Bulletin of the Volcanological Society of Japan最新文献

{"title":"Temporal Variations of the Petrological Features of the Juvenile Materials during 2006 to 2010 from Showa Crater, Sakurajima Volcano, Kyushu, Japan(＜Special Section＞Sakurajima Special Issue)","authors":"A. Matsumoto, M. Nakagawa, M. Amma-Miyasaka, M. Iguchi","doi":"10.18940/KAZAN.58.1_191","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_191","url":null,"abstract":". Iguchi, M., Ohta, Y., Ueki, S., Tameguri, T., Sonoda, T., Takayama, T. and Ichikawa, N. (2011) Evaluation of volcanic activity of Sakurajima volcano in 2010. Annuals of Disas. Prev. Res. Inst., Kyoto Univ., 54, 171-184 (in Japanese with English abstract). Iguchi, M., et al. (2013) Volcanic activity and the mechanism of explosive eruptions at Showa crater of Sakurajima volcano. Bull. Volcanol. Soc. Japan, (in Japanese with English abstract, in this issue). in this issue). Kamo, K. (1978) Some phenomena before the summit eruptions at Sakura-zima volcano. Bull. Volcanol. Soc. Japan, Temporal Variations of the Petrological Features of the Juvenile Materials during 2006 to 2010 from Showa Crater, Sakurajima Volcano, Kyushu, Japan 209","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122783774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical Ground Deformation Associated with the Volcanic Activity of Sakurajima Volcano, Japan during 1996-2010 as Revealed by Repeated Precise Leveling Surveys(＜Special Section＞Sakurajima Special Issue)","authors":"Keigo Yamamoto, Tadaomi Sonoda, Tetsuro Takayama, N. Ichikawa, T. Ohkura, S. Yoshikawa, H. Inoue, T. Matsushima, K. Uchida, M. Nakamoto","doi":"10.18940/KAZAN.58.1_137","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_137","url":null,"abstract":". Ishihara, K. (1981) A quantitative relation between the ground deformation and the volcanic material ejected. Abstract, 1981 IAVCEI Symposium –Arc Volcanism–, 143. Kamo, K. (1978) Some phenomena before the summit eruptions at Sakura-zima vocano. Bull. Volcanol. Soc. Japan., 23, 53-64 (in Japanese with English abstract). Lu, Z., Dzurisin D., Biggs J., Wicks Jr. C. and McNutt, S. (2010) Ground surface deformation patterns, magma supply, and magma storages at Okmok volcano, Alaska, from InSAR analysis: 1. Interpretation deformation, 1997-2008. J. Geophy. Res., 115, B00B02, doi: 10.1029/2009JB006969. Mogi, K. (1958) Relations between the eruption of various Keigo YAMAMOTO, Tadaomi SONODA, Tetsuro TAKAYAMA, Nobuo ICHIKAWA, Takahiro OHKURA, Shin YOSHIKAWA, Hiroyuki INOUE, Takeshi MATSUSHIMA, Kazunari UCHIDA and Manami NAKAMOTO 150","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"294 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132241875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations of Color and Leachate Contents of Volcanic Ashes from Sakurajima Volcano, Japan(＜Special Section＞Sakurajima Special Issue)","authors":"I. Miyagi, H. Shinohara, J. Itoh","doi":"10.18940/KAZAN.58.1_213","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_213","url":null,"abstract":"To understand magma degassing processes near the top of volcanic conduit, we investigated a series of volcanic ashes from the Sakurajima volcano, Japan. We describe temporal changes in the color and the amount of leachates (Cl, F, S) of ash erupted from 1981 to 2011. Based on the amount of leachates present, ash samples are classified into two major groups: one is with a molar S/Cl ratio of〜10, and another with S/Cl of〜1 and that is relatively depleted in S. Ash samples that were erupted during 1981-1991 from the Minamidake summit crater belong to the latter group. Ashes erupted from the Showa crater in early 2008 belong the former group, of which the S content was found to decrease systematically through time, although in 2011, ashes of the latter group erupted for the first time from this crater. Based on coloration, the ash samples in this study are classified into two groups: one with a yellowish color, another with a less yellowish color. The coloration of the former group can be explained by the existence of yellowish native sulfur as well as other hydrothermally altered minerals. We observed positive correlations between the interval of successive eruptions and both the yellowness and the amount of ash leachates. Our interpretation is that the observed temporal changes in volcanic ash result from a transition in the amount of fumarolic sulfur accumulation in partly solidified magma near