Deep Electromagnetic Studies from Land, Sea, and Space: Progress Status in the Past 10 Years

Surveys in Geophysics

Volumn 33, Issue 1, 2012, Pages 169-209

  Kuvshinov, A V ^a  

^a ETH ZURICH   (Switzerland)

Author keywords

Electrical conductivity in the mantle; Frequency and time domain approaches; Global EM inversion; Multi dimensional conductivity models; Observatory, MT, cable, and satellite induction data; Sources of magnetospheric, ionospheric and oceanic origin; Water in upper mantle and transition zone

Indexed keywords

DATA INTERPRETATION; ELECTRICAL CONDUCTIVITY IN THE MANTLE; FREQUENCY DOMAINS; GLOBAL EM INVERSION; MULTI-DIMENSIONAL CONDUCTIVITY MODELS; QUASI-ONE-DIMENSIONAL; TIME-DOMAIN APPROACH;

BUILDINGS; CABLES; DATA PROCESSING; ELECTRIC CONDUCTIVITY; ELECTROMAGNETISM; GEOMAGNETISM; MAGNETOSPHERE; OBSERVATORIES;

EARTH (PLANET);

DATA INTERPRETATION; EARTH SCIENCE; ELECTRICAL CONDUCTIVITY; ELECTROMAGNETIC METHOD; GEOMAGNETIC FIELD; IONOSPHERE; MAGNETOSPHERE; MAGNETOTELLURIC METHOD; MANTLE STRUCTURE; OCEANOGRAPHY; ONE-DIMENSIONAL MODELING; SATELLITE DATA; SATELLITE MISSION; THREE-DIMENSIONAL MODELING; TRANSITION ZONE;

EID: 82955236141     PISSN: 01693298     EISSN: None     Source Type: Journal    
DOI: 10.1007/s10712-011-9118-2     Document Type: Review

References (133)

