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161. Overview of first Wendelstein 7-X high-performance operation

Author

Klinger, T., primary, Andreeva, T., additional, Bozhenkov, S., additional, Brandt, C., additional, Burhenn, R., additional, Buttenschön, B., additional, Fuchert, G., additional, Geiger, B., additional, Grulke, O., additional, Laqua, H.P., additional, Pablant, N., additional, Rahbarnia, K., additional, Stange, T., additional, von Stechow, A., additional, Tamura, N., additional, Thomsen, H., additional, Turkin, Y., additional, Wegner, T., additional, Abramovic, I., additional, Äkäslompolo, S., additional, Alcuson, J., additional, Aleynikov, P., additional, Aleynikova, K., additional, Ali, A., additional, Alonso, A., additional, Anda, G., additional, Ascasibar, E., additional, Bähner, J.P., additional, Baek, S.G., additional, Balden, M., additional, Baldzuhn, J., additional, Banduch, M., additional, Barbui, T., additional, Behr, W., additional, Beidler, C., additional, Benndorf, A., additional, Biedermann, C., additional, Biel, W., additional, Blackwell, B., additional, Blanco, E., additional, Blatzheim, M., additional, Ballinger, S., additional, Bluhm, T., additional, Böckenhoff, D., additional, Böswirth, B., additional, Böttger, L.-G., additional, Borchardt, M., additional, Borsuk, V., additional, Boscary, J., additional, Bosch, H.-S., additional, Beurskens, M., additional, Brakel, R., additional, Brand, H., additional, Bräuer, T., additional, Braune, H., additional, Brezinsek, S., additional, Brunner, K.-J., additional, Bussiahn, R., additional, Bykov, V., additional, Cai, J., additional, Calvo, I., additional, Cannas, B., additional, Cappa, A., additional, Carls, A., additional, Carralero, D., additional, Carraro, L., additional, Carvalho, B., additional, Castejon, F., additional, Charl, A., additional, Chaudhary, N., additional, Chauvin, D., additional, Chernyshev, F., additional, Cianciosa, M., additional, Citarella, R., additional, Claps, G., additional, Coenen, J., additional, Cole, M., additional, Cole, M.J., additional, Cordella, F., additional, Cseh, G., additional, Czarnecka, A., additional, Czerski, K., additional, Czerwinski, M., additional, Czymek, G., additional, da Molin, A., additional, da Silva, A., additional, Damm, H., additional, de la Pena, A., additional, Degenkolbe, S., additional, Dhard, C.P., additional, Dibon, M., additional, Dinklage, A., additional, Dittmar, T., additional, Drevlak, M., additional, Drewelow, P., additional, Drews, P., additional, Durodie, F., additional, Edlund, E., additional, van Eeten, P., additional, Effenberg, F., additional, Ehrke, G., additional, Elgeti, S., additional, Endler, M., additional, Ennis, D., additional, Esteban, H., additional, Estrada, T., additional, Fellinger, J., additional, Feng, Y., additional, Flom, E., additional, Fernandes, H., additional, Fietz, W.H., additional, Figacz, W., additional, Fontdecaba, J., additional, Ford, O., additional, Fornal, T., additional, Frerichs, H., additional, Freund, A., additional, Funaba, T., additional, Galkowski, A., additional, Gantenbein, G., additional, Gao, Y., additional, García Regaña, J., additional, Gates, D., additional, Geiger, J., additional, Giannella, V., additional, Gogoleva, A., additional, Goncalves, B., additional, Goriaev, A., additional, Gradic, D., additional, Grahl, M., additional, Green, J., additional, Greuner, H., additional, Grosman, A., additional, Grote, H., additional, Gruca, M., additional, Guerard, C., additional, Hacker, P., additional, Han, X., additional, Harris, J.H., additional, Hartmann, D., additional, Hathiramani, D., additional, Hein, B., additional, Heinemann, B., additional, Helander, P., additional, Henneberg, S., additional, Henkel, M., additional, Hernandez Sanchez, J., additional, Hidalgo, C., additional, Hirsch, M., additional, Hollfeld, K.P., additional, Höfel, U., additional, Hölting, A., additional, Höschen, D., additional, Houry, M., additional, Howard, J., additional, Huang, X., additional, Huang, Z., additional, Hubeny, M., additional, Huber, M., additional, Hunger, H., additional, Ida, K., additional, Ilkei, T., additional, Illy, S., additional, Israeli, B., additional, Jablonski, S., additional, Jakubowski, M., additional, Jelonnek, J., additional, Jenzsch, H., additional, Jesche, T., additional, Jia, M., additional, Junghanns, P., additional, Kacmarczyk, J., additional, Kallmeyer, J.-P., additional, Kamionka, U., additional, Kasahara, H., additional, Kasparek, W., additional, Kazakov, Y.O., additional, Kenmochi, N., additional, Killer, C., additional, Kirschner, A., additional, Kleiber, R., additional, Knauer, J., additional, Knaup, M., additional, Knieps, A., additional, Kobarg, T., additional, Kocsis, G., additional, Köchl, F., additional, Kolesnichenko, Y., additional, Könies, A., additional, König, R., additional, Kornejew, P., additional, Koschinsky, J.-P., additional, Köster, F., additional, Krämer, M., additional, Krampitz, R., additional, Krämer-Flecken, A., additional, Krawczyk, N., additional, Kremeyer, T., additional, Krom, J., additional, Krychowiak, M., additional, Ksiazek, I., additional, Kubkowska, M., additional, Kühner, G., additional, Kurki-Suonio, T., additional, Kurz, P.A., additional, Kwak, S., additional, Landreman, M., additional, Lang, P., additional, Lang, R., additional, Langenberg, A., additional, Langish, S., additional, Laqua, H., additional, Laube, R., additional, Lazerson, S., additional, Lechte, C., additional, Lennartz, M., additional, Leonhardt, W., additional, Li, C., additional, Li, Y., additional, Liang, Y., additional, Linsmeier, C., additional, Liu, S., additional, Lobsien, J.