Temperature-Dependent Newtonian Rheology in Advection-Convection Geodynamical Model for Plate Spreading in Eastern Volcanic Zone, Iceland

DOI: 10.4236/gep.2015.35003   PDF   HTML   XML   3,535 Downloads   4,000 Views   Citations

Abstract

Geodynamic process as advection-convection of the Mid-Atlantic Ocean Ridge (MAR), that is exposed on land in Iceland is investigated. Advection is considered for the plate spreading velocity. Geodetic GPS data during 2000-2010 is used to estimate plate spreading velocity along a profile in the Eastern Volcanic Zone (EVZ), Iceland striking N102E, approximately parallel to the NUVEL-1A spreading direction between the Eurasian and North American plates. To predict subsurface mass flow patterns, temperature-dependent Newtonian rheology is considered in the finite-element models (FEM). All models are considered 2-D with steady-state, incompressible rheology whose viscosity depends on the subsurface temperature distribution. The thickness of lithosphere along the profile in the EVZ is identified by 700C isotherm and 1022 Pa s iso-viscosity, those reach 50 ± 3 km depth at distance of 100 km from rift axis. Geodetic observation and model prediction results show the ~90% of spreading is accommodated within ~45 km of the rift axis in each direction. Model predicts ~8.5 mm.yr-1 subsidence at the surface of rift center when magmatic plumbing is inactive. The rift center (the highest magmatic influx is ~11 mm.yr-1) in model shifts ~10 - 20 km west to generate observed style surface deformation. The spreading velocity, isotherm and depth of isotherm are the driving forces resulting in the surface deformation. These three parameters have more or less equal weight. However, as the center of deformation in the EVZ shifts and most of the subsidence takes place in the volcanic system that is currently the active which is the located of plate axis.

Share and Cite:

