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Sample records for ryukyu islands japan

  1. Paleo-tsunami and storm records inferred from coastal boulders along the Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Goto, K.; Miyagi, K.; Imamura, F.

    2012-12-01

    After the 11 March 2011 Tohoku-oki earthquake and tsunami (Mw=9.0) at off the coast of Tohoku district of Japan, re-evaluation of the occurrence of large earthquake and tsunami along the subduction zone is one of the major issues in Japan. Along the Ryukyu trench, there are no known thrust type earthquakes of magnitude greater than 8.0 in the last 300 years [Ando et al., 2009, 2012], although there is one possible exception: the AD1771 event at the southern Ryukyu Islands which is characterized by the ~30 m run-up heights. Hence, the occurrence of tsunamigenic large earthquake along the Ryukyu trench in the past and future is controversial. The lack of thousands of years geological record of past earthquake and tsunami such as the sandy tsunami deposits along the Ryukyu trench has made the discussion more difficult, because there are very few suitable places to study such deposits. On the other hand, numerous coastal boulders are reported on the fringing reefs of each island [e.g. Goto et al., 2010]. They are mostly composed of the coralline and reef rocks and are regarded as useful markers of the past large tsunamis and storm events. In fact, some of them are fossil Porites sp. and hence 14C dating is possible for determining the depositional age [e.g. Araoka et al., 2010]. Moreover, boulders of tsunami and storm wave origins at Ryukyu Islands can be differentiated because difference of the wave lengths of tsunami and storm wave are affected the clast size and spatial distributions of boulders on the wide fringing reef (~1500 m) [e.g. Goto et al., 2010]. Therefore, presence or absence of tsunami boulders at each island may provide useful information of occurrence of past large tsunamis and the causative earthquakes along the Ryukyu Trench. In this study, we show the clast size and spatial distributions of more than 2,500 boulders at 11 islands along the Ryukyu trench. Based on the geological study and hydrodynamic analyses, boulders on the reefs at the Sakishima

  2. Terrestrial gamma radiation dose rate in Ryukyu Islands, subtropical region of Japan.

    PubMed

    Furukawa, M; Kina, S; Shiroma, M; Shiroma, Y; Masuda, N; Motomura, D; Hiraoka, H; Fujioka, S; Kawakami, T; Yasuda, Y; Arakawa, K; Fukahori, K; Jyunicho, M; Ishikawa, S; Ohomoto, T; Shingaki, R; Akata, N; Zhuo, W; Tokonami, S

    2015-11-01

    In order to explain the distribution of natural radiation level in the Asia, in situ measurements of dose rate in air due to terrestrial gamma radiation have been conducted in a total of 21 islands that belong to Ryukyu Islands (Ryukyu Archipelago), subtropical rejoin of southwest Japan. Car-borne surveys have also been carried out in Okinawa-jima, the biggest island of the archipelago. Based on the results for these measurements, arithmetic mean, the maximum and the minimum of the dose rates at 1 m in height from the unpaved soil ground in the archipelago were estimated to be 47, 165 and 8 nGy h(-1), respectively. A comparative study of car-borne data obtained prior to and subsequent to the 2011 Fukushima nuclear accident, as for Okinawa-jima, indicated that the nuclear accident has no impact on the environmental radiation at the present time. PMID:26065703

  3. The Quaternary adakite distribution of Kyushu Island, Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Yoshikawa, M.; Takemura, K.

    2011-12-01

    The Quaternary volcanoes are widely distributed in Kyusu Island, Japan. Philippine Sea plate is subducting beneath Kyushu. Clear distribution of deep seismic foci is observed below the Quaternary volcanoes in southern area, but not in northern area. Notsu et al. (1990, JVGR) examined the contribution of subduction to the magma source, and emphasized that no slab derived material is observed in northern area from Sr isotopic compositions. Volcanic activity similar to the within-plate type volcanism has been also emphasized for the magma genesis of this area (e.g. Kita et al, 2001, JVGR). However, we found adakitic rocks, which show high Sr/Y ratios and low Y concentrations (e.g. Defant and Drummond, 1990, Nature) from some Quaternary volcanoes in north Kyushu on the basis of published data (Otha et al, 1990, GANKO; Itoh, 1990, GANKO). Therefore, the magma genesis is still controversial. We studied lateral variations of Sr, Nd and Pb isotopic and trace element compositions for Quaternary volcanics from Kyushu to investigate the magma genesis. From the results, a clear variation of Sr/Y ratio, decreasing from north to south, is observed along the volcanic front. Some of the Sr/Y ratio of the most northern part of Kyusu shows the value >100. The all analyzed Pb isotope compositions show a single liner trend in 208Pb/204Pb v.s. 206Pb/204Pb diagram. The liner trend of Pb isotope ratios can be explained by the binary mixing of the Shikoku Basin basalt and tereginious sediment which might be a constituent of the subducting slab. The similar binary mixing relationships are found in Sr and Nd isotopic systematics. The isotopic characteristics of the Quaternary magma in Kyushu can be explained by the magma generation process of island arc, in spite of the lack of deep seismic foci in northern area. It is considered that high and low Sr/Y ratios suggest the contributions of partial melt in the north and aqueous fluid derived from subducting slab in the south, respectively. If

  4. The preliminary results of new submarine caldera on the west of Kume-jima island, Central Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Harigane, Y.; Ishizuka, O.; Shimoda, G.; Sato, T.

    2014-12-01

    The Ryukyu Arc occurs between the islands of Kyushu and Taiwan with approximately 1200 km in the full length. This volcanic arc is caused by subduction of the Philippine Sea plate beneath the Eurasia Plate along the Ryukyu trench, and is composed of forearc islands, chains of arc volcanoes, and a back-arc rift called Okinawa Trough. The Ryukyu Arc is commonly divided into three segments (northern, central and southern) that bounded by the Tokara Strait and the Kerama Gap, respectively (e.g., Konishi 1965; Kato et al., 1982). Sato et al. (2014) mentioned that there is no active subaerial volcano in the southwest of Iotori-shima in the Central Ryukyu Arc whereas the Northern Ryukyu Arc (i.e., the Tokara Islands) has active frontal arc volcanoes. Therefore, the existence of volcanoes and volcanotectonic history of active volcanic front in the southwestern part of the Central Ryukyu Arc are still ambiguous. Detailed geophysical and geological survey was mainly conducted using R/V Kaiyou-maru No.7 during GK12 cruise operated by the Geological Survey of Japan/National Institute of Advanced Industrial Science and Technology, Japan. As a result, we have found a new submarine volcanic caldera on the west of Kume-jima island, where located the southwestern part of Central Ryukyu Arc. Here, we present (1) the bathymetrical feature of this new submarine caldera for the first time and (2) the microstructural and petrological observations of volcanic rocks (20 volcanic samples in 13 dredge sites) sampled from the small volcanic cones of this caldera volcano. The dredged samples from the caldera consist of mainly rhyolite pumice with minor andesites, Mn oxides-crust and hydrothermally altered rocks. Andesite has plagioclase, olivine and pyroxene phenocrysts. Key words: volcanic rock, caldera, arc volcanism, active volcanic front, Kume-jima island, Ryukyu Arc

  5. Two new dwarfgobies of the genus Eviota from the Ryukyu Islands, Japan (Teleostei: Gobiidae).

    PubMed

    Greenfield, David W; Suzuki, Toshiyuki; Shibukawa, Koichi

    2014-01-01

    Two species of dwarfgoby are described from the Ryukyu Islands, Japan. Eviota flebilis n. sp. belongs to cephalic sensory-pore system pattern 2 (lacking only IT pore), has a dorsal/anal fin-ray formula of 8/7, unbranched pectoral-fin rays, the 5th pelvic-fin ray 12.9% of the 4th, a distinctive narrow, red-orange line under the eye, and a dark vertical line at the caudal-fin base. Eviota specca n. sp. has a cephalic sensory-pore system pattern 1 (complete), has a dorsal/anal-fin formula of 8/8, the body heavily sprinkled with chromatophores, and a single dark spot on the upper pectoral-fin base. PMID:24871515

  6. Quisarctus yasumurai gen. et sp. nov. (Arthrotardigrada: Halechiniscidae) from a submarine cave, off Iejima, Ryukyu Islands, Japan.

    PubMed

    Fujimoto, Shinta

    2015-01-01

    Quisarctus yasumurai gen. et sp. nov. (Arthrotardigrada: Halechiniscidae) is described from the submarine cave 'Daidokutsu', off Iejima, Okinawa Islands, Ryukyu Islands, Japan. It is characterised by a cylindrical body, long primary clava and shorter lateral cirrus inserted on a common cirrophore, and simple digits of unequal lengths (without folds, peduncles, proximal pads, pretarsi, or wrinkles) that terminate in a sheathed, small, crescent-shaped claw with a minute calcar. Quisarctinae subfam. nov. is erected for this unique new genus. PMID:25947769

  7. Mechanism of early meteoric diagenesis in carbonate dune sands, Tarama Island, Ryukyu Islands, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kumai, N.; Matsuda, H.

    2012-12-01

    Carbonate sediments are useful for the interpretation of depositional environments and environmental changes because their components and chemistry reflect depositional environments sensitively. However, primary records on their depositional environments are often modified by various types of early carbonate diagenesis immediately after their deposition. Longman (1980) pointed out that sedimentary textures and mineral compositions of carbonate sediments near a subaerial exposure surface are easily changed by dissolution and cementation associated with early meteoric diagenesis. Hudson (1977) also suggested that their primary stable carbon and oxygen isotopic compositions are altered by early meteoric diagenesis. In this way, the qualitative changes of carbonate sediments with early meteoric diagenesis are well known. On the other hand, the quantitative changes, time scale and detailed mechanisms of early meteoric diagenesis are not fully understood at present. To clarify the detailed mechanism of early meteoric diagenesis, the Upper Pleistocene carbonate dune sands in Tarama Island, the Ryukyu Islands, southwestern Japan, were analyzed. These sediments consist mainly of unconsolidated to weakly-consolidated carbonate sands, composed mainly of a variety of shallow marine bioclasts. Detailed petrographical observation and XRD and isotopic analyses were carried out. As a result of examinations of these carbonate sediments, low-Mg calcite (LMC), high-Mg calcite (HMC) and aragonite (ARG) contents of unconsolidated carbonate sands (UCS) are 20 to 47%, 0 to 44% and 33 to 54%, respectively. On the other hand, LMC, HMC and ARG contents of weakly-consolidated carbonate sands (WCS) are 64 to 95%, 0 to 18% and 5 to 18%, respectively. δ13C and δ18O values of UCS have narrow ranges of 0.51 to 1.70‰ and -1.87 to -1.46‰, respectively. On the other hand, δ13C and δ18O values of WCS have wide ranges of -4.67 to 0.62‰ and -4.82 to 2.92‰, respectively. The mineral and

  8. Two new dwarfgobies (Teleostei: Gobiidae) from the Ryukyu Islands, Japan: Eviota flavipinnata and Eviota rubrimaculata.

    PubMed

    Suzuki, Toshiyuki; Greenfield, David W; Motomura, Hiroyuki

    2015-01-01

    Two new species of Eviota from Yoron Island, the Ryukyu Islands, Japan, are described. Both species belong to the cephalic sensory-canal pore system pattern 2 (lacking only the H [IT] pore); have some pectoral-fin rays branched; have a dorsal/anal-fin formula of 9/8; no dark spot over the ural centrum; no prominent distinct dark spots on the pectoral-fin base; no postocular spots; and no strong dark spots on the caudal fin. The species share the most characters with E. afelei, E. bimaculata and E. punctulata, but differ from Eviota afelei and E. punctulata by having two versus three dark marks over the anal-fin base, and from Eviota bimaculata by lacking the two dark, prominent occipital spots present in that species. Both species differ from all other described species of Eviota in fresh coloration. Eviota flavipinnata has bright golden-yellow dorsal fins and an orange anal fin, and a fifth pelvic-fin ray that is 12% the length of the fourth ray. Eviota rubrimaculata has clear dorsal fins with red spots, large red spots on the body, and lacks the fifth pelvic-fin ray. PMID:26623818

  9. A new species of the palaemonid shrimp genus Palaemonella Dana, 1852 (Crustacea: Decapoda: Caridea) from Okinawa Island, Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Yamada, Yusuke

    2015-01-01

    The palaemonid shrimp genus Palaemonella Dana, 1852 is currently represented by 21 formally described species worldwide, of which 17 species are known from the Indo-West Pacific. In this study, a new species, P. okunoi, is described and illustrated on the basis of two ovigerous female specimens collected from coastal waters in Okinawa Island, Ryukyu Islands, Japan, at depths of 5-30 m. The new species closely resembles P. hachijo Okuno, 1999, but the shorter rostrum, more anteriorly located postrostral teeth on the carapace, the presence of a pair of submedian teeth on the fourth thoracic sternite and the less slender pereopods distinguish P. okunoi n. sp. from P. hachijo. The discovery of the present new species raises the number of Japanese species of Palaemonella to eight. An updated key to the Indo-West Pacific species of the genus is presented. PMID:26249444

  10. Island of Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The island of Okinawa, (26.5N, 128.0E) largest of the Ryukyu Islands, Japan. The Ryukyu island group lies south of the main home islands of Japan in an arc towards the Chinese island Republic of Taiwan. As is typical throughout the Japanese home islands, intense urban development can be observed all over the island in this near vertical view.

  11. Indoapseudes bamberi sp. nov. (Crustacea: Tanaidacea: Pagurapseudidae: Hodometricinae) from Iriomote Island, Ryukyu Islands, southwestern Japan.

    PubMed

    Kakui, Keiichi; Naruse, Tohru

    2015-01-01

    We describe Indoapseudes bamberi sp. nov., based on a specimen from Funaura Bay, Iriomote Island, Japan. This species can be distinguished from its five congeners by having the combination of the antenna with a squama and pereopods 1 and 2 with one dorsal spine on the basis. We also determined part of the nucleotide sequence for the cytochrome c oxidase subunit I (COI) gene in I. bamberi, and present a key to Indoapseudes species. PMID:26250310

  12. A new species of the pontoniine shrimp genus Eupontonia (Crustacea: Decapoda: Caridea: Palaemonidae) from the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Minemizu, Ryo

    2014-01-01

    A third species of the pontoniine shrimp genus Eupontonia Bruce, 1971, E. gracilipes n. sp., is described and illustrated on the basis of a single female specimen collected from shallow water of Ishigaki Island, southern Ryukyu Islands, Japan. The new species is readily distinguished from the two congeneric species, E. noctalbata Bruce, 1971 and E. oahu Bruce, 2010, by a number of morphological characters, including the presence of a distinct postrostral median ridge and of the postrostral median tooth on the carapace. It is considered to be a free-living species. The generic diagnosis of Eupontonia is slightly emended to accommodate the present new species. A key in aid of identification of species of Eupontonia is provided. PMID:24872045

  13. Marine terraces caused by fast steady uplift and small coseismic uplift and the time-predictable model: Case of Kikai Island, Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Shikakura, Yosuke

    2014-10-01

    Kikai Island, a part of the Ryukyu Islands in southwest Japan, is rimmed by marine terraces. This island has been studied in detail because these marine terraces record the fastest crustal uplift in Japan. Geological studies of the raised Holocene reef have concluded that coseismic uplift has been generating marine terraces since 6.3 ka. Analysis of GPS data suggests that Kikai Island is steadily uplifted several mm/yr. To examine the discrepancy between geological and geodetic surveys, I numerically modeled nearshore processes and simulated the generation of marine terraces under two conditions: 1) large stepwise uplift and no steady uplift and 2) steady uplift and small stepwise uplift. As a result, the emergence time of the marine terraces is the same and the heights of the terrace cliffs are consistent with the time-predictable recurrence model for large earthquakes. This result shows the possibility of overestimate of magnitudes of the past earthquakes.

  14. Two new species of ghost shrimp assigned to the genus Cheramus Spence Bate, 1888 (Crustacea: Decapoda: Axiidea: Callianassidae) from the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Maenosono, Tadafumi; Fujita, Yoshihisa

    2014-01-01

    Two new species of the callianassid ghost shrimp are described and illustrated on the basis of specimens from the Ryukyu Islands, Japan. These are provisionally assigned to the genus Cheramus Spence Bate, 1888, and appear closest to Callianassa acutirostella Sakai, 1988, also provisionally transferred to Cheramus herewith. These three species can be differentiated by characters of the telson, third maxilliped, chelipeds and uropod. The taxonomic status of Cheramus is briefly discussed. PMID:25543584

  15. Additional record of Rayllianassa amboinensis (de Man, 1888) from Japan, and description of a new species from Okinawa Island, Ryukyu Islands (Crustacea: Decapoda: Axiidea: Callianassidae).

    PubMed

    Komai, Tomoyuki; Fujita, Yoshihisa; Maenosono, Tadafumi

    2014-01-01

    Two species referred to the callianassid ghost shrimp genus Rayllianassa Komai & Tachikawa, 2008 are reported herewith. Additional locality records from Japan are provided for R. amboinensis (de Man, 1888), and the synonymy of Callianassa ngochoae Sakai, 1999 with R. amboinensis is discussed. It is shown that R. amboinensis is associated with sponges or alcyonacean soft corals, representing unusual habitats for callianassids. Rayllianassa rudisulcus n. sp. is described on the basis of a single ovigerous female from shallow soft sediment in Ohura Bay, Okinawa Island, Ryukyu Islands. The new species is distinguished from R. amboinensis by the absence of a dorsal oval on the carapace, the antennal peduncle being longer than the antennular peduncle, and the different shape of the third maxilliped. The status of Rayllianassa is also briefly discussed. PMID:25081469

  16. Development of coral reefs of the Ryukyu Islands (southwest Japan, East China Sea) during Pleistocene sea-level change

    NASA Astrophysics Data System (ADS)

    Nakamori, T.; Iryu, Y.; Yamada, T.

    1995-11-01

    The Pleistocene coral reef deposits called the Ryukyu Group are widely distributed through the Ryukyu Islands. Lithofacies are represented by conglomerate, calcareous sandstone and limestones. The limestones can be divided into six lithofacies on the basis of macro-benthos and large foraminifers. They are coral, rhodolith, Cycloclypeus-Operculina, Halimeda, and poorly- to well-sorted detrital limestones. Their depositional environments are reconstructed referring to the depth range of the Recent coral reef biota around the Ryukyu Islands. Depositional history of the Ryukyu Group is recorded in a stratigraphic cross-section on Toku-no-shima. Sequence stratigraphical units are recognized in the vertical section of the limestones. Units 1 and 3 are considered to have been formed when the relative sea-level was high, while Units 2 and 4 were deposited during the low stands of sea-level. It is noteworthy that the coral limestones of the Units 2 and 4 were accumulated during glacial stages. The generalized sequence of the limestones is deduced from a transition probability on Miyako-jima. It begins with the Cycloclypeus-Operculina limestone and is followed by rhodolith limestone and ends with coral limestone. These facies indicate a shallowing upward succession.

  17. 16ch high-resolution seismic reflection surveys on the active fault of upper fore-arc slope off Okinawa Island, central Ryukyu Island Arc, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Arai, K.; Inoue, T.; Sato, T.; Tuzino, T.

    2010-12-01

    The Ryukyu Island Arc extends from Kyushu to Taiwan, a distance of 1,200 km, along the Ryukyu Trench where the Philippine Sea Plate is subducting beneath the Eurasian Plate. The Okinawa Trough, a back arc basin has formed behind the Ryukyu Island Arc in late Pliocene to early Pleistocene. The research cruises of GH08 (from 28th July to 29th August 2008) and GH09 (from 16th July to 17th August 2009) were carried out around Okinawa Island, which is located on the central Ryukyu Island Arc. More than 4,500 miles multi channel high-resolution seismic profiles were acquired during these two cruises by the GI-gun (355cu. inch) or the Cluster-gun (30+30 cu. inch) systems with 16ch digital streamer cable. Survey area in the southeast off Okinawa Island is located on the upper fore-arc slope. Seismic reflections of the upper fore-arc slope show a distinct reflector which may represent erosional unconformable surface. The distinct reflector had tilted southeastward and was overlain by the stratified sediments. No obvious deformation such as the fold and faults parallel to the Ryukyu Trench axis was found under the upper slope. In contrast, some active faults which were perpendicular to the Ryukyu Trench axis (NW-SE direction) were observed. The most conspicuous normal fault was found on north off Okinawa Island. The fault with 70-80°dipping toward northeast has been active since the early Pleistocene inferred from seismic stratigraphy and calcareous nannofossil biochronology. The maximum displacement reaches to 0.7 s two way travel time in depth. An average of maximum vertical displace component of the normal fault may reach up to ten cm/1000 years. Seismic profiles indicate that the tilting of Ryukyu Island Arc forward to the Ryukyu Trench plays the important role of formation of the fault in a NW-SE direction.

  18. Differential timing of vertical-axis block rotations in the northern Ryukyu Arc: Paleomagnetic evidence from the Koshikijima Islands, Japan

    NASA Astrophysics Data System (ADS)

    Tonai, Satoshi; Suganuma, Yusuke; Ashi, Juichiro; Itaya, Tetsumaru; Oiwane, Hisashi; Kiyokawa, Shoichi

    2011-01-01

    Over 300 samples for paleomagnetic analysis and K-Ar dating were collected from 27 sites at NW-SE and NE-SW trending dike swarms (herein, NW dikes and NE dikes, respectively) in the Koshikijima Islands, northern Ryukyu Arc. The NW dikes are Middle Miocene in age and have directions (D = - 37.7 ∘, I = 51.8 ∘, α95 = 9.6 ∘, and κ = 40.8) that are deflected westward relative to the stable eastern Asian continent. Conversely, the NE dikes, of Late Miocene age, have directions (D = 16.1 ∘, I = 57.7 ∘, α95 = 7.1 ∘, and κ = 41.9) that show no such deflection. These differences are interpreted as indicating that the Koshikijima Islands underwent approximately 40 ∘ of counter-clockwise rotation during the Middle to Late Miocene. A synthesis of the paleomagnetic and structural data suggests a three-stage history of extensional deformation: (1) displacement upon normal faults (F 1 faults) without vertical-axis block rotation, (2) strike-slip reactivation of F 1 faults and oblique-normal displacement on NE-SW-trending faults (F 2 faults) with vertical-axis block rotation, and (3) oblique-normal displacement on F 2 faults without vertical-axis block rotation. Regional differences in the timing and amount of counter-clockwise vertical-axis block rotations indicate that the northern Ryukyu Arc rotated as several distinct rigid blocks.

  19. New records of two species of the coral reef shrimp genus Thor Kingsley, 1878 (Crustacea: Decapoda: Thoridae) from the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki; Okuno, Junji; Minemizu, Ryo

    2015-01-01

    The caridean shrimp genus Thor Kingsley, 1878 (Thoridae) is currently represented by 14 species distributed in shallow tropical to subtropical waters in the Indo-Pacific, East Pacific and West Atlantic oceans. In this study, two species of the genus are reported on the basis of material from Okinawa and Kume islands in the Ryukyu Archipelago, southern Japan. Thor leptochelus (Xu & Li, 2015) n. comb., recently described from Xisha Islands, China and originally assigned to Thinora Bruce, 1997, is transferred to Thor. Relationship of the species to three congeneric species (T. cordelli Wicksten, 1996, T. spinipes Bruce, 1983 and T. spinosus Boone, 1935) is discussed. The second is T. marguitae Bruce, 1973, representing the rediscovery since the original description and new record for Japanese waters. The four specimens of T. leptochelus were all free-living, whereas the single specimen of T. marguitae was found to be associated with a solitary fungiid coral, as previously reported. PMID:26623904

  20. A new genus and new species of Paguridae (Crustacea: Decapoda: Anomura) from shallow subtidal waters in Okinawa Island, the Ryukyu Islands, Japan.

    PubMed

    Komai, Tomoyuki

    2015-01-01

    During a survey on decapod crustacean fauna of shallow coral reefs and nearby environments in Okinawa Island, Ryukyu Archipelago, Japan, four specimens of a small but distinctive undescribed species of pagurid hermit crab, which could not be referred to any known genus, were collected. The new taxon, Eutrichopagurus shirakawai n. gen., n. sp., is described and illustrated herein. The new genus is characterized by the possession of 11 pairs of deeply quadriserial phyllobranchiate gills, the third maxilliped with well-developed crista dentata and one or two accessory teeth on the ischium, the presence of unpaired left gonopore in the female, the absence of paired first pleopods in the female, and the telson with prominent tuft of setae on the lateral margin of the posterior lobes; the male is unknown at present. It appears close to Trichopagurus de Saint Laurent, 1968, but the deeply quadriserial gills immediately distinguish Eutrichopagurus from Trichopagurus. The new genus is also compared with other genera characterized by the possession of 11 pairs of quadriserial phyllobranchiate gills and the lack of paired first pleopods in females. PMID:25781092

  1. Evaluation of genetic introgression from domesticated pigs into the Ryukyu wild boar population on Iriomote Island in Japan.

    PubMed

    Murakami, K; Yoshikawa, S; Konishi, S; Ueno, Y; Watanabe, S; Mizoguchi, Y

    2014-08-01

    We evaluated genetic introgression from domesticated pigs into the Ryukyu wild boar (RWB) population on Iriomote Island based on their genetic structure and diversity. We used a combination of mitochondrial DNA D-loop region (596 bp) polymorphisms and 23 microsatellite markers. RWBs (n = 130) were collected from 18 locations on Iriomote Island and compared with 66 reference samples of European and Asian domestic pigs. We identified six distinct haplotypes, involving 22 single nucleotide polymorphisms (including one insertion) in the RWB population. The phylogenetic tree had two branches: the RWB group and domestic lineage. Fourteen of 130 RWBs (10.8%) belonged to the European domestic lineage, including 11 RWBs from the Panari Islands, northwest of Iriomote Main Island (IMI). The heterozygosity values, total number of alleles, number of effective alleles and polymorphism information content of the RWB groups were lower than those of the European domestic groups. The RWB population on IMI had a lower heterozygous deficiency index (FIS = 0.059) than did the other populations, which indicates that this population was more inbred. There was a large genetic distance (FST = 0.560) between RWBs on IMI and the Meishan populations. Structure analysis using the 23 microsatellite markers revealed that 16 RWBs had an admixture pattern between RWB and domesticated pig breeds. These results suggest that gene flow may have occurred from domestic pigs to RWBs and demonstrate that there was low genetic variation in the IMI population. PMID:24754898

  2. Peltogasterella sensuru n. sp. (Crustacea: Cirripedia: Rhizocephala) from off Okinawa Island (Ryukyu Archipelago, Japan) with remarks on its single brood externae.

    PubMed

    Yoshida, Ryuta; Hirose, Mamiko; Hirose, Euichi

    2015-09-01

    Peltogasterella sensuru n. sp. infests Pagurixus hermit crabs inhabiting rocky shores off Okinawa Island (Ryukyu Archipelago, Japan). This species is clearly distinguishable from Peltogasterella gracilis (Boschma, 1927): the stalk emerges from the middle part of the externa in the present species and P. sulcata (Lilljeborg, 1859), while the stalk in P. gracilis emerges from the posterior end of the externae. The new species differs from P. sulcata based on the morphology of the mantle aperture. Peltogasterella sensuru n. sp. repeatedly produces single brood externae that have not been previously observed in species belonging to the suborder Kentrogonida Delage, 1884. We also determined partial sequences of the COI gene and 16S rRNA gene of the new species for use as molecular markers for species identification. PMID:26249520

  3. A new cave-dwelling species of the alpheid shrimp genus Salmoneus Holthuis, 1955 (Crustacea: Decapoda: Caridea) from the Ryukyu Islands, southern Japan.

    PubMed

    Komai, Tomoyuki; Yamada, Yusuke; Yunokawa, Kyo

    2015-01-01

    A new species of the alpheid shrimp genus Salmoneus Holthuis, 1955, S. antricola n. sp., is described and illustrated on the basis of a single ovigerous specimen from an aphotic marine cave at a depth of 12 m, off Ie Island, Okinawa Islands, the Ryukyu Archipelago. It is morphologically similar to five species presently referred to the S. jarli (Holthuis, 1951) species group: S. erasimorum Dworschak, Anker & Abed-Navandi, 2000, S. komaii Anker, 2011, S. paulayi Anker, 2011, S. poupini Anker, 2011, and S. sketi Fransen, 1991. However, the minor cheliped with an elongate carpus being subequal to the chela, the lack of teeth on the cutting edges of the minor cheliped fingers, and the very slender third to fifth pereopods are obvious characters that distinguish S. antricola n. sp. from all of its presumed close relatives. Among the 50 species of Salmoneus, only S. sketi and the present new species are known from marine caves. PMID:26624318

  4. Two new species of Dracoderes (Kinorhyncha: Dracoderidae) from the Ryukyu Islands, Japan, with a molecular phylogeny of the genus.

    PubMed

    Yamasaki, Hiroshi

    2015-01-01

    Two new species, Dracoderes snufkini sp. nov. and Dracoderes toyoshioae sp. nov., are described from Okinawa, southern Japan. Diagnostic characters of D. snufkini include: lateroventral tubules on segments 2 and 5; a thick, plump middorsal spine on segments 2 and 9; thick plump paradorsal spines on segments 3-8, alternately laterally displaced; and a ventral primary pectinate fringe on segment 1, with long, wide conspicuous tips. Diagnostic characters of Dracoderes toyoshioae include: a middorsal subcuticular structure on segment 1; paradorsal subcuticular structures on segments 2-9, alternately laterally displaced; paradorsal acicular spines arising from subcuticular structures, at least on segment 5; ventrolateral acicular spines on segment 1; lateral accessory tubules on segment 2; lateral accessory subcuticular structures on segments 2-7; lateroventral tubules on segment 5; and lateroventral subcuticular structures on segments 2-10. Molecular phylogenetic analyses based on 18S rRNA, 28S rRNA and mitochondrial COI sequences indicate that D. abei and D. nidhug are more closely related to one another than either is to D. snufkini or D. toyoshioae. PMID:26249958

  5. Holocene sea-level change and tectonic uplift deduced from raised reef terraces, Kikai-jima, Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Sugihara, Kaoru; Nakamori, Toru; Iryu, Yasufumi; Sasaki, Keiichi; Blanchon, Paul

    Kikai-jima (Kikai Island) is surrounded by four Holocene raised coral reef terraces, which are thought to be an offlapping sequence of reef deposits caused by combined effects of seismic uplift and Holocene sea-level change. Many studies in this region have investigated Holocene sea-level changes and reef growth, but there are relatively few in which reliable sea-level indicators are given. We have found that Pocillopora verrucosa, one of the most abundant coral species on the upper-reef slopes of fringing reefs in the Ryukyus, has its peak abundance at a depth of 1.5 m. Therefore, this species is considered ideal for the analysis of relative sea-level change and can be used as a dipstick for the Holocene reef deposits in this area. Based on the distribution of P. verrucosa on the four Holocene raised terraces, we calculate relative paleo-mean sea levels to be 10.8-11.1 and 8.5-8.9 m for Terrace I, 5.0-5.3 m for Terrace II, 4.0-4.3 m for Terrace III and 1.9-2.5 m for Terrace IV. These results, combined with hitherto known and newly measured radiometric dates (103 total), clearly show that the four terraces formed in response to repeated seismic uplifts at 6.3, 4.1, 3.1 and 1.4 ka, and that sea level was higher than present between 7.0 and 6.3 ka.

  6. Divergence and long-distance overseas dispersals of island populations of the Ryukyu five-lined skink, Plestiodon marginatus (Scincidae: Squamata), in the Ryukyu Archipelago, Japan, as revealed by mitochondrial DNA phylogeography.

    PubMed

    Kurita, Kazuki; Hikida, Tsutomu

    2014-04-01

    We assessed the historical biogeography of the Ryukyu five-lined skink, Plestiodon marginatus, and related species (P. stimpsonii and P. elegans). Our specific aims were to reveal the origin, tim- ing, and route of the colonization to three volcanic islands in the northern Tokara Group of the northern Ryukyus: Kuchinoshima, Nakanoshima, and Suwanosejima. We conducted phylogenetic analyses and divergence time estimation using a partial sequence of the mitochondrial cytochrome b gene for P. marginatus collected from across its whole range (the northern and central Ryukyus), and for P. stimpsonii (from the Yaeyama Group of the southern Ryukyus) and P. elegans (from Taiwan). Our results suggest three major clades (A, B, and C). Clades A and B consist of P. marginatus, excluding the Kuchinoshima population, and Clade C consisted of the Kuchinoshima population, P. stimpsonii, and P. elegans. These clades are estimated to have diverged during the Late Miocene to the Late Pliocene. Among the three examined northern Tokara populations, the Kuchinoshima population was shown to be a sister group of P. stimpsonii. The two other populations from Nakanoshima and Suwanosejima Islands were closely related to P. marginatus from the northern part of the Okinawa Group and that from Kodakarajima Island in the southern Tokara Group, respectively. These populations are estimated to have diverged from their respective related spe cies in various ages of the Early to Late Pleistocene, suggesting that they colonized the islands by independent overseas dispersals of approximately 50-850 km via the Kuroshio Current. Taxonomic implications for P. marginatus are also discussed. PMID:24694220

  7. Three-Dimensional Seismic Attenuation Structure in the Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Komatsu, M.; Takenaka, H.

    2015-12-01

    Tomographic studies have been conducted to retrieve 3D seismic attenuation structure around Japan Arc since 1980s. However, in the Ryukyu Arc, 3D attenuation structures has never been estimated. It is important to estimate the 3D attenuation structure in this region, since there are highly active volcanos and seismicity between the Okinawa Trough and the Ryukyu Trench. In this study, we estimate 3D seismic attenuation structure in the Ryukyu Arc. We use seismic waveform data recorded by seismic observation networks of NIED, JMA and Kagoshima University, from 2004/06 to 2014/05. We select seismic events of more than 4,500. Since the Ryukyu Arc region are so wide, we separate it into three subregions: Sakishima Islands, Okinawa Islands and Amami Islands subregions. Before calculating the attenuation quantity t*, the corner frequency of the source spectrum for each event is estimated by using an omega square model. The t* is estimated from the amplitude decay rate from the source-corrected spectra. We then invert the t* data to the attenuation structure by a 3D tomographic technique using the non-negative least squares method. Our estimated attenuation structure has the remarkable features: in Sakishima Islands subregion, high attenuation zone exists beneath northern Ishigaki Island. This region corresponds to the Okinawa Trough. High attenuation zone also exists beneath Hateruma Island in upper crust. It corresponds to the accretionary prism formed by subducting Philippine Sea Plate. In Amami Islands subregion, high attenuation zone is located along volcanic front. Low attenuation zone spreads over subducting Philippine Sea slab in all subregions.Acknowledgements: We used JMA Unified Hypocenter Catalogs and seismic waveform data recorded by NIED, JMA and Kagoshima University. We also used a computer program by Zhao et al. (1992, JGR) for the tomographic analysis.