-F., additional, Loesser, D., additional, Loizu Cisquella, J., additional, Lore, J., additional, Lorenz, A., additional, Losert, M., additional, Lücke, A., additional, Lumsdaine, A., additional, Lutsenko, V., additional, Maaßberg, H., additional, Marchuk, O., additional, Matthew, J.H., additional, Marsen, S., additional, Marushchenko, M., additional, Masuzaki, S., additional, Maurer, D., additional, Mayer, M., additional, McCarthy, K., additional, McNeely, P., additional, Meier, A., additional, Mellein, D., additional, Mendelevitch, B., additional, Mertens, P., additional, Mikkelsen, D., additional, Mishchenko, A., additional, Missal, B., additional, Mittelstaedt, J., additional, Mizuuchi, T., additional, Mollen, A., additional, Moncada, V., additional, Mönnich, T., additional, Morisaki, T., additional, Moseev, D., additional, Murakami, S., additional, Náfrádi, G., additional, Nagel, M., additional, Naujoks, D., additional, Neilson, H., additional, Neu, R., additional, Neubauer, O., additional, Neuner, U., additional, Ngo, T., additional, Nicolai, D., additional, Nielsen, S.K., additional, Niemann, H., additional, Nishizawa, T., additional, Nocentini, R., additional, Nührenberg, C., additional, Nührenberg, J., additional, Obermayer, S., additional, Offermanns, G., additional, Ogawa, K., additional, Ölmanns, J., additional, Ongena, J., additional, Oosterbeek, J.W., additional, Orozco, G., additional, Otte, M., additional, Pacios Rodriguez, L., additional, Panadero, N., additional, Panadero Alvarez, N., additional, Papenfuß, D., additional, Paqay, S., additional, Pasch, E., additional, Pavone, A., additional, Pawelec, E., additional, Pedersen, T.S., additional, Pelka, G., additional, Perseo, V., additional, Peterson, B., additional, Pilopp, D., additional, Pingel, S., additional, Pisano, F., additional, Plaum, B., additional, Plunk, G., additional, Pölöskei, P., additional, Porkolab, M., additional, Proll, J., additional, Puiatti, M.-E., additional, Puig Sitjes, A., additional, Purps, F., additional, Rack, M., additional, Récsei, S., additional, Reiman, A., additional, Reimold, F., additional, Reiter, D., additional, Remppel, F., additional, Renard, S., additional, Riedl, R., additional, Riemann, J., additional, Risse, K., additional, Rohde, V., additional, Röhlinger, H., additional, Romé, M., additional, Rondeshagen, D., additional, Rong, P., additional, Roth, B., additional, Rudischhauser, L., additional, Rummel, K., additional, Rummel, T., additional, Runov, A., additional, Rust, N., additional, Ryc, L., additional, Ryosuke, S., additional, Sakamoto, R., additional, Salewski, M., additional, Samartsev, A., additional, Sanchez, E., additional, Sano, F., additional, Satake, S., additional, Schacht, J., additional, Satheeswaran, G., additional, Schauer, F., additional, Scherer, T., additional, Schilling, J., additional, Schlaich, A., additional, Schlisio, G., additional, Schluck, F., additional, Schlüter, K.-H., additional, Schmitt, J., additional, Schmitz, H., additional, Schmitz, O., additional, Schmuck, S., additional, Schneider, M., additional, Schneider, W., additional, Scholz, P., additional, Schrittwieser, R., additional, Schröder, M., additional, Schröder, T., additional, Schroeder, R., additional, Schumacher, H., additional, Schweer, B., additional, Scott, E., additional, Sereda, S., additional, Shanahan, B., additional, Sibilia, M., additional, Sinha, P., additional, Sipliä, S., additional, Slaby, C., additional, Sleczka, M., additional, Smith, H., additional, Spiess, W., additional, Spong, D.A., additional, Spring, A., additional, Stadler, R., additional, Stejner, M., additional, Stephey, L., additional, Stridde, U., additional, Suzuki, C., additional, Svensson, J., additional, Szabó, V., additional, Szabolics, T., additional, Szepesi, T., additional, Szökefalvi-Nagy, Z., additional, Tancetti, A., additional, Terry, J., additional, Thomas, J., additional, Thumm, M., additional, Travere, J.M., additional, Traverso, P., additional, Tretter, J., additional, Trimino Mora, H., additional, Tsuchiya, H., additional, Tsujimura, T., additional, Tulipán, S., additional, Unterberg, B., additional, Vakulchyk, I., additional, Valet, S., additional, Vano, L., additional, van Milligen, B., additional, van Vuuren, A.J., additional, Vela, L., additional, Velasco, J.-L., additional, Vergote, M., additional, Vervier, M., additional, Vianello, N., additional, Viebke, H., additional, Vilbrandt, R., additional, Vorköper, A., additional, Wadle, S., additional, Wagner, F., additional, Wang, E., additional, Wang, N., additional, Wang, Z., additional, Warmer, F., additional, Wauters, T., additional, Wegener, L., additional, Weggen, J., additional, Wei, Y., additional, Weir, G., additional, Wendorf, J., additional, Wenzel, U., additional, Werner, A., additional, White, A., additional, Wiegel, B., additional, Wilde, F., additional, Windisch, T., additional, Winkler, M., additional, Winter, A., additional, Winters, V., additional, Wolf, S., additional, Wolf, R.C., additional, Wright, A., additional, Wurden, G., additional, Xanthopoulos, P., additional, Yamada, H., additional, Yamada, I., additional, Yasuhara, R., additional, Yokoyama, M., additional, Zanini, M., additional, Zarnstorff, M., additional, Zeitler, A., additional, Zhang, D., additional, Zhang, H., additional, Zhu, J., additional, Zilker, M., additional, Zocco, A., additional, Zoletnik, S., additional, and Zuin, M., additional

