Abstract
The tectonics of North Iceland is dominated by interaction of the Iceland hot spot and the mid-oceanic Kolbeinsey Ridge. Transform movement along the transition zone, often called Tjörnes Fracture Zone, and the seismicity it generates has been documented in the past. This study uses the seismicity data of the permanent South Iceland Lowland (SIL) network to quantify velocity structure from travel time inversion. The SIL seismic dataset is capable of illuminating parts of the region in a 3D seismic velocity inversion, primarily between 7 and 12 km depth, with less resolution elsewhere because of the sparse setup of the monitoring network. The problem has been analysed in 1, 2 and 3 dimensions and evaluated with 4 different inversion tools. The study reports a correlation of a seismic velocity anomaly in compressional wave velocity v p and shear wave velocity v s with the Husavik-Flatey fault and a further subsurface lineament stretching between the islands of Flatey and Grimsey. Finally, our results support a decrease of crustal thickness between the mainland and the island of Grimsey.
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References
Anderson, D.L. and Whitcomb, J.H., 1973, The dilatancy diffusion model of earthquake prediction. In: Kovach, R.L. and Nur, A. (eds.), Proceedings of the conference on tectonic problems of the San Andreas Fault system, Stanford University Press, California pp. 417–426.
Angenheister, G., RRISP working group, 1980, Reykjanes Ridge Iceland Seismic Experiment (RRISP 77), J. Geophys. 47, 228–238.
Barton, C.A., Zoback, M.D. and Moos, D., 1995, Fluid flow along potentially active faults in crystalline rock, Geology 23, 683– 686.
Bjarnason, I.T., Menke, W., Flovenz, O. and Caress, D., 1993, Tomographic image of the mid-Atlantic plate boundary in southwestern Iceland, J. Geophys. Res. 98, 6607–6622.
Botz, R., Winckler, G., Bayer, R., Schmitt, M., Schmidt, M., Garbe-Schönberg, D., Stoffers, P. and Kristjansson, J.K., 1999, Origin of trace gases in submarine hydrothermal vents of the Kolbeinsey Ridge, Earth Planet. Sci. Lett. 171, 83–93.
Brandsdottir, B., Detrick, R., Driscoll, N. and Kent, G., 2002, Pilot study of the Tjörnes Fracture Zone, offshore Northern Iceland, using High Resolution Multichannel Seismic Reflection Profiling and CHIRP Sonar, AGU fall meeting 2002.
Byerlee, J.D., 1990, Friction, overpressure, and fault normal compression, Geophys. Res. Let. 17, 2109–2203.
Byerlee, J.D., 1993, Model for episodic flow of high-pressure water in fault zones before earthquakes, Geology 21, 303–306.
Chauvel, C. and Hemond, C., 2000, Melting of a complete section of recycled oceanic crust: Trace element and Pb isotopic evidence from Iceland, G-cubed, 1999GC000002.
Crampin, S., 1993, A review of the effects of crack geometry on wave propagation through aligned cracks, Can. J. Expl. Geophys. 29, 03–17.
Dahm, T., 2000, On the shape and velocity of fluid-filled fractures in the Earth, Geophys. J. Int 142, 181–192.
Dahm, T. and Becker, T., 1998, On the elastic and viscous properties of media containing strongly interacting in-plane cracks, Pure appl. Geophys. 151, 1–16.
Darbyshire, F.A., Bjarnasson, I.T., White, R.S. and Flovenz, O.G., 1998, Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile, Geophys. J. Int. 135, 1131–1149.
Darbyshire, F.A., Priestley, K.F., White, R.S., Stefansson, R., Gudmundsson, G.B. and Jakobsdottir, S.S., 2000, Crustal structure of central and northern Iceland from analysis of teleseismic receiver functions, Geophys. J. Int. 143(1), 163–184.
Eberhart-Phillips, D., 1986, Three-dimensional P and S velocity structure in Northern California Coast ranges from inversion of local earthquake arrival times, Bull. Seis. Soc. Am. 76, 1025– 1052.
Eberhart-Phillips, D., 1993, Local earthquake tomography: Earthquake source regions. In: Iyer, H.M. and Hirahara, K. (Eds.), Seismic tomography: Theory and practice, Chapmann Hall, New York, pp. 613–643.
Flovenz, O.G., 1980, Seismic strcuture of the Icelandic crust above layer three and the relation between body wave velocity and the alteration of basaltic crust, J. Geophys. 47, 211–220.
Flovenz, O.G. and Gunnarson, K., 1991, Seismic crustal structure in Iceland and surrounding area, Tectonophysics 189, 1–17.