1. Alexandrescu Mandea M, Gilbert D, Le Mouel J-L, Hulot G, Saracco G (1999) An estimate of average lower mantle conductivity by wavelet analysis of geomagnetic jerks. J Geophys Res 104(B8): 17735-17745.
2. Baba K, Utada H, Goto T, Kasaya T, Shimizu H, Tada N (2010) Electrical conductivity imaging of the Philippine Sea upper mantle using seafloor magnetotelluric data. Phys Earth Planet Int. doi: 10. 1016/j. pepi. 2010. 09. 010.
3. Balasis G, Egbert GD (2006) Empirical orthogonal function analysis of magnetic observatory data: Further evidence for non-axisymmetric magnetospheric sources for satellite induction studies. Geophys Res Lett 33: L11311. doi: 10. 1029/2006GL025721.
4. Balasis G, Egbert GD, Maus S (2004) Local time effects in satellite estimates of electromagnetic induction transfer functions. Geophys Res Lett 31: L16610. doi: 10. 1029/2004GL020147.
5. Banks R (1969) Geomagnetic variations and the electrical conductivity of the upper mantle. Geophys J R Astr Soc 17: 457-487.
6. Becker TW, Boschi L (2002) A comparison of tomographic and geodynamic mantle models. Geochem Geophys Geosyst 3: 1003. doi: 10. 1029/2001GC000168.
7. Beiner J (1973) Analysis in phases of diffusion PI-C-12 beneath 300 MEV. Nucl Phys B53: 349-365.
8. Bendat J, Piersol A (1968) Random data: analysis and measurement procedure. Wiley, New York.
9. Bercovici D, Karato SI (2003) Whole-mantle convection and the transition-zone water filter. Nature 425: 39-44.
10. Byrd R, Lu P, Nocedal J, Zhu C (1995) A limited memory algorithm for bound constrained optimization. SIAM J Sci Comput 5: 1190-1208.
11. Chamalaun FH, Barton CE (1993) Electromagnetic induction in the Australian crust: results from the Australia-wide array of geomagnetic stations. Explor Geophys 24: 179-186.
12. Chapman S, Price A (1930) The electric and magnetic state of the interior of the Earth as inferred from terrestrial magnetic variations. Phil Trans R Soc Lond A 229: 427-460.
13. Chulliat A, Lalanne X, Gaya-Pique LR, Truong F, Savary J (2009) The new Eastre Island magnetic observatory. In: Love JJ (ed) Proceedings of the XIIIth IAGA workshop on geomagnetic observatory instruments, data acquisition and processing. US Geological Survey Open-File Report 20091226, pp 47-53.
14. Constable S, Constable C (2004) Observing geomagnetic induction in magnetic satellite measurements and associated implications for mantle conductivity. Geochem Geophys Geosyst 5: Q01006. doi: 10. 1029/2003GC000634.
15. Constable S, Parker RL, Constable C (1987) Occam's inversion: a practical algorithm for generating smooth models from electromagnetic sounding data. Geophysics 52: 289-300.
16. Egbert G, Booker JR, Schultz A (1992) Very long period magnetotellurics at Tucson observatory: estimation of impedances. J Geophys Res 97: 15113-15128.
17. Erofeeva S, Egbert G (2002) Efficient inverse modeling of barotropic ocean tides. J Ocean Atmos Technol 19: 183-204.
18. Faccena C, Jolivet L, Piromallo C, Morelli A (2003) Subduction and the depth of convection in the Mediterranean mantle. J Geophys Res 108(B2): 2099.
19. Fainberg E, Kuvshinov A, Mishina L, Singer B (1990) The new approach to global deep soundings. Pure Appl Geophys 134: 527-531.
20. Fujii I, Schultz A (2002) The 3D electromagnetic response of the Earth to ring current and auroral oval excitation. Geophys J Int 151: 689-709.
21. Fukao Y, Widiyantoro S, Obayashi M (2001) Stagnant slabs in the upper and lower mantle transition region. Rev Geophys 39: 291-323.
22. Fukao Y, To A, Obayashi M (2003) Whole mantle P-wave tomography using P and PP-P data. J Geophys Res 108(B1): 2021. doi: 10. 1029/2001JB000989.
23. Fukao Y, Koyama T, Obayashi M, Utada H (2004) Trans-Pacific temperature field in the mantle transition region derived from seismic and electromagnetic tomography. Earth Planet Sci Lett 217: 425-434.
