Shear wave splitting across the Iceland hot spot: Results from the ICEMELT experiment

Journal of Geophysical Research: Solid Earth

Volumn 107, Issue 12, 2002, Pages

  Bjarnason, Ingi T ^a   Silver, Paul G ^b   Rümpker, Georg ^c   Solomon, Sean C ^b  

^a UNIVERSITY OF ICELAND   (Iceland)

^b GEOPHYSICAL LABORATORY   (United States)

^c GFZ GERMAN RESEARCH CENTRE FOR GEOSCIENCES   (Germany)

Author keywords

Anisotropy Hot spot; Iceland; Mantle flow; Plate motion; Shear wave splitting

Indexed keywords

HOT SPOT; MANTLE PLUME; S-WAVE; SEISMIC ANISOTROPY; UPPER MANTLE; WAVE SPLITTING;

ICELAND;

EID: 0037507308     PISSN: 21699313     EISSN: 21699356     Source Type: Journal    
DOI: None     Document Type: Article

References (61)

1. Ben Ismaïl, W., and D. Mainprice, An olivine fabric database: An overview of upper mantle fabrics and seismic anisotropy, Tectonophysics, 296, 145-157, 1998.
2. Bjarnason, I. T., How thick is the lithosphere in Iceland? How large is the velocity inversion in the asthenosphere and what does it mean? (abstract), Eos Trans. AGU, 80(46), Fall Meet. Suppl., F645, 1999.
3. Bjarnason, I. T., W. Menke, O. G. Flóvenz, and D. Caress, Tomographic image of the Mid-Atlantic plate boundary in southwestern Iceland, J. Geophys. Res., 98, 6607-6622, 1993.
4. Bjarnason, I. T., C. J. Wolfe, S. C. Solomon, and G. Gudmundson, Initial results from the ICEMELT experiment: Body-wave delay times and shear-wave splitting across Iceland, Geophys. Res. Lett., 23, 459-462, 1996. (Correction, Geophys. Res. Lett., 23, 903, 1996.)
5. Blackman, D. K., and J.-M. Kendall, Sensitivity of teleseismic body waves to mineral texture and melt in the mantle beneath a mid-ocean ridge, Philos. Trans. R. Soc. London, Ser. A, 355, 217-231, 1997.
6. Blackman, D. K., J.-M. Kendall, P. R. Dawson, H.-R. Wenk, D. Boyce, and J. Phipps Morgan, Teleseismic imaging of subaxial flow at mid-ocean ridges: Traveltime effects of anisotropic mineral texture in the mantle, Geophys. J. Int., 127, 415-426, 1996.
7. Chase, C. G., Asthenospheric counterflow: A kinematic model, Geophys. J. R. Astron. Soc., 56, 1-18, 1979.
8. Christensen, N. I., The magnitude, symmetry and origin of upper mantle anisotropy based on fabric analyses of ultramafic tectonites, Geophys. J. R. Astron. Soc., 76, 89-111, 1984.
9. Darbyshire, F. A., I. T. Bjarnason, R. S. White, and Ó. G. Flóvenz, Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile, Geophys. J. Int., 135, 1131-1149, 1998.
10. Evans, J. R., and I. S. Sacks, Deep structure of the Iceland plateau, J. Geophys. Res., 84, 6859-6866, 1979.
11. Francis, T. J. G., Generation of seismic anisotropy in the upper mantle along the mid-oceanic ridges, Nature, 221, 162-165, 1969.
12. Gripp, A. G., and R. G. Gordon, Current plate velocities relative to the hotspots incorporating the NUVEL-1 global plate motion model, Geophys. Res. Lett., 17, 1109-1112, 1990.
13. Hager, B. H., and R. W. Clayton, Constraints on the structure of mantle convection using seismic observations, flow models, and the geoid, in Mantle Convection: Plate Tectonics and Global Dynamics, edited by W. R. Peltier, pp. 657-763, Gordon and Breach, New York, 1989.
14. Hager, B. H., and R. J. O'Connell, Kinematic models of large-scale flow in the Earth's mantle, J. Geophys. Res., 84, 1031-1048, 1979.
15. Ito, G., J. Lin, and C. W. Gable, Dynamics of mantle flow and melting at a ridge-centered hotspot: Iceland and the Mid-Atlantic Ridge, Earth Planet. Sci. Lett., 144, 53-74, 1996.
16. Ito, G., Y. Shen, G. Hirth, and C. J. Wolfe, Mantle flow, melting, and dehydration of the Iceland mantle plume, Earth Planet. Sci. Lett., 165, 81-96, 1999.
17. Kendall, J.-M., Teleseismic arrivals at a mid-ocean ridge: Effects of mantle melt and anisotropy, Geophys. Res. Lett., 21, 301-304, 1994.
