Precipitation history of the Lake Biwa area in central Japan over the last 145 ka     

JULE XIAO  YOSHIO INOUCHI  HISAO KUMAI  SHUSAKU YOSHIKAWA  YOICHI KONDO  KEIICHI TAKAHASHI 《Boreas: An International Journal of Quaternary Research》2004,33(1):74-81

The fluvial quartz flux (FQF, g cm ^-2  ka ^-1 ) to Lake Biwa of central Japan is developed as a proxy of variations in palaeoprecipitation over the lake catchment. Lake Biwa sediments spanning the last c. 145 ka are characterized by 4 main intervals when the FQF values were significantly greater than 2 g cm ^-2  ka ^-1 , and 5 main periods during which FQF values were lower. Three of the intervals with high FQF values occur from c. 128 to 78 ka BP, with peak values at c. 122, 101 and 82 ka BP; the fourth of two narrow peaks exists between c. 48 and 35 ka BP. Three main periods with lower FQF values intervene between intervals of high FQF values, and two others lie before c. 128 ka BP and after c. 35 ka BP. The data imply that palaeoprecipitation over the lake catchment increased during the intervals of high FQF values, and decreased during the periods of lower FQF values. High FQF values between c. 48 and 35 ka BP are interpreted to reflect an effective runoff of meltwater from the surrounding mountains during the interstade of the last glaciation. Relatively low FQF values during the early Holocene are interpreted to reveal a sluggish northward retreat of the polar front in the North Pacific Ocean that suppressed the northward advance of the summer monsoonal front and regional precipitation. During the last interglaciation, the increasing trend of FQF values is interpreted to indicate a progressive expansion of the Sea of Japan related to the rise in global sea level, which increased moisture advection to, and precipitation within, the Lake Biwa region.  相似文献   

Long-term trend of the partial pressure of carbon dioxide (pCO₂) in surface waters of the western North Pacific, 1984–1993     

HISAYUKI YOSHIKAWA INOUE  HIDEKAZU MATSUEDA  MASAO ISHII  KATSUHIKO FUSHIMI  MICHIO HIROTA  ICHIO ASANUMA  YOSHIO TAKASUGI 《Tellus. Series B, Chemical and physical meteorology》1995,47(4):391-413

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Tyatya Volcano, southwestern Kuril arc: Recent eruptive activity inferred from widespread tephra   总被引：2，自引：0，他引：2  

MITSUHIRO  NAKAGAWA  YOSHIHIRO  ISHIZUKA †  TAKASHI  KUDO  MITSUHIRO  YOSHIMOTO ‡  WATARU  HIROSE  YOSHIO  ISHIZAKI  NOBUO  GOUCHI  YOSHIO  KATSUI  ALEXANDER W.  SOLOVYOW  GENRIKH S.  STEINBERG  ARSLAN I.  ABDURAKHMANOV 《Island Arc》2002,11(4):236-254

Abstract Tyatya Volcano, situated in Kunashir Island at the southwestern end of Kuril Islands, is a large composite stratovolcano and one of the most active volcanoes in the Kuril arc. The volcanic edifice can be divided into the old and the young ones, which are composed of rocks of distinct magma types, low‐ and medium‐K series, respectively. The young volcano has a summit caldera with a central cone. Recent eruptions have occurred at the central cone and at the flank vents of the young volcano. We found several distal ash layers at the volcano and identified their ages and sources, that is, tephras of ad 1856, ad 1739, ad 1694 and ca 1 Ka derived from three volcanoes of Hokkaido, Japan, and caad 969 from Baitoushan Volcano of China/North Korea. These could provide good time markers to reveal the eruptive history of the central cone, which had continued intermittently with Strombolian eruptions and lava flow effusions since before 1 Ka. Relatively explosive eruptions have occurred three times at the cone during the past 1000 years. We revealed that, topographically, the youngest lava flows from the cone are covered not by the tephra of ad 1739 but by that of ad 1856. This evidence, together with a report of dense smoke rising from the summit in ad 1812, suggests that the latest major eruption with lava effusion from the central cone occurred in this year. In 1973, after a long period of dormancy, short‐lived phreatomagmatic eruptions began to occur from fissure vents at the northern flank of the young volcano. This was followed by large eruptions of Strombolian to sub‐Plinian types occurring from several craters at the southern flank. The 1973 activity is evaluated as Volcanic Explosivity Index = 4 (approximately 0.2 km³), the largest eruption during the 20th century in the southwestern Kuril arc. The rocks of the central cone are strongly porphyritic basalt and basaltic andesite, whereas the 1973 scoria is aphyric basalt, suggesting that magma feeding systems are definitely different between the summit and flank eruptions.  相似文献   

Distribution of the partial pressure of CO₂ in surface water (pCO₂^w) between Japan and the Hawaiian Islands: pCO₂^w–SST relationship in the winter and summer     

HISAYUKI Y. INOUE  MASAO ISHII  HIDEKAZU MATSUEDA  TAKESHI KAWANO  AKIHIKO MURATA  YOSHIO TAKASUGI 《Tellus. Series B, Chemical and physical meteorology》2003,55(2):456-465

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