the top of volcanic conduit, which we interpret to reflect the mean residence time of the magma. The magma probably periodically renewed in response to ash eruption and/or magma convection near the top of the volcanic conduit.","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129635109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal Variation for Magmatic Chemistry of the Sakurajima Volcano and Aira Caldera Region, Southern Kyushu, Southwest Japan since 61 ka and Its Implications for the Evolution of Magma Chamber System(＜Special Section＞Sakurajima Special Issue)","authors":"Masaki Takahashi, T. Otsuka, Hisashi Sako, H. Kawamata, M. Yasui, T. Kanamaru, Mei Otsuki, Tetsuo Kobayashi, K. Ishihara, D. Miki","doi":"10.18940/KAZAN.58.1_19","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_19","url":null,"abstract":"The temporal variation of magmatic chemistry and the evolution of magma chamber system of the Sakurajima volcano and Aira caldera region since 61 ka are studied based on the whole-rock major element, incompatible trace element and rare earth element chemistry of the eruptive products. The magmas of the Sakurajima volcano and Aira caldera region since 61 ka consist of four groups: (1) basaltic to basaltic andesitic magma of the mantle origin, (2) rhyolitic to high silica rhyolitic magma of the crustal origin, (3) dacitic magma and (4) andesitic magma produced by magma mixing of the mafic magma of mantle origin and the crustal felsic magma. Around 61 to 60 ka, basaltic to basaltic andesitic, andesitic and rhyolitic magmas were active in the Aira caldera region, and the Shikine andesite and the Iwato pyroclastic flow deposit were erupted. After a dormant period of about twenty-four thousands of years, the rhyolitic magmatism resumed and the voluminous high silica rhyolitic magma erupted at 29 ka to form the large-scale Osumi pumice fall and Ito pyroclastic flow deposits. The felsic magma produced the Iwato pyroclastic flow deposit and the Osumi pumice fall and Ito pyroclastic flow deposits were similar in composition; the latter high silica rhyolite can be derived from the former rhyolite by crystallization differentiation. The rhyolitic to high silica rhyolitic magma chamber system was stable and long-lived with duration of about thirty thousands of years. The magmatic activity of the Sakurajima volcano began at 26 ka after a quiescent period of about three thousands of years. The Moeshima rhyolitic magma discharged at 13.8 ka in the Aira caldera constitute another magma chamber system different from that of the Sakurajima volcano. The magma chamber system of the Sakurajima volcano was composed of the low Ti-P type and high Ti-P type dacitic and andesitic magmas. The magma chamber system of the low Ti-P type, which was active from about 14 to 4 ka, comprises at least the three sub-systems based on the whole-rock chemistry, while that of the historical eruption since 8 th C is restricted to the high Ti-P type and consists of the three sub-systems, the youngest of which has been active since the subaqueous An-ei eruption at 1779AD. The duration of the activity of each magma chamber sub-system of the Sakurajima volcano is rather short, the time span of which is thousands to several hundreds of years.","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128268809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shallow Velocity Structure Beneath the Aira Caldera and Sakurajima Volcano as Inferred from Refraction Analysis of the Seismic Experiment in 2008(＜Special Section＞Sakurajima Special Issue)","authors":"H. Miyamachi, Chisato Tomari, H. Yakiwara, M. Iguchi, Takeshi Tameguri, Keigo Yamamoto, T. Ohkura, Takashi Ando, K. Onishi, H. Shimizu, Y. Yamashita, H. Nakamichi, T. Yamawaki, J. Oikawa, S. Ueki, T. Tsutsui, H. Mori, M. Nishida, Hideyuki Hiramatsu, T. Koeda, Y. Masuda, Kouji Katou, K. Hatakeyama, Tetsuo Kobayashi","doi":"10.18940/KAZAN.58.1_227","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_227","url":null,"abstract":"We performed refraction analysis for the first P-wave arrival time data observed in the seismic experiment in 2008, and estimated a shallow velocity model up to 3 km depth beneath the Aira caldera and Sakurajima volcano. We found that a basement layer with a velocity of 4.6-5.0 km/s, which corresponds to geologically the Shimanto Group, inclines toward the central part of the Aira caldera. A low velocity zone with a velocity of 4.2-4.4 km/s is