24. Haber E, Ascher UM, Oldenburg DW (2004) Inversion of 3D electromagnetic data in frequency and time domain using an inexact all-at-once approach. Geophysics 69: 1216-1228.
25. Hae R, Ohtani E, Kubo T, Koyama T, Utada H (2006) Hydrogen diffusivity in wadsleyite and water distribution in the mantle transition zone. Earth Planet Sci Lett 243: 141-148.
26. Huang XG, Xu YS, Karato SI (2005) Water content in the transition zone from electrical conductivity of wadsleyite and ringwoodite. Nature 434: 746-749.
27. Ichiki M, Uyeshima M, Utada U, Guoze Z, Ji T, Mingzhi M (2001) Upper mantle conductivity structure of the back-arc region beneath northeastern China. Geophys Res Lett 28: 3773-3776.
28. Iitaka T, Hirose K, Kawamura K, Murakami M (2004) The elasticity of the MgSiO3 postperovskite phase in the Earths lowermost mantle. Nature 430: 442-445.
29. Inoue T, Yurimoto H, Kudoh Y (1995) Hydrous modified spinel, Mg1. 75SiH0. 5O4: a new water reservoir in the mantle transition zone. Geophys Res Lett 22: 117-120.
30. Ito E, Katsura T (1989) A temperature profile of the mantle transition zone. Geophys Res Lett 16: 425-428.
31. Jiracek GR (1990) Near-surface and topographic distortions in electromagnetic induction. Surv Geophys 11: 163-203.
32. Karato S (1990) The role of hydrogen in the electrical conductivity of the upper mantle. Nature 347: 272-273.
33. Karato S (1993) Importance of anelasticity in the interpretation of seismic tomography. Geophys Res Lett 20: 1623-1626.
34. Karato S (2006) Remote sensing of hydrogen in Earth's mantle. Rev Miner Geochem 62: 343.
35. Karato S, Dai LD (2009) Comments on "Electrical conductivity of wadsleyite as a function of temperature and water content" by Manthilake et al. Phys Earth Planet Interiors 174: 19-21.
36. Kelbert A, Egbert G, Schultz A (2008) Non-linear conjugate gradient inversion for global EM induction: resolution studies. Geophys J Int 173: 365-381.
37. Kelbert A, Schultz A, Egbert G (2009a) Global electromagnetic induction constraints on transition-zone water content variations. Nature 460: 1003-1007.
38. Kelbert A, Egbert G, Schultz A (2009b) Spatial variability of mantle transition zone water content: evidence from global electromagnetic induction data. Abstracts of AGU Fall Meeting, San-Francisco.
39. Kennett B, Engdahl E (1991) Traveltimes for global earthquake location and phase identification. Geophys J Int 105: 429-465.
40. Khan A, Connolly JAD, Olsen N (2006) Constraining the composition and thermal state of the mantle beneath Europe from inversion of long-period electromagnetic sounding data. J Geophys Res 111: B10102. doi: 10. 1029/2006JB004270.
41. Khan A, Boschi L, Connolly JAD (2009) On mantle chemical and thermal heterogeneities and anisotropy as mapped by inversion of global surface wave data. J Geophys Res 114: B09305. doi: 10. 1029/2009JB006399.
42. Khan A, Kuvshinov A, Semenov A (2010) On the heterogeneous electrical conductivity structure of the Earth's mantle with implications for transition zone water content. J Geophys Res 116: B01103. doi: 10. 1029/2010JB007458.
43. Korte M, Mandea M, Linthe HJ, Hemshorn A, Kotze P, Ricaldi E (2009) New geomagnetic field observations in the South Atlantic Anomaly region. Ann Geophys 52: 65-82.
44. Koyama T (2001) A study on the electrical conductivity of the mantle by voltage measurements of submarine cables. PhD thesis, University of Tokyo.
45. Koyama T, Shimizu H, Utada H, Ichiki M, Ohtani E, Hae R (2006) Water content in the mantle transition zone beneath the North Pacific derived from the electrical conductivity anomaly. AGU Geophys Monogr Ser 168: 171-179.
46. Kuvshinov A (2008) 3-D global induction in the oceans and solid Earth: recent progress in modeling magnetic and electric fields from sources of magnetospheric, ionospheric, and oceanic origin. Surv Geophys 29: 139-186. doi: 10. 1007/s10712-008-9045-z.