Islam, M. and Sturkell, E. (2015) Temperature-Dependent Newtonian Rheology in Advection-Convection Geodynamical Model for Plate Spreading in Eastern Volcanic Zone, Iceland. Journal of Geoscience and Environment Protection, 3, 14-26. doi: 10.4236/gep.2015.35003.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] Einarsson, P. (2008) Plate Boundaries, Rifts and Transforms in Iceland. Jokull, 58, 35-58.
[2] LaFemina, P.C., Dixon, T.H., Malservisi, R., árnadóttir, T., Sturkell, E., Sigmundsson, F. and Einarsson, P. (2005) Geodetic GPS Measurements in South Iceland: Strain Accumulation and Partitioning in a Propagating Ridge System. Journal of Geophysical Research, 110, 1-21. http://dx.doi.org/10.1029/2005JB003675
[3] árnadóttir, T., Jiang, W., Feigl, K.L., Geirsson, H. and Sturkell, E. (2006) Kenematic Models of Plate Boundary Deformation in Sourthwest Iceland Derived from GPS Observation. Journal of Geophysical Research, 111, 1-16. http://dx.doi.org/10.1029/2005JB003907
[4] árnadóttir, T., Lund, B., Jiang, W., Geirsson, H., Bjornsson, H., Einarsson, P. and Sigurdsson, T. (2009) Glacial Rebound and Plate Spreading: Results from the First Countrywide GPS Observations in Iceland. Geophysical Journal International, 177, 691-716. http://dx.doi.org/10.1111/j.1365-246X.2008.04059.x
[5] Scheiber-Enslin, S.E., LaFemina, P.C., Sturkell, E., Hooper, A.J. and Webb, S.J. (2011) Geodetic Investigation of Plate Spreading along a Propagating Ridge: The Eastern Volcanic Zone, Iceland. Geophysical Journal International, 1-20. http://dx.doi.org/10.1111/j.1365-246x.2011.05243.x
[6] Geirsson, H., LaFemina, P., árnadóttir, T., Sturkell, E., Sigmundsson, F., Travis, M., et al. (2012) Volcano Deformation at Active Plate Boundaries: Deep Magma Accumulation at Hekla Volcano and Plate Boundary Deformation in South Iceland. Journal of Geophysical Research, 117, 1-18. http://dx.doi.org/10.1029/2012JB009400
[7] Pedersen, R., Sigmundsson, F. and Masterlark, T. (2009) Rheologic Controls on Inter-Rifting Deformation of the Northern Volcanic Zone, Iceland. Earth and Planetary Science Letters, 281, 14-26. http://dx.doi.org/10.1016/j.epsl.2009.02.003
[8] Islam, M.T., Sturkell, E., Sigmundsson, F. and ófeigsson, B.G. (2013) Temperature-Dependent Non-Linear Rheological Models of Plate Spreading in Iceland [abs]. EGU General Assembly, 15, EGU2013-11236.
[9] Jakobsson, S.P. (1979) Outline of the Petrology of Iceland. Jokull, 29, 57-73.
[10] S?mundsson, K. (1986) Suberial Volcanism in the Western North Atlantic. In: Vogt, P.R. and Tucholke, B.E., Eds., The Geology of North America: The Western North Atlantic Region, Geological Society of America, Boulder, 69-86.
[11] Jóhannesson, H. and Somundsson, K. (1998) Geological Map of Iceland, 1:500000. Bedrock Geology. 2nd Edition, Icelandic Institute of Natural History, Reykjavik.
[12] Darbyshire, F.A., Priestley, K.F., White, R.S., Stefánsson, R., Gudmundsson, G.B. and Jakobsdóttir, S.S. (2000) Crustal Structure of Central and Northern Iceland from Analysis of Teleseismic Receiver Functions. Geophysical Journal International, 143, 163-184. http://dx.doi.org/10.1046/j.1365-246x.2000.00224.x
[13] Kaban, M.K., Flóvenz, ó. and Pálmason, G. (2002) Nature of the Crust-Mantle Transition Zone and the Thermal State of the Upper Mantle Beneath Iceland from Gravity Model-ling. Geophysical Journal International, 149, 281-299. http://dx.doi.org/10.1046/j.1365-246X.2002.01622.x
[14] Brandsdóttir, B. and Menke, W.H. (2008) The Seismic Structure of Iceland. J?kull, 58, 17-34.
[15] Bjarnason, I.T. and Schmeling, H. (2009) The Lithosphere and Astheo-nosphere of the Iceland Hotspot from Surface Waves. Geophysical Journal International, 178, 394-418. http://dx.doi.org/10.1111/j.1365-246X.2009.04155.x
[16] Flóvenz, ó.G. and Somundsson, K. (1993) Heat Flow and Geothermal Processes in Iceland and Surrounding Area. Tectonophysics, 189, 1-17. http://dx.doi.org/10.1016/0040-1951(91)90483-9
[17] Bj?rnsson, A. (2008) Temperature of the Icelandic Crust: Inferred from Electical Conductivity, Temperature Gradient, and Maximum Depth of Earthquakes. Tectonophyscs, 447, 136-141. http://dx.doi.org/10.1016/j.tecto.2006.02.027
[18] Durbyshire, et al. (2000)
[19] DeMets, C., Gor-don, R. and Argus, D. (2010) Geologically Current Plate Motions. Geophysical Journal International, 181, 1-80. http://dx.doi.org/10.1111/j.1365-246X.2009.04491.x
[20] S?mundsson, K. (1974) Evolution of the Axial Rifting Zone in Northern Iceland and the Tjornes Fracture Zone. Bulletin of the Geological Society of America, 85, 495-504. http://dx.doi.org/10.1130/0016-7606(1974)85<495:EOTARZ>2.0.CO;2