  8. Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in the Ryukyu Islands tree rat (Diplothrix legata).

    PubMed

    Okano, Tsukasa; Haga, Atsushi; Mizuno, Eriko; Onuma, Manabu; Nakaya, Yumiko; Nagamine, Takashi

    2014-04-01

    Angiostrongylus cantonensis is a zoonotic nematode with rodents serving as natural definitive hosts. We report A. cantonensis in the Ryukyu Islands tree rat (Diplothrix legata, Thomas, 1906), a native endangered species in Japan. Adult and larvae of A. cantonensis were macroscopically, histologically, and genetically detected in three tree rats collected between August 2011 and January 2012 in the Yambaru area of Okinawa Prefecture, Japan. Pathologic observations of the lungs of rats showed that infection may be lethal. We also conducted a retrospective genetic survey of helminths parasitic in lung in cryopreserved lung samples of Ryukyu Islands tree rats collected between 2007 and 2011 in the Yambaru area and found A. cantonensis DNA in one of 29 samples, which was collected in December 2010. PMID:24499332

  9. Multiple colonizations lead to cryptic biodiversity in an island ecosystem: comparative phylogeography of anchialine shrimp species in the Ryukyu Archipelago, Japan.

    PubMed

    Weese, David A; Fujita, Yoshihisa; Santos, Scott R

    2013-09-01

    Archipelagos of the Indo-West Pacific are considered to be among the richest in the world in biodiversity, and phylogeographic studies generally support either the center of origin or the center of accumulation hypothesis to explain this pattern. To differentiate between these competing hypotheses for organisms from the Indo-West Pacific anchialine ecosystem, defined as coastal bodies of mixohaline water fluctuating with the tides but having no direct oceanic connections, we investigated the genetic variation, population structure, and evolutionary history of three caridean shrimp species (Antecaridina lauensis, Halocaridinides trigonophthalma, and Metabetaeus minutus) in the Ryukyu Archipelago, Japan. We used two mitochondrial genes--cytochrome c oxidase subunit I (COI) and large ribosomal subunit (16S-rDNA)--complemented with genetic examination of available specimens from the same or closely related species from the Indian and Pacific Oceans. In the Ryukyus, each species encompassed 2-3 divergent (9.52%-19.2% COI p-distance) lineages, each having significant population structure and varying geographic distributions. Phylogenetically, the A. lauensis and M. minutus lineages in the Ryukyus were more closely related to ones from outside the archipelago than to one another. These results, when interpreted in the context of Pacific oceanographic currents and geologic history of the Ryukyus, imply multiple colonizations of the archipelago by the three species, consistent with the center of accumulation hypothesis. While this study contributes toward understanding the biodiversity, ecology, and evolution of organisms in the Ryukyus and the Indo-West Pacific, it also has potential utility in establishing conservation strategies for anchialine fauna of the Pacific Basin in general. PMID:24088794

  10. Tsunami hazard mitigation in tourism in the tropical and subtropical coastal areas: a case study in the Ryukyu Islands, southwest of Japan

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.

    2006-12-01

    Life and economy (including tourism) in tropical and subtropical coastal areas, such as Okinawa Prefecture (Ryukyu) are highly relying on the sea. The sea has both "gentle" side to give people healing and "dangerous" side to kill people. If we are going to utilise the sea for marine tourism such as constructing resort facilities on the oceanfront, we should know all of the sea, including the both sides of the sea: especially the nature of tsunamis. And also we islanders should issue accurate information about the sea towards outsiders, especially tourists visiting the island. We have already learned a lesson about this issue from the Sumatra tsunami in 2004. However, measures against the tsunami disaster by marine tourism industry are still inadequate in these areas. The goal of tsunami hazard mitigation for those engaged in tourism industry in tropical and subtropical coastal areas should be as follows. (1) Preparedness against tsunamis: "Be aware of the characteristics of tsunamis." "Prepare tsunamis when you feel an earthquake." "Prepare tsunamis when an earthquake takes place somewhere in the world." (2) Maintenance of an exact tsunami hazard map under quantitative analyses of the characteristics of tsunamis: "Flooding areas by tsunami attacks are dependent not only on altitude but also on amplification and inundation due to the seafloor topography near the coast and the onland topographic relief." "Tsunami damage happens repeatedly." (3) Maintenance of a tsunami disaster prevention manual and training after the manual: "Who should do what in case of tsunamis?" "How should the resort hotel employees lead the guests to the safe place?" Such a policy for disaster prevention is discussed in the class of the general education of "Ocean Sciences" in University of the Ryukyus (UR) and summer school for high school students. The students (most of them are from Okinawa Prefecture) consider, discuss and make reports about what to do in case of tsunamis as an islander

  11. Halechiniscidae (Heterotardigrada, Arthrotardigrada) of Oura Bay, Okinawajima, Ryukyu Islands, with descriptions of three new species.

    PubMed

    Fujimoto, Shinta

    2015-01-01

    Marine tardigrades of the family Halechiniscidae (Heterotardigrada: Arthrotardigrada) are reported from Oura Bay, Okinawajima, one of the Ryukyu Islands, Japan, including Dipodarctus sp., Florarctuswunai sp. n., Halechiniscuschurakaagii sp. n., Halechiniscusyanakaagii sp. n. and Styraconyx sp. The attributes distinguishing Florarctuswunai sp. n. from its congeners is a combination of two characters, the smooth dorsal cuticle and two small projections of the caudal alae caestus. Halechiniscuschurakaagii sp. n. is differentiated from its congeners by the combination of two characters, the robust cephalic cirrophores and the scapular processes with flat oval tips, while Halechiniscusyanakaagii sp. n. can be identified by the laterally protruded arched double processes with acute tips situated dorsally at the level of leg I. A list of marine tardigrades reported from the Ryukyu Islands is provided. PMID:25755627

  12. New records of the squat lobster genus Munida Leach, 1820 (Crustacea: Decapoda: Anomura: Munididae) from deep-water off Okinawa Islands, Ryukyu Islands, Japan, with description of a new species.

    PubMed

    Komai, Tomoyuki; Higashiji, Takuo

    2016-01-01

    Two species of the squat lobster genus Munida Leach, 1820, M. pollioculus n. sp. and M. zebra Macpherson, 1994, are recorded from deep-waters off Okinawa Islands, the Ryukyu Islands, at depths of 1000 m and 495 m, respectively. The new species closely resembles M. clevai Macpherson, 1999 and M. microps Alcock, 1894, but it differs from the latter two in the absence of a proximal spine on the mesial margin of the cheliped dactylus and the more stout dactylus of the second pereopod. Munida zebra is first recorded from the Northwest Pacific, as well as Japanese waters, with its geographical range extended to the north from the previously known southwestern Pacific localities. PMID:27394885

  13. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part II: sponge-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from the canals of their sponge hosts throughout the Ryukyu Archipelago, Japan. Eleven new species are described in the genus Leucothoe with valuable location data and host records. An identification key to sponge-dwelling Leucothoidae of the Ryukyu Archipelago is provided. PMID:22328858

  14. Reproductive traits of the Ryukyu long-furred rat (Diplothrix legata) on Okinawa-jima Island.

    PubMed

    Okano, Tsukasa; Nakata, Katsuhi; Nakaya, Yumiko; Nagamine, Takashi; Onuma, Manabu

    2015-06-01

    The Ryukyu long-furred rat, Diplothrix legata, is a large rodent distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island, Japan. This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles. We performed theriogenological examinations of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had remarkably large preputial glands. Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were observed from September through February, and seminiferous diameter was significantly large (216 ± 27 µm, n=12) during this time in adults; testes length changed in a similar pattern. These findings indicate that the mating season may occur from September through February. Size (body length) at sexual maturity was estimated to be >560 mm in both sexes. From observation of corpora lutea and placental scars, litter size was estimated to range from 2 to 12 (average=6, n=4). These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species. PMID:25649850

  15. Enhancement of Eddy Heat Transport due to the Anticyclonic Submesoscale Eddies around Ryukyu Islands near Kuroshio in East China Sea

    NASA Astrophysics Data System (ADS)

    Kamidaira, Y.; Uchiyama, Y.; Mitarai, S.; Miyazawa, Y.

    2014-12-01

    A synoptic, regional downscaling experiment of Kuroshio off Ryukyu Islands, Japan, exhibits the evident predominance of submesoscale anticyclonic eddies over cyclones in the narrow strip between Kuroshio and the islands (Uchiyama et al., 2013). In the present study, the mechanism and impacts of the anticyclone dominance are examined with a detailed oceanic downscaling model in a double nested ROMS configuration at the horizontal resolution of 3km (ROMS-L1) and 1km (ROMS-L2), forced by the assimilative JCOPE2 oceanic reanalysis and the JMA GPV-MSM atmospheric hindcast. The model results are extensively validated against a variety of data including shipboard hydrography and satellite altimetry and temperature data to show a good agreement. An alternative ROMS-L2 experiment is also conducted to examine topographic effects on the anticyclones around the Ryukyu Islands by eliminating all the island topography above z > -1000 m, while the other configurations are held unchanged. If the islands are removed, the submesoscale negative vortices on the eastern side of the Kuroshio become much weaker than those of the original case with the islands. The experiment clearly demonstrates that dominance of the negative vorticity between Kuroshio and the Ryukyu Islands is caused by enhanced lateral shear due to the concentrated Kuroshio mean current associated with appropriate formation of the eastern branch, the northward-drifting Ryuku Current, and resultant eddy shedding in the narrow channel between the continental shelf of the East China Sea and the Okinawan ridge. A diagnostic eddy heat flux analysis illustrates that the submesoscale anticyclonic eddies play a crucial role in enhancing the eddy heat transport and thus the lateral mixing between Kuroshio and the islands as compared to those in the coarser resolution models (L1 and JCOPE2), resulting in promoting regional larval and material transport from Kuroshio to the islands.

  16. Situation Report--Hong Kong, Malawi, Pakistan, Panama, Philippines, Ryukyu Islands (Okinawa), Sabah, Sarawak.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in eight foreign countries are presented in these situation reports. Countries included are Hong Kong, Malawi, Pakistan, Panama, Philippines, Ryukyu Islands (Okinawa), Sabah, and Sarawak. Information is provided where appropriate and available, under two topics, general background and family planning…

  17. Variations of short-term slow slip events along the Nankai Trough to the Ryukyu Trench, southwest Japan

    NASA Astrophysics Data System (ADS)

    Nishimura, T.

    2013-12-01

    ETSs (Episodic Tremor and Slips) occur at a depth of 30-40 km on the plate interface of the subducting Philippine Sea plate along the Nankai trough, southwest Japan (e.g., Obara, 2010). Low-frequency tremors along the Nankai Trough suddenly disappeared southwest of the Bungo Channel between Shikoku and Kyushu, which is a junction between the southwest Honshu arc along the Nankai Trough and the Ryukyu arc along the Ryukyu Trench. Any short-term SSEs (slow slip events) have never been reported southwest of the Bungo Chanel, though Mw~7 long-term SSEs repeated in the Bungo Channel every ~6 years (e.g., Ozawa et al., 2013). Here, we apply a SSE detection method using continuous GNSS data (Nishimura et al., 2013) to find out SSEs in a region along the Nankai Trough to the Ryukyu Trench. We also compare the detected SSEs with epicenters of low-frequency tremors, very-low-frequency earthquakes (VLFEs), and regular earthquakes and discuss along-trench variations on short-term SSE characteristics. Daily coordinates of ~800 GEONET GNSS stations in southwest Japan were used to detect displacements caused by short-term SSEs. We divided a whole region into three regions for spatial filtering to reduce a noise of GNSS data. We fitted a step function with a linear trend to spatial-filtered daily coordinates to detect significant displacements in a direction opposite to the relative plate motion between the Philippine Sea plate and southwest Japan. If Akaike's information criterion expressing data fits exceeds a threshold, three-dimensional displacements were inverted to estimate a rectangular fault along the plate interface. We found more than 200 probable short-term SSEs in the region over 16 years. In western Shikoku, we detected 49 Mw ~6.0 ETSs. SSEs with a similar magnitude are found at the same depth range in northeast Kyushu without tremors although the number of detected SSEs is only 10. In the further southwest region, we found several shallow SSEs at a depth of 10-40 km

  18. Tsunami recurrence inferred from soil deposits on Ishigaki island along the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Ando, M.; Shishikura, M.; Tu, Y.; Nakamura, M.; Arashiro, Y.

    2012-12-01

    The Ryukyu trench at the northwestern boundary of the Philippine Sea plate had no known thrust earthquakes Mw>8.0 in approximately the last 250 years. Due to this lack of associated large thrust earthquakes, an accepted common idea is that Ryukyu trench is aseismic. However, in 1771 a large tsunami struck Ishigaki islands and Miyako islands with the run-up height of up to 30-35 m. The 1771 source is suggested to be a tsunami (slow) earthquake with Mw=8.0 that occurred near the trench axis. Furthermore, very-low frequency earthquakes at shallow depths near the trench axis and slow-slip events at depths of 30km have been identified in the western Ryukyu trench. These findings suggest that the Ryukyu subduction zone has the potential to generate large thrust earthquakes. If the slip deficit has accumulated at the interface, the accumulated slip of more than 30 m would cause a large earthquake and a huge tsunami. Considering the abovementioned findings, estimate for the size and recurrence intervals of past tsunamis along the western Ryukyu trench was undertaken through excavation surveys of the Holocene deposits in Ishigaki and Miyako islands. The excavated sites are located on the lower Holocene marine terraces and implemented using a geoslicer or backhoes at 10 sites on November 2011 and June 2012. Stratigraphic and foraminiferal assemblages of tsunami sediment were compared with shallow beach sand to gain information on sediment source and depositional style. Based on the excavations, two tsunami layers were identified at 5 sites and provided estimates of sedimentation ages. The results obtained from stratigaraphic and foraminiferal analyses together with C14 dates of tsunami sediment indicated an event between 9-11th C. on Ishigaki and another or the same event occurred between 11th C. and 1771 on Miyako island. Consequently, if the 1771 earthquake is the only event that had occurred in the last 300 years over the 120 km, large earthquakes would potentially occur

  19. Genome-wide SNP analysis reveals population structure and demographic history of the ryukyu islanders in the southern part of the Japanese archipelago.

    PubMed

    Sato, Takehiro; Nakagome, Shigeki; Watanabe, Chiaki; Yamaguchi, Kyoko; Kawaguchi, Akira; Koganebuchi, Kae; Haneji, Kuniaki; Yamaguchi, Tetsutaro; Hanihara, Tsunehiko; Yamamoto, Ken; Ishida, Hajime; Mano, Shuhei; Kimura, Ryosuke; Oota, Hiroki

    2014-11-01

    The Ryukyu Islands are located to the southwest of the Japanese archipelago. Archaeological evidence has revealed the existence of prehistoric cultural differentiation between the northern Ryukyu islands of Amami and Okinawa, and the southern Ryukyu islands of Miyako and Yaeyama. To examine a genetic subdivision in the Ryukyu Islands, we conducted genome-wide single nucleotide polymorphism typing of inhabitants from the Okinawa Islands, the Miyako Islands, and the Yaeyama Islands. Principal component and cluster analyses revealed genetic differentiation among the island groups, especially between Okinawa and Miyako. No genetic affinity was observed between aboriginal Taiwanese and any of the Ryukyu populations. The genetic differentiation observed between the inhabitants of the Okinawa Islands and the Miyako Islands is likely to have arisen due to genetic drift rather than admixture with people from neighboring regions. Based on the observed genetic differences, the divergence time between the inhabitants of Okinawa and Miyako islands was dated to the Holocene. These findings suggest that the Pleistocene inhabitants, whose bones have been found on the southern Ryukyu Islands, did not make a major genetic contribution, if any, to the present-day inhabitants of the southern Ryukyu Islands. PMID:25086001

  20. Mantle wedge anisotropy beneath the Japan and Ryukyu arcs from teleseismic receiver functions - Implications for mantle flow and wedge hydration

    NASA Astrophysics Data System (ADS)

    Wirth, E. A.; Long, M. D.; Mccormack, K. A.

    2012-12-01

    Many fundamental aspects of the mantle wedge above subducting slabs, such as the dynamics of mantle flow and the transport of water and melt, have yet to be fully understood. A complete characterization of seismic anisotropy can yield powerful constraints on mantle flow and the degree of mantle wedge hydration. In this study, we characterize the geometry and strength of anisotropy in the mantle wedges beneath northeast Japan and the Ryukyu arc, which overlie the subducting Pacific and Philippine Sea plates, respectively. We compute radial and transverse component P-to-S receiver functions from 15 stations of the F-net array using the multitaper correlation receiver function estimator (Park and Levin, 2000). In both regions, we observe P-to-SV converted energy on radial component receiver functions that are consistent with conversions originating at the subducting oceanic Moho and the top of the subducting oceanic crust. We also observe P-to-SH conversions on the transverse component receiver functions that are consistent with the presence of multiple anisotropic and/or dipping layers. We compute synthetic receiver functions using a forward modeling scheme to create models for the depths, thicknesses, and strengths of the anisotropic layers beneath both northeast Japan and Ryukyu. Beneath Ryukyu, we detect evidence for a layer of strong anisotropy and high Vp/Vs ratio directly above the slab, consistent with the presence of serpentinite. We see no evidence of this signature in receiver functions from northeast Japan; instead, we see evidence for relatively modest anisotropy due to olivine fabric. We also detect a low-velocity region in the mantle wedge beneath northeast Japan, which may be consistent with the presence of partial melt. Since the presence of serpentinite indicates significant hydration of the wedge, the contrast in anisotropic structure between Ryukyu and northeast Japan has important implications for our understanding of slab hydration and how water

  1. Situation Report--Antigua, Dominican Republic, Grenada, Guatemala, Honduras, Philippines, Ryukyu Islands, St. Lucia, and St. Vincent.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Data relating to population and family planning in nine foreign countries are presented in these situation reports. Countries included are: Antigua, Dominican Republic, Grenada, Guatemala, Honduras, Philippines, Ryukyu Islands (Okinawa), St. Lucia, and St. Vincent. Information is provided under two topics, general background and family planning…

  2. Descriptions of two azooxanthellate Palythoa species (Subclass Hexacorallia, Order Zoantharia) from the Ryukyu Archipelago, southern Japan

    PubMed Central

    Irei, Yuka; Sinniger, Frederic; Reimer, James Davis

    2015-01-01

    Abstract Two new species of zoantharians (Hexacorallia, Zoantharia, Sphenopidae), Palythoa mizigama sp. n. and Palythoa umbrosa sp. n., are described from the Ryukyu Archipelago, southern Japan. Unlike almost all other known Palythoa spp., both species are azooxanthellate and inhabit low-light environments such as floors or sides of caves, crevasses, or hollows of shallow coral reefs. The two species were initially considered to be the same species from their similar habitat environments and highly similar morphological features. However, phylogenetic analyses of nuclear internal transcribed spacer (ITS) ribosomal DNA, mitochondrial 16S ribosomal DNA, and cytochrome oxidase subunit I (COI) sequences revealed that these two species have a genetically distant relationship within the genus Palythoa. Morphological characteristics, including polyp size, tentacle number, external/internal coloration, and types and sizes of cnidae were examined in this study. As a result, only tentacle coloration was found to be useful for the morphological distinction between the two species. Palythoa mizigama possesses white tentacles with black horizontal stripes while Palythoa umbrosa possesses white tentacles without any stripe patterns. Considering their distant phylogenetic relationship, it can be assumed that their unique yet similar morphological and ecological characteristics developed independently in each species as an example of parallel evolution. PMID:25685008

  3. [An exploration of the training of medical talents in China for Ryukyu islands based on the Liu qiu bai wen (One Hundred Question of Ryukyu)].

    PubMed

    He, Lanping

    2014-09-01

    Ryukyu sent more than 20 batches of returned students to China for studying during the Ming and Qing Dynasties, many of whom were studying medicine. Liu qiu bai wen (One Hundred Question of Ryukyu) was the record of discussion between Cao Cunxin, a famous doctor of the Qing Dynasty, and the oversea disciples of Lü Fengyi from Ryukyu. However, it was not only a medical book, but also served as an important witness on overseas dissemination of TCM, and the fresh case of Chinese training medical talented persons for Ryukyu. Training Ryukyu medical students in the Qing Dynasty was good for the expansion of Chinese medicine in the Ryukyu, and promoted the development and social progress of the Ryukyu medicine and health, made a significant contribution to maintain the friendly relationship between the two countries. PMID:25579213

  4. The current system east of the Ryukyu Islands as revealed by a global ocean reanalysis

    NASA Astrophysics Data System (ADS)

    Thoppil, Prasad G.; Metzger, E. Joseph; Hurlburt, Harley E.; Smedstad, Ole Martin; Ichikawa, Hiroshi

    2016-02-01

    The structure and variability of the Ryukyu Current System (RCS), which forms the western boundary current along the eastern slope of the Ryukyu Islands, are studied using results from a 32-layer, 1/12.5° global HYbrid Coordinate Ocean Model (HYCOM) and Navy Coupled Ocean Data Assimilation (NCODA) reanalysis for the period 1993-2012. It is confirmed that the reanalysis realistically reproduces salient features of the observed currents at three sections southeast of Miyakojima, Okinawa and Amami-Ohshima. The mean velocity sections show well-developed subsurface velocity maxima between 700 and 900 m. The current core southeast of Amami-Ohshima shows year-to-year variations with cyclonic (anticyclonic) circulation east of Amami-Ohshima generating weak (strong) velocity cores. Interaction of the RCS with an anticyclonic eddy often produces a two-core velocity structure, with a surface core in the upper 300 m and a deeper core near 700-900 m. The horizontal structure of the RCS at 15 m depth shows a well-developed northeastward current northeast of Okinawa, which is partly fed by the southwestward extension of the anticyclonic recirculation gyre. The RCS forms a continuous northeastward current from Miyakojima to Amami-Ohshima below 500 m with shoreward intensification. The circulation at 2000 m shows a seasonal flow reversal, which is northeastward from December to June and southwestward from August to October with July and November being the transition months. The volume transports across these three sections have respective mean values of 0.6, 6.2 and 12.4 Sv (1 Sv ≡ 106 m3 s-1) and standard deviations of 10.2, 7.1 and 11.3 Sv. They have dominant seasonal variations with the maximum in winter and spring and the minimum in summer. The interannual variation of the transport anomaly, which co-varies with the RCS core, results from westward propagating mesoscale eddies arriving from the Pacific interior.

  5. Two new species of Asellota (Crustacea, Isopoda) from coral reefs on Iriomote Island, Okinawa, Japan

    PubMed Central

    Shimomura, Michitaka; Naruse, Tohru

    2015-01-01

    Abstract Pleurocope iriomotensis sp. n. and Prethura tuberculata sp. n. are described from Iriomote Island, Ryukyu Archipelago, southern Japan. These are the first records of Pleurocope from the Pacific and of Prethura from the Asian Pacific coast. Pleurocope iriomotensis differs from its congeners in having lateral spine-like processes on pereonite 4 and coxal plates of pereonite 7. Prethura tuberculata can be distinguished from its single congener in having a lateral short projection of protopod of pleopod 2. PMID:26448712

  6. Detailed bathymetry and magnetic anomaly inthe Central Ryukyu Arc, Japan: implications for a westward shift of the volcanic front after ~2.1 Ma

    NASA Astrophysics Data System (ADS)

    Sato, T.; Oda, H.; Ishizuka, O.; Arai, K.

    2014-12-01

    Detailed bathymetry and magnetic anomalies in the southern part of the Central Ryukyu Arc reveal recent volcanic structures in a southwestward extension of the active volcanic front of the Ryukyu Arc. A line of bathymetric highs running subparallel to this recent volcanic front was observed ~20 km to the east. A set of small, sharply defined magnetic anomalies extends southward from this line of bathymetric highs to the islands Kume-jima and Aguni-jima, suggesting the former existence of an ancient volcanic front. The ages of volcanic rocks from these islands indicate that magmatic activity along the ancient volcanic front continued until at least ~2.1 Ma. The presence of magnetic anomalies between the two volcanic fronts suggests that the volcanic front has moved gradually westward. This shift can be explained by the termination of asthenospheric upwelling and/or the rapid retreat of the Ryukyu Trench after its change in subduction direction.

  7. Detailed bathymetry and magnetic anomaly in the Central Ryukyu Arc, Japan: implications for a westward shift of the volcanic front after approximately 2.1 Ma

    NASA Astrophysics Data System (ADS)

    Sato, Taichi; Oda, Hirokuni; Ishizuka, Osamu; Arai, Kohsaku

    2014-12-01

    Detailed bathymetry and magnetic anomalies in the southern part of the Central Ryukyu Arc reveal recent volcanic structures in a southwestward extension of the active volcanic front of the Ryukyu Arc. A line of bathymetric highs running subparallel to this recent volcanic front was observed approximately 20 km to the east. A set of small, sharply defined magnetic anomalies extends southward from this line of bathymetric highs to the islands Kume-jima and Aguni-jima, suggesting the former existence of an ancient volcanic front. The ages of volcanic rocks from these islands indicate that magmatic activity along the ancient volcanic front continued until at least approximately 2.1 Ma. The presence of magnetic anomalies between the two volcanic fronts suggests that the volcanic front has moved gradually westward. This shift can be explained by the termination of asthenospheric upwelling and/or the rapid retreat of the Ryukyu Trench after its change in subduction direction.

  8. A new genus and species of hatschekiid copepod (Siphonostomatoida) from groupers (Actinopterygii: Serranidae) collected off the Ryukyu Archipelago, Japan.

    PubMed

    Uyeno, Daisuke

    2013-01-01

    A new genus and species of copepod, Mihbaicola sakamakii n. g., n. sp., belonging to the siphonostomatoid family Hatschekiidae, is described based on the females collected from inside the tissue of the branchiostegal membrane in three species of the groupers, Epinephelus fasciatus (Forsskål) (type-host), E. merra Bloch and Cephalopholis leopardus (Lacépède), collected off Okinawa-jima Island and Iriomote-jima Island, Ryukyu Archipelago, North Pacific Ocean. The new genus can be distinguished from other hatschekiid genera by a combination of the following characters in the female: the head is composed of the cephalosome and the pedigerous somite; the cephalothorax is expanded into a pair of posteroventral lobes carrying leg 1; legs 1 and 2 are biramous and composed of the protopod and both rami are 2-segmented; leg 3 is absent; and leg 4 is represented by a rounded lobe with a chitinous pointed apical process. PMID:23263944

  9. American Dissertations on Foreign Education: A Bibliography with Abstracts. Volume XVII. Pacific: American Samoa, Fiji, Guam, Papua New Guinea, Ryukyu Islands, Solomon Islands, Tonga, Trust Territory of the Pacific Islands (Micronesia), Tubuai (French Polynesia), Western Samoa.

    ERIC Educational Resources Information Center

    Parker, Franklin, Ed.; Parker, Betty June, Ed.

    The editors attempt to examine and abstract all locatable doctoral dissertations completed in the United States, Canada, and some European countries that pertain to the Pacific area. Specifically, these dissertations deal with American Samoa, Fiji, Guam, Papua New Guinea, Ryukyu Islands, Solomon Islands, Tonga, Trust Territory of the Pacific…

  10. Catastrophic impact of typhoon waves on coral communities in the Ryukyu Islands under global warming

    NASA Astrophysics Data System (ADS)

    Hongo, Chuki; Kawamata, Hideki; Goto, Kazuhisa

    2012-06-01

    Typhoon-generated storm waves generally cause mechanical damage to coral communities on present-day reefs, and the magnitude and extent of damage is predicted to increase in the near future as a result of global warming. Therefore, a comprehensive understanding of potential future scenarios of reef ecosystems is of prime interest. This study assesses the current status of coral communities on Ibaruma reef, Ryukyu Islands, on the basis of field observations, engineering and fluid dynamic models, and calculations of wave motion, and predicts the potential effects of a super-extreme typhoon (incident wave height,H = 20 m; wave period, T = 20 s) on the reef. On the present-day reef, massive corals occur in shallow lagoons and tabular corals occur from the reef crest to the reef slope. The observed distribution of corals, which is frequently attacked by moderate (H = 10 m, T = 10 s) and extreme (H = 10 m, T = 15 s) typhoons, is consistent with the predictions of engineering models. Moreover, this study indicates that if a super-extreme typhoon attacks the reef in the near future, massive corals will survive in the shallow lagoons but tabular corals on the reef crest and reef slope will be severely impacted. The findings imply that super-extreme typhoons will cause a loss of species diversity, as the tabular corals are important reef builders and are critical to the maintenance of reef ecosystems. Consequently, reef restoration is a key approach to maintaining reef ecosystems in the wake of super-extreme typhoons.

  11. Melting features along the western Ryukyu slab edge (northeast Taiwan) and Ryukyu slab tear (southernmost Okinawa Trough): Seismic evidence

    NASA Astrophysics Data System (ADS)

    Lin, J.; Hsu, S.; Sibuet, J.

    2003-12-01

    Behind the sedimentary Ryukyu arc lies the Okinawa Trough whose termination is located at the tip of the Ilan plain (northern Taiwan), just above the Ryukyu slab edge. The present-day active volcanic front, located 80-100 km above the Ryukyu slab, extends from Japan to Kueishantao Island, an islet situated 10-km offshore the Ilan plain. 3370 earthquakes recorded in northern Taiwan by 65 seismic land stations between December 1990 and May 1999 were used to determine the 3-D Vp and Vs velocity structures and Vp/Vs ratios. A low Vp, low Vs and high Vp/Vs sausage like body, about 20 km in diameter, lies within the Eurasian mantle wedge, on top of the western Ryukyu slab extremity, from depths ranging between 20 km and 100 km. We suggest that the friction of the Ryukyu slab edge against the Eurasian lithosphere and/or the upwelling of the underlying Philippine Sea plate lithospheric mantle around the slab edge would cause an abnormal heating resulting in the formation of partial melt. Part of this melt feeds obliquely the Kueishantao andesitic Island. An abnormal amount of volcanism occurs within the Okinawa Trough, east of a slab tear located 140 km from the Ryukyu slab edge. The power spectrum analysis of magnetic data shows the presence of a thick crust located above the slab tear, suggesting that a similar pattern to the one identified above of the Ryukyu slab edge might exist in the slab tear region, feeding obliquely this area of abnormal volcanism.

  12. Biology of Anopheles saperoi, an Endemic Species in Okinawajima, the Ryukyu Archipelago, Japan.

    PubMed

    Mannen, Kosuke; Toma, Takako; Minakawa, Noboru; Higa, Yukiko; Miyagi, Ichiro

    2016-03-01

    Biological studies of Anopheles saperoi were conducted using larval and adult mosquito collections in the northern part of Okinawajima of the Ryukyu Archipelago from June 2009 to July 2010. Anopheles saperoi was the most collected species in the northern Okinawajima, except Motobu Peninsula, where it was not collected. The southern distribution of An. saperoi was Sugita Stream, Nago City. Anopheles saperoi was collected throughout the year with reproduction (gonotrophic cycle) observed year-round. Immature densities varied for Hinna and Yona streams, and were negatively affected by precipitation patterns. Human attraction activity of females varied for by study area and collection time and was positively affected by temperature, but negatively by heavy rainfall. The greatest female human attraction activity was observed during 3:00-5:00 p.m., with peak at twilight. Parity rates varied from 23.1% to 83.3% throughout the year. PMID:27105212

  13. Morphological and genetic diversity of Briareum (Anthozoa: Octocorallia) from the Ryukyu Archipelago, Japan.

    PubMed

    Miyazaki, Yu; Reimer, James Davis

    2014-10-01

    The primary problem hindering the study of octocorals is the disordered situation regarding their taxonomy, chiefly caused by insufficient knowledge of valid morphological taxonomic characters. Briareum is an octocoral genus found in the Atlantic and Pacific in shallow tropical and subtropical waters, and occurs in both encrusting and branching colony forms. Their simple morphology and morphological plasticity have hindered taxonomic understanding of this genus. In this study three morphologically distinct types (= type-1, -2, and -3) of Briareum from the Ryukyu Archipelago and their genetic diversity were examined. Colony, anthostele morphology, and sclerite length were examined for each type. Four molecular markers (mitochondrial cytochrome c oxidase subunit 1, mitochondrial mismatch repair gene, nuclear 18S ribosomal DNA, internal transcribed spacer 2 (ITS2)) were used to evaluate molecular phylogenetic status of these variations. Although one morphological type ("deep" small colonies, = type-3) showed small differences in nuclear ITS2 sequences compared to the other two types, the remaining types had identical sequences for all molecular markers examined. The results suggest extremely low genetic diversity despite highly variable morphology of Briareum species in Okinawa. Nevertheless, considering the distribution patterns and discontinuous morphology of type-3 compared to the other two morphotypes, genetic isolation of type-3 is plausible. In Briareum, small variances in nuclear ITS2 sequences of type-3 may have much more importance than in molecular phylogenies of other octocorals. Further phylogenetic investigations and comparison with Briareum specimens from other regions are necessary to conclusively taxonomically identify the three types. PMID:25284389

  14. Pilot experiments in the control of bancroftian filariasis in Japan and Ryukyu*

    PubMed Central

    Sasa, Manabu

    1963-01-01

    In this paper the author reviews the literature on the distribution and epidemiology of filariasis in Japan and discusses the extensive programme of research on the disease that is at present being carried out there. As part of this programme, comparative pilot experiments were started in 1958, in several areas of differing filariasis endemicity, with the object of determining the most effective and economical methods for preventing and treating the disease. The results so far obtained from these pilot experiments, which are still in progress, suggest that a close approach to the eradication of filariasis from the endemic areas could be reached through the administration of diethylcarbamazine at a suitable dosage to microfilaria carriers and the simultaneous application of control measures against the vector mosquitos. PMID:13986607

  15. Distribution of marine organisms and its geological significance in the modern reef complex of the Ryukyu Islands

    NASA Astrophysics Data System (ADS)

    Iryu, Yasufumi; Nakamori, Toru; Matsuda, Shinya; Abe, Osamu

    1995-11-01

    Extensive investigations of biota in the reef complex around the Ryukyu Islands have revealed ecologic specificity of many benthic organisms and have shown that characteristic assemblages are found in each of the topographic zones and sub-areas. The moat is divisible into a nearshore seagrass bed and an offshore sand bottom. Both inner reef flat and outer reef flat are characterized by abundant occurrences of hermatypic corals and nonarticulated coralline algae. However, the former is dominated by branching and foliaceous forms of corals and various, large, fleshy, erect forms of algae, whereas the latter is dominated by encrusting and tabular forms of corals, lacking these algae. Corals and coralline algae are not present on the reef crest, which is covered by rubble and gravel, where algal turf and Sargassum are spreading. Encrusting and tabular forms of corals flourish on the shallower part of the reef slope, with high coverage, while, with increasing depth, the coverage decreases and the dominating coral forms change, with hemispherical and encrusting forms on the middle part of reef slope, and foliaceous and encrusting forms on the deeper part of reef slope. Nonarticulated coralline algae are distributed throughout the reef slope. The composition of coral and coralline algal assemblages changes dramatically with increasing depth. Foraminiferal-algal nodules, rhodoliths, are the most abundant constituent on the island shelf, commonly with Cycloclypeus carpenteri. There are likely to be two types of shelves in tropical to subtropical regions: nutrient-rich Halimeda-dominant and nutrient-poor rhodolith-dominant. Sediments abundant in bryozoan skeletons occur occasionally on the shelf.