47. Kuvshinov A, Olsen N (2006) A global model of mantle conductivity derived from 5 years of CHAMP, Ørsted, and SAC-C magnetic data. Geophys Res Lett 33: L18301. doi: 10. 1029/2006GL027083.
48. Kuvshinov A, Utada H (2010) Anomaly of the geomagnetic Sq variation in Japan: effect from 3-D subterranean structure or the ocean effect? Geophys J Int. doi: 10. 1111/j. 1365-246X. 2010. 04809. x.
49. Kuvshinov A, Avdeev D, Pankratov O (1999) Global induction by Sq and Dst sources in the presence of oceans: bimodal solutions for non-uniform spherical surface shells above radially symmetric Earth models in comparison to observations. Geophys J Int 137: 630-650.
50. Kuvshinov A, Olsen N, Avdeev D, Pankratov O (2002) EM induction in the oceans and the anomalous behavior of coastal C-responses for periods up to 20 days. Geophys Res Lett 29(12): 1595. doi: 10. 1029/2001GL014409.
51. Kuvshinov A, Utada H, Avdeev D, Koyama T (2005) 3-D modelling and analysis of Dst C-responses in the North Pacific Ocean region, revisited. Geophys J Int 160: 505-526.
52. Kuvshinov A, Sabaka T, Olsen N (2006a) 3-D electromagnetic induction studies using the Swarm constellation: Mapping conductivity anomalies in the Earth's mantle. Earth Planets Space 58: 417-427.
53. Kuvshinov A, Junge A, Utada H (2006b) 3-D modelling the electric field due to ocean tidal flow and comparison with observations. Geophys Res Lett. doi: 10. 1029/2005GL025043.
54. Kuvshinov A, Manoj C, Olsen N, Sabaka T (2007) On induction effects of geomagnetic daily variations from equatorial electrojet and solar quiet sources at low and middle latitudes. J Geophys Res 112(B1): 0102. doi: 10. 1029/2007JB004955.
55. Kuvshinov A, Semenov A, Pankratov O, Jackson A, Olsen N (2008) 3-D imaging of mantle conductivity based on inversion of satellite C-responses: Proof of concept. Expanded abstract of 19 Workshop on Electromagnetic Induction in the Earth, Beijing, China.
56. Kuvshinov A, Semenov A, Pankratov O, Olsen N (2009) 3-D mapping of mantle conductivity from space. An approach and its verification. In: Proceedings of 2nd international Swarm science meeting, Potsdam.
57. Kuvshinov A, Velimsky J, Tarits P, Semenov A, Pankratov O, Toffner-Clausen L, Martinec Z, Olsen N, Sabaka T, Jackson A (2010) L2 products and performances for mantle studies with Swarm. ESA Final Report, 2010, 173 pp, http://esamultimedia. esa. int/docs/EarthObservation/Induction_Study_150110. pdf.
58. Lizarralde D, Chave A, Hirth G, Schultz A (1995) Long period magnetotelluric study using Hawaii-to-California submarine cable data: implications for mantle conductivity. J Geophys Res 100(B9): 17873-17884.
59. Mackie RL, Madden T (1993) Three-dimensional magnetotelluric inversion using conjugate gradients. Geophys J Int 115: 215-229.
60. Manthilake M, Matsuzaki T, Yoshino T, Yamashita S, Ito E, Katsura T (2009) Electrical conductivity of wadsleyite as a function of temperature and water content. Phys Earth Planet Int. doi: 10. 1016/j. pepi. 2008. 06. 001.
61. Martinec Z (2010) The forward and adjoint methods of global electromagnetic induction for CHAMP magnetic data. In: Freeden W, Nashed MZ, Sonar T (eds) Handbook of geomathematics, pp 565-624. doi: 10. 1007/978-3-642-01546-5_19.
62. Martinec Z, McCreadie H (2004) Electromagnetic induction modeling based on satellite magnetic vector data. Geophys J Int 157: 1045-1060.
63. Martinec Z, Velimsky J (2009) The adjoint sensitivity method of EM induction for CHAMP magnetic data. Geophys J Int 179: 1372-1396.
64. Matzka J, Olsen N, Fox Maule C, Pedersen L, Berarducci AM, Macmillan S (2009) Geomagnetic observations on Tristan da Cuhna, South Atlantic Ocean. Ann Geophys 52: 97-105.
65. Medin AE, Parker RL, Constable S (2007) Making sound inferences from geomagnetic sounding. Phys Earth Planet Int 160: 51-59.
66. Megnin C, Romanowicz B (2000) The three-dimensional shear velocity structure of the mantle from the inversion of body, urface and higher mode waveforms. Geophys J Int 143: 709-728.
