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Results from a magnetic survey and geomagnetic depth sounding in the post-eruption phase of the Barren Island volcano

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Abstract

The Geological Survey of India conducted a magnetic survey and geological studies in 1993 around Barren Island in the Andaman Sea on board the RV Samudra Manthan. Five ocean bottom magnetometers were deployed by the Indian Institute of Geomagnetism as a part of this cruise. The Curie isotherm profiles prepared from the seasurface magnetic data indicate a high heat flow in the east of Barren Island. These profiles also indicate the presence of a north-south structural barrier which has prevented upflow of volcanic material to the west of Barren Island. Ocean-bottom magnetometer data were recorded simultaneously at five sites for about 15 days and these have been used to determine the electrical conductivity structure beneath Barren Island. Magnetic variations recorded at the seafloor stations indicate a concentration of electric currents near the island instead of the usual effect where currents are deflected away from the island. Transfer functions, showing the relationship between the horizontal components of the seafloor stations and land station, have been computed and the quantitative estimates of the transfer functions across Barren Island indicate a high conducting zone at a depth of about 17–27 km. This zone may have been produced by an upwelling of the mantle material through the magma chamber. The structure of this conductive zone at the north and south of Barren Island seems to concentrate the flow of the subsurface electrical currents within the island and the current flow takes a sharp southward turn beneath the island. This north-south conducting zone may have caused a rise in the depth of the Curie isotherm mapped by a shipborne magnetic survey of this region. Most probably, a partial melting of this conductive zone (magma chamber) may have given rise to the volcanic activity on Barren Island.

References

  1. Agarwal, A. K. and J. T. Weaver, Regional electromagnetic induction around the Indian peninsula and Srilanka: a three-dimensional numerical model study using the thin sheet approximation, Phys. Earth. Planet. Sci., 54, 310–321, 1989.

  2. Beblo, M. and A. Bjornsson, Magnetotelluric investigation of the lower crust and upper mantle beneath Iceland, J. Geophys., 45, 1–16, 1978.

  3. Chhibber, H. L., Geology of Burma, 538 pp., Macmillan & Co., London, 1934.

  4. Cianciara, B. and H. Mareek, Geophysical anomaly interpretation of potential fields by means of singular point method and filtering, Geophys. Prosp., 27, 251–260, 1979.

  5. Cochrane, N. A. and R. D. Hyndman, A new analysis of geomagnetic depth sounding from western Canada, Can. J. Earth. Sci., 7, 1208–1218, 1970.

  6. Condie, K. C., Plate Tectonics and Crustal Evolution, 3rd ed., 476 pp., Pergamon Press, Oxford, England, 1982.

  7. Cox, C., J. H. Filloux, and J. Larsen, Electromagnetic studies of ocean currents and electrical conductivity below the ocean floor, in The Sea, 4, pp. 637–693, Wiley, New York, 1970.

  8. Cox, C., J. H. Filloux, D. I. Gough, J. Larsen, K. Poehls, R. V. Herzen, and R. Winter, Atlantic lithosphere sounding, J. Geomag. Geoelectr., 32, Suppl., 13–32, 1980.

  9. Curray, J. R., D. G. Moore, L. A. Lawyer, F. J. Emmel, R. W. Raitt, M. Henry, and R. Kieckhefer, Tectonics of the Andaman Sea and Burma, in Geological and Geophysical Investigations of Continental Margins, edited by J. S. Watkins et al., AAPG Memoir., 29, 29, 189–198, 1979.

  10. Curray, J. R., F. J. Emmel, D. G. Moore, and R. W. Raitt, Structure, tectonics and geological history of the north eastern Indian Ocean, in The Ocean Basins and Margins, 6, edited by A. E. M. Nairn and F. G. Stehli, pp. 399-450, Plenum Publn., New York, 1982.

  11. Dasgupta, S. and M. Mukhopadhyay, Seismicity and plate deformation below the Andaman arc, northeast Indian ocean, Tectonophysics, 225, 529–542, 1993.

  12. Davies, A. R., On the maximum likelyhood regularization of fredholm convolution equations of the first kind, in Treatment of Integral Equations by Numerical Methods, edited by C. T. Baker and G. F. Miller, pp. 95–105, Academic Press, New York, 1982.

  13. Dawson, T. W. and J. T. Weaver, Three dimensional induction in a nonuniform thin sheet at the surface of a uniformally conducting earth, Geophys. J. R. Astron. Soc., 59, 445–462, 1979.

  14. Eguchi, T., S. Uyeda, and T. Maki, Seismotectonics and tectonic history of the Andaman Sea, Tectonophysics, 57, 35–51, 1979.

  15. EMSLAB group, The EMSLAB electromagnetic sounding experiment, EOS, Trans., 69, 173–194, 1988.

  16. Ferguson, I. J., F. E. M. Lilley, and J. H. Filloux, Geomagnetic induction in the Tasman Sea and electrical conductivity structure beneath the Tasman Sea floor, Geophys. J. Int., 102, 299–312, 1990.

  17. Filloux, J. H., Oceanic electric currents, geomagnetic variations and deep electrical conductivity structure of the ocean continent transition of Central California, Ph.D. Thesis, Scripps. Inst. of Oceanogr., Univ. of Calif., San Diego, 1967.

