Advertisement

Earth, Planets and Space

, Volume 57, Issue 5, pp 465–470 | Cite as

Geomagnetic paleointensity over 1.2 Ma from deep-tow vector magnetic data across the East Pacific Rise

  • Michiko YamamotoEmail author
  • Nobukazu Seama
  • Nobuhiro Isezaki
Open Access
Letter

Abstract

Deep-tow vector magnetic data have been acquired across the fast-spreading southern East Pacific Rise 18°S and inverted to magnetization intensity variations. Vector magnetic data are used to determine continuous magnetic intensity within intervals of constant polarity over the Matuyama and Brunhes periods up to the Cobb Mountain event at 1.19 Ma. A comparison of our deep-tow vector data and a sediment core-derived geomagnetic paleointensity timescale suggests that the short-wavelength magnetic anomaly signal is indeed of geomagnetic origin and can be used to date the seafloor with a high resolution. The crustal age determined from our date reveals a highly asymmetric spreading rate for the recent period (since 0.3 Ma).

Key words

Paleointensity variation vector magnetic anomaly data deep-tow survey East Pacific Rise 

References

  1. Auzende, J.-M., V. Ballu, R. Batiza, D. Bideau, J.-L. Charlou, M. H. Cormier, Y. Fouquet, P. Geistdoerfer, Y. Lagabrielle, J. Sinton, and P. Spadea, Recent tectonic, magmatic, and hydrothermal activity on the East Pacific Rise between 17°S and 19°S: Submersible observations, J. Geophys. Res., 101, 17995–18010, 1996.CrossRefGoogle Scholar
  2. Bergmanis, E., J. Sinton, S. White, K. C. Macdonald, R. Batiza, K. Rubin, T. K. P. Gregg, C. L. Van Dover, and K. Gronvold, Anatomy of a midocean ridge volcanic eruption: The Aldo-Kihi flow between 17°24′S and 17°34′S, East Pacific Rise, Eos Trans. AGU, 80(46), Fall Meet. Suppl., F1075, 1999.Google Scholar
  3. Bowers, N. E., S. C. Cande, J. S. Gee, J. A. Hildebrand, and R. L. Parker, Fluctuations of the paleomagnetic field during chron C5 as recorded in near-bottom marine magnetic anomaly data, J. Geophys. Res., 106, 26379–26396, 2001.CrossRefGoogle Scholar
  4. Bowles, J., L. Tauxe, J. Gee, D. McMillan, and S. Cande, Source of tiny wiggles in Chron C5: A comparison of sedimentary relative intensity and marine magnetic anomalies, Geochem. Geophys. Geosys., 4, 1049, doi:10.1029/2002GC000489, 2CrossRefGoogle Scholar
  5. Cande, S. C. and D. V. Kent, Ultrahigh resolution marine magnetic anomaly profiles: A record of continuous paleointensity variations?, J. Geophys. Res., 97, 15075–15083, 1992.CrossRefGoogle Scholar
  6. Carbotte, S. M., J. C. Mutter, and L. Xu, Contribution of volcanism and tectonism to axial and flank morphology of the southern East Pacific Rise, 17°10′–17°40′S, from a study of layer 2A geometry, J. Geophys. Res., 102, 10165–10184, 1997.CrossRefGoogle Scholar
  7. Cormier, M.-H. and K. C. Macdonald, East Pacific Rise 18°–19°S: Asymmetric spreading and ridge reorientation by ultrafast migration of axial discontinuities, J. Geophys. Res., 99, 543–564, 1994.CrossRefGoogle Scholar
  8. Cormier, M. H., D. S. Scheirer, and K. C. Macdonald, Evolution of the East Pacific Rise at 16°–19°S since 5 Ma: Bisection of overlapping spreading centers by new, rapidly propagating ridge segments, Marine Geophys. Res., 18, 53–84, 1996.CrossRefGoogle Scholar
  9. Detrick, R. S., A. J. Harding, G. M. Kent, J. A. Orcutt, J. C. Mutter, and P. Buhl, Seismic Structure of the Southern East Pacific Rise, Science, 259, 499–503, 1993.CrossRefGoogle Scholar
  10. Dyment, J. and J. Arkani-hamed, Spreading-rate-dependent magnetization of the oceanic lithosphere inferred from the anomalous skewness of marine magnetic anomalies, Geophys. J. Int., 121, 789–804, 1995.CrossRefGoogle Scholar