Published
2019
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171. Plasma parameter profile inference from limited data utilizing second-order derivative priors and physic-based constraints.

Author

Nishizawa, T., Cavedon, M., Dux, R., Reimold, F., and Toussaint, U. von

Subjects
*MONTE Carlo method, *MARKOV chain Monte Carlo, *LAXATIVES, *KRIGING, *GAUSSIAN processes, *PLASMA diagnostics
Abstract

A Bayesian framework has been used to improve the quality of inferred plasma parameter profiles. An integrated data analysis allows for coherent combinations of different diagnostics, and Gaussian process regression provides a reliable regularization process and systematic uncertainty estimation. In this paper, we propose a new profile inference framework that utilizes our prior knowledge about plasma physics, along with integrated data analysis and a Gaussian process. In order to facilitate the use of the Markov chain Monte Carlo sampling, we use a Gaussian process to define quantities corresponding to the second derivatives of the profiles. We validate the analysis technique by using a synthetic one-dimensional plasma, in which the transport properties are known and demonstrate that the proposed analysis technique can infer plasma parameter profiles from line-integrated measurements only. Furthermore, we can even infer unknown parameters in our physics models when our physics knowledge on the system is incomplete. This analysis framework is applicable to laboratory plasmas and provides a means to investigate plasma parameters, to which standard diagnostics are not directly sensitive. [ABSTRACT FROM AUTHOR]

Published
2021
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173. Dependence of Perpendicular Viscosity on Magnetic Fluctuations in a Stochastic Topology

Author

Fridström, Richard, Chapman, B. E., Almagri, A. F., Frassinetti, Lorenzo, Brunsell, Per R., Nishizawa, T., Sarff, J. S., Fridström, Richard, Chapman, B. E., Almagri, A. F., Frassinetti, Lorenzo, Brunsell, Per R., Nishizawa, T., and Sarff, J. S.