18. Kuo, B.-Y., D. W. Forsyth, and M. Wysession, Lateral heterogeneity and azimuthal anisotropy in the North Atlantic determined from SS-S differential travel times, J. Geophys. Res., 92, 6421-6436, 1987.
19. Lithgow-Bertelloni, C., and M. A. Richards, The dynamics of Cenozoic and Mesozoic plate motions, Rev. Geophys., 36, 27-78, 1998.
20. Lithgow-Bertelloni, C., and P. G. Silver, Dynamic topography, plate driving forces and the African superswell, Nature, 395, 269-272, 1998.
21. Menke, W., B. Bransdottir, S. Jokobsdottir, and R. Stefansson, Seismic anisotropy in the crust at the mid-Atlantic plate boundary in south-west Iceland, Geophys. J. Int., 119, 783-790, 1993.
22. Menke, W., M. West, B. Bransdóttir, and D. Sparks, Compressional and shear velocity structure of the lithosphere in northern Iceland, Bull. Seismol. Soc. Am., 88, 1561-1571, 1998.
23. Montagner, J.-P., and T. Tanimoto, Global anisotropy in the upper mantle inferred from the regionalization of phase velocities, J. Geophys. Res., 95, 4797-4819, 1990.
24. Montagner, J.-P., and T. Tanimoto, Global upper mantle tomography of seismic velocities and anisotropies, J. Geophys. Res., 96, 20,337-20,351, 1991.
25. Nishimura, C. E., and D. W. Forsyth, Rayleigh wave phase velocities in the Pacific with implications for azimuthal anisotropy and lateral heterogeneities, Geophys. J., 94, 479-501, 1988.
26. Óskarsson, N., S. Steinthórsson, and G. E. Sigvaldason, Iceland geochemical anomaly: Origin, volcanotectonics, chemical fractionation and isotope evolution of the crust, J. Geophys. Res., 90, 10,011-10,025, 1985.
27. Pálmason, G., and K. Saemundsson, Iceland in relation to the Mid-Atlantic Ridge, Annu. Rev. Earth Planet. Sci., 2, 25-50, 1974.
28. Parmentier, E. M., and J. E. Oliver, A study of shallow mantle flow due to the accretion and subduction of lithospheric plates, Geophys. J. R. Astron. Soc., 57, 1-22, 1979.
29. Raitt, R. W., G. G. Shor, T. J. G. Francis, and G. B. Morris, Anisotropy of the Pacific upper mantle, J. Geophys. Res., 74, 3095-3109, 1969.
30. Ribe, N. M., U. R. Christensen, and J. Theissing, The dynamics of plume-ridge interaction, 1. Ridge-centered plumes, Earth Planet. Sci. Lett., 134, 155-168, 1995.
31. Ricard, Y., M. Richards, C. Lithgow-Bertelloni, and Y. Le Stunff, A geodynamic model of mantle density heterogeneity, J. Geophys. Res., 98, 21,895-21,909, 1993.
32. Rümpker, G., and T. Ryberg, New "Fresnel-zone" estimates for shear-wave splitting observations from finite-difference modeling, Geophys. Res. Lett., 27, 2005-2008, 2000.
33. Rümpker, G., and P. G. Silver, Apparent shear-wave splitting parameters in the presence of vertically-varying anisotropy, Geophys J. Int., 135, 790-800, 1998.
34. Rümpker, G., and P. G. Silver, Calculating splitting parameters for plume-type anisotropic structures of the upper mantle, Geophys. J. Int., 143, 507-520, 2000.
35. Savage, M. K., Seismic anisotropy and mantle deformation: What have we learned from shear wave splitting?, Rev. Geophys., 37, 65-106, 1999.
36. Savage, M. K., and A. F. Sheehan, Seismic anisotropy and mantle flow from the Great Basin to the Great Plains, western United States, J. Geophys. Res., 105, 13,715-13,734, 2000.
37. Schilling, J.-G., Iceland mantle plume: Geochemical study of Reykjanes Ridge, Nature, 242, 565-571, 1973.
38. Schilling, J.-G., Fluxes and excess temperatures of mantle plumes inferred from their interaction with migrating mid-ocean ridges, Nature, 352, 397-403, 1991.
39. Sheehan, A. F., and S. C. Solomon, Joint inversion of shear wave travel time residuals and geoid and depth anomalies for long-wavelength variations in upper mantle temperature and composition along the Mid-Atlantic Ridge, J. Geophys. Res., 96, 19,821-20,009, 1991.
