Shallow mantle temperatures under Europe from P and S wave tomography

Temperature is one of the key parameters controlling lithospheric and mantle dynamics and rheology. Using recent experimental data on elastic parameters and anelasticity, we obtain models of temperature at 50 to 200 km depth beneath Europe from the global P wave velocity model of Bijwaard et al. [1998] and the regional S wave velocity model of Marquering and Snieder [1996]. Forward modeling of seismic velocity allows us to assess the sensitivity of velocity to various parameters. In the depth range of interest, variations in temperature (when below the solidus) yield the largest effects. For a 100°C increase in temperature, a decrease of 0.5–2% in VP and 0.7–4.5% in VS is predicted, where the strongest decrease is due to the large effect of anelasticity at high temperature. The effect of composition is expected to give velocity anomalies 80 km the relative amplitudes of the European VP and VS anomalies are consistent with a thermal origin. At shallower depths, variations in crustal thickness and possibly the presence of partial melt appear to have an additional effect, mainly on S wave velocity. In regions where both P and S anomalies are well-resolved, VP- and VS-derived thermal models agree well with each other and with temperatures determined from surface heat flow observations. Furthermore, the thermal models are consistent with known tectonics. The inferred temperatures vary significantly, from around 400°C below an average mantle adiabat at 100 km depth under the Russian Platform and a 300°C increase from east to west across the Tornquist-Teisseyre zone to temperatures around the mantle adiabat in the depth range 50–200 km under areas with present surface volcanism. In spite of the uncertainties in the calculation of temperatures due to uncertainties in the experimental elastic parameters and anelasticity and uncertainties associated with tomographic imaging, we find that the tomographic models of the shallow mantle under Europe can yield useful estimates of the thermal structure.

[1]  Hiroki Sato.  Thermal structure of the mantle wedge beneath northeastern Japan: Magmatism in an island arc from the combined data of seismic anelasticity and velocity and heat flow , 1992 .

[2]  J. Woodhouse,et al.  Comparison of P and S station corrections and their relationship to upper mantle structure , 1997 .

[3]  I. Jackson,et al.  The Earth's Mantle: Composition and Temperature of the Earth's Mantle: Seismological Models Interpreted through Experimental Studies of Earth Materials , 1998 .

[4]  R. Snieder,et al.  Waveform inversions and the significance of surface-wave mode coupling , 1996 .

[5]  H. Schmeling,et al.  Numerical models on the influence of partial melt on elastic, anelastic and electric properties of rocks. Part I: elasticity and anelasticity , 1985 .

[6]  Holloway,et al.  Melting Temperature and Partial Melt Chemistry of H2O-Saturated Mantle Peridotite to 11 Gigapascals , 1997, Science.

[7]  B. Kennett,et al.  Joint seismic tomography for bulk sound and shear wave speed in the Earth's mantle , 1998 .

[8]  R. S. Hart,et al.  Attenuation models of the earth , 1978 .

[9]  B. Mitchell,et al.  A Back-Projection Method For Imaging Large-Scale Lateral Variations of Lg Coda Q With Application to Continental Africa , 1990 .

[10]  G. Panza,et al.  The gross features of the lithosphere-asthenosphere system in Europe from seismic surface waves and body waves , 1980 .

[11]  T. Murase,et al.  The use of laboratory velocity data for estimating temperature and partial melt fraction in the low‐velocity zone: Comparison with heat flow and electrical conductivity studies , 1989 .

[12]  S. Saxena,et al.  Assessed data on heat capacity, thermal expansion, and compressibility for some oxides and silicates , 1992 .

[13]  H. Mao,et al.  Elasticity of forsterite to 16 GPa and the composition of the upper mantle , 1995, Nature.

[14]  E. Engdahl,et al.  Global teleseismic earthquake relocation with improved travel times and procedures for depth determination , 1998, Bulletin of the Seismological Society of America.

[15]  Brian J. Mitchell,et al.  ANELASTIC STRUCTURE AND EVOLUTION OF THE CONTINENTAL CRUST AND UPPER MANTLE FROM SEISMIC SURFACE WAVE ATTENUATION , 1995 .

[16]  S. Karato,et al.  Importance of anelasticity in the interpretation of seismic tomography , 1993 .

[17]  R. Snieder,et al.  SHEAR-WAVE VELOCITY STRUCTURE BENEATH EUROPE, THE NORTHEASTERN ATLANTIC AND WESTERN ASIA FROM WAVEFORM INVERSIONS INCLUDING SURFACE-WAVE MODE COUPLING , 1996 .