67. Mochizuki E, YokoyamaY ShimizuI, Hamano Y (1997) Spherical harmonic analysis in terms of unevenly distributed observation points and its applications to geomagnetic data. J Geomag Geoelecr 49: 1013-1033.
68. Mosegaard K (1998) Resolution analysis of general inverse problems through inverse Monte Carlo sampling. Inverse Probl 14: 405-416.
69. Neal SL, Mackie RL, Larsen JC, Schultz A (2000) Variations in the electrical conductivity of the upper mantle beneath North America and the Pacific Ocean. J Geophys Res 105(B4): 8229-8242.
70. Nocedal J, Wright SJ (2006) Numerical optimization. Springer, Berlin.
71. Obayashi M, Sugioka H, Yoshimitsu H, Fukao Y (2006) High temperature anomalies oceanward of subducting slabs at the 410 km discontinuity. Earth Planet Sci Lett 243: 149-158.
72. Oganov AR, Ono S (2004) Theoretical and experimental evidence for a postperovskite phase of MgSiO3 in Earth's D'' layer. Nature 430: 445-448.
73. Ohta K, Onoda S, Hirose K, Sinmyo R, Shimizu K, Sata N, Ohishi Y, Yasuhara A (2008) The electrical conductivity of post-perovskite in Earth's D" layer. Science 320: 89-91.
74. Olsen N (1998) The electrical conductivity of the mantle beneath Europe derived from C-Responses from 3 h to 720 h. Geophys J Int 133: 298-308.
75. Olsen N (1999a) Long-period (30 days-1 year) electromagnetic sounding and the electrical conductivity of the lower mantle beneath Europe. Geophys J Int 138: 179-187.
76. Olsen N (1999b) Induction studies with satellite data. Surv Geophys 20: 309-340.
77. Olsen N, Kuvshinov A (2004) Modelling the ocean effect of geomagnetic storms. Earth Planets Space 56: 525-530.
78. Olsen N, Vennerstrøm S, Friis-Christensen E (2002) Monitoring magnetospheric contributions using ground-based and satellite magnetic data. In: Reigber C, Luehr H, Schwintzer P (eds) First CHAMP mission results for gravity, magnetic and atmospheric studies. Springer, New York, pp 245-250.
79. Olsen N, Haagmans R, Sabaka T, Kuvshinov A, Maus S, Purucker M, Rother M, Lesur V, Mandea M (2006) The Swarm end-to-end mission simulator study: separation of the various contributions to Earth's magnetic field using synthetic data. Earth Planets Space 58: 359-370.
80. Olsen N, Sabaka T, Gaya-Pique (2007) Study of an improved comprehensive magnetic field inversion analysis for Swarm. DNSC Scientific Report 1/2007 Danish National Space Center Copenhagen.
81. Olsen N, Mandea M, Sabaka TJ, Toeffner-Clausen L (2009) CHAOS-2-a geomagnetic field model derived from one decade of continuous satellite data. Geophys J Int 23: 5-7. doi: 10. 1111/j. 1365-246X. 2009. 04386. x.
82. Olsen N, Hulot G, Sabaka TJ (2010) Sources of the geomagnetic field and the modern data that enable their investigation. In: Freeden W, Nashed MZ, Sonar T (eds) Handbook of geomathematics, pp 106-124. doi: 10. 1007/978-3-642-01546-5_5.
83. Pankratov O, Kuvshinov A (2010) General formalism for the efficient calculation of derivatives of EM frequency domain responses and derivatives of the misfit. Geophys J Int 181: 229-249.
84. Pankratov O, Avdeev D, Kuvshinov A (1995) Electromagnetic field scattering in a homogeneous Earth: a solution to the forward problem. Phys Solid Earth 31: 201-209.
85. Parker RL, Whaler K (1981) Numerical methods for establishing solutions to the inverse problem of electromagnetic induction. J Geophys Res 86: 9574-9584.
86. Prieto GA, Parker RL, Thomson DJ, Vernon FL, Graham RL (2007) Reducing the bias of multitaper spectrum estimates. Geophys J Int 171: 1269-1281.
87. Riedel K, Sidorenko A (1995) Minimum bias multiple taper spectral estimation. IEEE Trans Signal Process 43: 188-195.
88. Roberts RG (1984) The long-period electromagnetic response of the earth. Geophys J R Astr Soc 78: 547-572.
89. Rodi W, Mackie RL (2000) Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion. Geophysics 66: 174-187.