Abstract

In a magnetically confined plasma with a stochastic magnetic field, the dependence of the perpendicular viscosity on the magnetic fluctuation amplitude is measured for the first time. With a controlled, similar to tenfold variation in the fluctuation amplitude, the viscosity increases similar to 100-fold, exhibiting the same fluctuation-amplitude-squared dependence as the predicted rate of stochastic field line diffusion. The absolute value of the viscosity is well predicted by a model based on momentum transport in a stochastic field, the first in-depth test of this model., QC 20180614

Published
2018
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175. Performance of Wendelstein 7-X stellarator plasmas during the first divertor operation phase

Author

Wolf, R. C., Alonso, A., Akaslompolo, S., Baldzuhn, J., Beurskens, M., Beidler, C. D., Biedermann, C., Bosch, H. -S., Bozhenkov, S., Brakel, R., Braune, H., Brezinsek, S., Brunner, K. -J., Damm, H., Dinklage, A., Drewelow, P., Effenberg, F., Feng, Y., Ford, O., Fuchert, G., Gao, Y., Geiger, J., Grulke, O., Harder, N., Hartmann, D., Helander, P., Heinemann, B., Hirsch, M., Hofel, U., Hopf, C., Ida, K., Isobe, M., Jakubowski, M. W., Kazakov, Y. O., Killer, C., Klinger, T., Knauer, J., Konig, R., Krychowiak, M., Langenberg, A., Laqua, H. P., Lazerson, S., Mcneely, P., Marsen, S., Marushchenko, N., Nocentini, R., Ogawa, K., Orozco, G., Osakabe, M., Otte, M., Pablant, N., Pasch, E., Pavone, A., Porkolab, M., Puig Sitjes, A., Rahbarnia, K., Riedl, R., Rust, N., Scott, E., Schilling, J., Schroeder, R., Stange, T., Von Stechow, A., Strumberger, E., Sunn Pedersen, T., Svensson, J., Thomson, H., Turkin, Y., Vano, L., Wauters, T., Wurden, G., Yoshinuma, M., Zanini, M., Zhang, D., Andreeva, T., Brandt, C., Burhenn, R., Buttenschon, B., Geiger, B., Tamura, N., Thomsen, H., Wegner, T., Abramovic, I., Alcuson, J., Aleynikov, P., Aleynikova, K., Ali, A., Anda, G., Ascasibar, E., Bahner, J. P., Baek, S. G., Balden, M., Banduch, M., Barbui, T., Behr, W., Beidler, C., Benndorf, A., Biel, W., Blackwell, B., Blanco, E., Blatzheim, M., Ballinger, S., Bluhm, T., Bockenhoff, D., Boswirth, B., Bottger, L. -G., Borchardt, M., Borsuk, V., Boscary, J., Brand, H., Brauer, T., Bussiahn, R., Bykov, V., Cai, J., Calvo, I., Cannas, B., Cappa, A., Carls, A., Carralero, D., Carraro, L., Carvalho, B., Castejon, F., Charl, A., Chaudhary, N., Chauvin, D., Chernyshev, F., Cianciosa, M., Citarella, R., Claps, G., Coenen, J., Cole, M., Cole, M. J., Cordella, F., Cseh, G., Czarnecka, A., Czerski, K., Czerwinski, M., Czymek, G., Da Molin, A., Da Silva, A., De La Pena, A., Degenkolbe, S., Dhard, C. P., Dibon, M., Dittmar, T., Drevlak, M., Drews, P., Durodie, F., Edlund, E., Van Eeten, P., Ehrke, G., Elgeti, S., Endler, M., Ennis, D., Esteban, H., Estrada, T., Fellinger, J., Flom, E., Fernandes, H., Fietz, W. H., Figacz, W., Fontdecaba, J., Fornal, T., Frerichs, H., Freund, A., Funaba, T., Galkowski, A., Gantenbein, G., Garcia Regana, J., Gates, D., Giannella, V., Gogoleva, A., Goncalves, B., Goriaev, A., Gradic, D., Grahl, M., Green, J., Greuner, H., Grosman, A., Grote, H., Gruca, M., Guerard, C., Hacker, P., Han, X., Harris, J. H., Hathiramani, D., Hein, B., Henneberg, S., Henkel, M., Hernandez