Flovenz, O.G. and Saemundsson, K., 1993, Heat flow and geothermal processes in Iceland, Tectonophysics 189, 1–17.
Furnes, H., Dilek, Y., Skjerlie, K.P., Ryttvad, H.L. and Fonneland, H., 1998, Variations in basaltic geochemistry along a propagating rift of the late Ordovician marginal basin of the West Norwegian Caledonides, Terra Nova, 10, 21, doi:10.1046/j.1365-3121.1998.00163.x.
GSC Atlantic, 2003, Rock properties database, http://gsca.nrcan.gc.ca/pubprod/rockprop/cgi-bin/plot_setup_e.php.
Geiger, L., 1910, Herdbestimmung bei Erdbeben aus den Ankunftszeiten. Nachrichten von der Königlichen Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse, 331–349.
Georgsson, L.S., Fridleifsson, G.O., Olafsson, M. and Flovenz, O.G., 2000, The Geothermal exploration of the Öxarfjördur high-temperature area, NE-Iceland, Proceedings of the world geothermal congress, Kyushu-Tohoku, Japan, 2000.
Gudmundsson, A., Brynjolfsson, S. and Jonsson, M.T., 1993, Structural analysis of a transform fault-rift zone junction in North Iceland, Tectonophysics 220, 205–221.
Haslinger, F., Kissling, E., Ansorge J., Hatzfeld, D., Papadimitrou, E., Karakostas, V., Makropoulos, K., Kahle, H.G. and Peter, Y., 1999, 3d crustal structure from local earthquake tomography around the gulf of Arta (Ionian region, NW Greece), Tectonophysics 304, 210–218.
Holbrook, W.S., Mooney, W.D. and Christensen, N.J., 1992, Seismic velocity structure of the deep continental crust, in: Fountain, D., Arculus, R., Kay and R.W. (eds.), Continental lower crust, Elsevier, Amsterdam, pp. 451–464.
Iturrino, G.J., Ildefonse, B. and Boitnott, G., 2002, Velocity structure of the lower oceanic crust: Results from Hole 735B, Atlantis II Fracture Zone. In: Natland, J.H., Dick, H.J.B., Miller, D.J. and VonHerzen, R.P. (eds.), Proc. Ocean Drill. Program, Scientific results 176, 1–71.
Jouanne, F., Villemin, T., Ferber, V., Maveyraud, C., Ammann, J., Henriot, O. and Got, J.L., 1999, Seismic risk at the rift-transform junction in north Iceland, Geophys. Res. Lett. 26, 3689– 3692.
Kaban, M.K., Flovenz, O.G. and Palmason, G., 2002, Nature of the crust-mantle transition zone and the state of the upper mantle beneath Iceland from gravity modelling, Geophys. J. Int. 149, 281–299.
Kissling, E., Ellsworth, W.L., Eberhart-Phillips, D. and Kradolfer, U., 1991, Initial reference models in seismic tomography, J. Geophys. Res. 99, 19635–19646.
Kodaira, S., Mjelde, R., Gunnarsson, K., Shiobara, M. and Shimamura, H., 1997, Crustal structure of the Kolbeinsey Ridge, North Atlantic, obtained by use of ocean bottom seismographs, J. Geophys. Res. 102, B2, 3131–3151.
Kuhn, T., Riedel, C., Herzig, P.M. and Theilen, F., submitted to Marine Geology, Shallow 3D structure of the Grimsey Lineament offshore North Iceland.
Lee, C.A., 2003, Compositional variation of density and seismic velocities in natural peridotites at STP conditions: Implications for seismic imaging of compositional heterogeneities in the upper mantle, J. Geophys. Res. 108, 2441, doi:10.1029/2003JB002413, 2003.
Liping, B., Jianguo, D., Wei, L. and Wenge, Z., 2003, Experimental studies of electrical conductivities and p-wave velocities of Gabbro at high pressures and high temperatures, Science in China Series D 46, 895–908.
Ludwig, R.J., Iturrino, G.J. and Rona, P.A. 1998, Velocity-porosity-relationship of sulfate, sulfide and basalt samples from the TAG hydrothermal mound, In: Herzig, P.M., Humpris, S.E., Miller, D.J. and Zierenberg, R.A. Proceedings of the ODP, Scientific results 158, 313–327.
McMaster, R.L., Schilling, J.G.E. and Pinet, P.E., 1977, Plate boundary within Tjörnes Fracture Zone on northern Iceland's insular margin, Nature 269, 663–667.
Menke, W., West, M., Brandsdottir, B. and Sparks, D., 1998, Compressional and shear velocity structure of the lithosphere in northern Iceland, Bull. Seis. Soc. Am. 88, 1561–1571.