  18. Filloux, J. H., Ocean-floor magnetotelluric sounding over north-central Pacific, Nature, 269, 297–301, 1977.

  19. Fisher, R. A., Statistical Methods for Research Workers, 13th ed., 356 pp., Hafner, New York, 1958.

  20. Heinson, G. S. and F. E. M. Lilley, Thin sheet EM modelling of Tasman Sea, Explor. Geophys., 20, 177–180, 1989.

  21. Hermance, J. F. and G. D. Garland, Deep electrical structure under Iceland, J. Geophys. Res., 74, 3797–3800, 1968.

  22. Jozwick, W. and D. Beamish, A thin sheet model of electromagnetic induction in northern England and southern Scotland, Geophys. J. R. Astron. Soc., 85, 629–643, 1986.

  23. Kumar, M. R., N. Purnachandra Rao, and S. V. Chalam, A seismotectonic study of the Burma and Andaman arc regions using centroid moment tensor data, Tectonophysics, 253, 155–165, 1996.

  24. Lilley, F. E. M., J. H. Filloux, I. J. Ferguson, N. L. Bindoff, and P. J. Mulhearn, The Tasman project of seafloor magnetotelluric exploration: experiment and observation, Phys. Earth Planet. Inter., 53, 405–421, 1989.

  25. Mukhopadhyay, M., Seismotectonics of subduction and backarc rifting under the Andaman Sea, Tectonophysics, 108, 229–239, 1984.

  26. Mukhopadhyay, M., Gravity anomalies and deep structure of the Andaman arc, Mar. Geophys. Res., 9, 197–210, 1988.

  27. Mukhopadhyay, M. and M. R. Krishna, Gravity field and deep structure of the Bengal fan and its surrounding continental margins, northeast Indian Ocean, Tectonophysics, 186, 365–386, 1991.

  28. Pederson, L. B., Relation between potential fields and some equivalent sources, Geophysics, 56, 961–971, 1991.

  29. Peter, G., L. A. Weeks, and R. E. Burns, A reconnaissance geophysical survey in the Andaman Sea and across the Andaman-Nicobar Island arc, J. Geophys. Res., 71(2), 495–509, 1966.

  30. Phoels, K. A. and R. P. Von Herzen, Electrical resistivity structure beneath the northwest Atlantic Ocean, Geophys. J. R. Astron. Soc., 47, 331–347, 1976.

  31. Price, A. T., The induction of electric current in non-uniform thin sheet and shells, Q. J. Mech. Appl. Math., 2, 283–310, 1949.

  32. Price, A. T., The theory of geomagnetic induction, Phys. Earth Planet. Inter., 7, 227–273, 1973.

  33. Rodolfo, K. S., Bathymetry and marine geology of the Andaman basin and tectonic implications for SE Asia, Am. Assoc. Pet. Geol. Bull., 52, 2422–2437, 1969.

  34. Schmucker, U., Anomalies of geomagnetic variations in the southwestern United States, Bull. Scrips. Inst. Oceanogr., 13, 1–165, 1970.

  35. Schmucker, U., Interpretation of induction anomalies above non-uniform surface layers, Geophysics, 36, 156–165, 1971.

  36. Schmucker, U., Electromagnetic induction in thin sheets: integral equations and model studies in two dimensions, Geophys. J. Int., 121, 173–190, 1995.

  37. Segawa, J., Y. Hamano, H. Utada, and H. Toh, A sea floor magnetometer model OBM-S4, J. Geod. Soc. Japan, 32, 248–273, 1986.

  38. Shankland, T. J. and H. S. Waff, Partial melting and conductivity anomalies in the upper mantle, J. Geophys. Res., 82, 5409–5417, 1977.

  39. Shimakawa, Y. and Y. Honkura, Electrical conductivity structure beneath the Ryukyu Trench-Arc system and its relation to the Philippine Sea Plate, J. Geomag. Geoelectr., 43, 1–20, 1991.

  40. Treitel, S., W. O. Clement, and R. K. Kaul, The spectral determination of the depths to burried magnetic basement rocks, Geophys. J. R. Astron. Soc., 24, 415–428, 1971.

  41. Vasseur, G. and P. Weidelt, Bimodal electromagnetic induction in nonuniform thin sheet with an application to the northern Pyrenean induction anomaly, Geophys. J. R. Astron. Soc., 51, 445–462, 1977.

  42. Weaver, J. T., Regional induction in Scotland; An example of three dimensional numerical modeling using the thin sheet approximation, Phys. Earth Planet. Inter., 28, 161–180, 1982.

  43. Yukutake, T., J. H. Filloux, J. Segawa, Y. Hamano, and H. Utada, Preliminary report on a magnetotelluric array study in the northwest Pacific, J. Geomag. Geoelectr., 35, 575–587, 1983.

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Correspondence to B. Banerjee.

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Banerjee, B., Rao, P.B.V.S., Gupta, G. et al. Results from a magnetic survey and geomagnetic depth sounding in the post-eruption phase of the Barren Island volcano. Earth Planet Sp 50, 327–338 (1998) doi:10.1186/BF03352119

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Keywords

  • Magma Chamber
  • Magnetic Survey
  • Magnetic Profile
  • Curie Depth
  • Curie Isotherm