90. Romanowicz B (2003) Global mantle tomography: progress status in the past 10 years. Ann Rev Earth Planet 31: 303-328.
91. Sabaka TJ, Olsen N, Purucker ME (2004) Extending comprehensive models of the Earth's magnetic feld with Oersted and CHAMP data. Geophys J Int 159: 521-547.
92. Santos FAM, Soares A, Nolasco R, Rodrigues H, Luzio R, Palshin N, ISO-3D Team (2003) Lithosphere conductivity structure using the CAM-1 (Lisbon-Madeira) submarine cable. Geophys J Int 155: 591-600.
93. Schmucker U (1970) Anomalies of geomagnetic variations in the south-western United States. Bull Scripps Inst Ocean, Unif Calif 13: 1-165.
94. Schmucker U (1979) Erdmagnetische Variationen und die elektrische Leitfahigkeit in tieferen Schichten der Erde. Sitzungsbericht und Mitteilungen Braunschweigische Wiss Gesellschaft, Sonderheft 4: 45-102.
95. Schmucker U (1999a) A spherical harmonic analysis of solar daily variations in the years 1964-1965: response estimates and source fields for global induction - I. Methods. Geophys J Int 136: 439-454.
96. Schmucker U (1999b) A spherical harmonic analysis of solar daily variations in the years 1964-1965: response estimates and source fields for global induction-II. Results. Geophys J Int 136: 455-476.
97. Schmucker U (2003) Horizontal spatial gradient sounding and geomagnetic depth sounding in the period range of daily variations, In: Protokoll über das Kolloquium Elektromagnetische Tiefenforschung, Königstein, pp 228-237.
98. Schultz A (2010) EMScope: a continental scale magnetotelluric observatory and data discovery resource. Data Sci J 8: IGY6-IGY20.
99. Schultz A, Larsen JC (1987) On the electrical conductivity of the mid-mantle: I. Calculation of equivalent scalar MT response functions. Geophys J R Astr Soc 88: 733-761.
100. Schultz A, Pritchard G (1999) A three-dimensional inversion for large scale structure in a spherical domain. In: Spies B, Oristaglio M (eds) Three dimensional electromagnetics. Geophysical Developments Series, vol 7. Society of Exploration Geophysicists, pp 451-476.
101. Schuster A (1889) The diurnal variation of terrestrial magnetism. Phil Trans R Soc Lond A 180: 467-518.
102. Semenov V, Jozwiak W (2006) Lateral variations of the mid-mantle conductance beneath Europe. Tectonophys 416: 279-288.
103. Semenov A, Kuvshinov A (2010) Spatial distribution of the mantle conductivity as seen from the 3-D inversion of ground-based C-responses. Geophysical Research Abstracts 12 EGU2010-12565.
104. Semenov V, Shuman V (2010) Impedances for induction soundings of the Earth' mantle. Acta Geophys 58: 527-542.
105. Semenov V, Pek J, Adam A, Jozwiak W, Ladanyvskyy B, Logvinov I, Pushkarev P, Vozar J (2008) Electrical structure of the upper mantle beneath Central Europe: results of the CEMES project. Acta Geophys 56: 957-981.
106. Shimizu H, Utada H (1999) Ocean hemisphere geomagnetic network: its instrumental design and perspective for long-term geomagnetic observations in the Pacific. Earth Planets Space 51: 917-932.
107. Shimizu H, Koyama T, Baba K, Utada H (2009) Three-dimensional geomagnetic response functions for global and semi-global scale induction problems. Geophys J Int 178: 123-144.
108. Shimizu H, Koyama T, Baba K, Utada H (2010a) Revised 1-D mantle electrical conductivity structure beneath the north Pacific. Geophys J Int 180: 1030-1048.
109. Shimizu H, Utada H, Baba K, Koyama T, Obayashi M, Fukao Y (2010b) Three-dimensional imaging of electrical conductivity in the mantle transition zone beneath the North Pacific Ocean by a semi-global induction study. Phys Earth Planet Int. doi: 10. 1016/j. pepi.
110. Singer B (1995) Method for solution of Maxwell's equations in nonuniform media. Geophys J Int 120: 590-598.
111. Singer B, Kuvshinov A, Mishina L, Fainberg E (1993) Global geomagnetic sounding: new methodology and results. Phys Solid Earth 29: 35-43.