located in a depth range 1.5-3 km in the central part of the caldera. This low velocity zone suggests high activity of the magma plumbing system from the deep magma reservoir distributed beneath the caldera. It is found that the basement layer steeply falls down from 1 km to 2.5 km in depth along the northwestern boundary of the Kagoshima graben. The velocity structure in Sakurajima volcano is characterized by a zone with a velocity of 3.6-3.7 km/s. Moreover, we present a possibility that the underground structure strongly restricts an expanse of a focal region of each different type of the volcanic earthquakes.","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132275640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Renovated Ballistic Equation of Ejected Blocks and Its Application to the 1982 and 1983 Sakurajima Eruptions(＜Special Section＞Sakurajima Special Issue)","authors":"Takeo Suzuki, Y. Nishida, K. Niida","doi":"10.18940/KAZAN.58.1_281","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_281","url":null,"abstract":"We propose a ballistic equation of ejected volcanic blocks that is renovated by considering air resistance, wind velocity and direction dependence of the initial velocity. In the equation, we treat the air resistance as a vector that coincides with the opposite direction of flight. By comparing the calculated results based on the equation of motion and the observed data, such as spatial distribution of landed blocks, initial velocities by successive photos and so on, we tried to reproduce kinematic aspects of the ejected blocks at the 1982 and 1983 eruptions of Sakurajima Volcano, Kyushu, Japan.","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114591142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical and Sr-Nd-Pb Isotopic Constraints on the Origin and Magmatic Evolution of Quaternary Lavas of Sakurajima Volcano, Southern Kyushu Island, Japan(＜Special Section＞Sakurajima Special Issue)","authors":"T. Shibata, J. Suzuki, M. Yoshikawa, Tetsuo Kobayashi, D. Miki, K. Takemura","doi":"10.18940/KAZAN.58.1_43","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_43","url":null,"abstract":"We present the results of a detailed petrogenetic study employing newly determined whole-rock major and trace element geochemical analyses and Sr-Nd-Pb isotopic compositions of andesitic and dacitic Quaternary lavas of Sakurajima volcano, a post-caldera volcano situated within the Aira caldera of Japan. Similar geochemical and isotopic investigations are also carried out on basaltic rocks from pre-caldera stage and monogenetic volcanoes from near Sakurajima volcano. Quaternary lavas of Sakurajima volcano analyzed in this study are classified as porphyritic andesites or dacites that contain a mineral assemblage of orthopyroxene, clinopyroxene, and plagioclase, with or without olivine, in a groundmass exhibiting either hyalo-ophitic or hyalopilitic textures. The trace element characteristics of these samples are similar to those of typical island arc magmas, showing clear evidence of Nb depletion along with enrichments in Rb, K, and Pb, which suggests the addition of aqueous fluids to the mantle wedge during melt generation. The Sr, Nd, and Pb isotopic compositions plot close to a mixing curve between MORB-type mantle and sediments of the Philippine Sea Plate, but displaced a bit towards more radiogenic compositions. Plots of Zr versus Nb concentration in these lavas yield a linear trend that falls on a compositional mixing line between the values for mid-ocean ridge basalt (MORB) and average continental crust. Collectively, these observations indicate that the primary source magmas for the Quaternary lavas of Sakurajima volcano were initially generated by partial melting of MORB-type mantle wedge that had already been hydrated by fluids derived from the subducting Philippine Sea Plate. The additional contribution of significant amounts of crustal material during magma evolution is also evident from the Zr/Nb ratios and Sr-Nd-Pb isotopic compositions of the analyzed andesites and dacites of Sakurajima lava samples. From the mixing relation of Sr-Nd-Pb isotopic compositions, it is suggested that the sedimentary rocks of Shimanto Group can be a source of the crustal materials. Although most of the major element oxide compositions of these lavas show a single linear trend on each of the Harker diagrams, two different trends are clearly discernible on each of the P2O5, and TiO2 versus