  16. Distant Mt. Fuji, Island of Honshu Japan

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This distant view of Mt. Fuji, on the main home island of Honshu, Japan (34.0N, 139.0E) was taken from about 450 miles to the south. Evan at that great distance, the majestic and inspiring Mt. Fuji is still plainly visible and easily recognized as a world renowned symbol of Japan. The snow capped extinct volcano lies just a few miles south of Tokyo.

  17. The radiolarian evidence for the accretion of the Fu-saki Formation with the inferred oceanic plate stratigraphy: A case of weakly-metamorphosed accretionary complex in Ishigaki Jima, southern Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Nakae, Satoshi

    2013-09-01

    The island of Ishigaki Jima, located in the western part of the southern Ryukyu Arc, Japan, is underlain by a basement comprising the Tumuru and Fu-saki formations. The former is a pelitic glaucophane schist with a metamorphic age of 220-190 Ma, and the latter is a weakly metamorphosed accretionary complex, composed mainly of chert, mudstone and sandstone with minor amounts of limestone and mafic rocks. The Fu-saki Formation was weakly metamorphosed at ∼140 Ma. Latest Carboniferous-Early Jurassic microfossils have been obtained from the limestones, cherts and siliceous mudstones of this formation, but no fossils have been collected from the phyllitic mudstones. The radiolarian fauna of the phyllitic mudstones described herein indicates a late Pliensbachian-early Toarcian (Early Jurassic) age. This result, when combined with existing data, enables the reconstruction of an oceanic plate stratigraphy, showing a succession of (in ascending order) Upper Carboniferous-Triassic cherts, Sinemurian-lower Pliensbachian siliceous mudstones and upper Pliensbachian-lower Toarcian phyllitic mudstones and sandstones. The radiolarians from the phyllitic mudstones are important in constraining the timing of the accretion of the Fu-saki Formation to the base of the Tumuru Formation.

  18. Description of a new genus and a new species of gaeticine crab (Crustacea: Brachyura: Varunidae) from the Ryukyu Islands, and a review of Acmaeopleura Stimpson, 1858, and Sestrostoma Davie & N.K. Ng, 2007.

    PubMed

    Naruse, Tohru

    2015-01-01

    Acmaeopleura parvula Stimpson, 1858, the type species of the varunid Acmaeopleura Stimpson, 1858, is redescribed, and a neotype is designated. Examination of all three species of the gaeticine Sestrostoma Davie & N.K. Ng, 2007, revealed that, although the diagnostic characters of Sestrostoma proposed by the previous study are variable and mostly overlap with those of Acmaeopleura, they can still be distinguished from each other by the characters of the carapace, the thoracic sternite 2, the third maxillipeds, and the ambulatory legs. The subfamilial position of Acmaeopleura was assessed by comparing it with all gaeticine genera. Gaetice Gistel, 1848, the type genus of the subfamily, has a very characteristic structure of the third maxilliped and the anterior sternal plate, which are partially shared with Gopkittisak Naruse & Clark, 2009, Brankocleistostoma Števčić, 2011, Sestrostoma and Acmaeopleura in different combinations. The generic diagnostic characters of these four genera are unique among Varunidae and they are tentatively placed in Gaeticinae. A new genus and new species, which is allied to Sestrostoma but clearly distinguishable from all varunine genera, is described from Iriomote Island, Ryukyu Islands, Japan. PMID:25781740

  19. Fundamental structure model of island arcs and subducted plates in and around Japan

    NASA Astrophysics Data System (ADS)

    Iwasaki, T.; Sato, H.; Ishiyama, T.; Shinohara, M.; Hashima, A.

    2015-12-01

    The eastern margin of the Asian continent is a well-known subduction zone, where the Pacific (PAC) and Philippine Sea (PHS) plates are being subducted. In this region, several island arcs (Kuril, Northeast Japan, Southwest Japan, Izu-Bonin and Ryukyu arcs) meet one another to form a very complicated tectonic environment. At 2014, we started to construct fundamental structure models for island arcs and subducted plates in and around Japan. Our research is composed of 6 items of (1) topography, (2) plate geometry, (3) fault models, (4) the Moho and brittle-ductile transition zone, (5) the lithosphere-asthenosphere boundary, and (6) petrological/rheological models. Such information is basic but inevitably important in qualitative understanding not only for short-term crustal activities in the subduction zone (particularly caused by megathrust earthquakes) but also for long-term cumulative deformation of the arcs as a result of strong plate-arc/arc-arc interactions. This paper is the first presentation of our research, mainly presenting the results of items (1) and (2). The area of our modelling is 12o-54o N and 118o-164o E to cover almost the entire part of Japanese Islands together with Kuril, Ryukyu and Izu-Bonin trenches. The topography model was constructed from the 500-m mesh data provided from GSJ, JODC, GINA and Alaska University. Plate geometry models are being constructed through the two steps. In the first step, we modelled very smooth plate boundaries of the Pacific and Philippine Sea plates in our whole model area using 42,000 earthquake data from JMA, USGS and ISC. For 7,800 cross sections taken with several directions to the trench axes, 2D plate boundaries were defined by fitting to the earthquake distribution (the Wadati-Benioff zone), from which we obtained equi-depth points of the plate boundary. These equi-depth points were then approximated by spline interpolation technique to eliminate shorter wave length undulation (<50-100 km). The obtained

  20. Submerged karst landforms observed by multibeam bathymetric survey in Nagura Bay, Ishigaki Island, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kan, Hironobu; Urata, Kensaku; Nagao, Masayuki; Hori, Nobuyuki; Fujita, Kazuhiko; Yokoyama, Yusuke; Nakashima, Yosuke; Ohashi, Tomoya; Goto, Kazuhisa; Suzuki, Atsushi

    2015-01-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the southern Ryukyu Islands, Japan. The coastal seafloor at depths shallower than ~ 130 m has been subjected to repeated and alternating subaerial erosion and sedimentation during periods of Quaternary sea-level lowstands. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. Although these submerged karst landforms are covered by thick postglacial reef and reef sediments, their shapes and sizes are distinct from those associated with coral reef geomorphology. The submerged landscape of Nagura Bay likely formed during multiple glacial and interglacial periods. According to our bathymetric results and the aerial photographs of the coastal area, this submerged karst landscape appears to have developed throughout Nagura Bay (i.e., over an area of approximately 6 × 5 km) and represents the largest submerged karst in Japan.

  1. A Crustal Structure Study of the Southern Ryukyu Subduction Zone by Using the Aftershock Data

    NASA Astrophysics Data System (ADS)

    Cho, Y.; Lin, J.; Lee, C.

    2011-12-01

    The region along the Ryukyu subduction zone is known as a tsunami disaster zone. The biggest tsunami (85 m) of Japan history was recorded in the Ishigaki Island, Ryukyu, in 1771. The paleo-tsunami events show that it has a frequency of about 150 years. This thread makes the Ryukyu subduction zone as a concerned field for the earthquake studies. However, due to the long distance from the east coast of Taiwan, this is an area out of the effective earthquake detection zone from the Central Weather Bureau network. A main shock of M = 6.9 occurred near the Ishigaki Island in 2009 August 17. After this event, we quickly deployed the OBS and found many aftershocks with the magnitude greater than 5.0. The main shock was 240 km, NE direction from the Hualien city, Taiwan. If a tsunami occurred, it took only less than 15 minutes to arrive the coast. From the recorded data, we picked the P- and S-wave using the 1-D module (iasp91). There were 1500 recorded events during those time range, and most of the earthquakes were located around the Nanao Basin. Based on this, we study the southern Ryukyu subduction zone structure by using the results from focal mechanism solution. From the earthquake relocation it shows that two main groups of aftershocks. They tend in northwest - southeast with a left-lateral strike-slip fault. The left-lateral strike-slip fault is the main structures that link with the splay faults at the southern Ryukyu Trench. The stability and extension of the splay faults are one of the major concerns for the occurrence of mega earthquake. More than 500-km long of the splay fault, such as that in the Indonesia, Chile and Japan subduction zones, has attacked by mega earthquakes in the recent years. The second group of those aftershocks was located in the Gagua Ridge near the Ryukyu Trench. This group may represent the ridge structure relate to the Taitung canyon fault. The front of Ryukyu Trench was being as a locked subduction zone where it is easily to

  2. Activity of Small Repeating Earthquakes along Izu-Bonin and Ryukyu Trenches

    NASA Astrophysics Data System (ADS)

    Hibino, K.; Matsuzawa, T.; Uchida, N.; Nakamura, W.; Matsushima, T.

    2014-12-01

    There are several subduction systems near the Japanese islands. The 2011 Mw9.0 Tohoku-oki megathrust earthquake occurred at the NE Japan (Tohoku) subduction zone. We have revealed a complementary relation between the slip areas for huge earthquakes and small repeating earthquakes (REs) in Tohoku. Investigations of REs in these subduction zones and the comparison with Tohoku area are important for revealing generation mechanism of megathrust earthquakes. Our target areas are Izu-Bonin and Ryukyu subduction zones, which appear to generate no large interplate earthquake. To investigate coupling of plate boundary in these regions, we estimated spatial distribution of slip rate by using REs. We use seismograms from the High Sensitivity Seismograph Network (Hi-net), Full Range Seismograph Network of Japan (F-net), and permanent seismic stations of Japan Meteorological Agency (JMA), Tohoku University, University of Tokyo, and Kagoshima University from 8 May 2003 (Izu-Bonin) and 14 July 2005 (Ryukyu) to 31 December 2012 to detect REs along the two trenches, by using similarity of seismograms. We mainly follow the procedure adopted in Uchida and Matsuzawa (2013) that studied REs in Tohoku area to compare our results with the REs in Tohoku. We find that the RE distribution along the Ryukyu trench shows two bands parallel to the trench axis. This feature is similar to the pattern in Tohoku where relatively large earthquakes occur between the bands. Along the Izu-Bonin trench, on the other hand, we find much fewer REs than in Tohoku or Ryukyu subduction zones and only one along-trench RE band, which corresponds to the area where the subducting Pacific plate contacts with the crust of the Philippine Sea plate. We also estimate average slip rate and coupling coefficient by using an empirical relationship between seismic moment and slip for REs (Nadeau and Johnson, 1998) and relative plate motion model. As a result, we find interplate slip rate in the deeper band is higher than

  3. Photosymbiotic ascidians from Pari Island (Thousand Islands, Indonesia).

    PubMed

    Hirose, Euichi; Iskandar, Budhi Hascaryo; Wardiatno, Yusli

    2014-01-01

    Photosymbiotic ascidian fauna were surveyed in the subtidal zone off Pari Island in the Thousand Islands (Java Sea, Indonesia). Nine species were recorded: Didemnum molle, Trididemnum miniatum, Lissoclinum patella, L. punctatum, L. timorense, Diplosoma gumavirens, D. simile, D. simileguwa, and D. virens. All of these species have been previously recorded in the Ryukyu Archipelago, Japan. Diplosoma gumavirens and D. simileguwa were originally described from the Ryukyu Archipelago in 2009 and 2005, respectively, and all of the observed species are potentially widely distributed in Indo-West Pacific coral reefs. PMID:25061385

  4. Two new species in the Echinoderes coulli group (Echinoderidae, Cyclorhagida, Kinorhyncha) from the Ryukyu Islands, Japan

    PubMed Central

    Yamasaki, Hiroshi; Fujimoto, Shinta

    2014-01-01

    Abstract Two new species belonging to the Echinoderes coulli group are described with their external morphologies and sequences of nuclear 18S rRNA and 28S rRNA genes, and mitochondrial COI gene. The first species, Echinoderes komatsui sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 8, laterodorsal tubules on segment 10, inverted triangle or wide oval shaped large sieve plates, lateral terminal accessory spines in female, and short tips of ventral pectinate fringe on segment 10. The second species, Echinoderes hwiizaa sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 7–9, midlateral tubules on segment 8, laterodorsal tubules on segment 10, large narrow oval shaped sieve plates on segment 9, and thick, short and blunt lateral terminal spines about 10–15% of trunk length. The diagnostic characters and key to species of E. coulli group are provided as well. PMID:24624018

  5. Two new species in the Echinoderes coulli group (Echinoderidae, Cyclorhagida, Kinorhyncha) from the Ryukyu Islands, Japan.

    PubMed

    Yamasaki, Hiroshi; Fujimoto, Shinta

    2014-01-01

    Two new species belonging to the Echinoderes coulli group are described with their external morphologies and sequences of nuclear 18S rRNA and 28S rRNA genes, and mitochondrial COI gene. The first species, Echinoderes komatsui sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 8, laterodorsal tubules on segment 10, inverted triangle or wide oval shaped large sieve plates, lateral terminal accessory spines in female, and short tips of ventral pectinate fringe on segment 10. The second species, Echinoderes hwiizaa sp. n., is characterized by absence of acicular spines, and presence of lateroventral tubules on segments 5 and 7-9, midlateral tubules on segment 8, laterodorsal tubules on segment 10, large narrow oval shaped sieve plates on segment 9, and thick, short and blunt lateral terminal spines about 10-15% of trunk length. The diagnostic characters and key to species of E. coulli group are provided as well. PMID:24624018

  6. Submerged Humid Tropical Karst Landforms Observed By High-Resolution Multibeam Survey in Nagura Bay, Ishigaki Island, Southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kan, H.; Urata, K.; Nagao, M.; Hori, N.; Fujita, K.; Yokoyama, Y.; Nakashima, Y.; Ohashi, T.; Goto, K.; Suzuki, A.

    2014-12-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the South Ryukyu Islands, Japan. This is the first description of submerged humid tropical karst using multibeam bathymetry. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results with a grid size of 1 m over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. We assume that Nagura Bay was a large karst basin in which older limestone remained submerged, thus preventing corrosion and the accumulation of reef sediments during periods of submersion, whereas the limestone outcropping on land was corroded during multiple interglacial and glacial periods. Based on our bathymetric result together with aerial photographs of the coastal area, we conclude that the submerged karst landscape has likely developed throughout the whole of Nagura Bay, covering an area of ~6 × 5 km. Accordingly, this area hosts the largest submerged karst in Japan. We also observed abundant coral communities during our SCUBA observations. The present marine conditions of Nagura Bay are characterized by low energy (calm sea) and low irradiance owing to the terrestrial influence. Such conditions have been emphasized by the presence of large undulating landforms, which cause decreases in wave intensity and irradiance with depth. These characteristics have acted to establish unique conditions compared to other coral reef areas in the Ryukyu Islands. It may play an important role in supporting the regional coral reef ecosystem.

  7. Estimation of coupling factor in the northern part of Ryukyu trench by using 2D FEM

    NASA Astrophysics Data System (ADS)

    Nakao, S.; Maeno, S.; Goto, K.

    2009-12-01

    Philippine Sea plate (PH) subducts beneath Ryukyu Arc, where Nansei Islands are located, at the Ryukyu trench. Coupling factor has been studied in the subduction zones around the Japan Island since GEONET GPS network of GSI, Japan were deployed. The coupling factors of zero and 13 % in this subduction zone were estimated. The northern part of Okinawa trough spreads in the direction of East-West. It is difficult to make a model of subduction zone that spreading of Okinawa trough is taken into account. We make 2-dimensional Finite Element (FEM) model to calculate the displacement pattern on the plate. The 2-D model is taken into account for the subduction of PH plate and spreading of Okinawa trough. GeoFEST FEM program (Parker et al, 2008) is used in this calculation. We also try to estimate coupling factor by trial and error mothod. We make two cross sections which are perpendicular to the trench axis of Ryukyu trench. One is located on Tanegashima Island and the other is Amami-Oshima Island. The boundary of subducted PH plate is determined based on the hypocenter distribution by Goto et al. (2008). The thickness of Ryukyu Arc is 25km based on the structure of seismic velocity by Iwasaki et al. (1990). Elastic constants of crust and mantle are adopted by Suito et al. (2002). The direction of movement of PH plate with respect to the Ryukuy Arc is derived from Euler vectors: one is Amur plate with respect to PH plate (Miyazaki and Heki, 2001) and the other is the direction of Ryukyu Arc with respect to Amur plate (Nishimura et al., 2004). The direction of subduction of PH plate with respect to Ryukyu Arc is calculated by using Euler vectors which estimated by Nishimura et al. (2004). Spreading rate of Okinawa trough is given at upper part of the western edge of the 2-D model. Amount of spreading of Okinawa trough is calculate at the western potion of Ryukyu Arc by the Euler vector of Nishimura et al. (2004). The depth of coupling region of plates is from 20 to 30km

  8. Studies on the chironomid midges (Diptera, Chironomidae) of the Nansei Islands, southern Japan.

    PubMed

    Sasa, M

    1990-06-01

    The Nansei Islands are located in the subtropical zone of the western Pacific Ocean between Kyushu and Taiwan, and are composed of the two main island groups, the Amami and the Ryukyu Archipelagoes. This area has been known for the presence of a number of indigenous animal species. Prior to the present studies, collections of the chironomids mainly in the urban areas of the three main islands of the Ryukyus were carried out by Sasa and Hasegawa, and a total of 42 species, including 25 new species, were recorded. Additional collections of the chironomids mainly in the mountainous areas of this region were carried out by the present author during 1988 and 1989, and a total of 26 species (including 12 new species) were recorded from Amami Island, and a total of 27 species (including 10 new species) were recorded from the Ryukyu Islands. Eight species among them, including 3 new species, were common to the two archipelagos. PMID:2214255

  9. Elucidation of denitrification mechanism in karstic Ryukyu limestone aquifer

    NASA Astrophysics Data System (ADS)

    Hijikawa, K.

    2014-12-01

    Nitrate (NO3-) concentrations in public water supplies have risen above acceptable levels in many areas of the world including Japan, largely as a result of contamination by human and animal waste and overuse of fertilizers. A previous study has characterized nitrate concentrations in groundwater in this area is a higher than the upper value (44mgL-1) of environmental quality criteria on one hands. On the other hand, there exists points where the concentration of nitric acid is not detected, which suggests the possibility of denitrification. During early 2000, a new analytical procedure for nitrate isotopic measurement, termed the "denitrifier method", was established. With the development of the nitrate isotope tracer method, much research has been reported detailing sources of groundwater nitrate and denitrification mechanisms. This study presents a pilot case study (in the southern part of Okinawa Main Island, Japan, where Ryukyu limestone is extensively distributed) using the combined stable isotope ratios of major elements (C, N and S) as net recorders of the biogeochemical reactions with the aim of elucidation of denitrification mechanism in Ryukyu limestone aquifer. As a result, significant decreases in nitrate concentrations due to denitrification were observed in groundwater at some locations, which induced increases in isotope ratios up to 59.7‰ for δ15NNO3. These points of groundwater were located above the cutoff wall of the underground dam and near the fault. It is considered that the residence time of the groundwater is longer than the other points at these denitrification points, and that reduction condition tends to be formed in the groundwater. However, the rapid rise of the groundwater level due to rainfall is likely to occur in the Ryukyu limestone aquifer, where the ground water was found to have changed dynamically from the reduction condition to the oxidation condition which a denitrification (has not occured)does not occur. Moreover, the

  10. Exhumation of Triassic HP-LT rocks by upright extrusional domes and overlying detachment faults, Ishigaki-jima, Ryukyu islands

    NASA Astrophysics Data System (ADS)

    Osozawa, Soichi; Wakabayashi, John

    2012-10-01

    The Tomuru Formation of Ishigaki-jima in the southernmost part of the Ryukyu arc, comprises blueschist facies subduction complex rocks metamorphosed in Triassic time. D1 structures related to subduction, blueschist facies mineral growth, and possibly early stages of exhumation, are deformed by D2 structures that appear to reflect the last stage of exhumation. D2 structures define several anticlines with parasitic overturned folds verging away from anticlinal axes. The shortening recorded by this deformation appears to reflect upward extrusion relative to flanking material. The anticlines are flanked by detachment faults with normal sense-of-shear parallel to D2 vergence. Hanging wall rocks that include the Fusaki Formation, an accretionary prism with early Cretaceous metamorphic ages, and late Eocene limestone, conglomerate, and andesitic volcanics. The Eocene strata contain metamorphic detritus derived from the Tomuru and Fusaki Formations indicating pre-late Eocene surface exposure of these units. Ultramafic rocks and gabbro blocks of the Tomuru Formation were incorporated by sedimentary sliding into the trench prior to subduction and high-pressure metamorphism rather than being emplaced as diapirs along a post-metamorphic fault as previously proposed. Geochronologic, metamorphic, and thermal considerations suggest exhumation of the Tomuru Formation to relatively shallow crustal depths prior to or concurrent with early Cretaceous metamorphism of the Fusaki Formation. Arcward-vergent thrusting may have placed the younger, and formerly structurally lower, subduction complex (Fusaki Formation) over the older one (Tomuru Formation). D2 extrusional doming began after the emplacement of the Fusaki Formation at high structural levels. The D2 transport directions are subparallel to the strike of the orogen suggesting that the upright extrusion may have occurred along a forearc strike-slip fault system. This final stage of exhumation concluded in the late Eocene with

  11. Occurrence of bovine dermatophilosis in the southernmost islands of Japan.

    PubMed

    Kinjo, E; Motonaga, H; Matayoshi, E; Kudo, S; Watanabe, K; Hara, M; Tabuchi, K; Momotani, E; Azuma, R

    1981-01-01

    Such cutaneous symptoms as characteristic incrustation and alopecia were noticed in 25 calves of the indigenous Japanese Black breed grazing on subtropical islands in Japan over a period of April, 1978 to February, 1980. These islands were Ishigaki, Kuro, Yonaguni and Tarama belonging to the Sakishima Islands. Microbiological and pathological examination on three of these calves revealed that the calves were affected with dermatophilosis caused by Dermatophilus congolensis. The disease in these calves seemed to be the same as that reported previously in other countries, since it attacked young calves in a humid district with an abundant rainfall. It broke out first on Ishigaki Island and subsequently on the other islands in 3 years. Discussion was made on factors inducing these outbreaks. PMID:7341992

  12. Discrepancy in the degree of population differentiation between color-morph frequencies and neutral genetic loci in the damselfly Ischnura senegalensis in Okinawa Island, Japan.

    PubMed

    Inomata, Nobuyuki; Hironaka, Kumiko; Sawada, Kouji; Kuriwada, Takashi; Yamahira, Kazunori

    2015-06-01

    Evaluation of relative contribution of natural selection and stochastic processes to population differentiation has been of great interest in evolutionary biology. In a damselfly, Ischnura senegalensis, females show color dimorphism (gynochrome vs. androchrome), and color-morph frequencies are known to greatly vary among local populations within Okinawa Island, a small island of Ryukyu Archipelago, Japan. In this study, to examine the effects of natural selection and stochastic processes on the within-island variation in color-morph frequencies, we compared the degree of population differentiation at the color-morph locus with that at a mitochondrial DNA region and ten nuclear microsatellite loci. F ST values at the neutral loci were close to zero, indicating presence of sufficient gene flow (dispersal of adult individuals) between the local populations. In contrast, F ST values at the color-morph locus were significantly different from zero. These results suggest that variation in female color-morph frequencies observed among local populations in Okinawa Island has been caused by divergent selection acting on the phenotype and/or genes tightly linked with the color locus. PMID:25633100

  13. [Three Cases of Tsutsugamushi Disease in Miyakojima Island, Okinawa, Japan].

    PubMed

    Nakamura, Kei; Shinzato, Takashi

    2015-03-01

    Tsutsugamushi disease (Scrub thyphus) has been reported from all over Japan except the Hokkaido area. In Okinawa, only one patient was reported in 2001, who was infected outside Okinawa Prefecture. The first case infected in Okinawa was reported at Miyakojima Island in 2008. We report herein on the second case diagnosed in 2010, and the third and fourth in 2011, and all three patients were suspected to have been infected at Ikemajima Island adjacent to the island of Miyakojima. The patients recovered without any severe complications after antibiotic therapy with tetracyclines. We should take Tsutsugamushi disease into consideration in the differential diagnosis for a patient with fever, skin rash, and/or eschar even in the Okinawa area. Implementation of appropriate information and education about the disease should be carried out for local residents and tourists. PMID:26552125

  14. Mid to late Holocene sea-surface temperature reconstruction using fossil corals from Kume Island, Ryukyu, Japan

    NASA Astrophysics Data System (ADS)

    Seki, A.; Yokoyama, Y.; Suzuki, A.; Kawakubo, Y.; Okai, T.; Miyairi, Y.; Matsuzaki, H.; Namizaki, N.; Kan, H.

    2012-12-01

    The relative warmth and stability of the Holocene was punctuated by several brief cold events. Although these cold events on a global scale are widely reported, the lack of records from regions such as the East China Sea (ECS) results in an incomplete understanding of the underlying cooling mechanism. Late Quaternary climate anomaly, at around 4.2 ka evidence found in elsewhere, is a time of such abrupt climate change, and mechanisms of this event have not been understood. Here, we present a coral-based paleo-SST (sea-surface temperature) reconstruction from the ECS to unveil Holocene variability in strength of the Kuroshio Western Boundary Current and the East Asian Monsoon (EAM). Our new data confirm that cold conditions prevailed at 3.8 cal kyr BP, and were started after 4.5 cal kyr BP. The timing of this cold event is consistent with previously reported Pulleniatina Minimum Event (PME, 4.5-3.0 ka) (e.g., Ujiié and Ujiié, 1999). While PME had not been resolved seasonality, our high-resolution data clearly indicate a different seasonal response of summer and winter SST . This result provides an important insight into the mechanism of the millennium scale cold event in the ECS, where the region affected by EAM (Seki et al., 2012).

  15. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    PubMed

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands. PMID:26513585

  16. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan

    PubMed Central

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J.; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands. PMID:26513585

  17. Effects of herbicides on coral and seasonal distribution in water and sediments collected from rivers and coral reefs of the Ryukyu Archipelago, Japan

    NASA Astrophysics Data System (ADS)

    Kaneshiro, A.; Fujimura, H.; Oomori, T.; Gima, S.; Suzuki, Y.; Casareto, B. E.; Higuchi, T.; Sagawa, T.

    2011-12-01

    Introduction Coral reefs are subjected to artificial chemicals such as herbicide and pesticides. Diuron [N'-(3, 4-dichlorophenyl)-N, N-dimethylurea] is one of the active constituent contained in a herbicide. Although acute effects of diuron on coral are reported by several researchers, longer-period toxicity with lower level concentration and synergistic effect between the herbicide and soil sedimentation from river water have not been studied. We investigated the concentration level, distribution, seasonal variation and accumulation of several herbicides and pesticides in coral reef and river in Ishigaki Island and Okinawa Island, and estimated the rates of carbon production of calcification and photosynthesis to access the effects of herbicides on coral. Materials and Methods Water and sediment samples were collected from Todoroki river and Shiraho coral reef in Ishigaki Island and several rivers from Okinawa Island in August 2010 to August 2011. Diuron and other active constituents were extracted using a solid-phase column and measured with a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Corals for the experiment were collected from Okinawa Island and incubated in glass bottles. Seawater adjusted several concentrations of herbicide was continuously supplied to the bottles. Coral calcification and photosynthesis were estimated based on the change in total alkalinity and pH during a few hours when we temporary cease the water flow. Results and Discussion Higher diuron of 563 ng/L in water and 26 μg/kg in sediment was detected at the headwater of the Todoroki river in Ishigaki. in June. Sugarcane plantation is prevailing in Todoroki river area and rainwater can tend to gather topographically to upstream of the river. The higher concentration at the headwater decreased to 23 ng/L toward the river mouth. On the whole, the concentrations were higher during summer and lower in the other seasons in Ishigaki. On the other hand, seasonal variation was not

  18. Japan.

    PubMed

    1987-02-01

    Japan is composed of 4 main islands and more than 3900 smaller islands and has 317.7 persons/square kilometer. This makes it one of the most densely populated nations in the world. Religion is an important force in the life of the Japanese and most consider themselves Buddhists. Schooling is free through junior high but 90% of Japanese students complete high school. In fact, Japan enjoys one of the highest literacy rates in the world. There are over 178 newspapers and 3500 magazines published in Japan and the number of new book titles issued each year is greater than that in the US. Since WW1, Japan expanded its influence in Asia and its holdings in the Pacific. However, as a direct result of WW2, Japan lost all of its overseas possessions and was able to retain only its own islands. Since 1952, Japan has been ruled by conservative governments which cooperate closely with the West. Great economic growth has come since the post-treaty period. Japan as a constitutional monarchy operates within the framework of a constitution which became effective in May 1947. Executive power is vested in a cabinet which includes the prime minister and the ministers of state. Japan is one of the most politically stable of the postwar democracies and the Liberal Democratic Party is representative of Japanese moderate conservatism. The economy of Japan is strong and growing. With few resources, there is only 19% of Japanese land suitable for cultivation. Its exports earn only about 19% of the country's gross national product. More than 59 million workers comprise Japan's labor force, 40% of whom are women. Japan and the US are strongly linked trading partners and after Canada, Japan is the largest trading partner of the US. Foreign policy since 1952 has fostered close cooperation with the West and Japan is vitally interested in good relations with its neighbors. Relations with the Soviet Union are not close although Japan is attempting to improve the situation. US policy is based on

  19. Japan.

    PubMed

    1989-02-01

    Japan consists of 3900 islands and lies off the east coast of Asia. Even though Japan is one of the most densely populated nations in the world, its growth rate has stabilized at .5%. 94% of all children go to senior high school and almost 90% finish. Responsibility for the sick, aged, and infirmed is changing from the family and private sector to government. Japan was founded in 600 BC and its 1st capital was in Nara (710-1867). The Portuguese, the 1st Westerners to make contact with Japan in 1542, opened trade which lasted until the mid 17th century. US Navy Commodore Matthew Perry forced Japan to reopen in 1854. Following wars with China and Russia in the late 1800s and early 1900s respectively, Japan took part in World Wars I and II. In between these wars Japan invaded Manchuria and China. The US dropped an atomic bomb on Hiroshima and Nagasaki and the Japanese surrendered in September, 1945 ending World War II (WWII). Following, WWII, the Allied Powers guided Japan's establishment as a nonthreatening nation and a democratic parliamentary government (a constitutional monarchy) with a limited defense force. Japan remains one of the most politically stable of all postwar democracies. The Liberal Democratic Party's Noboru Takeshita became prime minister in 1987. Japan has limited natural resources and only 19% of the land is arable. Japanese ingenuity and skill combine to produce one of the highest per hectare crop yields in the world. Japan is a major economic power, and its and the US economies are becoming more interdependent. Its exports, making up only 13% of the gross national product, mainly go to Canada and the US. Many in the US are concerned, however, with the trade deficit with Japan and are seeking ways to make trade more equitable. Japan wishes to maintain good relations with its Asian neighbors and other nations. The US and Japan enjoy a strong, productive relationship. PMID:12178004

  20. Magma Genesis of Sakurajima, the Quaternary post- Aira caldera volcano, southern Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Suzuki, J.; Yoshikawa, M.; Kobayashi, T.; Miki, D.; Takemura, K.

    2012-12-01

    Sakurajima volcano is the Quaternary post-caldera volcano of Aira caldera, which was caused by the eruption of huge amount of silicic pyroclastics, situated on Ryukyu arc, southern Kyushu Island, Japan. This volcano is quite active, so it can be considered that the preparation of next caldera-forming eruption with huge amount of silicic magma is proceeding. It is, therefore, expected that the investigation of magma genesis of Sakurajima volcano give us information for the mechanism generating huge amount of silicic magma, which cause the caldera formation. We analyzed major and trace elements with Sr, Nd and Pb isotopic compositions of volcanic rocks from Sakurajima volcano. We sampled (ol) - opx - cpx - pl andesite and dacite from almost all the volcanic units defined by Fukuyama and Ono (1981). In addition to Sakurajima samples, we also studied basaltic rocks erupted at pre-caldera stage of the Aira caldera to estimate the primary magma of Sakurajima volcano. Major and trace element variations generally show linear trends on the Harker diagrams, with the exception of P2O5 and TiO2. Based on the trend of P2O5 vs.SiO2, we divided studied samples low-P (P2O5 < 0.15 wt. %) and high-P (P2O5 > 0.15 wt. %) groups and these groups also display two distinct trends on TiO2-SiO2 diagram. The composition of trace elements shows typical island arc character as depletion of Nb and enrichments of Rb, K and Pb, suggesting addition of aqueous fluids to the mantle wedge. The Zr and Nb concentrations make a liner trend (Zr/Nb = 27) and this trend across from tend of MORB (Zr/Nb = 35) to that of crustal materials (Zr/Nb=17). The Sr, Nd and Pb isotopic compositions broadly plot to on the mixing curve connecting MORB-type mantle and sediments of the Philippine Sea Plate, indicating that the primary magma was generated by partial melting of MORB-type mantle wedge, which was hydrated with fluids derived from the subducted Philippine Sea sediments. But we found that our data plot apart

  1. Numerical analysis of the paleotsunami sizes through simulation of a large coralline boulder movement at Ishigaki Island, Japan

    NASA Astrophysics Data System (ADS)

    Hisamatsu, A.; Goto, K.; Imamura, F.