Minshull, T.A., Muller, M.R., Robinson, C.J., White, R.S. and Bickle, M.J., 1998, Is the oceanic Moho a serpentinization front? In: Mills, R.A. and Harrison, K. (eds.), Modern ocean floor processes and the geological record, Geol. Soc. London, Spec. Publ. 148, 71–80.
Mjelde, R., Kasahara, J., Shimamura, H., Kamimura, A., Kanazawa, T., Kodaira, S., Raum, T. and Shiobara, H., 2002, Lower crustal seismic velocity anomalies; magmatic underplating or serpentinized peridotite? Evidence from the Vöring Margin, NE Atlantic, Marine Geophys. Res. 23, 169–183.
Mizuno, T., 2003, The subsurface observation of fault-zone trapped waves: Applications to investigations of the deep structure of active faults, Bull. Earthq. Res. Inst. 78, 91–106.
Mochizuki, M., Kodaira, S., Shiobara, H., Shiamura, H., Brandsdottir, B., Sturkell, E., Gudmundsson, G. and Stefanson, R., 1995, Seismicity in the Tjörnes Fracture Zone off North Iceland, Derived from an OBS observation (in japanese).
Neben, S., 1992, Der Aufbau des südlichen Kolbeinseyrückens, Doctoral thesis, University of Kiel.
O'Connell, R.J. and Budiansky, B., 1974, Seismic velocity in dry and saturated cracked solids, J. Geophys. Res. 79, 5412–5426.
Paige, C.C. and Saunders, M., 1982, LSQR: An algorithm for sparse linear eqiuations and sparse least squares, ACM Trans. Math. Software 8, 43–71.
Palmason, G., 1971, Crustal structure of Iceland from explosion seismology, Soc. Sci. Iceland X, 1–187.
Parsons, T., Christensen, N.I. and Wiltshire, H.G., 1995, Velocities of southern Basin and Range xenoliths: Insights on the nature of lower crustal reflectivity and composition, Geology 23, 129– 132.
Pettigrew, T.L. and Holloway, G.L., 2000. Hammer drill: An overview and post Leg 179 update, JOIDES J. 24, 19–21.
Planke, S. and Cambray, H., 1998, Seismic properties of flood basalts on rifted volcanic margins based on Ocean Drilling Program (ODP) Hole 917A downhole data, Proc. Ocean Drill. Program Sci. Results 152, 453–462.
Podvin, P. and Lecomte, I., 1991, Finite difference computation of traveltimes in very contrasted velocity models: A massively parallel approach and its associated tools, Geophys. J. Int. 105, 271–284.
Rice, J.R., 1992, Fault stress states, pore pressure distributions, and the weakness of the San Andreas Fault, In: Evans, T.F. Wong (ed.) Fault Mechanics and transport properties of rocks, b. London, Academic pp. 475–503.
Riedel, C., 2001, Self-organizing seafloor mapping of the Tjörnes Fracture Zone/Iceland, Doctoral thesis, University of Kiel (available via internet connection http://e-diss.uni-kiel.de/diss_500).
Riedel, C. and Theilen, F., 2000, Cruise report R/V Poseidon 252, Institut für Meereskunde, University of Kiel, p. 17 (available via internet connection http://www.geophysik.uni-kiel.de/~criedel/kolbein/geophysics.pdf).
Riedel, C., Schmidt, M., Botz, R. and Theilen, F., 2001, The Grimsey hydrothermal field offshore Northern Iceland: Crustal structure, faulting and related gas venting, Earth Plan. Sci. Let. 193, 409–421.
Riedel, C., Petersen, T., Theilen, F. and Neben, S., 2003, High b-values in the leaky segment of the Tjörnes Fracture Zone north of Iceland: Are they evidence for shallow magmatic heat sources?, J. Volcanol. Geotherm. Res. 128, 15–29.
Riedel, C. and Dahm, T., 2003, Optimizing the 1D-velocity model and relocating earthquakes in the Tjörnes Fracture Zone, 63. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, SL 29, pp. 285–286.
Rögnvaldsson, S.T., Gudmundsson, A. and Slunga, R., 1998, Seismotectonic analysis of the Tjörnes Fracture Zone, an active transform fault in north Iceland, J. Geophys. Res. 103, B12, 30117–30129.
Sato, H. and Ito, K., 2001, H2O fluid distribution in mantle rock at 1 Gpa, constraints from V s -V p /V s diagram, Bull. Earthquake Res. Inst., Univ. Tokyo 76, 305–310.