  11. Fujiwara, T. and H. Fujimoto, Seafloor geomagnetic vector anomaly of the intersection of the Mid-Atlantic Ridge and the Kane Transform Fault: Implications for magnetization of the oceanic crust, J. Geophys. Res., 103, 30335–30349, 1998.CrossRefGoogle Scholar
  12. Gee, J., S. C. Cande, J. A. Hildebrand, K. Donnelly, and R. L. Parker, Geomagnetic intensity vatiation over the past 780 kyr obtained from near-seafloor magnetic anomalies, Nature, 408, 827–832, 2000.CrossRefGoogle Scholar
  13. Guyodo, Y. and J. P. Valet, Relative variations in geomagnetic intensity from sedimentary records: the past 200,000 years, Earth Planet. Sci. Lett., 143, 23–36, 1996.CrossRefGoogle Scholar
  14. Guyodo, Y. and J. P. Valet, Global changes in intensity of the Earth’s magnetic field during the past 800 kyr, Nature, 399, 249–252, 1999.CrossRefGoogle Scholar
  15. Guyodo, Y., C. Richter, and J. P. Valet, Paleointensity record from Pleistocene sediments (1.4–0 Ma) off the California Margin, J. Geophys. Res., 104, 22953–22964, 1999.CrossRefGoogle Scholar
  16. Hooft, E. E. E., H. Schouten, and R. S. Detrick, Constraining crustal emplacement processes from the variation in seismic layer 2A thickness at East Pacific Rise, Earth Planet. Sci. Lett., 142, 289–309, 1996.CrossRefGoogle Scholar
  17. Hooft, E. E. E., R. S. Detrick, and G. M. Kent, Seismic structure and indicators of magma budget along the southern East Pacific Rise, J. Geophys. Res., 102, 27319–27340, 1997.CrossRefGoogle Scholar
  18. Hussenoeder, S. A., M. A. Tivey, and H. Shouten, Direct inversion of potential fields from an uneven track with application to the Mid-Atlantic Ridge, Geophys. Res. Lett., 22, 3131–3134, 1995.CrossRefGoogle Scholar
  19. Hussenoeder, S. A., M. A. Tivey, H. Shouten, and R. C. Searle, Nearbottom magnetic survey of the Mid-Atlantic Ridge axis, 24°–24°40′N: Implications for crustal accretion at slow spreading ridges, J. Geophys. Res., 101, 22051–22069, 1996.CrossRefGoogle Scholar
  20. Johnson, H. P. and M. A. Tivey, Magnetic properties of zero-age oceanic crust; a new submarine lava flow on the Juan de Fuca Ridge, Geophys. Res. Lett., 22, 175–178, 1995.CrossRefGoogle Scholar
  21. Lonsdale, P., Segmentation of the Pacific-Nazca spreading center, 1°N– 20°S, J. Geophys. Res., 94, 12197–12225, 1989.CrossRefGoogle Scholar
  22. Meynadier, L., J. P. Valet, R. Weeks, N. J. Shackleton, and V. L. Hagee, Relative geomagnetic intensity of the field during the last 140 ka, Earth Planet. Sci. Lett., 114, 39–57, 1992.CrossRefGoogle Scholar
  23. Mutter, J. C., S. M. Carbotte, W. Su, L. Xu, P. Buhl, R. S. Detrick, G. M. Kent, J. A. Orcutt, and A. J. Harding, Seismic Images of Active Magma Systems Beneath the East Pacific Rise Between 17°05′ and 17°35′S, Science, 268, 391–395, 1CrossRefGoogle Scholar
  24. Perram, L. J., K. C. Macdonald, and S. P. Miller, Deep-tow magnetics near 20?S on the East Pacific Rise: A study of short wavelength anomalies at a very fast spreading canter, Marine Geophys. Res., 12, 235–245, 1990.CrossRefGoogle Scholar
  25. Pouliquen, G., Y. Gallet, P. Patriat, J. Dyment, and C. Tamura, A geomagnetic record over the last 3.5 million years from deep-tow magnetic anomaly profiles across the Central Indian Ridge, J. Geophys. Res., 106, 10941–10960, 2CrossRefGoogle Scholar
  26. Rea, D. K. and R. J. Blakely, Short-wavelength magnetic anomalies in a region of rapid seafloor spreading, Nature, 225, 126–128, 1975.CrossRefGoogle Scholar