    2013-12-01

    Sakishima Islands (southern Ryukyu Islands), Japan, have been frequently affected by large tsunamis through the historical ages. The AD1771 Meiwa tsunami was an extreme event and the run-up height was ~30 m in maximum. The source model of the AD1771 Meiwa tsunami is still controversial: (1) earthquake plus landslide, (2) tsunami earthquake, and (3) splay fault models. The islands were also affected by the prehistoric tsunamis according to the geological evidence. For example, numerous coral boulders that were transported by paleotsunamis, including AD1771 event, were reported at the islands. The corals that constitute the boulders had once lived in the coral reefs fringing the islands and died when they were cast ashore to the land. Therefore, it is possible to estimate the timing of their deposition by using radiocarbon dating technique. In fact, the radiocarbon dating of Porites tsunami boulders at Sakishima Islands indicates that tsunamis had occurred repeatedly within a 150-400 years interval. However, the sizes of each tsunami are still uncertain. Hence, an important question has remained: whether there were any tsunami(s) in the past that were equivalent or larger in size comparing with the AD1771 Meiwa tsunami. In this study, we numerically investigated the transportation of a very large paleotsunami boulder at the southeastern part of Ishigaki Island, one of Sakishima Islands, using a boulder transport model in order to evaluate the sizes of paleotsunamis prior to the AD1771 event. The boulder that we used is called 'tsunami ufu-ishi' and it is the largest coralline boulder (>500 t) in Ishigaki Island. It is deposited approx. 100 m from the shoreline and 10 m in elevation. It was probably transported from the coral reef by the tsunami around 2000 years ago according to the radiocarbon dating. However, it is not necessarily that the boulder reached its present position due to one tsunami event 2000 years ago. In fact, according to the paleomagnetic analysis

  2. Forearc deformation and megasplay fault system of the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Hsu, S.; Yeh, Y.; Sibuet, J.; Tsai, C.; Doo, W.

    2011-12-01

    A great tsunami caused by a subduction earthquake had struck south Ryukyu islands and killed ~12000 people in 1771. Here we report the existence of a megasplay fault system along the south Ryukyu forearc. Analyses of deep multi-channel seismic reflection profiles indicate that the megasplay fault system is rising from the summit of a ~1 km high mount sitting on a ~5° landward dipping subducted plate interface. The fault system has accumulated large strain as evidenced by the active and widespread normal faults in the inner wedge. The along-trench length of the megasplay fault system is estimated to be ~450 km. The origin of this south Ryukyu megasplay fault system is linked to the subduction of elevated ridges parallel to the fracture zones. In contrast, no similar splay fault system is found in the west of 125. 5°E where the oblique subduction has produced shear zones along the south Ryukyu forearc. We infer that the megasplay fault system is responsible for the 1771 south Ryukyu tsunami. Likewise, after a quiescence of ~240 years, a near-future great earthquake and tsunami is anticipated as the extensional feature is strongly widespread over the south Ryukyu forearc.

  3. Distinct Phylogeographic Structures of Wild Radish (Raphanus sativus L. var. raphanistroides Makino) in Japan.

    PubMed

    Han, Qingxiang; Higashi, Hiroyuki; Mitsui, Yuki; Setoguchi, Hiroaki

    2015-01-01

    Coastal plants with simple linear distribution ranges along coastlines provide a suitable system for improving our understanding of patterns of intra-specific distributional history and genetic variation. Due to the combination of high seed longevity and high dispersibility of seeds via seawater, we hypothesized that wild radish would poorly represent phylogeographic structure at the local scale. On the other hand, we also hypothesized that wild radish populations might be geographically differentiated, as has been exhibited by their considerable phenotypic variations along the islands of Japan. We conducted nuclear DNA microsatellite loci and chloroplast DNA haplotype analyses for 486 samples and 144 samples, respectively, from 18 populations to investigate the phylogeographic structure of wild radish in Japan. Cluster analysis supported the existence of differential genetic structures between the Ryukyu Islands and mainland Japan populations. A significant strong pattern of isolation by distance and significant evidence of a recent bottleneck were detected. The chloroplast marker analysis resulted in the generation of eight haplotypes, of which two haplotypes (A and B) were broadly distributed in most wild radish populations. High levels of variation in microsatellite loci were identified, whereas cpDNA displayed low levels of genetic diversity within populations. Our results indicate that the Kuroshio Current would have contributed to the sculpting of the phylogeographic structure by shaping genetic gaps between isolated populations. In addition, the Tokara Strait would have created a geographic barrier between the Ryukyu Islands and mainland Japan. Finally, extant habitat disturbances (coastal erosion), migration patterns (linear expansion), and geographic characteristics (small islands and sea currents) have influenced the expansion and historical population dynamics of wild radish. Our study is the first to record the robust phylogeographic structure in wild

  4. Distinct Phylogeographic Structures of Wild Radish (Raphanus sativus L. var. raphanistroides Makino) in Japan

    PubMed Central

    Han, Qingxiang; Higashi, Hiroyuki; Mitsui, Yuki; Setoguchi, Hiroaki

    2015-01-01

    Coastal plants with simple linear distribution ranges along coastlines provide a suitable system for improving our understanding of patterns of intra-specific distributional history and genetic variation. Due to the combination of high seed longevity and high dispersibility of seeds via seawater, we hypothesized that wild radish would poorly represent phylogeographic structure at the local scale. On the other hand, we also hypothesized that wild radish populations might be geographically differentiated, as has been exhibited by their considerable phenotypic variations along the islands of Japan. We conducted nuclear DNA microsatellite loci and chloroplast DNA haplotype analyses for 486 samples and 144 samples, respectively, from 18 populations to investigate the phylogeographic structure of wild radish in Japan. Cluster analysis supported the existence of differential genetic structures between the Ryukyu Islands and mainland Japan populations. A significant strong pattern of isolation by distance and significant evidence of a recent bottleneck were detected. The chloroplast marker analysis resulted in the generation of eight haplotypes, of which two haplotypes (A and B) were broadly distributed in most wild radish populations. High levels of variation in microsatellite loci were identified, whereas cpDNA displayed low levels of genetic diversity within populations. Our results indicate that the Kuroshio Current would have contributed to the sculpting of the phylogeographic structure by shaping genetic gaps between isolated populations. In addition, the Tokara Strait would have created a geographic barrier between the Ryukyu Islands and mainland Japan. Finally, extant habitat disturbances (coastal erosion), migration patterns (linear expansion), and geographic characteristics (small islands and sea currents) have influenced the expansion and historical population dynamics of wild radish. Our study is the first to record the robust phylogeographic structure in wild

  5. Field Observations of Meteotsunami in Kami-koshiki Island, Japan

    NASA Astrophysics Data System (ADS)

    Asano, T.; Yamashiro, T.; Nishimura, N.

    2012-12-01

    BACKGROUND Meteotsunami; atmospherically induced destructive ocean waves in the tsunami frequency band, are known in Japan by the local term "abiki", literally meaning "net-dragging waves" in Japanese. Large abiki occur in bays and harbors along the west coast of Kyushu almost every year during winter and early spring. On 24-25 February, 2009, Urauchi Bay, located on west coast of Kami-Koshiki Island on the southeast coast of Kyushu, was subjected to a destructive meteotsunami. In this event, a maximum sea surface height of 3.1 m was observed at the inner part of the bay. At least 18 boats capsized and eight houses were flooded. This event surpassed the previous record height for an abiki in Japan: 278 cm in Nagasaki Bay, also located west coast of Kyushu, in 1979. Generally, such an elongated inlet with narrow mouth as Urauchi bay provides calm water conditions even when offshore weather is stormy. Therefore, the area is regarded as a suitable place for the farming of large fish with a high market value. Possible damage to the extensive fish cage system as a result of meteotsunami events is of concern, especially because aquaculture is the main industry in the isolated islands. Forecasting of meteotsunami is a serious request from the local people. AIMS The objectives of the present study are to detect a meteotsunami event in Urauchi Bay and to clarify the meteorological and hydrodynamic conditions related to its occurrence. This work attempts to observe the whole process of a meteotsunami event: generation offshore, resonance while it propagates, and finally amplification in the bay. Observations were conducted over a period of 82 days; 12 January to 4 April, 2010, aiming to record large secondary oscillations. A comprehensive measuring system for sea level, current and barometric pressure fluctuations was deployed covering not only inside and near Urauchi Bay but also further offshore in the vicinity of Mejima in the East China Sea. MAIN RESULTS 1) Large

  6. Melting features along the Ryukyu slab tear, beneath the southwestern Okinawa Trough

    NASA Astrophysics Data System (ADS)

    Lin, Jing-Yi; Hsu, Shu-Kun; Sibuet, Jean-Claude

    2004-10-01

    The present-day active volcanic front associated with the Ryukyu subduction zone extends from Japan to the Ilan plain (northern Taiwan) and is located within the Okinawa Trough, 80-100 km above the Ryukyu slab. An abnormal amount of arc volcanism, which consists of basalt, andesite and rhyolite occurs within the southwestern Okinawa Trough, above a slab tear of the Ryukyu subduction zone (CBVT). The power spectrum analysis of magnetic data shows the occurrence of a thin crust above the slab tear and a thick crust beneath this volcanic area. We suggest that an excess of H2O-rich fluid might occur at the slab tear and might increase the melt flux. Both are conveyed obliquely to the uppermost mantle and lower crust CBVT magmas. After interactions, basaltic magmas would rise up, accounting for the contrast of magnetization between this volcanic body and the adjacent OT crust.

  7. A mega-splay fault system and tsunami hazard in the southern Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Hsu, Shu-Kun; Yeh, Yi-Ching; Sibuet, Jean-Claude; Doo, Wen-Bin; Tsai, Ching-Hui

    2013-01-01

    In April 1771, a subduction earthquake generated a great tsunami that struck the south Ryukyu islands and killed ˜12,000 people, whereas its mechanism is still enigmatic (Nakata and Kawana, 1995; Nakamura, 2006; Matsumoto et al., 2009). In this paper, we show its probable source on a mega-splay fault system existing along the southern Ryukyu forearc. Analyses of deep multi-channel seismic reflection profiles indicate that the mega-splay fault system is rising from the summit of a ˜1 km high ridge situated at a ˜5° landward dipping plate interface. An outer ridge marks the seafloor outcrop of the splay fault system and separates the landward inner wedge and the oceanward outer wedge. The inner wedge is uplifting and exhibits widespread normal faulting while the outer wedge shows folded structures. The mega-splay fault system is parallel to the Ryukyu Trench east of 125.5°E and is estimated to be ˜450 km long. The origin of this south Ryukyu mega-splay fault system is ascribed to a resistant subduction of the elevated transverse ridges associated with the subducting portion of the trench-parallel Luzon-Okinawa Fracture Zone. In contrast, no similar splay fault is found west of 125.5°E where the oblique subduction has produced large shear zones along the south Ryukyu forearc. We infer that a thrust earthquake linked to the mega-splay fault system is responsible for the south Ryukyu tsunami. However, another possible scenario of generating a large tsunami affecting the south Ryukyu islands is that the subducted ridge in the western end of the mega-splay fault system nucleated a large earthquake and simultaneously triggered the ˜100 km long E-W trending strike-slip fault west of 125.5°E and induced a southward-dipping tsunami-genic subsidence. In any case, after a quiescence of ˜241 yr, a large earthquake and tsunami is anticipated in the south Ryukyu forearc in the near future.

  8. Blood meal identification and feeding habits of uranotaenia species collected in the ryukyu archipelago.

    PubMed

    Toma, Takako; Miyagi, Ichiro; Tamashiro, Mikako

    2014-09-01

    To know the blood meal in the stomach of Uranotaenia species, blood-fed mosquitoes were collected by 4 methods at different sites in the mountain forest of 3 islands, Amamioshima, Okinawajima, and Iriomotejima in the Ryukyu Archipelago, Japan from 2005 to 2012. One hundred twenty-four blood-fed Uranotaenia mosquitoes of 7 species (Ur. jacksoni, nivipleura, ohamai, yaeyamana, annandalei, lateralis, and macfarlanei) were collected. The collection rates are 0.26, 0.6, 0.31, and 0.66 by black light trap, black light blue with dry ice trap, frog call trap, and sweeping net, respectively. The blood meals of 107 females (86.3%) were successfully identified by a polymerase chain reaction-based method. All Uranotaenia species fed on cold-blooded animals, especially amphibians (99.1%), and notably on frogs. They would feed readily on available frogs in a given region having no close connection with the breeding (calling) season of each frog. They also fed on reptiles (0.9%), but not on warm-blooded animals. PMID:25843097

  9. Verrucostoma, a new genus in the Bionectriaceae from the Bonin Islands, Japan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verrucostoma freycinetiae gen. et sp. nov. collected on dead leaves of Freycinetia boninensis (Pandanaceae) in Hahajima, Bonin (Ogasawara) Islands, Tokyo, Japan, is described and illustrated. The new genus is characterized by having pale orange perithecia with protuberances around the perithecial ap...

  10. Souther portion of Island of Kyushu, Japan, as seen from the Apollo 7

    NASA Technical Reports Server (NTRS)

    1968-01-01

    City of Kagoshima and Kagoshima Bay area of the southern portion of the island of Kyushu, Japan, as seen from the Apollo 7 spacecraft during its 9th revolution of the earth. Photographed from an altitude of 125 nautical miles, at ground elapsed time of 12 hours and 10 minutes.

  11. The 1768 and 1791 Okinawa tsunamis in the Ryukyu Trench region

    NASA Astrophysics Data System (ADS)

    Nakamura, M.

    2013-12-01

    Risk of the great earthquakes and tsunamis has been assumed to be low in the Ryukyu Trench because the interplate coupling is weak and great interplate earthquakes (> M8.0) had not been recorded historically for about 300 years. However, recent study revealed that the 1771 Yaeyama earthquake (M8.5 from tsunami heights distribution) at south Ryukyu Trench and the 1911 Kikaijima earthquake (M 8.0) at north-central Ryukyu Trench were the interplate earthquakes. We need re-examine the great historical earthquakes in the Ryukyu Trench. Two historical tsunamis which occurred on 1768 and 1791 in the Okinawa Island were documented in the old document 'Kyuyo' (formal chronicles of Ryukyu). I investigated the source fault model of two tsunami events using numerical simulations of tsunami and earthquake shaking, and showed that their events would be the interplate earthquakes. One earthquake occurred at noon of July 22th, 1768. The rock-walls of castle, grave of royal family were collapsed by the earthquake shaking around Naha, Okinawa Island. After the shaking, tsunami arrived Naha port and Zamami Island, which is west of Okinawa Island. Recorded tsunami heights were about 1 m at Naha port. Nine houses and rice fields were damaged by the inundation of the tsunami in the Zamami Island. Estimated tsunami heights were 4 and 5 m in the villages of the Zamami Island. The numerical modeling of tsunami and the estimation of earthquake shaking using empirical formula were employed, and the fault parameters of the 1768 earthquake were estimated. The faults were set to Okinawa Trough (M7.5 normal faults), southwest of Okinawa island (M7.5 normal faults), southwest of Okinawa island (M7.5 reverse fault), and Ryukyu Trench (M8.0 thrust faults). The computed tsunami heights and intensities of the ground shaking of the M7.5 reverse fault near the Zamami Island and the M8.0 interplate earthquake models are consistent with to the recorded ones. Another tsunami was also recorded in the

  12. Geographical origin of Leucobryum boninense Sull. & Lesq. (Leucobryaceae, Musci) endemic to the Bonin Islands, Japan

    PubMed Central

    Oguri, Emiko; Yamaguchi, Tomio; Tsubota, Hiromi; Deguchi, Hironori; Murakami, Noriaki

    2013-01-01

    Leucobryum boninense is endemic to the Bonin Islands, Japan, and its related species are widely distributed in Asia and the Pacific. We aimed to clarify the phylogenetic relationships among Leucobryum species and infer the origin of L. boninense. We also describe the utility of the chloroplast trnK intron including matK for resolving the phylogenetic relationships among Leucobryum species, as phylogenetic analyses using trnK intron and/or matK have not been performed well in bryophytes to date. Fifty samples containing 15 species of Leucobryum from Asia and the Pacific were examined for six chloroplast DNA regions including rbcL, rps4, partial 5′ trnK intron, matK, partial 3′ trnK intron, and trnL-F intergenic spacer plus one nuclear DNA region including ITS. A molecular phylogenetic tree showed that L. boninense made a clade with L. scabrum from Japan, Taiwan and, Hong Kong; L. javense which is widely distributed in East and Southeast Asia, and L. pachyphyllum and L. seemannii restricted to the Hawaii Islands, as well as with L. scaberulum from the Ryukyus, Japan, Taiwan, and southeastern China. Leucobryum boninense from various islands of the Bonin Islands made a monophylic group that was closely related to L. scabrum and L. javense from Japan. Therefore, L. boninense may have evolved from L. scabrum from Japan, Taiwan, or Hong Kong, or L. javense from Japan. We also described the utility of trnK intron including matK. A percentage of the parsimony-informative characters in trnK intron sequence data (5.8%) was significantly higher than that from other chloroplast regions, rbcL (2.4%) and rps4 (3.2%) sequence data. Nucleotide sequence data of the trnK intron including matK are more informative than other chloroplast DNA regions for identifying the phylogenetic relationships among Leucobryum species. PMID:23610621

  13. Unexpectedly complex gradation of coral population structure in the Nansei Islands, Japan.

    PubMed

    Zayasu, Yuna; Nakajima, Yuichi; Sakai, Kazuhiko; Suzuki, Go; Satoh, Noriyuki; Shinzato, Chuya

    2016-08-01

    To establish effective locations and sizes of potential protected areas for reef ecosystems, detailed information about source and sink relationships between populations is critical, especially in archipelagic regions. Therefore, we assessed population structure and genetic diversity of Acropora tenuis, one of the dominant stony coral species in the Pacific, using 13 microsatellite markers to investigate 298 colonies from 15 locations across the Nansei Islands in southwestern Japan. Genetic diversity was not significant among sampling locations, even in possibly peripheral locations. In addition, our results showed that there are at least two populations of A. tenuis in the study area. The level of genetic differentiation between these populations was relatively low, but significant between many pairs of sampling locations. Directions of gene flow, which were estimated using a coalescence-based approach, suggest that gene flow not only occurs from south to north, but also from north to south in various locations. Consequently, the Yaeyama Islands and the Amami Islands are potential northern and southern sources of corals. On the other hand, the Miyako Islands and west central Okinawa Island are potential sink populations. The Kerama Islands and the vicinity of Taketomi Island are potential contact points of genetic subdivision of coral populations in the Nansei Islands. We found that genetic population structure of A. tenuis in the Nansei Islands is more complex than previously thought. These cryptic populations are very important for preserving genetic diversity and should be maintained. PMID:27551399

  14. Detailed Analysis of Japanese Population Substructure with a Focus on the Southwest Islands of Japan

    PubMed Central

    Nishiyama, Takeshi; Kishino, Hirohisa; Suzuki, Sadao; Ando, Ryosuke; Niimura, Hideshi; Uemura, Hirokazu; Horita, Mikako; Ohnaka, Keizo; Kuriyama, Nagato; Mikami, Haruo; Takashima, Naoyuki; Mastuo, Keitaro; Guang, Yin; Wakai, Kenji; Hamajima, Nobuyuki; Tanaka, Hideo

    2012-01-01

    Uncovering population structure is important for properly conducting association studies and for examining the demographic history of a population. Here, we examined the Japanese population substructure using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC), which covers all but the northern region of Japan. Using 222 autosomal loci from 4502 subjects, we investigated population substructure by estimating FST among populations, testing population differentiation, and performing principal component analysis (PCA) and correspondence analysis (CA). All analyses revealed a low but significant differentiation between the Amami Islanders and the mainland Japanese population. Furthermore, we examined the genetic differentiation between the mainland population, Amami Islanders and Okinawa Islanders using six loci included in both the Pan-Asian SNP (PASNP) consortium data and the J-MICC data. This analysis revealed that the Amami and Okinawa Islanders were differentiated from the mainland population. In conclusion, we revealed a low but significant level of genetic differentiation between the mainland population and populations in or to the south of the Amami Islands, although genetic variation between both populations might be clinal. Therefore, the possibility of population stratification must be considered when enrolling the islander population of this area, such as in the J-MICC study. PMID:22509376

  15. Laboratory experiments and observations of cyclonic and anticyclonic eddies impinging on an island

    NASA Astrophysics Data System (ADS)

    Andres, Magdalena; Cenedese, Claudia

    2013-02-01

    experiments are conducted to investigate the interactions of self-propagating barotropic cyclones and baroclinic anticyclones with an island. Results are interpreted in the context of observations around Okinawa Island, Japan, where ubiquitous arrivals of cyclones and anticyclones on the southeastern side of the island influence the flow around it, thereby impacting both the Ryukyu Current's and the Kuroshio's transport. In the laboratory, baroclinic anticyclones generate a buoyant current that flows clockwise around an island whereas barotropic cyclones generate a counterclockwise current. In both cases, the interaction is governed by conservation of circulation Γ around the island, which establishes a balance between the dissipation along the island in contact with the eddy and the dissipation along the island in contact with the generated current. Laboratory results and scaling analysis suggest that the interaction between an anticyclone (cyclone) and Okinawa Island should result in an instantaneous increase (decrease) of the Ryukyu Current transport and a delayed increase (decrease) of the Kuroshio transport. The estimated delays are in good agreement with those obtained with field measurements suggesting that the dynamics at play in the laboratory may be relevant for the flow around Okinawa Island.

  16. A new strikingly-colored species of the genus Galathea Fabricius, 1793 (Crustacea: Decapoda: Anomura: Galatheidae) from the Ryukyu Islands, Japan.

    PubMed

    Osawa, Masayuki

    2015-01-01

    A new shallow-water squat lobster, Galathea ryuguu, is described on the basis of material obtained from a colony of unidentified sea fan of the genus Muricella Verrill, 1868. The new species is most closely allied to G. squamea Baba, 1979, but is distinguished by the ornamentation and armature of the carapace, third maxilliped, and ambulatory legs. PMID:26624645

  17. The variations of long time period slow slip events along the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Tu, Y. T.; Heki, K.

    2014-12-01

    Slow slip events (SSEs) are a type of slow earthquakes that can be observed with Global Positioning System (GPS) networks in the world. Those events are detected on intensely coupled plate boundaries such as Cascadia subduction zone (Dragert et al., 2001), western North America, Mexico (Kostoglodov et al., 2003), Alaska (Ohta et al., 2007) and Tokai and Boso areas (Ozawa et al., 2002, 2003), central Japan and are considered to have relations to large subduction thrust earthquakes. However, in southwestern Ryukyu trench where most of researchers believe that it should be a decoupled plate boundary, SSEs recur regularly and are located at a patch that is as deep as 20 to 40 km (Heki and Kataoka, 2008). For comprehending the characteristics and time variations of SSEs in this area, the GEONET GPS data of 16 years are used in this study. During 1997 to 2014, more than thirty SSEs are identified near Hateruma Island, Ryukyu. The average recurrence interval is calculated to be 6.3 months and release seismic moment is Mw 6.6 on average. However, the values of recurrence interval are not invariable. From 1997 to 2002, interval period of SSEs is 7.5 months, but during 2002 to 2008, the interval period decreases suddenly to 5.5 months. After 2008, the value restores to 7.2 months again. Furthermore, the slip amount of SSEs in this area varies with time. From 1997 to 2002, the slip is 9.5 cm/year; and during 2002 to 2008, the value slightly increases to 10.5 cm/year. However, in 2008 to 2013, the slip drops to 6.6 cm/year, but accord to the trend of cumulative slip, the slip value would increase in 2014. Considering these data, we find the slip values increase conspicuously in 2002 and 2013. Coincidentally, one Mw 7.1 thrust earthquake occurred in 2002 and earthquake swarm activity started in the Okinawa trough approximately 50km north of the SSE patch. In 2013, another earthquake swarm activity occurred in nearly the same area as the 2002 activity. This suggests that the

  18. Redescription of Alox chaunos Galil & Ng, 2007 (Crustacea: Decapoda: Brachyura: Leucosiidae) new to Japan; with notes on the male characters of A. latusoides (Sakai, 1937).

    PubMed

    Ohtsuchi, Naoya; Kawamura, Tomohiko

    2016-01-01

    The leucosiid crab Alox chaunos Galil & Ng, 2007 is reported from Japan for the first time, and redescribed on the basis of specimens from the Ryukyu Islands. The taxonomy of this species is discussed, and comparisons are made with A. rugosum (Stimpson, 1858), A. uru Naruse & Ng, 2006, and A. liklik Galil & Ng, 2015. Alox somphos Tan & Ng, 1995, is excluded from the fauna of Japan, the original record actually based on a specimen of A. chaunos. Male characters of A. latusoides are also described for the first time to differentiate this species from A. chaunos. PMID:27394895

  19. Melon fly, Bactrocera cucurbitae (Diptera: Tephritidae), infestation in host fruits in the Southwestern Islands of Japan before the initiation of Island-wide population suppression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern...

  20. Nematodes from raccoon dogs (Nyctereutes procyonoides viverrinus) introduced recently on Yakushima Island, Japan.

    PubMed

    Sato, Hiroshi; Suzuki, Kazuo; Aoki, Masanari

    2006-07-01

    Nematodes were collected from 14 raccoon dogs (Nyctereutes procyonoides viverrinus) on Yakushima Island, Kagoshima Prefecture (Kyushu), Japan, that were the progeny of recently introduced animals to this World Natural Heritage Area, probably within the last 2 decades. Seven nematode species (Toxocara tanuki, Ancylostoma kusimaense, Arthrostoma miyazakiense, Strongyloides planiceps, Trichuris vulpis, Gongylonema sp., and Dirofilaria immitis) were collected from the raccoon dogs. Two nematode species (Molineus legerae and Strongyloides martis) were collected from 2 Japanese weasels (Mustela itatsi) indigenous to this island that were killed by traffic accidents. Considering that foxes and other carnivores, except for weasels, dogs and cats, are not distributed on this island, most of soil-borne nematodes such as roundworms, hookworms, and threadworms in raccoon dogs should have been introduced by the original population from the mainland Japan, and the infection hence maintained at a high level by new generations. Recovery of the third-stage larvae of Gongylonema sp. from the esophagus of raccoon dogs was remarkably frequent (79%), suggesting that the animals might vigorously take insect hosts. Although S. martis have never been recorded from weasels in Japan until this study, this threadworm might be prevalent in a variety of mustelids in Eurasia. PMID:16891782

  1. Island-Arc Collision Dominates Japan's Sediment Flux to the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Codilean, A. T.; Korup, O.; Hayakawa, Y. S.; Matsushi, Y.; Saito, H.; Matsuzaki, H.

    2013-12-01

    Quantifying volumes and rates of delivery of terrestrial sediment to subduction zones is indispensable for refining estimates of the thickness of trench fills that may eventually control the location and timing of submarine landslides and tsunami-generating mega-earthquakes. Despite these motivating insights, knowledge about the rates of erosion and sediment export from the Japanese islands to their Pacific subduction zones has somewhat stagnated despite the increasing availability of highly resolved data on surface deformation, climate, geology, and topography. Traditionally, natural erosion rates across the island arc have been estimated from catchment topographic predictors of reservoir sedimentation rates that were recorded over several years to decades. We correct for a systematic bias in these predictions, and present new estimates of decadal to millennial-scale erosion rates of the Japanese terrestrial inner forearc, drawing on several unprecedented inventories of mass wasting, reservoir sedimentation, and concentrations of cosmogenic 10Be in river sands. Our data reveal that catchments draining Japan's eastern seaboard have distinctly different tectonic, lithological, topographic, and climatic characteristics, underscored by a marked asymmetric pattern of erosion rates along and across the island arc. Erosion rates are highest in the Japanese Alps that mark the collision of two subduction zones, where high topographic relief, hillslope and bedrock-channel steepness foster rapid denudation by mass wasting. Comparable, if slightly lower, rates characterize southwest Japan, most likely due to higher typhoon-driven rainfall totals and variability rather than the similarly high relief and contemporary uplift rates that are linked to subduction earthquake cycles, and outpace long-term Quaternary uplift. In contrast, our estimated erosion and flux rates are lowest in the inner forearc catchments that feed sediment into the Japan Trench. We conclude that

  2. Ribosomal DNA haplotype distribution of Bursaphelenchus xylophilus in Kyushu and Okinawa islands, Japan.

    PubMed

    Nose, Mine; Shiraishi, Susumu; Miyahara, Fumihiko; Ohira, Mineko; Matsunaga, Koji; Tobase, Masashi; Koyama, Takao; Yoshimoto, Kikuo

    2009-09-01

    Ribosomal DNA region sequences (partial 18S, 28S and complete ITS1, 5.8S, and ITS2) of the pinewood nematode (Bursaphelenchus xylophilus) were obtained from DNA extracted directly from wood pieces collected from wilted pine trees throughout the Kyushu and Okinawa islands, Japan. Either a 2569bp or 2573bp sequence was obtained from 88 of 143 samples. Together with the 45 rDNA sequences of pinewood nematode isolates previously reported, there were eight single nucleotide polymorphisms and two indels of two bases. Based on these mutations, nine haplotypes were estimated. The haplotype frequencies differed among regions in Kyushu island (northwest, northeast and center, southeast, and southwest), and the distribution was consistent with the invasion and spreading routes of the pinewood nematode previously estimated from past records of pine wilt and wood importation. There was no significant difference in haplotype frequencies among the collection sites on Okinawa island. PMID:22736814

  3. Superconducting gravimeter observation for identifying slow slip events at Ryukyu Trench

    NASA Astrophysics Data System (ADS)

    Imanishi, Y.; Nawa, K.; Tamura, Y.; Ikeda, H.; Miyaji, T.; Tanaka, Y.

    2012-12-01

    Analysis of the data from the dense GPS network of Japan (GEONET) revealed quasi-periodic occurrences of long-term slow slip events at the Ryukyu Trench (Heki and Kataoka, 2008). The recurrence period of the events is about half a year, much shorter than typically found in other regions where slow slips are known to take place. Therefore, this region provides an interesting field for investigating the nature of slow slip events. In February 2012, we started gravity observation using a superconducting gravimeter (SG) at the VERA Ishigakijima Station, National Astronomical Observatory of Japan. The Ishigakijima island is located slightly east off the presumed fault area of the slow slip events. Our purpose is to detect gravity changes associated with the slow slip events by making full use of the high resolution of the SG. Of particular interest is the possible effect of water on the slow slip events, which might be identified from gravity observations. In addition to the SG, we installed an FG5 absolute gravimeter at the Iriomotejima island, located about 10 km west of the Ishigakijima island. The SG used in this study (serial number CT36) is the one which was in operation at the Inuyama Seismological Observatory, Nagoya University for about ten years. Before moving it to Ishigakijima, we made a thorough examination of the instruments. Because we found a serious problem in transferring liquid helium because of the ice inside, we warmed up the Dewar to initialize it. This not only solved the ice problem but also resulted in a significant decrease of the heater power for the gravity sensor. As of this writing, we have about six months worth of data from the SG. The condition of the gravimeter is good except for the first month when temperature control was unstable. Because of the ground vibrations caused by the movement of the 20-m VLBI antenna (about 30 m apart from the SG), the noise level is significantly enhanced compared with other domestic SG stations. Also we

  4. The Role of Philippine Sea Plate to the Genesis of Quaternary Magmas of Northern Kyushu Island, Japan, Inferred from Along-Arc Geochemical Variations

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Yoshikawa, M.; Itoh, J.; Ujike, O.; Miyoshi, M.; Takemura, K.

    2013-12-01

    Quaternary volcanoes on Kyushu Island comprise volcanoes Himeshima, Futagoyama, Yufu-Tsurumi, Kuju, Aso, Kirishima and Sakurajima from north to south alongstrike the volcanic front. Adakitic lavas are observed from Yufu-Tsurumi and Kuju volcanoes in northern Kyushu (Kita et al., 2001; Sugimoto et al., 2007), whereas no Quaternary adakites were observed at Aso (e.g., Hunter, 1998) and the volcanoes south of Aso along the entire Ryukyu arc. Sugimoto et al. (2007) suggested that the trace element and Sr, Nd, and Pb isotopic compositions of adakitic magmas from Yufu-Tsurumi volcano indicate derivation of the magmas by partial melting of the subducting PSP. In contrast, Zellmer et al. (2012) suggested that these adakites may have formed by fractional crystallization of mantle-derived mafic magmas within the garnet stability field in the crust. The Honshu-Kyushu arc transition is a particular favorable setting to address these controversial models for the origin of the adakitic lavas, because of the potential relationship between the PSP materials and the alongstrike variation of the lava chemistry. The Palau-Kyushu ridge divides the oceanic crust of the PSP into northeastern and southwestern segments with ages of 26-15 (Shikoku Basin) and 60-40 Ma (West Philippine Basin), respectively (Mahony et al., 2011). Although there are no clear plate images beneath northern Kyushu, the northern extension of the Palau-Kyushu ridge potentially corresponds to the boundary between the SW Japan and Ryukyu arcs. If adakite genesis was related to the subducted slab rather than the overlying crust, then the spatial distribution of Quaternary adakites should correlate with the age of the subducted PSP. In order to test such correlation and elucidate the petrogenesis of the northern Kyushu adakites, we compiled major and trace elements and Sr-Nd-Pb isotope ratios from volcanoes along the arc front that includes the transition from adakitic to non-adakitic arc volcanism. Comprehensive

  5. Seismic structure of subducted Philippine Sea plate beneath the southern Ryukyu arc by receiver function and local earthquakes tomography

    NASA Astrophysics Data System (ADS)

    Nakamura, M.