Schweitzer, J., 1997, HYPOSAT – A new routine to locate seismic events. In: Semiannual Technical Summary, 1 Apr–30 Sep 97, NORSAR Scientific Rep. 1-97/98, November.
Sherburn, S., Bannister, S. and Bibby, H., 2003, Seismic velocity structure of the central Taupo Volcanic Zone, New Zealand, from local earthquake tomography, J. Volcanol. Geotherm. Res. 122, 69–88.
Sigurdsson, H., Schilling, J.G. and Meyer, P.S., 1978, Skagi and Langjökull volcanic zones in Iceland: 1. Petrology and structure, J. Geophys. Res. 83, 3971–3982.
Staples, R.K., White, R.S., Brandsdottir, B., Menke, W., Maguire, P.K.H. and McBride, J.H., 1997, Faroe-Iceland ridge experiment 1. Crustal structure of NE Iceland, J. Geophys. Res. 102, 7849–7866.
Stefanson, R., Bergerat, F., Bonafede, M., Bödvarsson, R., Crampin, S., Feigl, K.L., Roth, F., Sigmundsson, F. and Slunga, R., 1999, Earthquake prediction in a natural laboratory PRENLAB-TWO, porject report, http://hraun.vedur.is/ja/skyrslur/prenlab/ed-pren2/all/all.html.
Stracke, A., Zindler, A., Salters, V.J.M., McKenzie, D., Blichert-Toft, J., Albarede, F. and Grönvold, K., 2003, Theistareykir revisited, G-cubed, DOI:10.1029/201GC000201.
Slater, L., Jull, M., McKenzie, D. and Grönvold, K., 1998, Deglaciation effects on mantle melting under Iceland: Results from the northern volcanic zone, Earth Plan. Sci. Lett. 164, 151–164.
Svetov, S.A., 2001, Archean high-MgO volcanism in East Fennoscandia, Geoscience Australia, AGSO, http://geoserv.krc.karelia.ru/Rus/htm_files/Personal/Svetov%20S_A/AU_svetov_2001.pdf.
Taylor, B., Crook, K. and Sinton, J., 1994, Extensional transforms and ablique spreading centers, J. Geophys. Res. 99, 19707–19718.
Thorarinsson, S., 1937, Das Dalvik-Beben in Nordisland, Geografiska Annaler 19, 232–277.
Thors, K., 1982, Shallow seismic stratigraphy and structure of the southernmost part of the Tjörnes Fracture Zone, Jökull 32, 107–112.
Thurber, C. and Eberhart-Phillips, D., 1999, Local earthquake tomography with flexible gridding, Comp. Geosci. 25, 809– 818.
Tryggvasson, A., Rögnvaldsson, S.T. and Flovenz, O., 2002, Three dimensional seismic imaging of the P- and S-wave velocity structure and earthquake location beneath Southwest Iceland, Geophys. J. Int. 151, 848–866.
Walker, G.P.L., 1960, Zeolite zones and dike distribution in relation to the structure of the basalts of eastern Iceland, J. Geol. 68, 515–528.
Weir, N.R.W., White, R.S., Brandsdottir, B., Einarsson, H., Shimamura, H., Shiobara, H. and Team, R.F., 2002, Crustal structure of the northern Reykjanes Ridge and the Reykjanes peninsula, south-west Iceland, J. Geophys. Res.
Yamamoto, K., Sato, N. and Yabe, Y., 2002, Elastic property of damaged zone inferred from in-situ stresses mnear fault: The changes in seismic velocities caused by faulting, International workshop on physics of active faulting, Abstract volume, NIED, Tsukuba, Japan.
Young, K.D., Jancin, M., Voight, B. and Orkan, N.I., 1985, Transform deformation of Tertiary rocks along the Tjörnes Fracture Zone, North Central Iceland, J. Geophys. Res. 90, 9986–10010.
Zhao, D. and Mizuno, T., 1999, Crack density and saturation rate in the 1995 Kobe earthquake region, Geophys. Res. Lett. 26, 3213–3216.
Zverev, S.M., Litvinenko, I.V., Palmason, G., Yaroshevskaya, G.A., Osokin, N.N. and Akhmetjev, M.A., 1980, A seismic study of the rift zone in Northern Iceland, J. Geophys. 47, 191–201.
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Riedel, C., Tryggvason, A., Dahm, T. et al. The seismic velocity structure north of Iceland from joint inversion of local earthquake data. J Seismol 9, 383–404 (2005). https://doi.org/10.1007/s10950-005-8721-4
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DOI: https://doi.org/10.1007/s10950-005-8721-4