  27. Scheirer, D. S. and K. C. Macdonald, Variation in cross-sectional area of the axial ridge along the East Pacific Rise: Evidence for the magmatic budget of a fast spreading center, J. Geophys. Res., 98, 7871–7886, 1993.CrossRefGoogle Scholar
  28. Scheirer, D. S., D. W. Forsyth, M.-H. Cormier, and K. C. Macdonald, Shipboard geophysical indications of asymmetry and melt production beneath the East Pacific Rise near the MELT Experiment, Science, 260, 1221–1224, 1998.CrossRefGoogle Scholar
  29. Shah, A. K., M.-H. Cormier, W. B. F. Ryan, W. Jin, J. Sinton, E. Bergmanis, J. Carlut, A. Bradley, and D. Yoerger, Episodic dike swarms inferred from near-bottom magnetic anomaly maps at the southern East Pacific Rise, J. Geophys. Res., 108, doi:10.1029/2001JB000564, 2Google Scholar
  30. Sinton, J., E. Bergmanis, K. Rubin, R. Batiza, T. K. P. Gregg, K. Groenvold, K. C. Macdonald, and S. M. White, Volcanic eruptions on midocean ridge: New evidence from the superfast spreading East Pacific Rise, 17°–19°S, J. Geophys. Res., 107, 10.1029/2000JB000090, 2002.Google Scholar
  31. Tivey, M. A., Fine-scale magnetic anomaly field over the southern Juan de Fuca Ridge: Axial magnetization low and implications for crustal structure, J. Geophys. Res., 99, 4833–4855, 1994.CrossRefGoogle Scholar
  32. Tivey, M. A. and H. P. Johnson, The central anomaly magnetic high: Implications for ocean construction and evolution, J. Geophys. Res., 92, 12685–12694, 1987.CrossRefGoogle Scholar
  33. Tivey, M. A. and H. P. Johnson, Variations in oceanic crustal structure and implications for the fine-scale magnetic anomaly signal, Geophys. Res. Lett., 20, 1879–1882, 1993.CrossRefGoogle Scholar
  34. Urabe, T., E. T. Baker, J. Ishibashi, R. A. Feely, K. Marumo, G. J. Massoth, A. Maruyama, K. Shitashima, K. Okamura, J. E. Lupton, A. Sonoda, T. Yamazaki, M. Aoki, J. Gendron, R. Greene, Y. Kaiho, K. Kisimoto, G. Lebon, T. Matsumoto, K. Nakamura, A. Nishizawa, O. Okano, G. Paradis, K. Roe, T. Shibata, D. Tennant, T. Vance, S. L. Walker, T. Yabuki, and N. Ytow, The Effect of Magmatic Activity on Hydrothermal Venting Along the Superfast-Spreading East Pacific Rise, Science, 269, 1092–1095, 1CrossRefGoogle Scholar
  35. Wooldridge, A. L., C. G. A. Harrison, M. A. Tivey, P. A. Rona, and H. Schouten, Magnetic modeling near selected areas of hydrothermal activity on the Mid-Atlantic and Gorda Ridges, J. Geophys. Res., 97, 10911–10926, 1CrossRefGoogle Scholar
  36. Valet, J. P. and L. Meynadier, Geomagnetic field intensity and reversals during the past four million years, Nature, 366, 234–238, 1993.CrossRefGoogle Scholar
  37. Valet, J. P., J. Brassart, X. Quidelleur, V. Soler, P. Y. Gillot, and L. Hongre, Paleointensity variations across the last geomagnetic reversal at La Palma, Canary Islands, Spain, J. Geophys. Res., 104, 7577–7598, 1999.CrossRefGoogle Scholar
  38. Yamamoto, M. and N. Seama, Genetic Algorithm inversion of geomagnetic vector data using a 2.5 dimensional magnetic structure model, Earth Planets Space, 56, 217–227, 2004.CrossRefGoogle Scholar
  39. Yamazaki, T., Relative paleointensity of the geomagnetic field during Brunhes Chron recorded in North Pacific deep-sea sediment cores: orbital influence?, Earth. Planet. Sci. Lett., 169, 23–35, 1999.CrossRefGoogle Scholar

Copyright information

© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2005

Authors and Affiliations

  • Michiko Yamamoto
    • 1
    Email author
  • Nobukazu Seama
    • 2
  • Nobuhiro Isezaki
    • 3
  1. 1.Earth and Atmospheric SciencesCornell UniversityIthacaUSA
  2. 2.Research Center for Inland SeasKobe UniversityKobeJapan
  3. 3.Department of Earth ScienceChiba UniversityChibaJapan

Personalised recommendations