[18]  D. G. Isaak.  High‐temperature elasticity of iron‐bearing olivines , 1992 .

[19]  G. Ranalli.  Nonlinear flexure and equivalent mechanical thickness of the lithosphere , 1994 .

[20]  Walter H. F. Smith,et al.  New version of the generic mapping tools , 1995 .

[21]  M. J. R. Wortel,et al.  Regional scale tectonic evolution and the seismic velocity structure of the lithosphere and upper mantle: The Mediterranean region , 1994 .

[22]  H. Nataf,et al.  3SMAC: an a priori tomographic model of the upper mantle based on geophysical modeling , 1996 .

[23]  L. Bodri,et al.  Three-dimensional deep temperature modelling along the European geotraverse , 1995 .

[24]  A. Thompson.  Water in the Earth's upper mantle , 1992, Nature.

[25]  K. Fuchs,et al.  Upper mantle temperatures and lithosphere-asthenosphere system beneath the French Massif Central constrained by seismic, gravity, petrologic and thermal observations , 1997 .

[26]  Gerald M. Mavko,et al.  Velocity and attenuation in partially molten rocks , 1980 .

[27]  G. Nolet,et al.  Low S velocities under the Tornquist‐Teisseyre zone: Evidence for water injection into the transition zone by subduction , 1994 .

[28]  Gene Simmons,et al.  Elasticity of some mantle crystal structures: 1. Pleonaste and hercynite spinel , 1972 .

[29]  A. Kutoglu,et al.  Single-crystal compression and crystal structure of clinopyroxene up to 10 GPa , 1997 .

[30]  D. Toomey,et al.  Intergranular basaltic melt is distributed in thin, elogated inclusions , 1994 .

[31]  K. Furlong,et al.  Lateral variations in upper mantle thermal structure inferred from three‐dimensional seismic inversion models , 1989 .

[32]  Jun Ito,et al.  Elasticity of orthoenstatite , 1978 .

[33]  M. Bickle,et al.  The Volume and Composition of Melt Generated by Extension of the Lithosphere , 1988 .

[34]  H. Pollack,et al.  On the regional variation of heat flow, geotherms, and lithospheric thickness☆ , 1977 .

[35]  S. Cloetingh,et al.  Thermomechanical structure of European continental lithosphere: constraints from rheological profiles and EET estimates , 1996 .

[36]  E. R. Engdahl,et al.  Constraints on seismic velocities in the Earth from traveltimes , 1995 .

[37]  J. Plomerová,et al.  The lithosphere in central Europe—seismological and petrological aspects☆ , 1992 .

[38]  N. Umino,et al.  Three-Dimensional Q s Structure in the Northeastern Japan Arc , 1984 .

[39]  K. Leinenweber,et al.  In situ high P‐T X ray diffraction studies on three polymorphs (α, β, γ) of Mg2SiO4 , 1993 .

[40]  Suzanne Hurter,et al.  Heat flow from the Earth's interior: Analysis of the global data set , 1993 .

[41]  W. McDonough.  Constraints on the composition of the continental lithospheric mantle , 1990 .

[42]  A. Dziewoński,et al.  Thermal and chemical heterogeneity in the mantle: a seismic and geodynamic study of continental roots , 1995 .

[43]  H. Mao,et al.  Sound velocity and elasticity of single‐crystal forsterite to 16 GPa , 1996 .

[44]  Regionalized Temperature Variations in the Upper 400 km of the Earth's Mantle , 1995 .

[45]  A. J. Erlank,et al.  Assessment of the Vertical Extent and Distribution of Mantle Metasomatism below Kimberley, South Africa , 1988 .

[46]  A. Dziewoński,et al.  Joint inversions of seismic and geodynamic data for models of three—dimensional mantle heterogeneity , 1994 .

[47]  A. Jones,et al.  Metamorphism, Partial Melting, and K-Metasomatism of Garnet-Scapolite-Kyanite Granulite Xenoliths from Lashaine, Tanzania , 1983, The Journal of Geology.

[48]  Y. Niu.  Mantle melting and melt extraction processes beneath ocean ridges : evidence from abyssal peridotites , 1997 .

[49]  T. Jordan.  Structure and Formation of the Continental Tectosphere , 1988 .

[50]  Robert D. van der Hilst,et al.  Travel-time tomography of the European-Mediterranean mantle down to 1400 km , 1993 .

[51]  I. Jackson,et al.  The pressure dependence of the elastic moduli of single-crystal orthopyroxene (Mg0.8Fe0.2)SiO3 , 1993 .

