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Three-dimensional magnetization vector inversion of a seamount
Earth, Planets and Space volume 57, pages691–699(2005)
A three-dimensional non-uniform magnetic modeling is proposed to obtain information about a magnetization of a seamount, which was divided into many blocks modeled by layered and rectangular prisms, and parameters were assigned to each block describing magnetic three components. Our data were the magnetic total force on the sea. A set of linear observation equations was formulated in terms of three components of magnetization for each block. The solution was obtained by using the conjugate gradients method because of its fast and accurate advantages of calculation. In this inversion, a common set of three components was defined for several blocks to decrease the number of unknown parameters. A computer program has been tested with artificial data and applied to data of Daiichi Kashima Seamount observed during the first phase of the Kaiko project carried out with the R/V Jean Charcot in 1984. In the real application, the crustal structure was divided into three layers (top depth to 5 km depth, 5–6.5 km depth and 6.5–8 km depth). The result of the inversion shows that the top portion and the submerged western half of this seamount are covered with the low magnetization layers, and in the middle layer (5–6.5 km depth) of eastern half side, declinations, inclinations and intensities are almost northward, 15° and 3–5 A/m, respectively. In the third layer (6.5–8 km depth), the reverse magnetizations are revealed in the southeastern and northern sides of Daiichi Kashima Seamount and around Katori Seamount. These reverse magnetizations may reflect part of the magnetic lineations of the Pacific plate.
Bhattacharyya, B. K., Magnetic Anomalies due to prism-shaped bodies with arbitrary polarization, Geophysics, 29, 517–531, 1964.
Bjorch, A. and T. Elfving, Accelerated projection methods for computing pseudo inverse solutions of systems of linear equations, BIT, 19, 145–163, 1979.
Gee, J. S. and M. Nakanishi, Magnetic petrology and magnetic properties of western Pacific guyots: implications for seamount paleopoles, Proc. ODP Sci. Results, 144, 615–630, 1995.
Ishikawa, H. and N. Den, Analysis of geomagnetism of Daiichi-Kashima Seamount, Proc., SEGJ Conference, 71, 102–103, 1984.
Kaiko I Research Group, Topography and structure of trenches around Japan, Data of the Franco-Japanese Kaiko Project, Phase I, 305 pp., Ocean Res. Inst. Tokyo, 1986.
Kobayashi, K., J. P. Cadet, J. Aubouin, J. Boulegue, J. Dubois, R. Huene, L. Jolivet, T. Kanazawa, J. Kasahara, K. Koizumi, S. Lallemand, Y. Nakamura, G. Pautot, K. Suyehiro, S. Tani, H. Tokuyama, and T. Yamazaki, Normal faulting of the Daiichi-Kashima Seamount in the Japan Trench revealed by the Kaiko I cruise, Leg 3, Earth Planet. Sci. Lett., 83, 257–266, 1987.
Koppers, A. A. P., J. P. Morgan, J. W. Morgan, and H. Staudigel, Testing the fixed hotspot hypothesis using 40Ar/39Ar age progressions along seamount trails, Earth Planet. Sci. Lett., 185, 237–252, 2001.
Kubota, R., Y. Ueda, and K. Onodera, On the method of the three dimensional geomagnetic inversion, Proc., SEGJ Conference, 104, 309–313, 2001.
Le Pichon, X., K. Kobayashi, J. P. Cadet, T. Iiyama, K. Nakamura, G. Pautot, V. Renard, and the Kaiko Scientific Crew, Project Kaiko—Introduction, Earth Planet. Sci. Lett., 83, 183–185, 1987.
Mogi, A. and K. Nishizawa, Breakdown of a seamount on the bottom of the Japan Trench, Proc. Japan Acad., 56(5), Ser. B, 1980.
Nakanishi, M., Topographic expression of five fracture zones in the Northwestern Pacific Ocean, Geophysical Monograph, 77, 121–136, 1993.
Nakanishi, M. and J. S. Gee, Paleomagnetic investigations of volcanic ai]rocks of LEG 144 volcanic rocks: Paleolatitudes of the northwestern Pacific guyots, Proc. ODP Sci. Results, 144, 585–604, 1995.
Nakanishi, M., K. Tamaki, and K. Kobayashi, Mesozoic magnetic anomaly lineations and seafloor spreading history of the northwestern Pacific, J. Geophys. Res., 94, 15437–15462, 1989.
Parker, R. L., L. Shure, and J. A. Hildebrand, The application of inverse theory to seamount magnetism, Review of Geophysics, 25, 17–40, 1987.
Research Group for Daiichi-Kashima Seamount of Tokai University, Daiichi-Kashima Seamount, pp. 79–100, Tokai University Press, 1985.
Talwani, M., Computation with the help of a digital computer of magnetic anomalies caused by bodies of arbitrary shape, Geophysics, 30, 797–817, 1965.
Ueda, Y., Geomagnetic study on Seamounts Daiiti-Kasima and Katori with special reference to a subduction process of Daiiti-Kasima, J. Geomag. Geoelectr., 37, 601–625, 1985.
Ueda, Y., H. Nakagawa, K. Onodera, A. Suzuki, K. Kumagawa, and R. Kubota, 3D-geomagnetic structure of Miyake-jima Volcano before the eruption in 2000: an application of 3D-geomagnetic tomography method, Rept. Hydrogr. Res., 37, 19–36, 2001 (in Japanese with English abstract).
Vacquier, V., A machine method for computing the magnetization of a uniformly magnetized body from its shape and a magnetic survey, pp. 123–137, Benedum Earth Magnetism symposium, University of Pittsburgh Press, Pittsburgh, Pa., 1962.
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Kubota, R., Uchiyama, A. Three-dimensional magnetization vector inversion of a seamount. Earth Planet Sp 57, 691–699 (2005). https://doi.org/10.1186/BF03351849
- Magnetization vector
- magnetic modeling
- non-uniform magnetization