    2012-12-01

    Seismic coupling of the Ryukyu subduction zone is assumed to be weak from the lack of historical interplate large earthquakes. However, recent investigation of repeating slow slip events (Heki & Kataoka, 2008), shallow low frequency earthquakes (Ando et al., 2012), and source of 1771 Yaeyama mega-tsunami (Nakamura, 2009), showed that the interplate coupling is not weak in the south of Ryukyu Trench. The biannually repeating SSEs (Mw=6.5) occur at the depth of 20-40 km on the upper interface of the subducted Philippine Sea plate beneath Yaeyama region, where earthquake swarm occurred on 1991 and 1992. To reveal the relation among the crustal structure, earthquake swarms, and occurrence of slow slip events (SSE), local earthquake tomography and receiver function (RF) analysis was computed in the southwestern Ryukyu arc. A tomographic inversion was used to determine P and S wave structures beneath Iriomote Island in the southwestern Ryukyu region for comparison with the locations of the SSE. The seismic tomography (Thurber & Eberhart-Phillips, 1999) was employed. The P- and S- wave arrival time data picked manually by Japan Meteorological Agency (JMA) are used. The 6750 earthquakes from January 2000 to July 2012 were used. For the calculation of the receiver function, the 212 earthquakes whose magnitudes are over 6.0 and epicentral distances are between 30 and 90 degrees were selected. The teleseicmic waveforms observed at two short-period seismometers of the JMA, and one broadband seismometer of F-net of National Research Institute for Earth Science and Disaster Prevention were used. The water level method (the water level is 0.01) is applied to original waveforms. Assuming that each later phase in a RF is the wave converted from P to S at a depth, I transformed the time domain RF into the depth domain one along each ray path in a reference velocity model. The JMA2001 velocity model is used in this study. The results of tomography show that the low Vp and high Vp

  6. Paleotsunamis from the central Kuril Islands segment of the Japan-Kuril-Kamchatka subduction zone

    NASA Astrophysics Data System (ADS)

    MacInnes, Breanyn; Kravchunovskaya, Ekaterina; Pinegina, Tatiana; Bourgeois, Joanne

    2016-07-01

    Paleotsunami records from the central Kuril Island segment of the Japan-Kuril-Kamchatka subduction zone indicate that the region has been frequently inundated by tsunamis. As many as 20-22 tsunami deposits are recognized on Matua Island for the past 3300 yr with an average tsunami recurrence interval of ∼150 yr, and 34-36 tsunami deposits are evident on Simushir Island for the past 2350 yr with an average recurrence of ∼65 yr. These intervals are short, but comparable to other segments of the Japan-Kuril-Kamchatka subduction zone. Results from all survey locations reveal shortening recurrence intervals toward the present, especially for the last 600 yr, indicating a possible preservation bias. On Simushir, tsunamis at least 11 m higher than the modern tsunamis in 2006 and 2007 occurred every ∼300 yr on average. On Matua, tsunamis with slightly farther inundation than the 2006 and 2007 tsunamis occurred every ∼215 yr while those with at least 100 m farther inland inundation occur every ∼750 yr. Our paleotsunami record almost certainly includes tsunamis that are not from great subduction zone earthquakes in the central Kuril segment: we expect the Matua record includes volcanic tsunamis and the Simushir record includes tsunamis from the southern Kuril segment.

  7. Science education in Elementary school by using of "Geopark", Oki Islands, Japan

    NASA Astrophysics Data System (ADS)

    Oku, S.; Matsumoto, I.

    2012-12-01

    The Oki islands are located at Japan sea coast side of southwest Japan and belonging to Shimane Prefecture. And there is rich Nature which is consist of mainly alkaline volcanic rocks and metamorphic rocks. Aiming at authorization "Geopark" authorization of Oki Islands, Geologist, Biologist, and residents of Oki Islands are doing investigation and advertisement. Promotion of the science education which utilized the precious Nature, or environmental education is very important in the viewpoint of the science literacy which can protect a Nature and the earth. In this presentation, we mainly propose activity at an elementary school about how to advance the science education by using of this precious Nature. Children learn about the geology which constitutes the ground, and its petro-genesis in the Science of the sixth grade of elementary school. The viewpoint of having been formed by volcano, Earthquake, etc, in long global time is important for the precious and beautiful geology which constitutes the ground. It is at the same time important for a global change to teach also about often doing serious damage to human beings or a living thing with an Earthquake, a volcano, tsunami, etc. That is, we can push (teaching beautiful geology and a precious living thing using "Geopark"), and can learn about the blessing and disaster of a Nature. Moreover, teaching materials and teaching tools like a local textbook or a signboard with which a teacher and a resident can teach them to a child are required.

  8. Upper mantle structure beneath the Japan Islands using single-scattering analysis

    NASA Astrophysics Data System (ADS)

    Tonegawa, T.; Hirahara, K.; Shibutani, T.; Shiomi, K.

    2006-12-01

    In the Japan subduction zone where the Pacific plate is subducting, we can investigate the dynamics of the upper mantle beneath the subduction zone, such as the structure of the descending slab, the undulation of the seismic discontinuities and its relation, by imaging the detailed structure beneath the Japan Islands. The high sensitivity accelerometer (hereafter tiltmeter) network has recently been deployed with high-density spacing (700 stations in Japan) by NIED, and these tiltmeters can be used as long-period seismometer. In this study, we used these recordings to image upper mantle discontinuities, including the subducting Pacific slab from the Japan trench and the 410 and 660 km discontinuities, beneath the Japanese Islands by calculating receiver functions with teleseismic waves. For deconvolution, since tiltmeter seismograms have just horizontal component, we obtained source-time function by stacking all of vertical components observed at F-net broadband stations, that is, we consider these stacked waveforms as source-time functions. We applied a low- pass filter of 0.16 Hz. Assuming all later phases of P-coda in receiver function are the P-to-S scattered phases, we migrated time-domain receiver functions to depth section using 1-D JMA velocity model. As a result, the seismic discontinuities correspoding to the oceanic Moho and lower boundary of the descending slab can be imaged down to 400 km and 500 km depth, respectively. The 410 km and 660 km discontinuities are clearly imaged, and our result also shows a depression of the 660 km discontinuity affected by the stagnant slab.

  9. Paleomagnetic evidence for post-Late Miocene intra-arc rotation of South Kyushu, Japan

    NASA Astrophysics Data System (ADS)

    Kodama, Kazuto; Nakayama, Ken-Ichi

    1993-02-01

    Paleomagnetism of sedimentary rocks of the late Miocene Uchiumigawa Group exposed in southeast Kyushu yielded 17 tilt-corrected paleomagnetic directions with significant westward declinations. Fourteen of these were of reversed polarity, and three at the intervening horizons were of antipodal normal polarity. The overall formation mean direction is D = 322.0°, I = 48.6° with α95 = 6.0°. This is statistically indistinguishable from the mean direction of D = 331.2°, I = 41.3° with α95 = 9.9° for the middle Miocene deposits in Tanegashima Island of the northern Ryukyu arc. The common mean direction is D = 333.2°, I = 45.1° with α95 = 4.9°. This indicates that both south Kyushu and the northernmost Ryukyu arc have experienced 27° ± 6° of counterclockwise rotation with respect to the Eurasian continent after the latest Miocene, or during the last 6 m.y. This counterclockwise rotation cannot be fully explained by either a conventional model which links an arc rotation with the formation of back-arc oceanic crust, or the collision of the Kyushu-Palau ridge with southwest Japan arc. We propose that this intra-arc rotation took place during the period of extension of the continental crust behind the north Ryukyu arc. This study demonstrates that arc rotation may generally occur when the back-arc spreading is of a much less advanced phase.

  10. A large self-potential anomaly on Unzen volcano, Shimabra peninsula, Kyushu island, Japan

    NASA Astrophysics Data System (ADS)

    Hashimoto, T.; Tanaka, Y.

    1995-02-01

    Self-potential (SP) observation was carried out in the summit area of Unzen, one of the active volcanoes in Kyushu island, Japan. We found a positive SP anomaly in the vicinity of the newly extruded lava dome. The potential difference across the anomaly exceeds 1000 mV per 500 m. Streaming potentials associated with subsurface hydrothermal convection seem to be the most reasonable mechanism for the positive anomaly. In association with the first emergence of the lava dome a sharp increase of SP was detected, which is considered to be a result of the growth of the hydro-thermal system.

  11. Microsatellite markers for Leucobryum boninense (Leucobryaceae), endemic to the Bonin Islands, Japan1

    PubMed Central

    Oguri, Emiko; Yamaguchi, Tomio; Kajita, Tadashi; Murakami, Noriaki

    2013-01-01

    • Premise of the study: Microsatellite primers were developed for Leucobryum boninense, endemic to the Bonin Islands, Japan, to investigate its level of genetic diversity and population genetic structure. • Methods and Results: Using next-generation sequencing, 21 primer sets were developed, among which nine loci were polymorphic in the populations of the Bonin Islands. Among these polymorphic loci, the number of alleles per locus ranged from two to 10 (mean = 3.444) and the expected heterozygosity ranged from 0.066 to 0.801 (mean = 0.338). • Conclusions: These results indicate the utility of the nine microsatellite markers that we developed for population genetic studies of L. boninense. PMID:25202543

  12. Distribution characteristics of polychlorinated biphenyls (PCBs) in coastal areas of Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Sheikh, M. A.; Nakama, F.; Oomori, T.

    2007-07-01

    Surface sediment and seawater samples were collected from coastal areas around Okinawa Island from September 2001 to May 2002. The samples were analyzed for total polychlorinated biphenyl (PCB) levels and homolog composition. The results show that total PCB levels ranged from 0.32 to 128.7 ng/g (dry wt.) in sediment and 1.59 to 2.48 ng/L in seawater. The levels exceed the Environmental Quality Standard (EQS) for water pollution of Japan. The distribution of PCB homolog showed different patterns in the sediments and seawaters. Penta-chlorobiphenyls (CBs) comprised the main congener group in seawater, while hexa-CBs were more abundant homologs in the sediments. The heavily contaminated sites featured higher CBs, including penta-CBs, hexa-CBs, and hepta-CBs, than those in less contaminated sites where tri-CBs dominated. This study provides current distribution and geochemical behavior of PCBs in the coastal areas around Okinawa Island.

  13. Japan.

    ERIC Educational Resources Information Center

    Geiger, Rita; And Others

    The document offers practical and motivating techniques for studying Japan. Dedicated to promoting global awareness, separate sections discuss Japan's geography, history, culture, education, government, economics, energy, transportation, and communication. Each section presents a topical overview; suggested classroom activities; and easily…

  14. Coastal Impacts of the March 11th Tohoku, Japan Tsunami in the Galapagos Islands

    NASA Astrophysics Data System (ADS)

    Lynett, Patrick; Weiss, Robert; Renteria, Willington; De La Torre Morales, Giorgio; Son, Sangyoung; Arcos, Maria Elizabeth Martin; MacInnes, Breanyn Tiel

    2013-06-01

    On March 11, 2011 at 5:46:23 UTC (March 10 11:46:23 PM Galapagos Local Time), the Mw 9.0 Great East Japan Earthquake occurred near the Tohoku region off the east coast of Japan, spawning a Pacific-wide tsunami. Approximately 12,000 km away, the Galapagos Islands experienced moderate tsunami impacts, including flooding, structural damage, and strong currents. In this paper, we present observations and measurements of the tsunami effects in the Galapagos, focusing on the four largest islands in the archipelago; (from west to east) Isabela, Santiagio, Santa Cruz, and San Cristobal. Access to the tsunami affected areas was one of the largest challenges of the field survey. Aside from approximately ten sandy beaches open to tourists, all other shoreline locations are restricted to anyone without a research permit; open cooperation with the Galapagos National Park provided the survey team complete access to the Islands coastlines. Survey locations were guided by numerical simulations of the tsunami performed prior to the field work. This numerical guidance accurately predicted the regions of highest impact, as well as regions of relatively low impact. Tide-corrected maximum tsunami heights were generally in the range of 3-4 m with the highest runup of 6 m measured in a small pocket beach on Isla Isabela. Puerto Ayora, on Santa Cruz Island, the largest harbor in the Galapagos experienced significant flooding and damage to structures located at the shoreline. A current meter moored inside the harbor recorded relatively weak tsunami currents of less than 0.3 m/s (0.6 knot) during the event. Comparisons with detailed numerical simulations suggest that these low current speed observations are most likely the result of data averaging at 20-min intervals and that maximum instantaneous current speeds were considerably larger. Currents in the Canal de Itabaca, a natural waterway between Santa Cruz Island and a smaller island offshore, were strong enough to displace multiple 5

  15. Heterogeneous stress state of island arc crust in northeastern Japan affected by hot mantle fingers

    NASA Astrophysics Data System (ADS)

    Shibazaki, Bunichiro; Okada, Tomomi; Muto, Jun; Matsumoto, Takumi; Yoshida, Takeyoshi; Yoshida, Keisuke

    2016-04-01

    By considering a thermal structure based on dense geothermal observations, we model the stress state of the crust beneath the northeastern Japan island arc under a compressional tectonic regime using a finite element method with viscoelasticity and elastoplasticity. We consider a three-layer structure (upper crust, lower crust, and uppermost mantle) to define flow properties. Numerical results show that the brittle-viscous transition becomes shallower beneath the Ou Backbone Range compared with areas near the margins of the Pacific Ocean and the Japan Sea. Moreover, several elongate regions with a shallow brittle-viscous transition are oriented transverse to the arc, and these regions correspond to hot fingers (i.e., high-temperature regions in the mantle wedge). The stress level is low in these regions due to viscous deformation. Areas of seismicity roughly correspond to zones of stress accumulation where many intraplate earthquakes occur. Our model produces regions with high uplift rates that largely coincide with regions of high elevation (e.g., the Ou Backbone Range). The stress state, fault development, and uplift around the Ou Backbone Range can all be explained by our model. The results also suggest the existence of low-viscosity regions corresponding to hot fingers in the island arc crust. These low-viscosity regions have possibly affected viscous relaxation processes following the 2011 Tohoku-oki earthquake.

  16. Theoretical epidemiology on bovine ephemeral fever outbreaks in Tanegashima Island, Kagoshima Prefecture of Japan in 1988.

    PubMed

    Ogawa, T; Fujisono, S

    1992-10-01

    From the end of September to November 1988, a compact scale of bovine ephemeral fever (BEF) outbreaks occurred suddenly in Tanegashima island of Kagoshima Prefecture, southern part of Kyusyu island of Japan. The BEF outbreak pattern showed epidemical characteristics as follows; (1) outbreak spread from few foci to zone during one month, and (2) the disease might be transmitted in farms with a fixed probability of adequate contact. By using the above aspects, we attempted to analyze the disease theoretically with the application of Poisson distribution and Reed-Frost model. The BEF incidence in farms was in well accord with the Poisson distribution. As the very rare event occurred in unit time or in unit area in this epidemic, the cattle population at risk were equivalently susceptible to BEF virus in this island, due to the influence of no vaccination to BEF control before the first outbreak. Similarly, the epidemic curve of the Reed-Frost model was proved to fit well the incidence observed in a farm, and the probability of adequate contact was induced as p = 0.226. If the cattle population is less than 5 in this farm, the outbreak would not occur in the first instance. PMID:1420574

  17. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    NASA Astrophysics Data System (ADS)

    Guo, X. Y.; Zhu, X.-H.; Long, Y.; Huang, D. J.

    2013-04-01

    Based on absolute geostrophic velocity calculated from repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured at the same sections from 1964 to 2011, we obtained temporally averaged nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over a section) through 4 sections along the Kuroshio path from the East China Sea (sections PN and TK) to south of Japan (sections ASUKA and 137E). In addition, we examined section OK east of the Ryukyu Islands in order to understand the contribution of Ryukyu Current to the Kuroshio nutrient transport south of Japan. The mean nitrate flux shows a subsurface maximum core with a value of 10, 10, 11, 11, and 6 mol m-2 s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The depth of subsurface maximum core changes among five sections and is approximately 400, 500, 500, 400, and 800 m at sections PN, TK, ASUKA, 137E, and OK respectively. The mean downstream nitrate transport is 199.3, 176.3, 909.2, 1385.5, and 341.2 kmol m-1 at sections PN, TK, ASUKA, 137E, and OK respectively. The nutrient transports at these sections suggest the presence of Kuroshio nutrient stream from its upstream region to downstream. The deep current structure of Ryukyu Current (section OK) makes it contribute more nitrate transport than the Kuroshio in the East China Sea (section TK) to the Kuroshio south of Japan. In addition, the positive difference between the downstream nitrate transport through section ASUKA and the sum of nitrate transports through sections TK and OK, as well as the positive difference of downstream nitrate transport between sections 137E and ASUKA, suggest that the Kuroshio recirculation significantly intensifies the downstream (eastward) nitrate transport by the Kuroshio.

  18. Resurrection of Rhynchoplax Stimpson, 1858, with the description of two new species from Japan and Australia (Crustacea: Decapoda: Brachyura: Hymenosomatidae).

    PubMed

    Komai, Tomoyuki; Poore, Gary C B

    2016-01-01

    Rhynchoplax Stimpson, 1858, is resurrected from synonymy with Halicarcinus White, 1846. Rhynchoplax hondai Takeda & Miyake, 1971, a species based on an immature female, is rediagnosed and two new species, R. magnetica n. sp. from northeastern Australia and R. minutula n. sp. from the Ryukyu Islands, Japan, are described. They differ from R. hondai in the shape of the rostrum, form of the subhepatic region and the armature of the pereopodal meri. All differ from the type species R. messor Stimpson, 1858, in having a longer and simple rostrum without supraocular pseudorostral spines and the absence of a postocular spine. PMID:27394510

  19. Japan.

    ERIC Educational Resources Information Center

    Jones, Savannah C.

    Materials for a secondary level, interdisciplinary social studies course on Japan are divided into introductory information, 14 classroom units, and study and evaluation materials. Introductory material includes lists of objectives and skills, an outline of Japanese history, and an explanation of Japan's name and flag. The units cover the…

  20. Japan

    ERIC Educational Resources Information Center

    Hawkins, John N.

    1986-01-01

    Analyzes the intergroup relations in Japanese society and Japan's educational system. Challenges the view that Japan is a homogeneous society by presenting the various forms of discrimination against Koreans, Ainu, and the burakumin. Suggests that despite ostracism and isolation, groups can affect public policy and achieve social advancement. (SA)

  1. A new species of Jesogammarus from the Iki Island, Japan (Crustacea, Amphipoda, Anisogammaridae)

    PubMed Central

    Tomikawa, Ko

    2015-01-01

    Abstract A new species of anisogammarid amphipod, Jesogammarus (Jesogammarus) ikiensis sp. n., is described from freshwaters in the Iki Island, Nagasaki Prefecture, Japan, based on results of morphological and molecular analyses. The new species is distinguished from all members of the genus by the combination of small number of setae on dorsal margins of pleonites 1–3, short and small number of setae on posterior margins of peduncular articles of antennae, mandibular article 1 without setae, well developed posterior lobes of accessory lobes of coxal gills on gnathopod 2 and pereopods 3–5, and pectinate setae on palmar margin of female gnathopod 2. A key to all the species of Jesogammarus is provided. PMID:26692798

  2. LEPTOSPIROSIS AFTER RECREATIONAL EXPOSURE TO WATER IN THE YAEYAMA ISLANDS, JAPAN

    PubMed Central

    NARITA, MASASHI; FUJITANI, SHIGEKI; HAAKE, DAVID A.; PATERSON, DAVID L.

    2009-01-01

    Leptospirosis is a global zoonotic disease with a variety of clinical manifestations. We report an outbreak of leptospirosis in the Yaeyama Islands, Japan, in the summer of 1999 associated with heavy rainfall. Fourteen people were diagnosed with leptospirosis and required hospitalization. All cases were found to have exposure to contaminated soil or water. A history of recreational activities involving water sports was more frequent (71%) than occupational risk factors related to agriculture or construction (29%). Fever was the primary symptom in all cases, followed by chills (93%), headache (86%), myalgias (57%) and conjunctival suffusion (57%). All cases were successfully treated with antimicrobial therapy except one patient who improved spontaneously. Jarisch-Herxheimer reactions were seen in six cases (43%). The increasing incidence of leptospirosis related to recreational sports is an important public health problem in resort areas. A high-index of suspicion, early treatment, and prevention are crucial in this latently endemic area. PMID:16222003

  3. Holocene reef associated carbonate sediments and their Pleistocene counterparts, Miyako Islands, Ryukyus, southwest of Japan

    SciTech Connect

    Tsuji, Y.; Yamamura, T.; Kodato, T.; Sunouchi, H.

    1988-01-01

    Holocene carbonate sedimentary facies distribution, from sea level to shelf slope about 1,000 m in depth, and its relationship to bathymeltry, off Miyako Island, Ryukyus, southwest of Japan were clarified by surveys with sidescan sonar, sparker, uniboom, sea-bottom camera, and sediment sampler. Six facies were recognized using the acoustic data, sample analytical data, and sea-bottom photographs. These are as follows: (A) Reef facies: made mainly of autochthonous hermatypic corals and encrusting algae, 0-60 m deep. (B) Inter-reef muddy facies: consists of very fine sand-size carbonate fraction and line mud, 20-60 m deep surrounded area be reefal relief and islands. (C) Inter-reef and near-reef sandy facies: characterized by tests of shallow benthic foraminifera Calcarina and Marginopora, and Halimeda fragments, 0-90 m deep. (D) Rhodolith and large foraminiferal gravelly shelf facies: contains pebble to cobble-size rhodolith and/and foraminifera Cycloclypeus and Operculina, 60-200 m deep. (E) Bryozoan sandy shelf facies: rich in byrozoan fragments, 80-200 m deep. (F) Shelf slope pelagic foraminiferal facies: dominated by pelagic foraminifera and pteropod molluscan tests, deeper than 200 m. Counterparts of these facies in emerged Pleistocene limestone sequences have been recognized in outcrops and core samples. The results of the marine survey on Holocene deposits made it easy to interpret the Pleistocene depositional environments and sea level changes.

  4. Philippine Sea Slab and South-Ryukyu Arc Sliver Accommodation of Arc-Continent Collision East of Taiwan

    NASA Astrophysics Data System (ADS)

    Lallemand, S.; Theunissen, T.; Font, Y.; Schnurle, P.; Lee, C.; Liu, C.

    2011-12-01

    The southern termination of the Ryukyu arc-trench system underwent a complex polyphased and extremely rapid tectonic evolution during the last 5 to 8 My. At first, the relative motion of the Philippine Sea plate (PSP) has changed about 5 My ago from a northward to a northwestward motion relative to Eurasia. Secondly, the Ryukyu trench has propagated from east to west during the same time period resulting in a tectonic inversion along the former passive margin of the South China Sea into the active margin of the S-Ryukyu trench. Thirdly, the convergence rate along the neo-formed S-Ryukyu trench dramatically increased from 8 to 13 cm/yr since at least 2 My when the Southern Okinawa Trough (SOT) started to rift. At the same time, the oceanic subduction of the South China Sea beneath the northern Manila arc progressively evolved into a continental subduction of the Chinese platform at the origin of the Taiwan orogen. The timing of these various kinematic and tectonic events should have been recorded in the deformed sedimentary basins and fold-and-thrust belts in the region. Unfortunately, a large part is now below the sea-level and no or a few age constraints are available. The recent joint project between Taiwan-USA & France (TAIGER & ACTS) gave us the opportunity to considerably increase the resolution of the seismic imagery around the island and especially in the most highly deformed area east of Taiwan along the S-Ryukyu forearc. We already knew that the seismic activity focussed in this region but we ignored how the converging plates deformed. We can now argue that the PSP strongly deforms in the vicinity of its deep interaction with the root of the Taiwan orogen. The north-dipping PSP slab buckles and tears along two diverging directions with a down-faulted part subducting beneath the SOT.

  5. ASTER-SRTM Perspective of Mount Oyama Volcano, Miyake-Jima Island, Japan

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Mount Oyama is a 820-meter-high (2,700 feet) volcano on the island of Miyake-Jima, Japan. In late June 2000, a series of earthquakes alerted scientists to possible volcanic activity. On June 27, authorities evacuated 2,600 people, and on July 8 the volcano began erupting and erupted five times over that week. The dark gray blanket covering green vegetation in the image is the ash deposited by prevailing northeasterly winds between July 8 and 17. This island is about 180 kilometers (110 miles) south of Tokyo and is part of the Izu chain of volcanic islands that runs south from the main Japanese island of Honshu. Miyake-Jima is home to 3,800 people. The previous major eruptions of Mount Oyama occurred in 1983 and 1962, when lava flows destroyed hundreds of houses. An earlier eruption in 1940 killed 11 people.

    This image is a perspective view created by combining image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard NASA's Terra satellite with an elevation model from the Shuttle Radar Topography Mission (SRTM). Vertical relief is exaggerated, and the image includes cosmetic adjustments to clouds and image color to enhance clarity of terrain features.

    The ASTER instrument is a cooperative project between NASA, JPL, and the Japanese Ministry of International Trade and Industry.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the

  6. First record of Plethus Hagen (Trichoptera, Hydroptilidae) from Japan, with description of a species.

    PubMed

    Ito, Tomiko; Saito, Rie

    2016-01-01

    The tropical and subtropical caddisfly genus Plethus Hagen (Hydroptilidae) is recorded from Japan for the first time. The species, Plethus ukalegon Malicky and Chantaramongkol 2007, originally described from Taiwan, is redescribed based on material from Iriomote-jima and Ishigaki-jima, southern Ryukyu Islands, the southernmost region of Japan. Female and immature stages are newly described and compared with Indonesian congeners. The early instar larva was associated with the adult through mitochondrial DNA sequence comparisons, and is described in the genus Plethus for the first time. Larvae live in fast-flowing waters such as hygropetric zones, rapid streams, and waterfalls. Final instar larvae make flattened cases of silk that they attach tightly on smooth rock surfaces. PMID:27615852

  7. A high-resolution hindcast of sub-mesoscale Kuroshio-islands-tide interactions in the Izu Islands region, south of Japan

    NASA Astrophysics Data System (ADS)

    Sil, S.; Miyazawa, Y.; Varlamov, S.; Waseda, T.; Guo, X.

    2012-12-01

    The well known western boundary current, Kuroshio, is very strong near the Izu islands region south of Japan, therefore interaction of the strong current with the islands is important to study as the island topography plays an important role in the ocean dynamics. To provide high resolution (1 kilometer) oceanic conditions near Kouzu island, we have started to use Stony Brook Parallel Ocean Model (SBPOM) which is a parallelized, free-surface, sigma-coordinate, primitive equation ocean modeling code based on the Princeton Ocean Model (POM). The lateral boundary conditions and temperature and salinity fields are derived from the coarse resolution operational model (JCOPE) and the model is forced from three-hourly NCEP atmospheric forcing fields. The period covered from July 01, 2011 to March 31, 2012. The higher resolution model is able to show the variability of Kuroshio flow and its interaction with the Izu islands. The comparisons with the coarse resolution (3 kilometer and 10 kilometer) JCOPE models show how mesoscale regime transits to sub-mesoscale regime due to its resolution. The interaction with the Izu islands are clear from the SBPOM simulation which is not clear in the other two models in the subsurface level, however the mesoscale features are reasonable good in all models. It is found that the transition is significantly affected by the islands-Kuroshio interaction. The performance of the model increases when the higher resolution atmospheric forcing and tide are applied in the forcing fields. We are planning to compare the model result with buoy observation near the Kouzu island to understand the dynamics of the interaction of the Kuroshio flow with the island.

  8. Wintertime urban heat island modified by global climate change over Japan

    NASA Astrophysics Data System (ADS)

    Hara, M.

    2015-12-01

    Urban thermal environment change, especially, surface air temperature (SAT) rise in metropolitan areas, is one of the major recent issues in urban areas. The urban thermal environmental change affects not only human health such as heat stroke, but also increasing infectious disease due to spreading out virus vectors habitat and increase of industry and house energy consumption. The SAT rise is mostly caused by global climate change and urban heat island (hereafter UHI) by urbanization. The population in Tokyo metropolitan area is over 30 millions and the Tokyo metropolitan area is one of the biggest megacities in the world. The temperature rise due to urbanization seems comparable to the global climate change in the major megacities. It is important to project how the urbanization and the global climate change affect to the future change of urban thermal environment to plan the adaptation and mitigation policy. To predict future SAT change in urban scale, we should estimate future UHI modified by the global climate change. This study investigates change in UHI intensity (UHII) of major metropolitan areas in Japan by effects of the global climate change. We performed a series of climate simulations. Present climate simulations with and without urban process are conducted for ten seasons using a high-resolution numerical climate model, the Weather Research and Forecasting (WRF) model. Future climate projections with and without urban process are also conducted. The future projections are performed using the pseudo global warming method, assuming 2050s' initial and boundary conditions estimated by a GCM under the RCP scenario. Simulation results indicated that UHII would be enhanced more than 30% in Tokyo during the night due to the global climate change. The enhancement of urban heat island is mostly caused by change of lower atmospheric stability.

  9. Macrogenomic Evidence for the Origin of the Black Fly Simulium suzukii (Diptera: Simuliidae) on Okinawa Island, Japan

    PubMed Central

    Adler, Peter H.; Huang, Yao-Te; Reeves, Will K.; Kim, Sam Kyu; Otsuka, Yasushi; Takaoka, Hiroyuki

    2013-01-01

    To determine the geographic origin of the black fly Simulium suzukii on Okinawa Island, Japan, macrogenomic profiles derived from its polytene chromosomes were compared with those of mainland and other insular populations of S. suzukii and of the isomorphic Simulium tani species complex. The Okinawan population is a chromosomally unique cytoform, designated ‘D,’ which is essentially monomorphic and differs by about 27 fixed rearrangements from the chromosomal standard sequence for the subgenus Simulium and by two fixed differences from its nearest known relative, representing the type of S. suzukii, on the main islands of Japan. Chromosomal band sequences revealed two additional, sympatric cytoforms of S. suzukii, designated ‘A’ and ‘B,’ each with species status, in Korea, and a third cytoform, designated ‘C,’ on Hokkaido, Japan. A new cytoform, ‘K,’ of S. tani from Malaysia, representing the type of S. tani, is more closely related to cytoforms in Thailand, as are populations from Taiwan previously treated as S. suzukii but more closely aligned with S. tani and newly recognized as cytoform ‘L’ of the latter nominal species. Rooting of chromosomal band sequences by outgroup comparisons allowed directionality of chromosomal rearrangements to be established, enabling phylogenetic inference of cytoforms. Of 41 macrogenomic rearrangements discovered in the five new cytoforms, four provide evidence for a stepwise origin of the Okinawan population from populations characteristic of the main islands of Japan. The macrogenomic approach applied to black flies on Okinawa Island illustrates its potential utility in defining source areas for other species of flies including those that might pose medical and veterinary risks. PMID:23951001

  10. Molecular phylogeny and geographic distribution of wood-feeding cockroaches in East Asian Islands.

    PubMed

    Maekawa, K; Lo, N; Kitade, O; Miura, T; Matsumoto, T

    1999-11-01

    Molecular phylogenetic relationships of the wood-feeding cockroach genera Salganea and Panesthia (Blaberidae; Panesthiinae) in East Asian Islands (Ryukyu archipelago and Taiwan Island) were analyzed based on the DNA sequence of the complete mitochondrial cytochrome oxidase II gene. Unweighted parsimony analysis resulted in high bootstrap support for relationships within Panesthia taxa; however, some nodes were unresolved between members of Salganea. Comparison of the number of transitions and transversions with genetic distance at each codon position suggested that saturation of third-codon substitutions has occurred between certain pairs of taxa. Consequently, differential weighting of substitutions at these sites was performed, which resulted in a substantial increase in resolution of Salganea relationships. The inferred phylogenies for both genera displayed good correspondence to the geographical locations of populations but however did not agree with previous subspecies designations based on morphological characters. It appears that both cockroach genera invaded the Ryukyu archipelago from the Taiwan region via a land-bridge present in the Miocene period. Invasion of the main islands of Japan by these cockroaches most likely occurred before the formation of the Tokara Tectonic Strait. Our study suggests that several barriers to gene flow have arisen and persisted over the past approximately 10 million years, which have caused segregation and vicariant speciation of the cockroach taxa of this region. PMID:10603264

  11. Interface between shamanism and psychiatry in Miyako Islands, Okinawa, Japan: a viewpoint from medical and psychiatric anthropology.

    PubMed

    Shimoji, A

    1991-12-01

    This study is the first report regarding the borderland between psychiatry and shamanism in Miyako Islands, Okinawa, Japan. Folk healing practices are still flourishing on the islands. Most mentally ill persons we examined admitted to having consulted shamans. Although there is a need to assess the positive and negative effects of shamanistic practices on Miyako Islands' health care system as a whole, this report indicates the urgent need to come to terms with the interaction between shamanism and psychiatry on a multidimensional level. We describe here psychotic illness attributed to kandaari. These cases underline the importance of understanding "the explanatory model" (Kleinman 1979) of people as regards the causes and the effective healing of illness. From the viewpoint of medical and psychiatric anthropology, aspects of the treatment of such patients in the biocultural context are described. PMID:1813672

  12. Estimated pressure source on Kozu Island volcano, South Central Japan, from GPS measurements (July 1996-August 1999)

    NASA Astrophysics Data System (ADS)

    Kimata, Fumiaki; Kariya, Shin-ichi; Fujita, Masayuki; Matsumoto, Kunio; Tabei, Takao; Segawa, Jiro; Yamada, Akiko

    2000-11-01

    Although the Kozu Island Volcano, one of the Izu Islands Volcanoes in the south part Central Japan, is an active volcano, there is no record of the eruption for about 1100 years since the last eruption in 833 A.D. Since 1988, frequent earthquake swarms are observed around the Kozu Island, and the uplift of 2-4 cm/yr is observed on the island by tidal observations. Station velocities detected by GPS measurements since 1989 show velocities that differ from the convergent velocity of the Philippine Sea plate calculated from plate motion models. A local GPS network with 12 stations is occupied around the volcano, and the GPS measurements are repeated every about six month since July 1996. Inflated deformation of 2-4 cm/yr are detected from the GPS measurements and the pressure source is estimated to be located in the northeastern part of the island at a depth of 2.1 km using Mogi solution. Negative gravity changes of more than 30 microgal are also measured above the pressure source in the period November 1998 to July 1999, consistent with uplift.