[52]  Gabi Laske,et al.  CRUST 5.1: A global crustal model at 5° × 5° , 1998 .

[53]  H. Kern,et al.  Thermal dehydration reactions characterised by combined measurements of electrical conductivity and elastic wave velocities , 1993 .

[54]  C. Sotin,et al.  Comparison between tomographic structures and models of convection in the upper mantle , 1996 .

[55]  D. Weidner,et al.  Elastic properties of hedenbergite , 1988 .

[56]  R. Meissner,et al.  The Moho in Europe ― Implications for crustal development , 1987 .

[57]  S. O’Reilly,et al.  Equilibration temperatures and elastic wave velocities for upper mantle rocks from eastern Australia: implications for the interpretation of seismological models , 1990 .

[58]  J. Plomerová,et al.  Models of seismic anisotropy in the deep continental lithosphere , 1993 .

[59]  I. Jackson,et al.  Upper mantle seismic anisotropy and lithospheric decoupling , 1981, Nature.

[60]  Greg Hirth,et al.  Water in the oceanic upper mantle: implications for rheology , 1996 .

[61]  D. L. Anderson,et al.  Absorption band Q model for the Earth , 1982 .

[62]  D. Weidner,et al.  Elasticity of diopside , 1979 .

[63]  D. Anderson,et al.  A model of dislocation-controlled rheology for the mantle , 1981, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[64]  Harmen Bijwaard,et al.  Closing the gap between regional and global travel time tomography , 1998 .

[65]  S. Karato,et al.  Water, partial melting and the origin of the seismic low velocity and high attenuation zone in the upper mantle , 1998 .

[66]  S. Karato,et al.  Defect microdynamics in minerals and solid state mechanisms of seismic wave attenuation and velocity dispersion in the mantle , 1990 .

[67]  C. Sotin,et al.  Computation of seismic profiles from mineral physics: the importance of the non-olivine components for explaining the 660 km depth discontinuity , 1998 .

[68]  K. Hoernle,et al.  Seismic and geochemical evidence for large-scale mantle upwelling beneath the eastern Atlantic and western and central Europe , 1995, Nature.

[69]  R. Miletich,et al.  Shear and compressional mode measurements with GHz ultrasonic interferometry and velocity-composition systematics for the pyrope-almandine solid solution series , 1997 .

[70]  D. L. Anderson,et al.  Seismic velocities in mantle minerals and the mineralogy of the upper mantle , 1989 .

[71]  R. Rudnick,et al.  Measured and calculated elastic wave velocities for xenoliths from the lower crust and upper mantle , 1990 .

[72]  S. Kirby.  Rheology of the lithosphere , 1983 .

[73]  H. Berckhemer,et al.  High temperature experiments on the elastic and anelastic behaviour of magmatic rocks , 1985 .

[74]  W. Griffin,et al.  4-D Lithosphere Mapping: methodology and examples , 1996 .

[75]  G. Nolet,et al.  Shear‐wave velocity variations in the upper mantle beneath central Europe , 1994 .

[76]  Jay D. Bass,et al.  Elasticity of single‐crystal orthoferrosilite , 1984 .

[77]  K. Furlong,et al.  Thermal structure of the continental lithosphere: constraints from seismic tomography , 1995 .

[78]  K. Fuchs,et al.  Styles of continental rifting: crust-mantle detachment and mantle plumes , 1997 .

[79]  A. C. Lees,et al.  Frequency dependence of q in the mantle underlying the shield areas of Eurasia. Final technical report, 15 November 1982-30 December 1984 , 1985 .

[80]  A. Yoneda.  Pressure Derivatives of Elastic Constants of Single Crystal MgO and MgAl2O4 , 1990 .

[81]  Naohiro Soga,et al.  Some elastic constant data on minerals relevant to geophysics , 1968 .

[82]  G. Ekström,et al.  A radial model of anelasticity consistent with long-period surface-wave attenuation , 1996 .

[83]  H. Nataf,et al.  The three-dimensional seismological model a priori constrained: Confrontation with seismic data , 1996 .

[84]  E. Aulbach,et al.  Shear modulus and Q of forsterite and dunite near partial melting from forced-oscillation experiments , 1982 .

[85]  K. Fuchs,et al.  Upper mantle temperatures from teleseismic tomography of French Massif Central including effects of composition, mineral reactions, anharmonicity, anelasticity and partial melt , 1996 .

[86]  G. Grünthal,et al.  Upper mantle anisotropy beneath central Europe from SKS wave splitting: Effects of absolute plate motion and lithosphere-asthenosphere boundary topography? , 1996 .