silica variation diagrams, and are subdivided into low-P and high-P geochemical groups. These two groups can also be distinguished when comparing their P2O5 and TiO2 contents and 87 Sr/ 86 Sr ratios, relative to their phenocrystic plagioclase modal abundances. The magma mixing trends of Sakurajima lavas, which seem to be extended from mono andesitic end-member to two different deictic end-members, are observed from the relationships of major element contents and 87 Sr/ 86 Sr ratios. In addition, the low-P versus high-P groups of lavas show distinctive distribution patterns, whereby the high-P lavas are surrounded by low-P lavas in the central to southern parts of the Saku","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129440108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Interpretation on Secular Changes in Deformation Caused by the 1914 Eruption of Sakurajima Volcano(＜Special Section＞Sakurajima Special Issue)","authors":"I. Yokoyama","doi":"10.18940/KAZAN.58.1_77","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_77","url":null,"abstract":"","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124487471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-Diurnal Tidal Periodicity Observed by an Ocean Bottom Seismometer Deployed at a Location Very Close to Seafloor Fumaroles in Wakamiko Caldera, Northeast of Sakurajima Volcano(＜Special Section＞Sakurajima Special Issue)","authors":"H. Yakiwara, S. Hirano, H. Miyamachi, Tetsuro Takayama, T. Yamazaki, Takeshi Tameguri, M. Iguchi","doi":"10.18940/KAZAN.58.1_269","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_269","url":null,"abstract":"An ocean bottom seismometer (OBS) recorded obvious semi-diurnal periodicity of the average velocity amplitudes of ground motions on the seafloor of Wakamiko Caldera (an active submarine volcano) northeast of Sakurajima Volcano in southwestern Kyushu, Japan. The ground motions were probably generated by the activity of the calderaʼs seafloor fumaroles, because we found bubbles ascending from those fumaroles just after deployment of the OBS. We compared changes in root-mean-square ground-velocity amplitudes in one-minute windows (RMSAs), tidal gravities (accelerations), and water levels during the observation period to obtain the characteristics of the periodicity. Those characteristics are summarized as follows: 1) We observed clear semi-diurnal periodicity of the RMSAs throughout September, 2007, though sometimes the periodicity was less obvious. 2) The timing of maxima RMSAs corresponded to maximum tidal gravities in the time domain. 3) The frequencies of four peaks seen in the power spectra of the changes in RMSAs were identical with those of the four major tidal components. 4) In detail, changes in RMSAs show saw-tooth shapes, and are irregular in periods of diurnal inequality. 5) Long-term or irregular changes in fumarole activity are possibly dominant in the period. The activity of hydrothermal fluids ascending from the deeper portion toward the seafloor fumaroles, which make up part of the circulation of a hydrothermal system, could be advanced as increasing upward tidal gravities (accelerations).","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123746281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absolute Gravity Variation at Sakurajima Volcano from April 2009 through January 2011 and its Relevance to the Eruptive Activity of Showa Crater(＜Special Section＞Sakurajima Special Issue)","authors":"S. Okubo, T. Kazama, Keigo Yamamoto, M. Iguchi, Yoshiyuki Tanaka, T. Sugano, Y. Imanishi, Wenke Sun, Mamoru Saka, A. Watanabe, S. Matsumoto","doi":"10.18940/KAZAN.58.1_153","DOIUrl":"https://doi.org/10.18940/KAZAN.58.1_153","url":null,"abstract":"and its relevance to the eruptive activity of Showa crater Shuhei Okubo1, Takahito Kazama2, Keigo Yamamoto3, Masato Iguchi3, Yoshiyuki Tanaka1, Yuichi Imanishi1, Wenke Sun4, Mamoru Saka1, Atsushi Watanabe1, Shigeo Matsumoto5 1Earthquake Research Institute, the University of Tokyo, Japan, 2Graduate School of Science, Kyoto University, Japan, 3Disaster Prevention Research Institute, Kyoto University, Japan, 4Graduate University of Chinese Academy of Sciences, Japan, 5Sumiko Consultants Co., Ltd, Japan E-mail: okubo@eri.u-tokyo.ac.jp","PeriodicalId":321973,"journal":{"name":"Bulletin of the Volcanological Society of Japan","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130391929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}