  13. P-wave anisotropic velocity tomography beneath the Japan islands: Large-scale images and details in the Kanto district

    NASA Astrophysics Data System (ADS)

    Ishise, M.; Koketsu, K.; Miyake, H.; Oda, H.

    2006-12-01

    The Japan islands arc is located in the convergence zone of the North American (NA), Amurian (AM), Pacific (PAC) and Philippine Sea (PHS) plates, and its parts are exposed to various tectonic settings. For example, at the Kanto district in its central part, these four plates directly interact with each, so that disastrous future earthquakes are expected along the plate boundaries and within the inland areas. In order to understand this sort of complex tectonic setting, it is necessary to know the seismological structure in various perspectives. We investigate the seismic velocity structure beneath the Japan islands in view of P-wave anisotropy. We improved a hitherto-known P-wave tomography technique so that the 3-D structure of isotropic and anisotropic velocities and earthquake hypocenter locations are determined from P-wave arrival times of local earthquakes [Ishise and Oda, 2005]. In the tomography technique, P-wave anisotropy is assumed to hold hexagonal symmetry with horizontal symmetry axis. The P-wave arrival times used in this study are complied in the Japan University Network Earthquake Catalog. The results obtained are summarized as follows; (1) the upper crust anisotropy is governed by the present-day stress field arising from the interaction between the plates surrounding the Japan islands arc, (2) the mantle anisotropy is caused by the present-day mantle flow induced by slab subduction and continental plate motion, (3) the old PAC slab keeps its original slab anisotropy which was captured when the plate was formed, while the youngest part of the PHS slab has lost the original anisotropy during its subduction and has gained new anisotropy which is controlled by the present-day stress field. We also carried out a further study on high-resolution seismic tomography for understanding the specific characteristics of the Kanto district. We mostly focused on the elucidation of the dual subduction formed by the PHS and PAC slabs using seismological data

  14. A new species of Plestiodon (Squamata: Scincidae) from Kuchinoshima Island in the Tokara Group of the Northern Ryukyus, Japan.

    PubMed

    Kurita, Kazuki; Hikida, Tsutomu

    2014-07-01

    A scincid lizard of the genus Plestiodon from Kuchinoshima Island in the Tokara Group of the Northern Ryukyus, Japan, has proved to be genetically and morphologically differentiated from any previously recognized species in the genus. We thus describe this island population as a new species, Plestiodon kuchinoshimensis. The new species shows characteristics of the P. latiscutatus species group, but differs from other species of this group by the combination of the following character states: postnasal absent; hatchling with five longitudinal light lines on dorsum; lateral light line on each side passing over ear opening and the sixth to eighth scale rows at midbody; dorsolateral light line beginning from behind supraoculars; patch of enlarged irregular scales on posterior femur absent; scale rows around midbody 27-32; and brownish background on the dorsal surface of the juvenile. PMID:25001918

  15. Electric and magnetic phenomena observed before the volcano-seismic activity in 2000 in the Izu Island Region, Japan

    PubMed Central

    Uyeda, S.; Hayakawa, M.; Nagao, T.; Molchanov, O.; Hattori, K.; Orihara, Y.; Gotoh, K.; Akinaga, Y.; Tanaka, H.

    2002-01-01

    Significant anomalous changes in the ultra low frequency range (≈0.01 Hz) were observed in both geoelectric and geomagnetic fields before the major volcano-seismic activity in the Izu Island region, Japan. The spectral intensity of the geoelectric potential difference between some electrodes on Niijima Island and the third principal component of geomagnetic field variations at an array network in Izu Peninsula started to increase from a few months before the onset of the volcano-seismic activity, culminating immediately before nearby magnitude 6 class earthquakes. Appearance of similar changes in two different measurements conducted at two far apart sites seems to provide information supporting the reality of preseismic electromagnetic signals. PMID:12032286

  16. Long-Range Transport of Perchlorate Observed in the Atmospheric Aerosols Collected at Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Arakaki, T.; Tanahara, A.; Oomori, T.; Miyagi, T.; Kadena, H.; Ishizaki, T.; Nakama, F.

    2007-12-01

    The study of perchlorate has become quite active in the U.S. in the last several years. Perchlorate has been recognized as a new environmental pollutant and it attracted much attention quickly in the world. The health concern about perchlorate stems from the fact that it displaces iodide in the thyroid gland, while iodine-containing thyroid hormones are essential for proper neural development from the fetal stage through the first years of life. In this study, we determined the concentrations of perchlorate ion present in the atmospheric aerosols collected in Okinawa Island, Japan. We then examined the relationships between the perchlorate concentrations and the environmental parameters and the climatic conditions peculiar to Okinawa. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS). Each sampling duration was one week. The quartz filters with aerosols were stirred with Milli-Q pure water for three hours before perchlorate ion was extracted. The extracted perchlorate ion concentrations were determined by ion chromatography (ICS-2000, DIONEX). The mean perchlorate concentration for the samples collected at CHAAMS was 1.83 ng/m3, and the minimum was 0.18 ng/m3. The samples collected during November 21-27, 2005, January 23-30, 2006 and April 24-01, 2006 had highest perchlorate concentrations. For these three samples, we performed back trajectory analysis, and found that the air mass for the three samples arrived from the Asian continent. A relatively strong correlation (r2 = 0.55) was found between perchlorate and nss-sulfate concentrations for the CHAAMS samples. Furthermore, we analyzed perchlorate in the soils and the fertilizers used for sugar cane farming around the CHAAMS area. The Milli-Q extract of the soil and the fertilizers did not contain any detectable levels of perchlorate ions. Therefore, it was suggested that perchlorate found in the atmospheric

  17. Coverage, Diversity, and Functionality of a High-Latitude Coral Community (Tatsukushi, Shikoku Island, Japan)

    PubMed Central

    Denis, Vianney; Mezaki, Takuma; Tanaka, Kouki; Kuo, Chao-Yang; De Palmas, Stéphane; Keshavmurthy, Shashank; Chen, Chaolun Allen

    2013-01-01

    Background Seawater temperature is the main factor restricting shallow-water zooxanthellate coral reefs to low latitudes. As temperatures increase, coral species and perhaps reefs may move into higher-latitude waters, increasing the chances of coral reef ecosystems surviving despite global warming. However, there is a growing need to understand the structure of these high-latitude coral communities in order to analyze their future dynamics and to detect any potential changes. Methodology/Principal Findings The high-latitude (32.75°N) community surveyed was located at Tatsukushi, Shikoku Island, Japan. Coral cover was 60±2% and was composed of 73 scleractinian species partitioned into 7 functional groups. Although only 6% of species belonged to the ‘plate-like’ functional group, it was the major contributor to species coverage. This was explained by the dominance of plate-like species such as Acropora hyacinthus and A. solitaryensis. Comparison with historical data suggests a relatively recent colonization/development of A. hyacinthus in this region and a potential increase in coral diversity over the last century. Low coverage of macroalgae (2% of the benthic cover) contrasted with the low abundance of herbivorous fishes, but may be reasonably explained by the high density of sea urchins (12.9±3.3 individuals m−2). Conclusions/Significance The structure and composition of this benthic community are relatively remarkable for a site where winter temperature can durably fall below the accepted limit for coral reef development. Despite limited functionalities and functional redundancy, the current benthic structure might provide a base upon which a reef could eventually develop, as characterized by opportunistic and pioneer frame-building species. In addition to increasing seawater temperatures, on-going management actions and sea urchin density might also explain the observed state of this community. A focus on such ‘marginal’ communities should be a

  18. Paleomagnetism of Harutagawa formation in the Hohi Volcanic Zone in northeastern part of Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Kudou, T.; Shibuya, H.

    2008-12-01

    The Beppu-Shimabara graben in the Hohi Volcanic Zone (HVZ) in northeastern part of Kyushu Island, Japan is thought to be a volcano-tectonic depression. Volcanic stratigraphy and age studies of the area have unraveled the late Pliocene structural formation history of HVZ (e.g. Kamata, 1994, Kido, 2007). The age and sedimentation rate of lacustrine deposits in HVZ is one of the keys for interpreting the temporal relation between the formation of Beppu-Shimabara graben and the huge pyroclastic flows appeared in the area. We study the magnetostratigraphy of the Harutagawa formation, which is one of those lacustrine deposits. The formation is dominated by conglomerates and mad stones to siltstones, in the lower and upper parts, respectively, but bares many tuff layers all over the formation. Fission track ages of two tuff layers, one is from lower part and the other is from upper part of Harutagawa formation, are determined as 3.86 ± 0.77Ma and 3.6 ± 0.2Ma, respectively (Kido, 2007). Samples for paleomagnetic analyses have been collected at 28 sites in several continuous outcrop of the Harutagawa formation. The sites are set to be spaced equally in the stratigraphy. Samples were collected by a portable electric motor drill. A few pilot specimens from each site are subjected to progressive thermal and alternating field (AF) demagnetization. However, AF demagnetization is not effective. All remaining specimens are, therefore, submitted to the progressive thermal demagnetization. The samples have mean magnetic intensity of 1.7 × 10- 4A/m and 7.7 × 10-5A/m before and after demagnetization, respectively. Samples from 6 sites have no stable component or are thought to be completely remagnetized by the present magnetic field. As the result, 22 sites are determined their polarities; 8 were reversed and 14 were normal. The normal polarity sites were correlative to Sidufjall, Nunivak and Cochiti subchrons in the Gilbert reversed polarity chron. This correlation indicates that

  19. Neural network analysis for geological interpretation of tomographic images beneath the Japan Islands

    NASA Astrophysics Data System (ADS)

    Kuwatani, T.; Toriumi, M.

    2009-12-01

    Recent advances in methodologies of geophysical observations, such as seismic tomography, seismic reflection method and geomagnetic method, provide us a large amount and a wide variety of data for physical properties of a crust and upper mantle (e.g. Matsubara et al. (2008)). However, it has still been difficult to specify a rock type and its physical conditions, mainly because (1) available data usually have a lot of error and uncertainty, and (2) physical properties of rocks are greatly affected by fluid and microstructures. The objective interpretation and quantitative evaluation for lithology and fluid-related structure require the statistical analyses of integrated geophysical and geological data. Self-Organizing Maps (SOMs) are unsupervised artificial neural networks that map the input space into clusters in a topological form whose organization is related to trends in the input data (Kohonen 2001). SOMs are powerful neural network techniques to classify and interpret multiattribute data sets. Results of SOM classifications can be represented as 2D images, called feature maps which illustrate the complexity and interrelationships among input data sets. Recently, some works have used SOM in order to interpret multidimensional, non-linear, and highly noised geophysical data for purposes of geological prediction (e.g. Klose 2006; Tselentis et al. 2007; Bauer et al. 2008). This paper describes the application of SOM to the 3D velocity structure beneath the whole Japan islands (e.g. Matsubara et al. 2008). From the obtained feature maps, we can specify the lithology and qualitatively evaluate the effect of fluid-related structures. Moreover, re-projection of feature maps onto the 3D velocity structures resulted in detailed images of the structures within the plates. The Pacific plate and the Philippine Sea plate subducting beneath the Eurasian plate can be imaged more clearly than the original P- and S-wave velocity structures. In order to understand more precise

  20. Influence of Land Development on Holocene Porites Coral Calcification at Nagura Bay, Ishigaki Island, Japan

    PubMed Central

    Sowa, Kohki; Watanabe, Tsuyoshi; Kan, Hironobu; Yamano, Hiroya

    2014-01-01

    To evaluate the relationships between coral calcification, thermal stress, and sedimentation and eutrophication linked to human impact (hereafter referred to as “land development”) by river discharge, we analyzed growth characteristics in the context of a paleoenvironment that was reconstructed from geochemical signals in modern and fossil (1.2 cal kyr BP and 3.5 cal kyr BP, respectively) massive Porites corals from Nagura Bay (“Nagura”) and from modern Porites corals from the estuary of the Todoroki River, Shiraho Reef (“Todoroki”). Both sites are on Ishigaki Island, Japan, and Nagura is located approximately 12 km west of Todoroki. At Nagura, the individual corals provide time windows of 13 (modern), 10 (1.2 cal kyr BP), and 38 yr in length (3.5 cal kyr BP). Here, we present the coral annual calcification for Nagura and Todoroki, and (bi) monthly resolved records of Sr/Ca (a proxy of sea surface temperature (SST)) and Ba/Ca (a proxy of sedimentation and nutrients related to land development) for Nagura. At Nagura, the winter SST was cooler by 2.8°C in the 1.2 cal kyr BP, and the annual and winter SSTs in the 3.5 cal kyr BP were cooler by 2.6°C and 4.6°C, respectively. The annual periodicity of Ba/Ca in modern coral is linked to river discharge and is associated with land development including sugar cane cultivation. Modern coral calcification also has declined with SST warming and increasing Ba/Ca peaks in winter. However, calcification of fossil corals does not appear to have been influenced by variations in Sr/Ca and Ba/Ca. Modern coral growth characteristics at Nagura and Todoroki indicate that coral growth is both spatially and temporally influenced by river discharge and land development. At Nagura, our findings suggest that land development induces negative thermal sensitivity for calcification in winter due to sugar cane harvest, which is a specifically modern phenomenon. PMID:24586393

  1. On relationships between heat island and sky view factor in the cities of Tama River basin, Japan

    NASA Astrophysics Data System (ADS)

    Yamashita, Shuji; Sekine, Kiyoshi; Shoda, Masahiro; Yamashita, Kohji; Hara, Yoshio

    This study aims at firstly identifying heat island phenomena, secondly relating heat island intensity to city size, and thirdly providing basic urban climatic information to city planners or ordinary citizens. Horizontal distributions of dry- and wet-bulb temperature were measured seasonally in small to medium sized cities by mobile observers. Also, at a fixed station, wind speed and wind direction in addition to temperature were observed. The cities selected for this were Tachikawa, Fuchu, Fussa, Higashimurayama and Akikawa, which are suburban cities in the W part of Tokyo. This area is part of the middle basin of Tama River. Observations were made both during the day and at night in winter (February and December), spring (March and May), summer (July and August) and autumn (October and November) over a period of maximum duration of 1.5 h. In all cities heat islands were observed to develop to some extent. Their intensities were largely dependent on weather conditions. Cities in Japan have been growing rapidly and randomly, and merging into neighbouring small cities or towns. This expansion is called sprawl. Due to these factors it is very difficult to determine a good indicator of city sizes, i.e. population or DID (Densely Inhabited District) population does not represent the effect of city size on heat island intensity. Sky view factors were determined using a fish-eye lens and a calculation chart. We therefore examined central urban area and sky view factor as a cause factor for heat islands. It is concluded that sky view factor is a very useful indicator of the effect of urbanization on heat island intensity.

  2. Upper mantle structure beneath the Japan Islands imaged by receiver function -With Hi-net tiltmeter data-

    NASA Astrophysics Data System (ADS)

    Tonegawa, T.; Hirahara, K.; Shibutani, T.; Shiomi, K.

    2005-12-01

    In the Japan subduction zone where the Pacific plate is subducting, we can investigate the dynamics of the upper mantle beneath the subduction zone by imaging the detailed structure beneath the Japan Islands. Recently, the undulation of the seismic discontinuities in the upper mantle beneath the Japan Islands has been well detected by receiver function (RF) analysis based on the broadband seismograms (e.g. Tonegawa et al., 2005). However, the density of broadband stations expanding throughout the Japan Islands is still insufficient (130 stations in Japan) to investigate the relation between the slab and 410 or 660 km discontinuities. The high sensitivity accelerometer (hereafter tiltmeter) network has recently been deployed with high-density spacing (700 stations in Japan) by NIED, and these tiltmeters can be used as long-period seismometer. If we can use the recordings obtained by the tiltmeter to disclose the structure of the upper mantle, it is possible to dramatically improve our knowledge on the dynamics of the upper mantle. In this study, we examine whether these recordings are available to demonstrate the seismic discontinuities in the upper mantle by calculating the RF from tiltmeter recordings. We select a tiltmeter station and a F-net (broadband network expanding in the Japan Islands) station, whose distance is approximately 4 km, and compare the recordings with velocity seismogram by changing the frequency band. Those RFs would be similar when applying the low-pass filter of longer than 6 sec. Based on this trial, we decide to set the low-pass filter of 6 and 10 sec, when producing the RFs from the tiltmeter recordings. Since tiltmeter seismograms have only the horizontal recordings, we need to obtain the vertical component or sourcetime function. Therefore, we make the sourcetime function by stacking all of vertical components obtained by F-net broadband stations, that is, we consider these stacked waveforms as sourcetime functions. For making the

  3. Seasonal variation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Nakajima, H.; Nakaema, F.; Arakaki, T.; Tanahara, A.

    2008-12-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the air pollution transported from Asian continent has gained a special attention in Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asian atmospheric aerosols because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. In 2005, Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) was established by the National Institute for Environmental Studies (NIES) at the northern tip of Okinawa Island, Japan to monitor the air quality of Asia. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon in the bulk aerosols collected at the CHAAMS, using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions.

  4. New records of the caridean shrimp genus Processa Leach, 1815 (Crustacea: Decapoda: Processidae) from Japan, with descriptions of two new species.

    PubMed

    Komai, Tomoyuki; Fujita, Yoshihisa

    2014-01-01

    Three species of the processid shrimp genus Processa Leach, 1815, including two new species, are reported from shallow coastal waters in Okinawa Island, Ryukyu Islands, Japan: P. affinis Hayashi, 1975, P. filipes n. sp. and P. hayashii n. sp. The present specimens of P. affinis represent the rediscovery and range extension of this poorly known species, originally described from Indonesia. Male characteristics of P. affinis are documented for the first time. The two new species are referred to the P. aequimana Paulson, 1875 species group. Processa filipes n. sp. is characteristic in the greatly elongate fifth pereopod and the transverse ridge on thoracic sternite 8 consisting of soft cuticle. Processa hayashii n. sp. is characterized by the presence of a deep concavity on the anterolateral margin of the carapace just inferior to the antennal tooth. The number of species of Processa known from Japanese waters is raised from five to eight. PMID:24870323

  5. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago

    PubMed Central

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-01-01

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history. PMID:26656261

  6. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago.

    PubMed

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-01-01

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history. PMID:26656261

  7. Melon Fly, Bactrocera cucurbitae (Diptera: Tephritidae), Infestation in Host Fruits in the Southwestern Islands of Japan Before the Initiation of Island-wide Population Suppression, as Recorded in Publications of Japanese Public Institutions.

    PubMed

    McQuate, Grant T; Teruya, Tadashi

    2015-01-01

    Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern Islands of Japan. It was subsequently eradicated from these islands by an eradication program that extended from 1972 to 1993. As part of an effort to develop a worldwide database on the status of fruits as hosts of melon fly, the infestation data gathered from host fruits collected in this eradication program, before the initiation of suppression activities, are summarized here. Bactrocera cucurbitae infestation was documented in 24 plant taxa of four plant families (Caricaceae, Cucurbitaceae, Moraceae, and Solanaceae), with the following four new hosts identified: Ficus erecta Thunb., F. pumila L. (Moraceae), Solanum erianthum D. Don (Solanaceae), and Zehneria liukiuensis Jeffrey ex Walker (Cucurbitaceae). PMID:26816487

  8. Melon Fly, Bactrocera cucurbitae (Diptera: Tephritidae), Infestation in Host Fruits in the Southwestern Islands of Japan Before the Initiation of Island-wide Population Suppression, as Recorded in Publications of Japanese Public Institutions

    PubMed Central

    McQuate, Grant T.; Teruya, Tadashi

    2015-01-01

    Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern Islands of Japan. It was subsequently eradicated from these islands by an eradication program that extended from 1972 to 1993. As part of an effort to develop a worldwide database on the status of fruits as hosts of melon fly, the infestation data gathered from host fruits collected in this eradication program, before the initiation of suppression activities, are summarized here. Bactrocera cucurbitae infestation was documented in 24 plant taxa of four plant families (Caricaceae, Cucurbitaceae, Moraceae, and Solanaceae), with the following four new hosts identified: Ficus erecta Thunb., F. pumila L. (Moraceae), Solanum erianthum D. Don (Solanaceae), and Zehneria liukiuensis Jeffrey ex Walker (Cucurbitaceae). PMID:26816487

  9. Underground dams for irrigation supplies in coastal limestone aquifer, Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Yasumoto, J.; Nakano, T.; Nawa, N.

    2011-12-01

    The use of underground dams to store water in regions with arid or tropical climates is a method that has received considerable attention in the last few decades. And now, for the tropical and subtropical islands that are highly vulnerable to climate change underground dams have been attracting attention again as a method of groundwater management. Okinawa Prefecture is Japan's southernmost prefecture, which consists of hundreds of islands in a chain over 1,000 km long, called the Ryukyu Islands which extend southwest from Kyushu to Taiwan. The national irrigation project of the Ryukyu Islands has been carried out, and several underground dams have been constructed. The Komesu and Giiza underground dams are first full scale underground dam facilities constructed for irrigation in Japan. The Komesu underground dam is a salt-water proof type. It prevents salt-water intrusion and provides storage fresh-water for irrigation in coastal limestone aquifer. Giiza underground dam is a dam up type for storage of fresh-water. These groundwater reservoirs are located in the coastal region of southern part of Okinawa (main island), where Ryukyu limestone is extensively distributed. We studied the behaviour of groundwater flow, saltwater intrusion and nitrate nitrogen (NO3-N) in groundwater in this region by using observation data of groundwater and springs through long term (from 1993 to 2010) monitoring. And, a groundwater flow and salt-water intrusion analysis have been conducted with three dimensional numerical model applied to these dam reservoir areas. The MODFLOW-NWT with SWI code and PEST was used to simulate the complex groundwater flow patterns. Through the comparison with simulation and observed data, it was concluded that the cut off wall of underground dams effectively stores the groundwater and prevents the salt-water intrusion in the reservoir areas. The observed groundwater levels at the reservoir areas were almost reproduced by the numerical model, but there

  10. Post-bomb coral Δ14C record from Iki Island, Japan: possible evidence of oceanographic conditions on the northern East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Mitsuguchi, Takehiro; Hirota, Masashi; Paleo Labo AMS Dating Group; Yamazaki, Atsuko; Watanabe, Tsuyoshi; Yamano, Hiroya

    2016-07-01

    In this study, a sea-surface water Δ14C record of AD 1966-2000 (i.e., after the atmospheric nuclear-bomb testing period of the mid-1950s to early 1960s) was reconstructed from a coral sample collected from Iki Island, western Japan. The island is located in the Tsushima Strait where the Tsushima Current flows from the East China Sea (ECS) continental shelf into the Sea of Japan, indicating a strong influence of the ECS shelf water on the island. It is widely accepted that the Tsushima Current originates in the area between the ECS shelf break and the Nansei Islands further offshore as a branch of the Kuroshio Current, although another possible origin is the Taiwan-Tsushima Current System. The Δ14C record from Iki Island shows the following evidence of a response to the atmospheric nuclear testing: (1) an increase from ~55‰ in 1966 to ~133‰ in 1970, (2) a plateau ranging between ~123 and ~142‰ during the 1970s to the late 1980s, and (3) a gradual decrease from ~115‰ in 1990 to ~83‰ in 2000. Comparison of this record with coral Δ14C records from the Nansei Islands (Okinawa Island, Ishigaki Island and Kikai Island), located ~160-280 km off the ECS shelf break and little influenced by the shelf water, suggests that the surface-water Δ14C around Iki Island was ~30-45‰ lower than that of the Nansei Islands from the mid-1960s to late 1970s, and that the Δ14C difference between Iki Island and the Nansei Islands decreased from the end of the 1970s to ~0-15‰ in the mid-1980s to 2000. The lower Δ14C around Iki Island can be explained as follows: (1) in contrast to the Nansei Islands area, the ECS shelf area is a vertically mixed, highly concentrated carbon reservoir significantly connected to subsurface and deeper waters outside the shelf area, strongly suggesting that the surface-water Δ14C of the shelf area (perhaps excepting very shallow innermost shelf areas) was significantly less sensitive to the atmospheric nuclear-bomb 14C spike than that of the

  11. Gravity changes observed during the long-term slow slip events at the Ryukyu Trench in May 2012 and December 2012

    NASA Astrophysics Data System (ADS)

    Tanaka, Y.; Imanishi, Y.; Okubo, S.; Nawa, K.; Ikeda, H.; Miyaji, T.; Kazama, T.; Okamura, S.; Miyazaki, T.; Nakamura, M.

    2013-12-01

    Long-term slow-slip events (SSEs) have been observed in many plate-boundary zones along the circum-Pacific seismic belt. Previous studies have revealed that high-pressure fluids supplied from the subducted oceanic plate can generate SSEs. SSEs in different areas have different recurrence intervals. In general, the tectonic stress accumulation rates and the frictional properties on the plate boundaries control the intervals. Therefore, their differences are considered to cause the differences in the intervals. However, variations in fluid pressure will also change the intervals, because they affect the effective normal stress. Variations in fluid pressure are predicted by the earthquake-cycle model based on the fault valve behavior of Sibson (1992). So far, variations in fluid pressure associated with SSEs have not been detected by field observations. If a massive fluid pressure change occurred, gravity change could be observed since the corresponding density redistribution in the underground occurred. In the Tokai district in Japan, the SSE occurred during the years from 2000 to around 2006, and gravity changes in 2004-2009 that could be explained by a fluid pressure variation were detected (Tanaka et al., 2010). However, the quality of the data was not good due to the lower temporal resolution of the campaign data and the observation period did not cover the whole cycle of the SSE. So, a clear evidence of fluid-pressure change has not been obtained yet. In this study, we conduct a continuous gravity measurement using two absolute gravimeters and a superconducting gravimeter in Ishigakijima and Iriomotejima Islands at the Ryukyu Trench where SSEs have occurred twice a year (Heki and Kataoka, 2008) to observe a transient gravity change during the whole cycle of an SSE. In this presentation, we report gravity changes during the two slow slip events that occurred in May 2012 and December 2012.

  12. Concentration of organic sun-blocking agents in seawater of beaches and coral reefs of Okinawa Island, Japan.

    PubMed

    Tashiro, Yutaka; Kameda, Yutaka

    2013-12-15

    The concentration of UV filters (UVFs) and UV light stabilizers (UVLSs) were measured in seawater and river water collected from sites at four beaches, two reefs, and one river on Okinawa Island, Japan. UVFs and/or UVLSs of 8-10 types were detected in beaches samples and 6-9 types were detected in reef samples. The total UVF concentrations at the beach sites were highest either in July or August with a maximum of 1.4 μg L(-1). The concentrations at the reef sites did not show peaks in summer and the maximum values were close to 10 ng L(-1). The detected UVF profiles reflected the ingredients of sunscreens used in each region. The highest UVLS concentrations at the reefs were observed not only in summer but also in June and September. The UVLS concentrations at the reefs were similar to or even higher than that at the beaches or in the river. PMID:24139648

  13. Distribution of trace metals in the Pacific Oyster, Crassostrea gigas, and crabs from the east coast of Kyushu Island, Japan

    SciTech Connect

    Szefer, P.; Frelek, K.; Geldon, J.

    1997-01-01

    Oysters are known to be exceptional accumulators of Zn and Cu, and their tissue concentrations appear to reflect contamination of metals. According to Lauenstein and Dolvin, oysters clearly have a greater affinity for Ag, Cu and Zn than do mussels, while mussels have greater affinity for Cr and Pb. Oysters have been considered to be potential bioindicators for monitoring metallic pollution in marine environments. Extensive investigations of oysters from the east coast of Kyushu Island, Japan, have been performed. The aim of the study was to examine spatial differences in metal concentrations in soft tissues of the Pacific oyster (Crassostrea gigas) and whole bodies (soft tissues with shells) of the crabs Goetice depressa and Leptodius exaratus inhabiting the Japanese coastal region of the Pacific. 18 refs., 3 figs.

  14. Food habits of fishes on an exposed sandy beach at Fukiagehama, South-West Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Nakane, Yukinori; Suda, Yusuke; Sano, Mitsuhiko

    2011-06-01

    To clarify the feeding habits and major food sources of sandy beach fishes, the gut contents of 55 fish species collected on a sandy beach at Fukiagehama, South-West Kyushu Island, Japan, were examined. Ontogenetic changes in food preference were recognized in nine species ( Hypoatherina valenciennei, Lateolabrax japonicus, Trachurus japonicus, Sillago japonica, Sphyraena japonica, Paralichthys olivaceus, Heteromycteris japonica, Paraplagusia japonica, and Takifugu niphobles). A cluster analysis based on dietary overlaps showed that the sandy beach fish assemblage comprised six trophic groups (mysid, amphipod, zooplankton, juvenile fish, terrestrial insect, and mollusk feeders). Of these, the first three groups were the most abundantly represented, whereas the last two were represented by only a single species. These results indicated that epibenthic macrofauna, such as mysids and gammaridean amphipods, and zooplankton, were important food resources for the fish assemblage at the study site, but infaunal macrobenthos, such as polychaetes and bivalves, being relatively unimportant.

  15. Observation of coral reefs on Ishigaki Island, Japan, using Landsat TM images and aerial photographs

    SciTech Connect

    Matsunaga, Tsuneo; Kayanne, Hajime

    1997-06-01

    Ishigaki Island is located at the southwestern end of Japanese Islands and famous for its fringing coral reefs. More than twenty LANDSAT TM images in twelve years and aerial photographs taken on 1977 and 1994 were used to survey two shallow reefs on this island, Shiraho and Kabira. Intensive field surveys were also conducted in 1995. All satellite images of Shiraho were geometrically corrected and overlaid to construct a multi-date satellite data set. The effects of solar elevation and tide on satellite imagery were studied with this data set. The comparison of aerial and satellite images indicated that significant changes occurred between 1977 and 1984 in Kabira: rapid formation in the western part and decrease in the eastern part of dark patches. The field surveys revealed that newly formed dark patches in the west contain young corals. These results suggest that remote sensing is useful for not only mapping but also monitoring of shallow coral reefs.

  16. Spatial variations in the Kuroshio nutrient transport from the East China Sea to south of Japan

    NASA Astrophysics Data System (ADS)

    Guo, X. Y.; Zhu, X.-H.; Long, Y.; Huang, D. J.

    2013-10-01

    Based on absolute geostrophic velocity, which was calculated using repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured in the same areas from 1964 to 2009, we obtained the temporally averaged nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over one section) of four sections across the Kuroshio from the East China Sea (sections PN and TK) to an area south of Japan (sections ASUKA and 137E). In addition, we examined section OK east of the Ryukyu Islands in order to understand how the Ryukyu Current contributes to the transport of nutrients by the Kuroshio south of Japan. The mean nitrate flux shows a subsurface maximum core with values of 9.6, 10.6, 11.2, 10.5, and 5.7 mol m-2 s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The depth of the subsurface maximum core changes among these five sections and is approximately 400, 500, 500, 400, and 800 m at sections PN, TK, ASUKA, 137E, and OK, respectively. The mean downstream nitrate transport is 204.8, 165.8, 879.3, 1230.4, and 338.6 kmol s-1 at sections PN, TK, ASUKA, 137E, and OK, respectively. The transport of nutrients in these sections suggests the presence of the Kuroshio nutrient stream from its upstream to downstream regions. The deep current structure of the Ryukyu Current (section OK) contributes to the same order of nitrate transport as does the Kuroshio from the East China Sea (section TK) to the area south of Japan; however, the former only has one-fifth the volume transport of the latter. A budget calculation suggests that the downstream increase of transported nitrate along the Kuroshio is mainly caused by the recirculation of nitrate into the Kuroshio. This conclusion, however, depends on water depth. In the upper layers (< 26.5σθ), the downstream change of nitrate concentration along the Kuroshio and that from the recirculation of nitrate has a significant contribution to the downstream

  17. Conservation of biodiversity: a critical time for the hermatypic corals of Japan

    NASA Astrophysics Data System (ADS)

    Veron, J. E. N.

    1992-04-01

    Results of a long-term study of the taxonomy, distribution and abundance of the hermatypic corals of the Ryukyu Is. and mainland Japan indicate that the present high diversity is threatened by a quantitative and qualitative decrease in available habitat caused by Acanthaster planci predation and human-induced environmental deterioration. Ninety-eight sites were studied, allowing detailed comparison between the three main groups of the Ryukyu Is. (Yaeyama, Okinawa and Amami Groups) and seven principal coral regions of mainland Japan (Tanegashima, Amakusa Is., the Tosashimizu and Kushimoto regions, and the Shirahama, Izu and Tateyama Peninsulas). Within this area, 400 species have been recorded and 9 additional species are recorded from the literature, from additional localities, or with doubt, from the Ryukyu Is. In non-mutually exclusive distribution and abundance categories for the Ryukyu Is. and mainland Japan: 129 species are common in at least some Japanese localities; 24 are widely dispersed within the Indo-Pacific, but occur in small, perhaps disjunct populations in Japan; 149 are uncommon throughout their Indo-west Pacific distribution ranges including Japan; 38 are restricted to the Yaeyama Group where all but three are uncommon or rare; 69 purely reefal (Ryukyu Is.) species are rare; 17 are rare in the Ryukyu Is. but are relatively common in mainaland locations; and 8 species appear to be endemic to mainland Japan and adjacent Asian countries. Some 37% of all Japanese hermatypic corals are uncommon throughout their range in Japan and are at some risk of regional extinction, 29% of others are rare and at substantial risk as they occur only in very limited areas of high diversity or in species-specific refuges. These sites are dientified. Of the 8 endemic species, 5 are primarily restricted to species-specific refuges. These data indicate an unstable situation. At least one third of all Japanese hermatypic species will eventually be at risk if the present

  18. Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The southern half of the island of Okinawa, Japan (26.5N, 128.0E) can be seen in this nearly cloud free view. Okinawa is part of the Ryuku Islands which extend from Taiwan northeastward to Kyushu, southernmost of the Japanese Home Islands. The large military base at Kadena, with large runways, is visible near the center of the scene. Kadena is one of several emergency landing sites around the world for the space shuttle.

  19. Vertical distribution of precipitation particles in Baiu frontal stratiform intense rainfall around Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Oue, M.; Ohigashi, T.; Tsuboki, K.; Nakakita, E.