112. Tarits P, Mandea M (2010) The heterogeneous electrical conductivity structure of the lower mantle. Phys Earth Planet Int. doi: 10. 1016/j. pepi. 2010. 08. 002.
113. Tarits P, Wahr J, Lognonne P (1992) Electrical conductivity heterogeneities in the mantle: correlation with mantle velocity structure. Abstracts of AGU Fall Meeting, San-Francisco.
114. Tarits P, Hautot S, Perrier F (2004) Water in the mantle: results from electrical conductivity beneath French Alps. Geophys Res Lett 31: L06612. doi: 10. 1029/2003GL019277.
115. Toffelmier DA, Tyburczy JA (2007) Electromagnetic detection of a 410-km-deep melt layer in the southwestern United States. Nature 447: 991-994.
116. Toh H, Hamano Y, Ichiki M, Utada H (2004) Geomagnetic observatory operates at the seafloor in the Northwest Pacific Ocean. EOS 85: 467, 473.
117. Toh H, Hamano Y, Ichiki M (2006) Long-term seafloor geomagnetic station in the northwest Pacific: A possible candidate for a seafloor geomagnetic observatory. Earth Planets Space 58: 697-705.
118. Toh H, Hamano Y, Goto T, Utada H (2010) Long-term seafloor electromagnetic observation in the northwest Pacific may detect the vector geomagnetic secular variation. Data Sci J 9: IGY100-IGY109.
119. Trampert J, Deschamps F, Resovsky J, Yuen D (2004) Chemical heterogeneities throughout the lower mantle. Science 306: 853-855.
120. Utada H, Koyama T, Shimizu H, Chave A (2003) A semi-global reference model for electrical conductivity in the mid-mantle beneath the north Pacific region. Geophys Res Lett 30(4): 1194-1198. doi: 10. 1029/2002GL016092.
121. Utada H, Koyama T, Obayashi M, Fukao Y (2009) A joint interpretation of electromagnetic and seismic tomography models suggests the mantle transition zone below Europe is dry. Earth Planet Sci Lett 281: 249-257.
122. Uyeshima M, Schultz A (2000) Geoelectromagnetic induction in a heterogeneous sphere: a new 3-D forward solver using a staggered-grid integral formulation. Geophys J Int 140: 636-650.
123. Velimsky J (2010) Electrical conductivity in the lower mantle: Constraints from CHAMP satellite data by time-domain EM induction modeling, Phys Earth Planet Int 180(3-4): 111-117. doi: 10. 1016/j. pepi. 2010. 02. 007.
124. Velimsky J, Martinec Z (2005) Time-domain, spherical harmonic-finite element approach to transient three-dimensional geomagnetic induction in a spherical heterogeneous Earth. Geophys J Int 161: 81-101.
125. Veli{dotless}msky J, Martinec Z, Everett ME (2006) Electrical conductivity in the Earth's mantle inferred from CHAMP satellite measurements-I. Data processing and 1-D inversion. Geophys J Int 166: 529-542.
126. Vozar J, Semenov V (2010) Compatibility of induction methods for mantle sounding. J Geophys Res 115: B03101. doi: 10. 1029/2009JB006390.
127. Wang D, Mookherjee M, Xu YS, Karato SI (2006) The effect of hydrogen on the electrical conductivity in olivine. Nature 443: 977-980.
128. Weidelt P (1972) The inverse problem of geomagnetic induction. Z Geophys 38: 257-289.
129. Weiss CJ (2010) Triangulated finite difference methods for global scale electromagnetic induction simulations of whole mantle electrical heterogeneities. Geochem Geophys Geosyst (submitted).
130. Xu Y, Poe BT, Shankland TJ, Rubie DC (1998) Electrical conductivity of olivine, wadsleyite, and ringwoodite under upper mantle conditions. Science 280: 1415-1418.
131. Yoshino T, Katsura T (2009) Reply to Comments on "Electrical conductivity of wadsleyite as a function of temperature and water content" by Manthilake et al. Discussion. Phys Earth Planet Interiors 174: 22-23.
132. Yoshino T, Matsuzaki T, Yamashina S, Katsura T (2006) Hydrous olivine unable to account for conductivity anomaly at the top of the asthenosphere. Nature 443: 973-976.
133. Yoshino T, Manthilake G, Matsuzaki T, Katsura T (2008) Dry mantle transition zone inferred from the conductivity of wadsleyite and ringwoodite. Nature 451: 326-329.