Sanchez, J., Hidalgo, C., Hollfeld, K. P., Holting, A., Hoschen, D., Houry, M., Howard, J., Huang, X., Huang, Z., Hubeny, M., Huber, M., Hunger, H., Ilkei, T., Illy, S., Israeli, B., Jablonski, S., Jakubowski, M., Jelonnek, J., Jenzsch, H., Jesche, T., Jia, M., Junghanns, P., Kacmarczyk, J., Kallmeyer, J. -P., Kamionka, U., Kasahara, H., Kasparek, W., Kenmochi, N., Kirschner, A., Kleiber, R., Knaup, M., Knieps, A., Kobarg, T., Kocsis, G., Kochl, F., Kolesnichenko, Y., Konies, A., Kornejew, P., Koschinsky, J. -P., Koster, F., Kramer, M., Krampitz, R., Kramer-Flecken, A., Krawczyk, N., Kremeyer, T., Krom, J., Ksiazek, I., Kubkowska, M., Kuhner, G., Kurki-Suonio, T., Kurz, P. A., Kwak, S., Landreman, M., Lang, P., Lang, R., Langish, S., Laqua, H., Laube, R., Lechte, C., Lennartz, M., Leonhardt, W., Li, C., Li, Y., Liang, Y., Linsmeier, C., Liu, S., Lobsien, J. -F., Loesser, D., Loizu Cisquella, J., Lore, J., Lorenz, A., Losert, M., Lucke, A., Lumsdaine, A., Lutsenko, V., Maassberg, H., Marchuk, O., Matthew, J. H., Marushchenko, M., Masuzaki, S., Maurer, D., Mayer, M., Mccarthy, K., Meier, A., Mellein, D., Mendelevitch, B., Mertens, P., Mikkelsen, D., Mishchenko, A., Missal, B., Mittelstaedt, J., Mizuuchi, T., Mollen, A., Moncada, V., Monnich, T., Morisaki, T., Moseev, D., Murakami, S., Nafradi, G., Nagel, M., Naujoks, D., Neilson, H., Neu, R., Neubauer, O., Neuner, U., Ngo, T., Nicolai, D., Nielsen, S. K., Niemann, H., Nishizawa, T., Nuhrenberg, C., Nuhrenberg, J., Obermayer, S., Offermanns, G., Olmanns, J., Ongena, J., Oosterbeek, J. W., Pacios Rodriguez, L., Panadero, N., Panadero Alvarez, N., Papenfuss, D., Paqay, S., Pawelec, E., Pedersen, T. S., Pelka, G., Perseo, V., Peterson, B., Pilopp, D., Pingel, S., Pisano, F., Plaum, B., Plunk, G., Poloskei, P., Proll, J., Puiatti, M. -E., Purps, F., Rack, M., Recsei, S., Reiman, A., Reimold, F., Reiter, D., Remppel, F., Renard, S., Riemann, J., Risse, K., Rohde, V., Rohlinger, H., Rome, M., Rondeshagen, D., Rong, P., Roth, B., Rudischhauser, L., Rummel, K., Rummel, T., Runov, A., Ryc, L., Ryosuke, S., Sakamoto, R., Salewski, M., Samartsev, A., Sanchez, E., Sano, F., Satake, S., Schacht, J., Satheeswaran, G., Schauer, F., Scherer, T., Schlaich, A., Schlisio, G., Schluck, F., Schluter, K. -H., Schmitt, J., Schmitz, H., Schmitz, O., Schmuck, S., Schneider, M., Schneider, W., Scholz, P., Schrittwieser, R., Schroder, M., Schroder, T., Schumacher, H., Schweer, B., Sereda, S., Shanahan, B., Sibilia, M., Sinha, P., Siplia, S., Slaby, C., Sleczka, M., Smith, H., Spiess, W., Spong, D. A., Spring, A., Stadler, R., Stejner, M., Stephey, L., Stridde, U., Suzuki, C., Szabo, V., Szabolics, T., Szepesi, T., Szokefalvi-Nagy, Z., Tancetti, A., Terry, J., Thomas, J., Thumm, M., Travere, J. M., Traverso, P., Tretter, J., Trimino Mora, H., Tsuchiya, H., Tsujimura, T., Tulipan, S., Unterberg, B., Vakulchyk, I., Valet, S., Van Milligen, B., Van Vuuren, A. J., Vela, L., Velasco, J. -L., Vergote, M., Vervier, M., Vianello, N., Viebke, H., Vilbrandt, R., Vorkoper, A., Wadle, S., Wagner, F., Wang, E., Wang, N., Wang, Z., Warmer, F., Wegener, L., Weggen, J., Wei, Y., Weir, G., Wendorf, J., Wenzel, U., Werner, A., White, A., Wiegel, B., Wilde, F., Windisch, T., Winkler, M., Winter, A., Winters, V., Wolf, S., Wright, A., Xanthopoulos, P., Yamada, H., Yamada, I., Yasuhara, R., Yokoyama, M., Zarnstorff, M., Zeitler, A., Zhang, H., Zhu, J., Zilker, M., Zocco, A., Zoletnik, S., Zuin, M., Science and Technology of Nuclear Fusion, Turbulence in Fusion Plasmas, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Physics, Technology, Plasma parameters, Divertor, Nuclear engineering, Plasma, Condensed Matter Physics, 01 natural sciences, 7. Clean energy, Electron cyclotron resonance, 010305 fluids & plasmas, law.invention, Magnetic field, law, 0103 physical sciences, Limiter, Wendelstein 7-X, 010306 general physics, ddc:600, Stellarator
Abstract