40. Shen, Y., S. C. Solomon, I. T. Bjarnason, and G. M. Purdy, Hot mantle transition zone beneath Iceland and the adjacent Mid-Atlantic Ridge inferred from P-to-S conversions at the 410- and 660-km discontinuities, Geophys. Res. Lett., 23, 3527-3530, 1996.
41. Shen, Y., S. C. Solomon, I. T. Bjarnason, and C. J. Wolfe, Seismic evidence for a lower-mantle origin of the Iceland plume, Nature, 395, 62-65, 1998.
42. Shen, Y., S. C. Solomon, I. Th. Bjarnason, G. Nolet, W. J. Morgan, R. M. Allen, K. Vogfjörd, S. Jakobsdóttir, R. Stefánsson, B. R. Julian, and G. R. Foulger, Seismic evidence for a tilted mantle plume and north-south mantle flow beneath Iceland, Earth Planet. Sci. Lett., 197, 261-272, 2002.
43. Silveira, G., E. Stutzmann, D.-A. Griot, J.-P. Montagner, and L. Mendes Victor, Anisotropic tomography of the Atlantic Ocean from Rayleigh surface waves, Phys. Earth Planet. Inter., 106, 257-273, 1998.
44. Silver, P. G., Seismic anisotropy beneath the continents: Probing the depths of geology, Annu. Rev. Earth Planet. Sci., 24, 385-432, 1996.
45. Silver, P. G., and W. W. Chan, Implications for continental structure and evolution from seismic anisotropy, Nature, 335, 34-39, 1988.
46. Silver, P. G., and W. W. Chan, Shear-wave splitting and subcontinental mantle deformation, J. Geophys. Res., 96, 16,429-16,454, 1991.
47. Silver, P. G., and W. E. Holt, The mantle flow field beneath western North America, Science, 295, 1054-1057, 2002.
48. Silver, P. G., and M. K. Savage, The interpretation of shear-wave splitting parameters in the presence of two anisotropic layers, Geophys. J. Int., 119, 949-963, 1994.
49. Sleep, N. H., Hotspots and mantle plumes: Some phenomenology, J. Geophys. Res., 95, 6715-6736, 1990.
50. Staples, R. K., R. S. White, B. Brandsdóttir, W. Menke, P. K. H. Maguire, and J. H. McBride, Färoe-Iceland Ridge Experiment, 1, Crustal structure of northeastern Iceland, J. Geophys. Res., 102, 7849-7866, 1997.
51. Steinberger, B., Slabs in the lower mantle-Results of dynamic modeling compared with tomographic images and the geoid, Phys. Earth Planet. Inter., 118, 241-257, 2000.
52. Vinnik, L. P., V. Farra, and B. Romanowicz, Azimuthal anisotropy in the Earth from observations of SKS at GEOSCOPE and NARS broadband stations, Bull. Seismol. Soc. Am., 79, 1542-1558, 1989.
53. Vogt, P. R., Asthenosphere motion recorded by the ocean floor south of Iceland, Earth Planet. Sci. Lett., 13, 153-160, 1971.
54. White, R. S., J. W. Bown, and J. R. Smallwood, The temperature of the Iceland plume and origin of outward propagating V-shaped ridges, J. Geol. Soc. London, 152, 1039-1045, 1995.
55. Wilcock, W. S. D., S. C. Webb, and I. T. Bjarnason, The effect of local wind on seismic noise near 1 Hz at the MELT site and in Iceland, Bull. Seismol. Soc. Am., 89, 1543-1557, 1999.
56. Wolfe, C. J., and P. G. Silver, Seismic anisotropy of oceanic upper mantle: Shear wave splitting methodologies and observations, J. Geophys. Res., 103, 749-771, 1998. (Correction, J. Geophys. Res., 103, 2791, 1998.)
57. Wolfe, C. J., and S. C. Solomon, Shear-wave splitting and implications for mantle flow beneath the MELT region of the East Pacific Rise, Science, 280, 1230-1232, 1998.
58. Wolfe, C. J., I. T. Bjarnason, J. C. VanDecar, and S. C. Solomon, Seismic structure of the Iceland mantle plume, Nature, 385, 245-247, 1997.
59. Woodward, R. L., and G. Masters, Global upper mantle structure for long-period differential travel times, J. Geophys. Res., 96, 6351-6377, 1991.
60. Yang, X., and K. M. Fischer, Constraints on North Atlantic upper mantle anisotropy from S and SS phases, Geophys. Res. Lett., 21, 309-312, 1994.
61. Zhang, S., and S. Karato, Lattice preferred orientation of olivine aggregates deformed in simple shear, Nature, 375, 774-777, 1995.