    2015-06-01

    The vertical distribution of precipitation particles in an intensely precipitating stratiform cloud associated with the Baiu front around Okinawa Island was observed. X-band polarimetric radar, disdrometer, and hydrometeor videosonde data were used to examine the precipitation processes. The cloud top was approximately 12 km above sea level, as convection was depressed while stratiform regions developed near Okinawa Island. In the rain region below 3 km, the mean median volume diameter of the raindrop size distribution (DSD) estimated from the radar variables was 1.55 mm, and the mean normalized intercept parameter was 104.12 mm-1 m-3 with a mean radar reflectivity of 40.5 dBZe. The DSD indicates that the stratiform precipitation was characterized by higher number concentrations of smaller drops than observed previously in convective cells in a Baiu frontal convective precipitation region around Okinawa Island. The DSD also suggests the presence of larger raindrops than in convective cells embedded in a Baiu frontal stratiform precipitation region around Okinawa Island. In the ice region at 5-6 km, just above the melting layer and 6 km below the cloud top, the differential reflectivity and specific differential phase showed positive values, and videosonde measurements revealed that the number concentration of column-, plate-, and capped-column-like crystals (maximum dimensions of ≥0.1 mm) was 112 L-1. The high number concentration of these crystals contributed to the intense stratiform rainfall associated with the Baiu front.

  20. Assessing tsunami-induced groundwater salinization and its temporal change: a numerical modelling study on the Niijima Island, Japan

    NASA Astrophysics Data System (ADS)

    Liu, Jiaqi; Tokunaga, Tomochika

    2016-04-01

    Groundwater is vulnerable to many natural hazards, including tsunami. As reported after the 2004 Indian Ocean earthquake and the 2011 Great East Japan earthquake, the generated massive tsunami inundations resulted in unexpected groundwater salinization in coastal areas. Water supply was strongly disturbed due to the significantly elevated salinity in groundwater. Supplying fresh water is one of the prioritized concerns in the immediate aftermath of disaster, and during long-term post-disaster reconstruction as well. The aim of this study is to assess the impact of tsunami on coastal groundwater system and provide guidelines on managing water resources in post-tsunami period. We selected the study area as the Niijima Island, a tsunami-prone area in Japan, which is under the risk of being attacked by a devastated tsunami with its wave height up to 30 m. A three-dimension (3-D) numerical model of the groundwater system on the Niijima Island was developed by using the simulation code FEFLOW which can handle both density- dependent groundwater flow and saturated-unsaturated flow processes. The model was justified by the measured water table data obtained from the field work in July, 2015. By using this model, we investigated saltwater intrusion and aquifer recovery process under different tsunami scenarios. Modelling results showed that saltwater could fully saturate the vadose zone and come into contact with groundwater table in just 10 mins. The 0.6 km2 of inundation area introduced salt mass equivalent to approximately 9×104 t of NaCl into the vadose zone. After the retreat of tsunami waves, the remained saltwater in vadose zone continuously intruded into the groundwater and dramatically salinized the aquifer up to about 10,000 mg/L. In the worst tsunami scenario, it took more than 10 years for the polluted aquifer to be entirely recovered by natural rainfall. Given that the groundwater is the only freshwater source on the Niijima Island, we can provide suggestions

  1. Newly found submerged reefs on the Miyako-Sone platform, Ryukyu Arc, northwestern Pacific

    NASA Astrophysics Data System (ADS)

    Arai, K.; Matsuda, H.; Sasaki, K.; Machiyama, H.; Inoue, T.; Iryu, Y.

    2013-12-01

    Bathymetric mapping and observations of the seafloor using a remotely operated vehicle were carried out on the top of the Miyako-Sone submarine platform, northeast of Miyako-jima, Ryukyu Islands, northwestern Pacific. The high-resolution bathymetric map provides a detailed geomorphology and spatial distribution of submerged reefs and terraces on the platform. Our observations show that a submerged reef occurs at a water depth of ca. 55 m as a barrier reef that are up to 500 m across (from east to west) and 1,000 m lonng (from north to south) with a prominent ridge structure (reef crest). The submerged reef deepens westward from the crest along which spurs and grooves are well developed. A shallow lagoon extends on the east of the crest. Submersible observations confirm that the submerged reef now serves a hard substrate on which soft corals and algae grow. Terraces form at a water depth of ca. 110 m around a submerged reef on the northwestern Miyako-Sone platform. Submersible observations show the terrace surface is extensivbely covered with modern rhodoliths and living larger benthic foraminifers. Well-preserved coral-reef topography likely indicates limited sediment transportion from Miyako-jima and Okinwa-jima islands to the Miyako-Sone submarine platform. We plan to provide chronological constraint by direct sampling from the submerged reef and terraces, which enable to delineate a global deglacial sea-level history especially during early deglacial times in the northwestern Pacific.

  2. Geographic genetic structure in two laticaudine sea kraits, Laticauda laticaudata and Laticauda semifasciata (Serpentes: Elapidae), in the Ryukyu-Taiwan region as inferred from mitochondrial cytochrome b sequences.

    PubMed

    Tandavanitj, Nontivich; Ota, Hidetoshi; Cheng, Yuan-Cheng; Toda, Mamoru

    2013-08-01

    The Ryukyu-Taiwan region is an island arch with intervening waters of varying distances and depths. This study examines the geographic genetic structure of two sympatric sea kraits, Laticauda laticaudata and L. semifasciata, in the region, to infer factors affecting the extent of dispersal and other biogeographical traits of these amphibious reptiles. Sequence analyses of the mitochondrial cytochrome b gene revealed four and 16 haplotypes for L. laticaudata (136 individuals) and L. semifasciata (177 individuals), respectively. For both species, population pairwise F ST analyses revealed significant genetic differentiations among islands and island groups, which are separated by deep straits, suggesting that deep waters serve as obstacles for dispersal in both species. Significant genetic differentiation was detected even among islands of the same basin in L. laticaudata, but not in L. semifasciata, and the isolation by distance analyses revealed no significant correlation between geographic and genetic distances in the former species. These results further suggest that L. laticaudata has stronger site fidelity or degree of philopatry than L. semifasciata. Based on the geographic genetic patterns, the historical biogeography of the two species in the Ryukyu-Taiwan region is also discussed. PMID:23915156

  3. Double saloon door tectonics in the Japan Sea, Fossa Magna, and the Japanese Island Arc

    NASA Astrophysics Data System (ADS)

    Martin, A. K.

    2011-01-01

    A number of criteria considered diagnostic of double saloon door rifting and seafloor spreading are matched by data from the Japanese Arc. These include: a pair of terranes, SW and NE Honshu, which rotated in opposite directions from 22-21 Ma to 14-11 Ma; rotated terranes which comprise a retro-arc fold/thrust belt attached to an accretionary wedge intruded by a magmatic arc; contemporaneous backarc extension from 24 to 21 Ma which is brought to a halt by progressive collision of the Izu-Bonin and Japan Arcs from 15 to 5 Ma; isolation of blocks of thicker continental crust by areas of thin continental or oceanic crust, during backarc rifting; such isolation may be due to simultaneous rifting or to progressively seaward rifts, associated with ridge jumps towards the subduction zone; opposite rotations are accommodated by subduction rollback demonstrated by seaward migration of the volcanic front from 30-26 Ma to 16-15 Ma; concurrent development of a major arc-orthogonal rift, the Fossa Magna, from 23-18 Ma to 14 Ma, which was thereafter inverted from 15 Ma to the Recent; a northeast propagating rift in the northern Japan Basin demonstrated by the relationship of linear magnetic anomalies to the mapped continent ocean boundary. Driving mechanisms for double saloon door tectonics are discussed in relation to various reconstructions of the northwest Pacific. Opposite rotational torques, leading to opposite terrane rotations, may be caused by rollback of a curved trench hingeline, or by the divergent slab sinking forces of the Pacific and Philippine Sea Plates.

  4. Eleven-years-long record of ferric hydroxide sedimentation in Satsuma Iwo-Jima island, Kagoshima, Japan

    NASA Astrophysics Data System (ADS)

    Ueshiba, T.; Kiyokawa, S.; Goto, S.; Oguri, K.; Ito, T.; Ikehara, M.; Yamaguchi, K. E.; Nagata, T.; Ninomiya, T.; Ikegami, F.

    2011-12-01

    Satsuma Iwo-Jima island is active in volcanic activity located about 40 km south of Kyushu Island, Japan. It has many hot springs, and is surrounded by patches of reddish brown and white colored seawater. Nagahama Bay, a small port located in the southern part of the island, retains reddish brown seawater and precipitates ferric hydroxide (Ninomiya and Kiyokawa, 2009). We conducted multidisciplinary study to investigate mechanisms and histories of precipitation of the sediments. From 2009 to 2011, we obtained 1.5m-long core samples in the bay that record sedimentation of mainly ferric hydroxide during the last 11~13 years since dredging in 1998. We compare their stratigraphy with (a) 11 years meteorological data and (b) volcanic activity record in that period. Stratigraphy: Thirteen short cores (<1m long) were collected from Nagahama Bay. The lower unit contains three layers of white and pink tuff beds (T1, T2 and T3) with thickness of 1~9cm. The upper unit mainly contains sand bed and reddish-brown mud. The tuff beds are mainly composed of volcanic glass. Sand bed is essentially a mixture of felsic rock fragments, volcanic glass, and ferric-rich fine materials. The reddish brown sediment between T1 and T2 has very fine orange-colored laminations (1~2mm thick/each). (a) Meteorological data: 11-years-long meteorological data of the Satsuma Iwo-Jima island suggest that heavy rainfalls (precipitation over 100mm/day) occurred in June 2000 (189mm/day), June 2001 (124.5mm/day), and June 2002 (122mm/day), and that three events of strong typhoon occurred in 2004 (maximum wind speed: 40.3m/s, 54.3m/s and 44.6m/s), 2005 (43.3m/s), and 2007 (50.2m/s). These meteorological events are reflected in, sometimes disturb, the sediment record. (b) Volcanic data: Volcanic activity has occurred from 1997 (Shinohara, 2002) to October 2004 (Japan Meteorological Agency, 2010). During that time, ash was spewed out from and deposited near the volcano. Tuffaceous beds in the sediments of

  5. Current status of tropical fruit breeding and genetics for three tropical fruit species cultivated in Japan: pineapple, mango, and papaya

    PubMed Central

    Ogata, Tatsushi; Yamanaka, Shinsuke; Shoda, Moriyuki; Urasaki, Naoya; Yamamoto, Toshiya

    2016-01-01

    Tropical fruit crops are predominantly produced in tropical and subtropical developing countries, but some are now grown in southern Japan. Pineapple (Ananas comosus), mango (Mangifera indica) and papaya (Carica papaya) are major tropical fruits cultivated in Japan. Modern, well-organized breeding systems have not yet been developed for most tropical fruit species. Most parts of Japan are in the temperate climate zone, but some southern areas such as the Ryukyu Islands, which stretch from Kyushu to Taiwan, are at the northern limits for tropical fruit production without artificial heating. In this review, we describe the current status of tropical fruit breeding, genetics, genomics, and biotechnology of three main tropical fruits (pineapple, mango, and papaya) that are cultivated and consumed in Japan. More than ten new elite cultivars of pineapple have been released with improved fruit quality and suitability for consumption as fresh fruit. New challenges and perspectives for obtaining high fruit quality are discussed in the context of breeding programs for pineapple. PMID:27069392

  6. Current status of tropical fruit breeding and genetics for three tropical fruit species cultivated in Japan: pineapple, mango, and papaya.

    PubMed

    Ogata, Tatsushi; Yamanaka, Shinsuke; Shoda, Moriyuki; Urasaki, Naoya; Yamamoto, Toshiya

    2016-01-01

    Tropical fruit crops are predominantly produced in tropical and subtropical developing countries, but some are now grown in southern Japan. Pineapple (Ananas comosus), mango (Mangifera indica) and papaya (Carica papaya) are major tropical fruits cultivated in Japan. Modern, well-organized breeding systems have not yet been developed for most tropical fruit species. Most parts of Japan are in the temperate climate zone, but some southern areas such as the Ryukyu Islands, which stretch from Kyushu to Taiwan, are at the northern limits for tropical fruit production without artificial heating. In this review, we describe the current status of tropical fruit breeding, genetics, genomics, and biotechnology of three main tropical fruits (pineapple, mango, and papaya) that are cultivated and consumed in Japan. More than ten new elite cultivars of pineapple have been released with improved fruit quality and suitability for consumption as fresh fruit. New challenges and perspectives for obtaining high fruit quality are discussed in the context of breeding programs for pineapple. PMID:27069392

  7. Relationship between Health-Seeking Behavior by Basic Health Examination and Subsequent Health Expenditure among Remote Island Inhabitants of Japan

    PubMed Central

    Kinjo, Aya; Myoga, Yoshinori; Osaki, Yoneatsu

    2014-01-01

    Background Convincing evidence has not been obtained as to whether having a basic health examination in the prime of life inhibits the surge of health expenditure in old age. Methods Data sources: Data on participants in the basic health examination from 1996 to 2000 among residents of a remote island in Japan, and individual health care expenditure data from March 2005 to February 2008. Study design: A community-based retrospective study. Data collection: Japanese residents who were subscribers to the National Health Insurance Scheme of Chibu Town from March 1996 to March 2007 and were aged 40 to 64 years in March 1996 (n = 179) were divided into 3 groups depending on the frequency of participating in the basic health examination over 5 years: 0 times (nontakers), 1 to 3 times (occasional takers), or 4 to 5 times (regular takers). The distribution of total health expenditure according to the frequency of having a basic health examination was determined, and the Cochrane-Armitage test was used for comparison. Results Nontakers formed the highest proportion of subjects with low expenditure (0–200,000 yen) (nontaker, occasional, regular: 38.5%, 24.1%, 23.5%; P = 0.002), and also accounted for the highest proportion of subjects with high expenditure (> 1,400,000 yen) (33.3%, 16.1%, 9.4%; P = 0.004). Conclusion Persons not participating in health examinations during middle age include a group with high future health care expenditure. PMID:25349465

  8. Characterization of early microbial communities on volcanic deposits along a vegetation gradient on the island of Miyake, Japan.

    PubMed

    Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

    2014-01-01

    The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species. PMID:24463576

  9. Entamoeba marina n. sp.; a New Species of Entamoeba Isolated from Tidal Flat Sediment of Iriomote Island, Okinawa, Japan.

    PubMed

    Shiratori, Takashi; Ishida, Ken-Ichiro

    2016-05-01

    The genus Entamoeba includes anaerobic lobose amoebae, most of which are parasites of various vertebrates and invertebrates. We report a new Entamoeba species, E. marina n. sp. that was isolated from a sample of tidal flat sediment collected at Iriomote Island, Okinawa, Japan. Trophozoites of E. marina were 12.8-32.1 μm in length and 6.8-15.9 μm in width, whereas the cysts were 8.9-15.8 μm in diam. and contained four nuclei. The E. marina cells contained a rounded nucleus with a small centric karyosome and uniformly arranged peripheral chromatin. Although E. marina is morphologically indistinguishable from other tetranucleated cyst-forming Entamoeba species, E. marina can be distinguished from them based on the combination of molecular phylogenetic analyses using SSU rDNA gene and the difference of collection sites. Therefore, we propose E. marina as a new species of the genus Entamoeba. PMID:26452446

  10. [Toxin profiles in fish implicated in ciguatera fish poisoning in Amami and Kakeroma Islands, Kagoshima Prefecture, Japan].

    PubMed

    Yogi, Kentaro; Oshiro, Naomasa; Matsuda, Seiko; Sakugawa, Satsuki; Matsuo, Toshiaki; Yasumoto, Takeshi

    2013-01-01

    Ciguatoxins (CTXs) responsible for ciguatera fish poisoning (CFP) in Amami Islands, Kagoshima, Japan in 2008 were determined by LC-MS/MS analysis. Ciguatoxin-1B (CTX1B), 54-deoxyCTX1B, and 52-epi-54-deoxyCTX1B were detected in Variola louti and Lutjanus monostigma. The toxin profile distinctly differed from that of a CFP-related fish from Miyazaki, which mainly contained ciguatoxin-3C type toxins. Toxin profiles were species-specific, as observed in fish from Okinawa. The LC-MS/MS and mouse bioassay (MBA) methods produced comparable data, though 54-deoxyCTX1B was not taken into consideration owing to the lack of toxicity data. To improve assessment, toxicity data for this compound are needed. A reef fish caught on the same occasion and judged nontoxic by MBA (<0.025 MU/g) was found to contain low levels of CTX, indicating a potential risk for CFP. PMID:24389468

  11. Sedimentary processes associated with sand and boulder deposits formed by the 2011 Tohoku-oki tsunami at Sabusawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Goto, Kazuhisa; Sugawara, Daisuke; Ikema, Satoko; Miyagi, Toyohiko

    2012-12-01

    This paper reports on the sedimentary processes of sand and boulder deposition at Sabusawa Island, Japan as a result of the 2011 Tohoku-oki tsunami. Boulders were composed of tuffaceous rocks and sourced from an earthquake-triggered slope failure as well as concrete fragments of seawall. They were scattered over the ground surface and did not form boulder ridges, although there was some local imbrication. The boulders were deposited on top of a sand layer indicating that the latter, possibly deposited from bed load, covered the ground surface first. This sand layer probably reduced friction allowing boulders to be transported more easily than might be expected across a hard ground with a high bottom friction. Sand deposits showed landward thinning and fining features, while the boulders showed a landward coarsening (tuffaceous boulders) or a landward fining (concrete boulders), indicating that large clasts were not necessarily scattered randomly but rather might have a clast size gradient with distance inland. These features are explained by the local topographic setting that constrained the directions of incoming and returning tsunami flows. Some clasts at the inland extent of the boulder field were covered by an upward fining sand layer. This feature suggests that the boulders were deposited prior to the suspended sands, with the latter subsequently laid down before the water level dropped below the top of the boulders. Such modern investigations of the sedimentary features of various sizes of grains and clasts immediately after a tsunami provide invaluable data for the reconstruction of inundation processes.

  12. Characterization of Early Microbial Communities on Volcanic Deposits along a Vegetation Gradient on the Island of Miyake, Japan

    PubMed Central

    Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

    2014-01-01

    The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species. PMID:24463576

  13. Properties of GPS noise at Japan islands before and after Tohoku mega-earthquake.

    PubMed

    Lyubushin, Alexey; Yakovlev, Pavel

    2014-01-01

    The field of 3-components GPS signals is analyzed for the network of 1203 stations at the Japanese islands from January 30 up to March 26, 2011. This time interval includes just over 40 days of observation before the Tohoku mega-earthquake on March 11, 2011 (M = 9.0) and nearly 16 days of observation following this event. The signals from each station are three-component time series with time step 30 minutes. We study the statistical properties of the random fluctuations of GPS signals before and after the seismic catastrophe after transition to increments. The values of wavelet-based spectral index for GPS noise components for each station were estimated separately for pieces of records before and after seismic event. The maps of the noise spectral index are constructed as the values for grid size of 50 × 50 nodes covering the region under study, based on information from 10 stations closest to each node. These maps clearly extract the region of future seismic catastrophe by relatively high noise spectral index. The using of principal components method distinguished this spatial anomaly more explicitly. These results support the hypothesis that statistical properties of random fluctuations of geophysical fields carry important information about earthquake preparation. PMID:25077067

  14. Characteristics of atmospheric aerosols containing heavy metals measured on Fukue Island, Japan

    NASA Astrophysics Data System (ADS)

    Hidemori, Takehiro; Nakayama, Tomoki; Matsumi, Yutaka; Kinugawa, Takashi; Yabushita, Akihiro; Ohashi, Masafumi; Miyoshi, Takao; Irei, Satoshi; Takami, Akinori; Kaneyasu, Naoki; Yoshino, Ayako; Suzuki, Ryota; Yumoto, Yayoi; Hatakeyama, Shiro

    2014-11-01

    To investigate transport and chemical compositions of fine aerosols in the East Asian region, aerosol chemical components and their mixing states were measured at Fukue Island in the spring of 2010. Off-line chemical analyses using an ion chromatographic analyzer and an inductively coupled plasma-mass spectrometer for the aerosols sampled by a high volume sampler have also been conducted. The mixing state and temporal variation of number concentrations of the particles containing lead (Pb) and vanadium (V) were studied by using a laser ionization single-particle aerosol mass spectrometer (LISPA-MS). The temporal variation of number concentrations of particles containing Pb measured by the LISPA-MS is well consistent with those obtained by the chemical analysis of the aerosols sampled by the high volume sampler. The Pb-containing particles were classified into four types from the statistical analysis on the basis of the single-particle mass spectra with assists of laboratory experiments. It is estimated that 52% of observed particles containing Pb were originated from coal combustion. The concentration-weighted trajectory (CWT) analysis suggests that these particles are mainly transported from China continent. The V-containing particles were classified into three types. The 41% of V-containing particles were internally mixed with sea salt and the result of CWT analysis suggests that the potentially anthropogenic V-containing particles possibility emitted from ships are mixing with sea salt in the region that is highly loaded with sea salt in the Pacific Ocean.

  15. Distinct diversity of the cag pathogenicity island among Helicobacter pylori strains in Japan.

    PubMed

    Azuma, Takeshi; Yamakawa, Akiyo; Yamazaki, Shiho; Ohtani, Masahiro; Ito, Yoshiyuki; Muramatsu, Atsushi; Suto, Hiroyuki; Yamazaki, Yukinao; Keida, Yoshihide; Higashi, Hideaki; Hatakeyama, Masanori

    2004-06-01

    The severity of Helicobacter pylori-related disease is correlated with the presence of a cag pathogenicity island (PAI). Genetic diversity within the cag PAI may have a modifying effect on the pathogenic potential of the infecting strain. We analyzed the complete cag PAI sequences of 11 representative Japanese strains according to their vacA genotypes and clinical effects and examined the relationship between the diversity of the cag PAI and clinical features. The cag PAI genes were divided into two major groups, a Western and a Japanese group, by phylogenetic analysis based on the entire cag PAI sequences. The predominant Japanese strains formed a Japanese cluster which was different from the cluster formed by Western strains. The diversity of the cag PAI was associated with the vacA and cagA genotypes. All strains with the s1c vacA genotype were in the Japanese cluster. In addition, all strains with the East Asian-type cagA genotype were also in the Japanese cluster. Patients infected with the Japanese-cluster strain had high-grade gastric mucosal atrophy. These results suggest that a distinct diversity of the cag PAI of H. pylori is present among Japanese strains and that this diversity may be involved in the development of atrophic gastritis and may increase the risk for gastric cancer. PMID:15184428

  16. Distinct Diversity of the cag Pathogenicity Island among Helicobacter pylori Strains in Japan

    PubMed Central

    Azuma, Takeshi; Yamakawa, Akiyo; Yamazaki, Shiho; Ohtani, Masahiro; Ito, Yoshiyuki; Muramatsu, Atsushi; Suto, Hiroyuki; Yamazaki, Yukinao; Keida, Yoshihide; Higashi, Hideaki; Hatakeyama, Masanori

    2004-01-01

    The severity of Helicobacter pylori-related disease is correlated with the presence of a cag pathogenicity island (PAI). Genetic diversity within the cag PAI may have a modifying effect on the pathogenic potential of the infecting strain. We analyzed the complete cag PAI sequences of 11 representative Japanese strains according to their vacA genotypes and clinical effects and examined the relationship between the diversity of the cag PAI and clinical features. The cag PAI genes were divided into two major groups, a Western and a Japanese group, by phylogenetic analysis based on the entire cag PAI sequences. The predominant Japanese strains formed a Japanese cluster which was different from the cluster formed by Western strains. The diversity of the cag PAI was associated with the vacA and cagA genotypes. All strains with the s1c vacA genotype were in the Japanese cluster. In addition, all strains with the East Asian-type cagA genotype were also in the Japanese cluster. Patients infected with the Japanese-cluster strain had high-grade gastric mucosal atrophy. These results suggest that a distinct diversity of the cag PAI of H. pylori is present among Japanese strains and that this diversity may be involved in the development of atrophic gastritis and may increase the risk for gastric cancer. PMID:15184428

  17. Tectonics and petroleum potential of sedimentary basins in the Bering, Okhotsk, Japan seas, and island arcs

    SciTech Connect

    Levin, L.E. )

    1993-09-01

    In this vast region located in the northwestern part of the Pacific rim, basins of two main genetic types possess petroleum potential. These two types are represented by basins of the recent active margin and basins of the transitional zone between analogs of the passive margin and the recent active margin. For basins of the active margin, the mean density of potential resources is estimated at 5000 MT/km[sup 2] or more. The total area of these basins is 324,000 km[sup 2] among which 120,000 km[sup 2] are in the Russian sector. Ultimate resources of hydrocarbons are estimated at 1.62 billing MT of oil equivalent. Basins of the zone, transitional from analogs of the passive margin to the recent active margin, are characterized by a number of factors favorable for petroleum occurrence. One of the important factors is the presence of rift trough and foredeeps that are potential sites for zones of oil and gas accumulation. The age of the rifts varies from the late Cretaceous through the Oligocene-Miocene in the Olyutorsky and Litke basins, to the Neogene in the Okhotsk Sea and Tatar-Japan basins. Only a small area of the rifts has been proven to contain zones of oil and gas accumulation. Based on the structural characteristics, the rifts are subdivided into oil-gas bearing, potentially oil-gas bearing, and nonprospective for hydrocarbon exploration. Potential hydrocarbon resources of basins of this type are estimated to be not less than 15.12 billion MT of oil equivalent including 9.2 billion MT in the Russian sector. New large zones of oil and gas accumulation are expected to be found both on the shallow shelf and in some deep-water basins such as in the Aleutian and Kuril basins.

  18. A new species of the genus Peltogaster Rathke, 1842 (Cirripedia: Rhizocephala: Peltogastridae) parasitizing the hermit crab Pagurixus boninensis (Melin, 1939) from the Bonin Islands, Japan.

    PubMed

    Yoshida, Ryuta; Naruse, Tohru

    2016-01-01

    A new rhizocephalan species, Peltogaster unigibba n. sp., is described from the host hermit crab, Pagurixus boninensis (Melin, 1939), from the Bonin Islands, Japan. Of the16 known species of Peltogaster now currently recognised, P. unigibba n. sp., and P. contorta Boschma, 1958 share a left lobe that projects beyond the mantle aperture. The two species can be distinguished from one another by the position of the opening of the mantle aperture. The new species most closely resembles P. naushonensis Reinhard, 1946 in its internal structure, but clearly differs in the relative length of the colleteric glands. Peltogaster unigibba n. sp. represents the first record of a rhizocephalan from the oceanic Bonin Islands, and the second record of a rhizocephalan from an oceanic island in the northern hemisphere. PMID:27470799

  19. An investigation for population maintenance mechanism in a miniature garden: genetic connectivity or independence of small islet populations of the Ryukyu five-lined skink.

    PubMed

    Kurita, Kazuki; Hikida, Tsutomu; Toda, Mamoru

    2014-01-01

    The Ryukyu five-lined skink (Plestiodon marginatus) is an island lizard that is even found in tiny islets with less than half a hectare of habitat area. We hypothesized that the island populations are maintained under frequent gene flow among the islands or independent of each other. To test our hypotheses, we investigated genetic structure of 21 populations from 11 land-bridge islands that were connected during the latest glacial age, and 4 isolated islands. Analyses using mitochondrial cytochrome b gene sequence (n = 67) and 10 microsatellite loci (n = 235) revealed moderate to high levels of genetic differentiation, existence of many private alleles/haplotypes in most islands, little contemporary migration, a positive correlation between genetic variability and island area, and a negative correlation between relatedness and island area. These evidences suggest a strong effect of independent genetic drift as opposed to gene flow, favoring the isolation hypothesis even in tiny islet populations. Isolation-by-distance effect was demonstrated and it became more prominent when the 4 isolated islands were excluded, suggesting that the pattern is a remnant of the land-bridge age. In a few island populations, however, the possibility of occasional overwater dispersals was partially supported and therefore could not be ruled out. PMID:25189776

  20. Asymmetrically multi-collapsed structure of Kikai caldera in southern off Kyushu Island, Japan: A reconstruction from seismic reflection images

    NASA Astrophysics Data System (ADS)

    Ikegami, F.; Kiyokawa, S.; Oiwane, H.; Nakamura, Y.; Kameo, K.; Minowa, Y.; Kuratomi, T.

    2012-12-01

    Kikai caldera (Matsumoto, 1943) is a mostly submerged highly active caldera complex located in the southern Japan 40 km off Kyushu Island. The caldera has bathymetrically two rims partially that are previously considered as older-outer and newer-inner ones (Yokoyama et al., 1966). The caldera is believed to be the source of Akahoya tephra (Machida and Arai, 1978) which date was determined as 7300 cal. BP (Fukusawa, 1995) which is the most recent VEI-7 class eruption in the eastern margin of Asia. Intense earthquakes (Naruo and Kobayashi, 2002), low-aspect ratio Koya ignimbrite (Maeno and Taniguchi, 2007) and tsunami (Geshi, 2009) are presumed to have taken place at the climax of the eruption. There are at least two other series of giant eruption deposits that are considered to have originated from the Kikai caldera (Ono et al., 1986) and this indicates that it has been serving as an eruptive center for the past 150,000 years. We conducted seismic reflection observations in two survey cruises (KT-10-18 and KT-11-11) in 2010 and 2011 using a research vessel Tansei-maru of JAMSTEC (Japan Agency for Marine-Earth Science and Technology). The sound source was a 150 cubic inches G-I gun with 10 seconds of shot interval, and a 48-channled streamer cable was used for acquisition. Totally 24 profiles were obtained with the speed of 4 knots. First, the absence of large fault in northern and western caldera rim indicates Kikai likely had an asymmetric "trapdoor" style collapse (Lipman, 1995) rather than the ideal "piston" type one. Inner and outer topographic rims at the east to south do correspond with large faults, however the both of them may have worked in 7300 BP eruption because they reach to the seafloor. Such asymmetric multi-collapse would provide some characteristics to the climactic pyroclastic flow in 7300 BP. Second, the bathymetric rise at the center of the caldera consists of high-amplitude surface and chaotic thick facies outwardly collapsed by intense normal

  1. Oceanic And Terrestrial Controls On Chlorophyll -a Abundance Around The Island Of Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Ikema, T.; Bryant, R. G.; Bigg, G. R.

    2007-12-01

    This research aims to understand key factors affecting ocean surface chlorophyll-a (Chl-a) blooms at a range of scales (both regional and near the coastal zone) around the Island of Okinawa in the western Pacific. The study region is characterised by both the actions of the Kuroshio Current (which brings warm water) and the Asian Monsoon (which provides moist southwest winds in summer and dry northern winds in winter). Due to these influences, Okinawa has a subtropical climate, with a rainy season in the summer months (MJ), and prevailing northerly winds in winter (NDJ). In order to better understand factors which may influence the timing and magnitude of Chl-a blooms in the vicinity of Okinawa, we applied empirical orthogonal function (EOF) analysis to a time series of AVHRR (monthly mean SST from 1985-2006) and SeaWIFS (monthly mean Chl-a from 1998 to 2006) data over two different spatial scales: domain 1 (D1) - a region of the ocean southeast of Kuroshio, and domain 2 (D2) - a sub-region near coastline focused on Okinawa itself. The first EOF mode of SST in regions D1 and D2 (which accounted for more than 90 % in each domain) showed a clear radiation-driven annual cycle: high SST in summer and low SST in winter. The first EOF mode of Chl-a in D1 (which accounted for 51 %) also demonstrated an annual cycle, but in this instance one that mirrored that of SST (i.e. low Chl-a in summer and high Chl-a in winter). The first mode Chl-a EOF in D2 (accounting for 63 % of the total variance) also has a similar annual cycle, displaying a significant correlation (r=0.75, p<0.001) with northerly wind magnitudes, lagged by 2 months, suggesting that the winter monsoon is a major control on the observed Chl-a bloom. However, extreme events such as typhoons can also cause a Chl-a bloom around the coast. As a result of further analysis of daily Chl-a data along the western coastline of Okinawa, it was found that some of the peaks of Chl-a were closely correlated with river

  2. Modelling of wave propagation and attenuation in the Osaka sedimentary basin, western Japan, during the 2013 Awaji Island earthquake

    NASA Astrophysics Data System (ADS)

    Asano, Kimiyuki; Sekiguchi, Haruko; Iwata, Tomotaka; Yoshimi, Masayuki; Hayashida, Takumi; Saomoto, Hidetaka; Horikawa, Haruo

    2016-03-01

    On 2013 April 13, an inland earthquake of Mw 5.8 occurred in Awaji Island, which forms the western boundary of the Osaka sedimentary basin in western Japan. The strong ground motion data were collected from more than 100 stations within the basin and it was found that in the Osaka Plain, the pseudo velocity response spectra at a period of around 6.5 s were significantly larger than at other stations of similar epicentral distance outside the basin. The ground motion lasted longer than 3 min in the Osaka Plain where its bedrock depth spatially varies from approximately 1 to 2 km. We modelled long-period (higher than 2 s) ground motions excited by this earthquake, using the finite difference method assuming a point source, to validate the present velocity structure model and to obtain better constraint of the attenuation factor of the sedimentary part of the basin. The effect of attenuation in the simulation was included in the form of Q(f) = Q0(f/f0), where Q0 at a reference frequency f0 was given by a function of the S-wave velocity, Q0 = αVS. We searched for appropriate Q0 values by changing α for a fixed value of f0 = 0.2 Hz. It was found that values of α from 0.2 to 0.5 fitted the observations reasonably well, but that the value of α = 0.3 performed best. Good agreement between the observed and simulated velocity waveforms was obtained for most stations within the Osaka Basin in terms of both amplitude and ground motion duration. However, underestimation of the pseudo velocity response spectra in the period range of 5-7 s was recognized in the central part of the Osaka Plain, which was caused by the inadequate modelling of later phases or wave packets in this period range observed approximately 2 min after the direct S-wave arrival. We analysed this observed later phase and concluded that it was a Love wave originating from the direction of the east coast of Awaji Island.

  3. Imaging and 2.5D Modeling of Receiver Functions from Deep Virtual Receivers in Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Takenaka, H.; Ueda, T.; Murakoshi, T.; Okamoto, T.