Wendelstein 7-X is the first comprehensively optimized stellarator aiming at good confinement with plasma parameters relevant to a future stellarator power plant. Plasma operation started in 2015 using a limiter configuration. After installing an uncooled magnetic island divertor, extending the energy limit from 4 to 80 MJ, operation continued in 2017. For this phase, the electron cyclotron resonance heating (ECRH) capability was extended to 7 MW, and hydrogen pellet injection was implemented. The enhancements resulted in the highest triple product (6.5 × 1019 keV m-3 s) achieved in a stellarator until now. Plasma conditions [Te(0) ≈ Ti(0) ≈ 3.8 keV, τE > 200 ms] already were in the stellarator reactor-relevant ion-root plasma transport regime. Stable operation above the 2nd harmonic ECRH X-mode cutoff was demonstrated, which is instrumental for achieving high plasma densities in Wendelstein 7-X. Further important developments include the confirmation of low intrinsic error fields, the observation of current-drive induced instabilities, and first fast ion heating and confinement experiments. The efficacy of the magnetic island divertor was instrumental in achieving high performance in Wendelstein 7-X. Symmetrization of the heat loads between the ten divertor modules could be achieved by external resonant magnetic fields. Full divertor power detachment facilitated the extension of high power plasmas significantly beyond the energy limit of 80 MJ.

Published
2019

188. Geochemistry of high-Mg andesitic rocks in NE Kamchatka

Author

Nishizawa T., Nakamura Hitomi, Churikova T., Gordeychik B., Ishizuka Osamu, Haraguchi Satoru, Miyazaki Takashi, Vaglarov Bogdan S., Ueki K., Toyama C., and Iwamori Hikaru

Subjects
38.37.25 Вулканология
Abstract

The northeast Kamchatka Peninsula is characterized by unique tectonic regimes: (i) the triple junction ~30 km off the east coast [1], (ii) subduction of the Emperor Seamount Chain [2], and (iii) possible asthenospheric flow between the mantle wedge and the sub-slab mantle via the edge of subducted Pacific slab [3]. Within this area, a monogenetic volcanic group occurs along the east coast, including high-Mg andesitic rocks and relatively primitive basalts (East Cones, EC [4]). We have conducted geochemical studies of the EC lavas, with bulk rock major and trace elements, Sr-Nd isotopic compositions, and K-Ar and Ar-Ar ages, based on which a possible contribution of subducted seamounts and its relation to the tectonic setting are discussed. The elemental and isotopic compositions indicate that the lavas from individual cones have distinct mantle sources with different amounts and/or compositions of slab-derived fluids. Based on mass balance, water content and melting phase relations, we estimate the melting P-T conditions to be ~1200 ℃ at 1.5 GPa, while the slab surface temperature is 620 – 730 ℃ (at 50-80 km depth). The Sr-Nd isotopic compositions is close to Late Cretaceous Emperor Seamount Chain, especially Detroit [5]. The K-Ar and Ar-Ar ages of the Middle to Late Pleistocene are consistent with the present tectonic setting after 2 Ma [6]. These results suggest that the EC lavas including high-Mg andesite and basalt were generated by mantle flux-melting induced by dehydration of a subducted seamount inheriting a local thermal anomaly [7, 8]

Published
2016

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