[21] Einarsson, P. (1991) Earthquakes and Present-Day Tectonism in Iceland. Tectonophysics, 189, 261-279. http://dx.doi.org/10.1016/0040-1951(91)90501-I
[22] Jónsson, S., Einarsson, P. and Sigmundsson, F. (1997) Extension across a Divergent Plate Boundary, the Eastern Volcanic Rift Zone, South Iceland, 1967-1994, Observed with GPS and Electronic Distance Measurements. Journal of Geophysical Research, 102, 11913-11929. http://dx.doi.org/10.1029/96JB03893
[23] Venzke, E., Wunderman, R.W., McClelland, L., Simkin, T., Luhr, J.F., Siebert, L. and Mayberry, G. (2002) Global Volcanism, 1968 to the Present. Digital Inf. Ser., GVP-4, Global Volcanism Program, Smithson. Inst., Washington DC. http://www.volcano.si.edu/gvp/reports/
[24] Okada, Y. (1985) Surface Deformation Due to Shear and Tensile Faults in a Half-Space. Bulletin of the Seismological Society of America, 75, 1135-1154.
[25] Sigmundsson, F. (2006) Iceland Geodynamics: Crustal Deformation and Divergent Plate Tectonics. Praxis Publishing, Chichester.
[26] Altamimi, Z., Collilieux, X., Legrand, J., Garayt, B. and Boucher, C. (2007) ITRF2005: A New Release of the International Terrestrial Reference Frame Based on Time Series of Station Positions and Earth Orientation Parameters. Journal of Geophysical Research, 112, 1-19. http://dx.doi.org/10.1029/2007JB004949
[27] Savage, J.C. and Burford, R.O. (1973) Geodetic Determination of Relative Plate Motion in Central California. Journal of Geophysical Research, 78, 832-854. http://dx.doi.org/10.1029/JB078i005p00832
[28] Gudmundsson, A. (1987) Tectonics of the Thingvellir Fissure Swarm, SW Iceland. Journal of Structural Geology, 9, 61-69. http://dx.doi.org/10.1016/0191-8141(87)90044-7
[29] Behn, M.D., Boettcher, M.S. and Hirth, G. (2007) Thermal Structure of Oceanic Transform Faults. Geology, 4, 307- 310. http://dx.doi.org/10.1130/G23112A.1
[30] Christensen, U. (1983) Convection in a Variable-Viscosity Fluid: Newtonian versus Power-Law Reheology. Earth and Planetary Science Letters, 64, 153-162. http://dx.doi.org/10.1016/0012-821X(83)90060-2
[31] Pagli, C., Sigmundsson, F., Lund, B., Sturkell, E., Geirsson, H., Einarsson, P., et al. (2007) Glacio-Isostatic Deformation around the Vatnajokull Ice Cap, Iceland, Induced by Recent Climate Warming: GPS Observations and Finite Element Modelling. Journal of Geophysical Research, 112, 1-12. http://dx.doi.org/10.1029/2006JB004421
[32] Jones, S.M. and Maclennan, J. (2005) Crustal Flow Beneath Iceland. Journal of Geophysical Research, 110, 1-19. http://dx.doi.org/10.1029/2004JB003592
[33] Turcotte, D.L. and Schubert, G. (2002) Geodynamics. 2nd Edition, Cambridge University Press, Cambridge. http://dx.doi.org/10.1017/CBO9780511807442
[34] COMSOL Multiphysics (2013) COMSOL Documentation, Version 4.3.2.152.
[35] Roland, E., Behn, M.D. and Hirth, G. (2010) Thermal-Mechanical Behavior of Oceanic Transform Faults: Implications for the Spatial Distribution of Seismicity. Geochemistry, Geophysics, Geosystems, 7, 1-15. http://dx.doi.org/10.1029/2010gc003034
[36] Barnhoorn, A., van der Wal, W. and Drury, M.R. (2011) Upper Mantle Viscosity and Lithospheric Thickness under Iceland. Journal of Geodynamics, 52, 260-270. http://dx.doi.org/10.1016/j.jog.2011.01.002
[37] Wu, P. (2004) Using Commercial Finite Element Packages for the Study of Earth Deformation, Sea Levels and the State of Stress. Geophysical Journal International, 158, 401-408. http://dx.doi.org/10.1111/j.1365-246X.2004.02338.x
[38] Larson, M.G. and Bengzon, F. (2009) The Finite Element Method: Theory, Implementation, and Practice. Department of Mathematics, Ume University, Ume.
[39] Fowler, C.M.R. (2005) The Solid Earth: An Introduction to Global Geophysics. 2nd Edition, Cambridge University Press, Cambridge.
[40] Pálmason, G. (1986) Model of Crustal Formation in Iceland, and Application to Submarine Mid-Ocean Ridge. In: Vogt, P.R. and Tucholke, B.E., Eds., The Geology of North America: The Western North Atlantic Region, Geo-logical Society of America, Boulder, 87-97. http://dx.doi.org/10.1130/dnag-gna-m.87
[41] Sigmundsson (2006)
[42] Sturkell, E., Islam, M.T., Sigmundsson, F., Geirsson, H. and LaFemina, P.C. (2013) Continuous Subsidence in the Thinvellir Rift Graben, Iceland: Geodetic Observations since 1996 Compared to Rheological Models of Plate Spreading [abs]. AGU Fall Meeting, 1810891.
[43] Hirsch, M.W., Smale, S. and Devaney, R.L. (2004) Phase Portraits for Planar Systems, in Differential Equation, Dynamical Systems & an Introduction to Chaos. 2nd Edition, ELSEVIER Academic Press, California.

  
comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.