Grenoble, France, 2006. Gillet-Chaulet, F., Gagliardini, O., Meyssonnier, J., Zwinger, T., and Ruokolainen, J.: Flow-induced anisotropy in polar ice and related ice-sheet flow modelling, J. Non-Newton. Fluid Mech., 134, 33–43, 2006. Greve, R.: Large-scale simulation of the Antarctic ice sheet over climate cycles, Presentation, Ice-Core-Consortium/Dating-Research-Consortium Meeting, National Institute of Polar Research, Tokyo, Japan, 26–27 October 2006, http://hdl.handle.net/2115/34433, Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP), 2006. Greve, R., Wang, Y., and Mügge, B.: Comparison of numerical schemes for the solution of the advective age equation in ice sheets, Ann. Glaciol., 35, 487–494, 2002. Greve, R., Placidi, L., and Seddik, H.: A~continuum-mechanical model for the flow of anisotropic polar ice, in: Proceedings of the 2nd International Workshop on Physics of Ice Core Records (PICR-2), edited by Hondoh, T., Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan, in press, 2009. Kameda, T., Motoyama, H., Fujita, S., and Takahashi, S.: Temporal and spatial variability of surface mass balance at Dome Fuji, East Antarctica, by the stake method from 1995 to 2006, J. Glaciol., 54, 107–116, 2008. Kawamura, K., Parrenin, F., Lisiecki, L., Uemura, R., Vimeux, F., Severinghaus, J P., Hutterli, M A., Nakazawa, T., Aoki, S., Jouzel, J., Raymo, M E., Matsumoto, K., Nakata, H., Motoyama, H., Fujita, S., Goto-Azuma, K., Fujii, Y., and Watanabe, O.: Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360,000 years, Nature, 448, 912–916, doi:10.1038/nature06015, 2007. Liu, H., Jezek, K., Li, B., and Zhao, Z.: Radarsat Antarctic Mapping Project digital elevation model version~2, Digital media, National Snow and Ice Data Center, Boulder, CO, USA, 2001. Lythe, M B., Vaughan, D G., and the BEDMAP Consortium: BEDMAP – bed topography of the Antarctic, 1:10 000 000 scale map, BAS (Misc) 9, Cambridge, British Antarctic Survey, 2000. Motoyama, H.: The second deep ice coring project at Dome Fuji, Antarctica, Sci. Drill., 5, 41–43, doi:10.2204/iodp.sd.5.05.2007, 2007. Motoyama, H., Furukawa, T., and Nishio, F.: Study of ice flow observations in Shirase drainage basin and around Dome Fuji area, East Antarctica, by differential GPS method, Nankyoku Shiry\=o (Antarctic Record), 52, 216–231, written in Japanese with English summary, 2008. Parrenin, F., Barnola, J.-M., Beer, J., Blunier, T., Castellano, E., Chappellaz, J., Dreyfus, G., Fischer, H., Fujita, S., Jouzel, J., Kawamura, K., Lemieux-Dudon, B., Loulergue, L., Masson-Delmotte, V., Narcisi, B., Petit, J.-R., Raisbeck, G., Raynaud, D., Ruth, U., Schwander, J., Severi, M., Spahni, R., Steffensen, J. P., Svensson, A., Udisti, R., Waelbroeck, C., and Wolff, E.: The EDC3 chronology for the EPICA Dome C ice core, Clim. Past, 3, 485–497, 2007. Pattyn, F.: Investigating the stability of subglacial lakes with a~full Stokes ice-sheet model, J. Glaciol., 54, 353–361, 2008. Placidi, L., Greve, R., Seddik, H., and Faria, S H.: Continuum-mechanical, anisotropic flow model, based on an anisotropic flow enhancement factor (CAFFE), Continuum Mech. Therm., submitted, 2008. Seddik, H.: A~full-Stokes finite-element model for the vicinity of Dome Fuji with flow-induced ice anisotropy and fabric evolution, Doctoral thesis, Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan, http://hdl.handle.net/2115/34136, Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP), 2008. Seddik, H., Greve, R., Placidi, L., Hamann, I., and Gagliardini, O.: Application of a~continuum-mechanical model for the flow of anisotropic polar ice to the EDML core, Antarctica, J. Glaciol., 54, 631–642, 2008. Watanabe, O., Kamiyama, K., Motoyama, H., Fujii, Y., Igarashi, M., Furukawa, T., Goto-Azuma, K., Saito, T., Kanamori, S., Kanamori, N., Yoshida, N., and Uemura, R.: General tendencies of stable isotopes and major chemical constituents of the Dome Fuji deep ice core, in: Global Scale Climate and Environment Study through Polar Deep Ice Cores, edited by Shoji, H. and Watanabe, O., pp. 1–24, National Institute of Polar Research, Tokyo, Japan, 2003. Zwinger, T., Greve, R., Gagliardini, O., Shiraiwa, T., and Lyly, M.: A~full Stokes-flow thermo-mechanical model for firn and ice applied to the Gorshkov crater glacier, Kamchatka, Ann. Glaciol., 45, 29–37, 2007.