    2014-12-01

    Receiver function analysis is very useful tool to image the seismic velocity structures. We apply it to image seismic structure beneath Kyushu island, Japan. Kyushu region is characterized by active subduction of the Philippine Sea plate (PHS) beneath the Eurasian plate and many active volcanoes. In this study, we use teleseismic records from Hi-net seismic stations (borehole stations) and F-net stations (near-surface stations) in Kyushu, which are supplied by the NIED. Because most of these seismic stations are located at the top or in the sedimentary layer, the records may include strong effect of reverberation within the sedimentary layer, and this effect makes the image of the structure unclear. To overcome this problem, we exploit the modified S-wavevector receiver functions (SWV-RFs). The SWV-RFs are derived by deconvolving the upgoing S-wave component with the upgoing P-wave component of the records. Although it was originally proposed for surface records by Reading et al. (2003, GRL), we use Takenaka and Murakoshi's (2010) method in which we virtually move the seismic sensor at the surface or in the borehole down to the top of the basement layer and calculate the SWV-RFs at that location for suppressing the sedimentary layer effect. This method needs the structure model from the surface to the virtual sensor location. Here we apply the Integrated Velocity Structure Model by the Headquarters for Earthquake Research Promotion. We take several cross sections in Kyushu Island to map the calculated SWV-RFs. We then interpret the continental Moho and low velocity zones in the SWV-RFs. The Moho depth beneath Kyushu varies from 25 km to 33 km. We found two types of exceptional occurrence of 'inverted' Moho (IM): one is the top of sill-like low velocity zones just under active volcanoes, and the other is non-sill type events beneath fore-arc regions of northern Kyushu, which may be attributed to dehydration of PHS. The latter-type IM has been observed by Abe et al

  4. Pleistocene intraplate magmatism in the Goto Islands, SW Japan: Implications for mantle source evolution and regional geodynamics

    NASA Astrophysics Data System (ADS)

    Hoang, Nguyen; Uto, Kozo; Matsumoto, Aki; Itoh, Jun'ichi

    2013-08-01

    We present geochemical, Sr, Nd and Pb isotopic data for the youngest back-arc tholeiitic and alkali basalts in the southern tip of Goto Islands along the Taiwan-Shinji Folded Belt in northwestern Kyushu, SW Japan. The data are compared with those more-or-less contemporaneous back-arc basalts elsewhere in the region and interpreted accordingly. Our sampling loci included Ukujima (ca. 1 Ma), Ojikajima and Kamigoto (from 0.6 Ma to 0.14) and six locations in the Fukue island area (ages between 0.7 and 0.02 Ma). The Ukujima tholeiites show the highest SiO2 (ca. 52.5 wt%), FeO* (13 wt%), TiO2 (>2.5 wt%) and lowest MgO (4 wt%) and CaO (7.5 wt%) contents whereas the alkali Kamigoto and most Ojikajima magmas show lower SiO2 (48 wt%) and higher MgO (8.5 wt%) and CaO (11 wt%). The Ukujima tholeiites also show the least radiogenic lead with closely similar 87Sr/86Sr and 143Nd/144Nd ratios ranging between 0.7038 and 0.7042, and between 0.51280 and 0.51285, respectively. Mantle-normalized incompatible element distributions are of alkali basalt-type exhibiting, along with the major element, significant spatio-temporal variations. Regardless of such differences the younger basalts, as compared with older 6-15 Ma eruptive products in Hirado (and those in Kita-Matsuura), northeastward along the belt, are the least radiogenic. The 15 Ma volcanics were erupted during episodes of lithospheric extension and show effects of crustal contamination. The 6-9 Ma tholeiites and alkali basalts appeared as regional extension gave way to compression and show hybrids of depleted mid-ocean ridge basalt-like (N-MORB) mantle and heterogeneous EM2 (enriched mantle type 2) (Uto et al., 2004). As extension diminished, deeper asthenospheric sources were tapped producing a range of enriched mantle type 1 (EM1)-contaminated N-MORB-like magmas in the younger (<1 Ma) Ukujima, Ojikajima-Kamigoto and Fukue volcanoes. This composition is believed to present throughout East and Southeast Asian asthenosphere.

  5. Seismic structure related to the Philippine Sea plate subduction beneath the southwestern Nansei-Shoto (Ryukyu) Trench

    NASA Astrophysics Data System (ADS)

    Nishizawa, A.; Kaneda, K.; Oikawa, M.; Horiuchi, D.; Fujioka, Y.

    2013-12-01

    The northwestern part of the Philippine Sea plate (PSP) is subducting beneath the Nansei-Shoto (Ryukyu) Trench. Earthquakes larger than M8 have not been recorded instrumentally in the southwestern part of the Ryukyu Trench. However, there was a large tsunami killed around 12,000 people in 1771 and the position of the source area has not been established. The direction of the PSP subduction is almost perpendicular to the Ryukyu Trench to the northeast of 126.5 E and changes to oblique to the southwest. Seismicity varies along the trench axis and lower seismicity seems to correspond to the free-air gravity anomaly high region in the forearc at around 126 E. On the other hand, the Okinawa-Luzon fracture zone extending from southwest to northeast on the PSP subducts beneath Ryukyu Trench to the northeast of 126 E and seems to relate to the high gravity anomaly. We carried out seismic experiments to elucidate these inhomogeneous crustal structures along the southwestern part of the trench and provide valuable information on potential source areas for large earthquakes and/or tsunamis. We conducted five seismic lines across southwestern Ryukyu Trench region. Multichannel reflection seismic (MCS) data using 240 ch. and 3000 m long hydrophone streamer were collected for airgun shots at an interval of 50 m. We also deployed ocean bottom seismographs (OBSs) as a receiver at an average interval of 5 km along each line. A tri-gun cluster with a volume of 1,050 (350 * 3) cubic inches (17.2 liters) was used for the reflection surveys and a non-tuned airgun array with a volume of 6,000 (1500 * 4) cubic inches (98 liters) was shot at an interval of 200 m (90 sec) for the wide-angle seismic survey. Depth conversion from the MCS time section was carried out using the refraction results. In this paper, we present the seismic structure related to the PSP subduction in the forearc region of the Nansei-Shoto island arc. The subducting Okinawa-Luzon fracture zone was able to be clearly

  6. On the fourth Diadema species (Diadema-sp) from Japan.

    PubMed

    Chow, Seinen; Kajigaya, Yoshikazu; Kurogi, Hiroaki; Niwa, Kentaro; Shibuno, Takuro; Nanami, Atsushi; Kiyomoto, Setuo

    2014-01-01

    Four long-spined sea urchin species in the genus Diadema are known to occur around the Japanese Archipelago. Three species (D. savignyi, D. setosum, and D. paucispinum) are widely distributed in the Indo-Pacific Ocean. The fourth species was detected by DNA analysis among samples originally collected as D. savignyi or D. setosum in Japan and the Marshall Islands and tentatively designated as Diadema-sp, remaining an undescribed species. We analyzed nucleotide sequences of the cytochrome oxidase I (COI) gene in the "D. savignyi-like" samples, and found all 17 individuals collected in the mainland of Japan (Sagami Bay and Kyushu) to be Diadema-sp, but all nine in the Ryukyu Archipelago (Okinawa and Ishigaki Islands) to be D. savignyi, with large nucleotide sequence difference between them (11.0%±1.7 SE). Diadema-sp and D. savignyi shared Y-shaped blue lines of iridophores along the interambulacrals, but individuals of Diadema-sp typically exhibited a conspicuous white streak at the fork of the Y-shaped blue iridophore lines, while this feature was absent in D. savignyi. Also, the central axis of the Y-shaped blue lines of iridophores was approximately twice as long as the V-component in D. savignyi whereas it was of similar length in Diadema-sp. Two parallel lines were observed to constitute the central axis of the Y-shaped blue lines in both species, but these were considerably narrower in Diadema-sp. Despite marked morphological and genetic differences, it appears that Diadema-sp has been mis-identified as D. savignyi for more than half a century. PMID:25054386

  7. Source Mechanism of May 30, 2015 Bonin Islands, Japan Deep Earthquake (Mw7.8) Estimated by Broadband Waveform Modeling

    NASA Astrophysics Data System (ADS)

    Tsuboi, S.; Nakamura, T.; Miyoshi, T.

    2015-12-01

    May 30, 2015 Bonin Islands, Japan earthquake (Mw 7.8, depth 679.9km GCMT) was one of the deepest earthquakes ever recorded. We apply the waveform inversion technique (Kikuchi & Kanamori, 1991) to obtain slip distribution in the source fault of this earthquake in the same manner as our previous work (Nakamura et al., 2010). We use 60 broadband seismograms of IRIS GSN seismic stations with epicentral distance between 30 and 90 degrees. The broadband original data are integrated into ground displacement and band-pass filtered in the frequency band 0.002-1 Hz. We use the velocity structure model IASP91 to calculate the wavefield near source and stations. We assume that the fault is squared with the length 50 km. We obtain source rupture model for both nodal planes with high dip angle (74 degree) and low dip angle (26 degree) and compare the synthetic seismograms with the observations to determine which source rupture model would explain the observations better. We calculate broadband synthetic seismograms with these source propagation models using the spectral-element method (Komatitsch & Tromp, 2001). We use new Earth Simulator system in JAMSTEC to compute synthetic seismograms using the spectral-element method. The simulations are performed on 7,776 processors, which require 1,944 nodes of the Earth Simulator. On this number of nodes, a simulation of 50 minutes of wave propagation accurate at periods of 3.8 seconds and longer requires about 5 hours of CPU time. Comparisons of the synthetic waveforms with the observation at teleseismic stations show that the arrival time of pP wave calculated for depth 679km matches well with the observation, which demonstrates that the earthquake really happened below the 660 km discontinuity. In our present forward simulations, the source rupture model with the low-angle fault dipping is likely to better explain the observations.

  8. A new species of the genus Ocadia (Testudines: Geoemydidae) from the middle Miocene of Tanegashima Island, southwestern Japan and its paleogeographic implications.

    PubMed

    Takahashi, Akio; Ōki, Kimihiko; Ishido, Takahiro; Hirayama, Ren

    2013-01-01

    A new geoemydid turtle, Ocadia tanegashimensis (Testudines: Geoemydidae) is described on the basis of a relatively well-preserved shell from the lower middle Miocene of Tanegashima Island, Kagoshima Prefecture, southwestern Japan. This species is clearly distinguished from two congeneric species (extant O. sinensis and O. nipponica from the middle Pleistocene of eastern Japan) due to the presence of the following character states: length of the entoplastron as long as the interhyoplastral suture, the costals dovetailed with one another in outline, the third pleural overlapping only the sixth and seventh peripherals. The present study suggests that the initial intrageneric diversification of Ocadia began not later than the early Miocene in eastern Asia. PMID:26295126

  9. Ryukyu Subduction Zone: 3D Geodynamic Simulations of the Effects of Slab Shape and Depth on Lattice-Preferred Orientation (LPO) and Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Tarlow, S.; Tan, E.; Billen, M. I.

    2015-12-01

    At the Ryukyu subduction zone, seismic anisotropy observations suggest that there may be strong trench-parallel flow within the mantle wedge driven by complex 3D slab geometry. However, previous simulations have either failed to account for 3D flow or used the infinite strain axis (ISA) approximation for LPO, which is known to be inaccurate in complex flow fields. Additionally, both the slab depth and shape of the Ryukyu slab are contentious. Development of strong trench-parallel flow requires low viscosity to decouple the mantle wedge from entrainment by the sinking slab. Therefore, understanding the relationship between seismic anisotropy and the accompanying flow field will better constrain the material and dynamic properties of the mantle near subduction zones. In this study, we integrate a kinematic model for calculation of LPO (D-Rex) into a buoyancy-driven, instantaneous 3D flow simulation (ASPECT), using composite non-Newtonian rheology to investigate the dependence of LPO on slab geometry and depth at the Ryukyu Trench. To incorporate the 3D flow effects, the trench and slab extends from the southern tip of Japan to the western edge of Taiwan and the model region is approximately 1/4 of a spherical shell extending from the surface to the core-mantle boundary. In the southern-most region we vary the slab depth and shape to test for the effects of the uncertainties in the observations. We also investigate the effect of adding locally hydrated regions above the slab that affect both the mantle rheology and development of LPO through the consequent changes in mantle flow and dominate (weakest) slip system. We characterize how changes in the simulation conditions affect the LPO within the mantle wedge, subducting slab and sub-slab mantle and relate these to surface observations of seismic anisotropy.

  10. Phosphorus and iron cycles during early diagenesis of Lake Kai-ike sediments, Kami-koshiki Island, southwest Japan

    NASA Astrophysics Data System (ADS)

    Iida, H.; Yamaguchi, K. E.; Oguri, K.

    2014-12-01

    A meromictic Lake Kai-ike is located on the northeastern margin of Kami-koshiki island, Japan. Permanent density stratification develops due to seawater infiltration through a gravel bar separating the lake from the ocean. The oxygenated surface water overlays a stagnant, saline, and anoxic deep water containing hydrogen sulfide. Purple sulfur bacteria (Chromatium sp.) inhabit the chemocline at 4.5m depth. At the lake bottom, green sulfur bacteria form microbial mat-like structures (Nakajima et al., 2003; Environ. Microbiol.). Such environment can be treated as a model for the past anoxic ocean, such as during Cretaceous OAEs (Oguri et al., 2003; Frontier Res. on Earth Evol.). A 25 cm-long KAI4 sediment core (Yamaguchi et al., 2010; Palaeo3) was used for two sequential extraction methods. SEDEX method (Ruttenberg, 1992; Limnol. Oceanogr.) was used for partitioning phosphorus-bearing species into Pabs (absorbed), PFe (Fe-bound), Pauth (authigenic), Pdet (detrital), and Porg (organic). Iron-bearing species were also divided into FeHCl (HCl-soluble), Fecarb (carbonate), Feox (oxide), Femag (magnetite), and Feresi (residue), following the method of Poulton et al. (2005; Chem. Geol.). At the uppermost part of KAI4 core, Porg was the most abundant P-bearing species (~90% of total P). The Porg content sharply decreased with increasing depth to 5cm. The second most abundant species was PFe; however, PFe and Feox contents remained constant throughout the whole depth. At sediment surface in present-day oxygenated ocean, Fe3+-(oxy)hydroxides trap phosphate diffusing from deeper-anoxic sediment, and the phosphate concentration in pore water becomes high enough to precipitate authigenic apatite (Slomp et al., 1996; J. Mar. Res.). In case of Lake Kai-ike, however, the amount of Fe3+-(oxy)hydroxides was small relative to that of Porg (PFe/Porg = ~0.1). We suggest that the excess phosphate not adsorbed on Fe3+-(oxy)hydroxides was diffused out to the overlying water mass, and the

  11. Phylogeography, Interaction Patterns and the Evolution of Host Choice in Drosophila-Parasitoid Systems in Ryukyu Archipelago and Taiwan.

    PubMed

    Novković, Biljana; Kimura, Masahito T

    2015-01-01

    Island biotas provide a great opportunity to study not only the phylogeographic patterns of a group of species, but also to explore the differentiation in their coevolutionary interactions. Drosophila and their parasitoids are exemplary systems for studying complex interaction patterns. However, there is a lack of studies combining interaction-based and molecular marker-based methods. We applied an integrated approach combining phylogeography, interaction, and host-choice behavior studies, with the aim to understand how coevolutionary interactions evolve in Drosophila-parasitoid island populations. The study focused on the three most abundant Drosophila species in Ryukyu archipelago and Taiwan: D. albomicans, D. bipectinata, and D. takahashii, and the Drosophila-parasitoid Leptopilina ryukyuensis. We determined mitochondrial COI haplotypes for samples representing five island populations of Drosophila and four island populations of L. ryukyuensis. We additionally sequenced parts of the autosomal Gpdh for Drosophila samples, and the ITS2 for parasitoid samples. Phylogenetic and coalescent analyses were used to test for demographic events and to place them in a temporal framework. Geographical differences in Drosophila-parasitoid interactions were studied in host-acceptance, host-suitability, and host-choice experiments. All four species showed species-specific phylogeographic patterns. A general trend of the haplotype diversity increasing towards the south was observed. D. albomicans showed very high COI haplotype diversity, and had the most phylogeographically structured populations, with differentiation into the northern and the southern population-group, divided by the Kerama gap. Differentiation in host suitability was observed only between highly structured populations of D. albomicans, possibly facilitated by restricted gene flow. Differentiation in host-acceptance in D. takahashii, and host-acceptance and host-choice in L. ryukyuensis was found, despite there

  12. Phylogeography, Interaction Patterns and the Evolution of Host Choice in Drosophila-Parasitoid Systems in Ryukyu Archipelago and Taiwan

    PubMed Central

    2015-01-01

    Island biotas provide a great opportunity to study not only the phylogeographic patterns of a group of species, but also to explore the differentiation in their coevolutionary interactions. Drosophila and their parasitoids are exemplary systems for studying complex interaction patterns. However, there is a lack of studies combining interaction-based and molecular marker-based methods. We applied an integrated approach combining phylogeography, interaction, and host-choice behavior studies, with the aim to understand how coevolutionary interactions evolve in Drosophila-parasitoid island populations. The study focused on the three most abundant Drosophila species in Ryukyu archipelago and Taiwan: D. albomicans, D. bipectinata, and D. takahashii, and the Drosophila-parasitoid Leptopilina ryukyuensis. We determined mitochondrial COI haplotypes for samples representing five island populations of Drosophila and four island populations of L. ryukyuensis. We additionally sequenced parts of the autosomal Gpdh for Drosophila samples, and the ITS2 for parasitoid samples. Phylogenetic and coalescent analyses were used to test for demographic events and to place them in a temporal framework. Geographical differences in Drosophila-parasitoid interactions were studied in host-acceptance, host-suitability, and host-choice experiments. All four species showed species-specific phylogeographic patterns. A general trend of the haplotype diversity increasing towards the south was observed. D. albomicans showed very high COI haplotype diversity, and had the most phylogeographically structured populations, with differentiation into the northern and the southern population-group, divided by the Kerama gap. Differentiation in host suitability was observed only between highly structured populations of D. albomicans, possibly facilitated by restricted gene flow. Differentiation in host-acceptance in D. takahashii, and host-acceptance and host-choice in L. ryukyuensis was found, despite there

  13. Genetic and biological characterization of Muko virus, a new distinct member of the species Great Island virus (genus Orbivirus, family Reoviridae), isolated from ixodid ticks in Japan.

    PubMed

    Ejiri, Hiroko; Lim, Chang-Kweng; Isawa, Haruhiko; Kuwata, Ryusei; Kobayashi, Daisuke; Yamaguchi, Yukie; Takayama-Ito, Mutsuyo; Kinoshita, Hitomi; Kakiuchi, Satsuki; Horiya, Madoka; Kotaki, Akira; Takasaki, Tomohiko; Maeda, Ken; Hayashi, Toshihiko; Sasaki, Toshinori; Kobayashi, Mutsuo; Saijo, Masayuki; Sawabe, Kyoko

    2015-12-01

    Among the tick-borne orbiviruses (genus Orbivirus, family Reoviridae), 36 serotypes are currently classified within a single virus species, Great Island virus. In this study, we report the first characterization of a tick-borne orbivirus isolated from the tick Ixodes turdus in Japan, which we identified as a new member of the species Great Island virus. The virus isolate, designated Muko virus (MUV), replicated and induced cytopathic effects in BHK-21, Vero E6, and CCL-141 cells and caused high mortality in suckling mice after intracerebral inoculation. Full genome sequence analysis showed that MUV shared the greatest phylogenetic similarity with Tribeč virus in terms of the amino acid sequences of all viral proteins except for outer capsid protein 1 (OC1; VP4 of MUV). Analysis of genome segment 9 in MUV detected an uninterrupted open reading frame that overlaps with VP6 (Hel), which putatively encodes a molecular and functional equivalent of NS4 from Great Island virus. Our study provides new insights into the geographic distribution, genetic diversity, and evolutionary history of the members of the species Great Island virus. PMID:26350980

  14. Estimation of locations and migration of debris flows on Izu-Oshima Island, Japan, on 16 October 2013 by the distribution of high frequency seismic amplitudes

    NASA Astrophysics Data System (ADS)

    Ogiso, Masashi; Yomogida, Kiyoshi

    2015-06-01

    In the early morning on 16 October 2013, large debris flows resulted in over 30 people dead on Izu-Oshima Island, Japan, which were induced by heavy rainfall from the approaching Typhoon 1326 (Wipha). We successfully estimated the locations and migration processes of five large events of the debris flows, using the spatial distribution of high-frequency seismic amplitudes recorded by a seismic network on the island. The flows occurred on the western flank of the island, almost at the same place as the site where large traces of debris flows were identified after the disaster. During each event of debris flows, the estimated locations migrated downstream with increasing time, from the caldera rim of Miharayama volcano in the center of the island to its western side with a speed of up to 30 m/s. The estimated time series of source amplitudes are different from event to event, exhibiting a large variety of flow sequences while they seem to have repeated at a relatively narrow area over several tens of minutes. The present approach may be utilized for early detection and warning for prevention and reduction of the present type of disasters in the future.

  15. Japan: Shikoku Island

    Atmospheric Science Data Center

    2016-08-24

    article title:  Aerosol Characterization Experiment over Asia   ... of 200 investigators from 11 countries participated in the Aerosol Characterization Experiment (ACE) field campaign in Asia, deploying ...

  16. Characterization of Heavy Metal Contents in the Bulk Atmospheric Aerosols Simultaneously Collected at Three Islands in Okinawa, Japan by X-ray fluorescence spectrometric method (XRF)

    NASA Astrophysics Data System (ADS)

    Oshiro, Y.; ITOH, A.; Azechi, S.; Somada, Y.; Handa, D.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2011-12-01

    We studied heavy metal contents of atmospheric aerosols using an X-ray fluorescence spectrometric method (XRF). The XRF method enables us to analyze heavy metal contents of bulk aerosols rapidly without any chemical pretreatments. We used an energy dispersive X-ray fluorescence spectrometer that is compact and portable. We prepared several different amounts of standard reference materials (NIES No.28) of Japanese National Institute of Environmental Studies on quartz filters for calibration curves. Then, we evaluated quantitative responses of XRF method by comparing with the metal contents determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after acid-digestion. Good linear relationships between X-ray intensity and amount of aerosol on filter were seen in the following 10 metals; Al, K, Ti, V, Fe, Ni, Rb, Ba, Pb and As. We then used XRF method to determine heavy metal contents in authentic atmospheric aerosols collected in Okinawa islands, Japan. Okinawa islands, consisting of many small islands, are situated east of Asian continent, and its location in Asian is well suited for studying long-range transport of air pollutants. Also, in Okinawa islands, maritime air mass prevails during summer, while Asian continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air mass which has been affected by anthropogenic activities such as industries and automobiles. Therefore, Okinawa region is suitable area for studying impacts of air pollutants from East Asia. We simultaneously collected bulk aerosol samples by using identical high-volume air samplers at 3 islands; Cape Hedo Atmospheric Aerosol Monitoring Station (CHAAMS, Okinawa island), Kume island (ca. 160 km south-west of CHAAMS), and Minami-Daitou island (ca. 320 km south-east of CHAAMS). We report and discuss spatial and temporal distribution of heavy metals

  17. First Report of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae) Infections in Invasive Rodents from Five Islands of the Ogasawara Archipelago, Japan

    PubMed Central

    Tokiwa, Toshihiro; Hashimoto, Takuma; Yabe, Tatsuo; Komatsu, Noriyuki; Akao, Nobuaki; Ohta, Nobuo

    2013-01-01

    Background Angiostrongylus cantonensis (Chen, 1935) is a parasite of murid rodents and causative agent of human neuro-angiostrongyliasis. In 2011, the Ogasawara Islands in the western North Pacific were assigned a World Natural Heritage site status. The occurrence of A. cantonensis is well documented in the Chichijima, Hahajima, and Anijima Islands. However, the occurrence of A. cantonensis in the other islands of the Ogasawara Islands has not been reported. Methodology/Principal Findings Between March 2010 and July 2011, 57 Rattus norvegicus and 79 R. rattus were collected from 9 islands (the Hahajima group: Anejima, Imoutojima, Meijima, Mukohjima, and Hirajima; Chichijima group: Minamijima; Mukojima group: Nakoudojima and Yomejima; and Iwojima group: Iwojima). Adult nematodes were found in the pulmonary artery of 46 R. norvegicus collected in the 5 islands of the Hahajima group (Anejima, Meijima, Imoutojima, Hrajima, and Mukohjima Islands). These nematodes were identified by molecular analysis as A. cantonensis. Comparison of the mitochondrial DNA sequences confirmed that all the samples from the Ogasawara Islands shared only a single lineage of A. cantonensis, which has been previously detected in the Okinawa, Hawaii, and Brazil. Conclusions/Significance We describe new endemic foci of rat angiostrongyliasis in the Hahajima group (Anejima, Meijima, Imoutojima, Hirajima, and Mukohjima Islands) of the Ogasawara Islands. These findings indicate that the endemic foci of A. cantonensis are widely distributed in the Ogasawara Islands. Although human cases have not yet been reported in the Ogasawara Islands, the widespread detection of A. cantonensis could be of importance from the perspective of public health. PMID:23950989

  18. Limited overwater dispersal and genetic differentiation of the snake-eyed skink (Cryptoblepharus nigropunctatus) in the Oceanic Ogasawara Islands, Japan.

    PubMed

    Hayashi, Fumio; Shima, Akina; Horikoshi, Kazuo; Kawakami, Kazuto; Segawa, Ryoko D; Aotsuka, Tadashi; Suzuki, Tadashi

    2009-08-01

    The genetic differentiation and speciation of lizards on oceanic islands may be affected by their rate of overwater dispersal. Cryptoblepharus is one of the most geographically widespread scincid lizards throughout the Indo-Pacific and Australian regions. Cryptoblepharus nigropunctatus is the northernmost species of the genus, dwelling on several small Pacific islands. To examine the colonization history of this lizard, mitochondrial 16S rDNA and D-loop sequences were compared among populations of the Ogasawara Islands consisting of four island groups (the Muko-jima, Chichi-jima, Haha-jima, and Kazan groups), and an isolated island, Minamitori-shima (Marcus Island). These four groups and Minamitori-shima have not been connected to each other because each is surrounded by deep sea (>100 m). DNA analyses showed that the lizard populations on individual islands had each representative haplotypes. The ancestors of C. nigropunctatus probably arrived on the islands from the southern Pacific Ocean via wave dispersal and differentiated to produce the present state. They appear to have dispersed from their origin along two independent pathways: one between Kitaiwo-to (Kazan group) and the Muko-jima and Chichi-jima groups, and the other among the Minamitori-shima, Minamiiwo-to (Kazan group), and Haha-jima groups. Limited long-distance overwater dispersal may be responsible for the genetic structure of the C. nigropunctatus populations on these oceanic islands. However, among the small islands within the same island group, D-loop haplotypes were shared and the local genetic diversity was usually high, suggesting frequent gene flow across the same group of islands. PMID:19719406

  19. Coseismic deformation due to the 2011 Tohoku earthquake: influence of 3-D plate structure around Japan

    NASA Astrophysics Data System (ADS)

    Hashima, A.; Freed, A. M.; Becker, T. W.; Sato, H.; Okaya, D. A.; Suito, H.; Hatanaka, Y.; Matsubara, M.; Takeda, T.; Ishiyama, T.; Iwasaki, T.

    2013-12-01

    Beneath the Japan islands, the Pacific plate descends from the east and the Philippine sea plate descends from the south, causing interaction of two slabs at depth. The 2011 M9 Tohoku earthquake in northern Japan had a source region with a length of ~500 km and a width of ~200 km and forced broad lithospheric and mantle regions in the region to deform. Here, we investigate the effects of slab geometry and 3D heterogeneity on the inversion of inferred coseismic slip and the resulting broad coseismic deformation throughout the region. We construct a 3-D finite element model (FEM) to generate Green's functions for use in a coseismic inversion study that allows considering the influence of complex slab geometry as well as heterogeneities in elastic structure on inferred slip. We utilize the large, land-based Japan GPS array as well as seafloor geodetic constraints in the inversion. We are particularly interested in how coseismic seafloor constraints influence inversion results. Our FEM considers a region of 4500 km x 4900 km x 670 km, incorporating the Pacific and the Philippine sea slabs by interpolating models for the Tohoku region and the Nankai trough, as well as the Kuril, Ryukyu and Izu-Bonin arcs. The model region is divided into about 500,000 tetrahedral elements with average dimension ranging from 20-100 km. We also test the role of gravity on coseismic results, with initial results suggesting that gravitational loading is not an important factor because of the shallow dip of the upper Pacific slab.Our long-term objective is to study the influence of the Tohoku earthquake on evolution of stresses throughout Japan due to both coseismic and postseismic processes, the latter including afterslip and viscoelastic relaxation. An accurate accounting of coseismic slip is very important to such an endeavor.

  20. Influence of Asian outflow on Rishiri Island, northernmost Japan: Application of radon as a tracer for characterizing fetch regions and evaluating a global 3D model

    NASA Astrophysics Data System (ADS)

    Zhu, Chunmao; Yoshikawa-Inoue, Hisayuki; Matsueda, Hidekadzu; Sawa, Yosuke; Niwa, Yosuke; Wada, Akira; Tanimoto, Hiroshi

    2012-04-01

    Atmospheric 222Rn was monitored from December 2008 to November 2010 on Rishiri Island (45°07‧N, 141°12‧E), northernmost Japan. Seasonal 222Rn variation was characterized by high concentrations from November to February and low concentrations from May to July, caused by the alternation of continental and maritime fetch regions. 222Rn tracer and back trajectory cluster analyses indicated that the predominant continental fetch region was southeastern Siberia and northeastern China. 222Rn emitted from China and South Korea, whose economies are growing rapidly, did not significantly affect the Rishiri site. The major maritime fetch region was the Sea of Okhotsk and the Bering Sea. A global three-dimensional model (NICAM-TM) accurately simulated 222Rn concentrations on Rishiri Island and in the seasonal fetch regions. The time series of 222Rn data will make it possible to evaluate the sources and sinks of atmospheric greenhouse gases being monitored at Rishiri Island, which complements other sites in the Asia-Pacific rim region, and to validate model simulations used to examine trans-boundary air pollution.

  1. Atmospheric mercury concentrations at two sites in the Kyushu Islands, Japan, and evidence of long-range transport from East Asia

    NASA Astrophysics Data System (ADS)

    Marumoto, Kohji; Hayashi, Masahiko; Takami, Akinori

    2015-09-01

    Continuous monitoring of atmospheric gaseous mercury at Fukuoka and Minamata in the Kyushu Islands, western Japan, was carried out from June 2012 to May 2013 to investigate the influence of long-range transport of mercury in the Asian region. Speciation data at Fukuoka indicated that approximately 99% of the atmospheric mercury was in the gaseous elemental form. The average concentration of gaseous elemental mercury (GEM) at Fukuoka was slightly higher than that of total gaseous mercury (TGM) at Minamata. Synchronous pollution events of higher concentrations of both GEM at Fukuoka and TGM at Minamata were frequently observed from late fall to early spring. We infer that these events occurred due to long-range transport of mercury rather than local, domestic emission sources because the two sites are far apart (about 150 km), and local sources would be unlikely to synchronously influence concentrations at both sites over such a long distance. The results of backward trajectory analyses indicated that these events occurred when air masses came from the Asian continent. In addition, the pollution events were often the result of cold fronts or migratory anticyclones that passed over the Kyushu Islands, often accompanied by descending cool and heavy air currents. Thus, these results indicate that, under specific climate conditions, higher concentrations of atmospheric mercury are transported to the Kyushu Islands from the Asian continent, and are evident in ground-based observations there.

  2. Fabric characterization associated with asthenospheric upwelling in the uppermost mantle, back-arc region of the southwest Japan arc: Evidence from peridotite xenoliths, Oki-Dogo Island

    NASA Astrophysics Data System (ADS)

    Satsukawa, Takako; Michibayashi, Katsuyoshi

    2010-05-01

    Oki-Dogo Island is an important site in terms of xenoliths because it makes the most continent ward occurrence of mantle peridotite xenoliths in the back-arc region of the southwest Japan arc. We describe the microstructure of peridotite xenoliths obtained from Oki-Dogo Island with aim of understanding the evolution of the uppermost mantle beneath the back-arc side of the Japan arc. Basement on the island consists of gneissic metamorphic complex. The alkaline basalts that contain the xenoliths were erupted during the Pliocene-Pleistocene after the opening of the Japan Sea which is thought to have occurred during the Oligocene-Miocene as a consequence of back-arc spreading. Peridotite xenoliths found on Oki-Dogo Island are up to 10 cm in size, show granular texture, and are mainly spinel lherzolites, with some harzburgites. Large xenoliths (> 3 cm) contain a foliation defined by compositional banding and aligned spinel grains, and a lineation defined by the long axes of spinel grains. All spinel lherzolites contain spinel with a low Cr# (=Cr/Fr+Al) (< 0.45); this feature, combined with their mineral assemblages and high NiO content in olivine, suggests that they are of residual origin. The Mg# (=Mg/Mg+Fe) of silicate minerals in some spinel lherzolites is lower (e.g. down to Fo86) than that in typical residual peridotites of the upper mantle, indicating that the observed Fe enrichment occurred in mantle rocks during metasomatism. We have measured crystallographic preferred orientations (CPOs) of olivine grains from highly polished thin sections using a scanning electron microscope equipped with an electron backscatter diffraction system. The dominant slip system in olivine, as determined from kink bands and CPO data, was {0kl}[100] slip. Moreover, peridotites with low olivine Mg# tend to show a AG-type ([010]-fiber) CPO pattern. This finding suggests that the peridotites were deformed in the presence of melt and represent various degrees of rock-melt interaction as

  3. Trial of multidisciplinary observation at an expandable sub-marine cabled station "off-hatsushima island observatory" in sagami bay, Japan.

    PubMed

    Kasaya, Takafumi; Mitsuzawa, Kyohiko; Goto, Tada-Nori; Iwase, Ryoichi; Sayanagi, Keizo; Araki, Eiichiro; Asakawa, Kenichi; Mikada, Hitoshi; Watanabe, Tomoki; Takahashi, Ichiro; Nagao, Toshiyasu

    2009-01-01

    Sagami Bay is an active tectonic area in Japan. In 1993, a real-time deep sea floor observatory was deployed at 1,175 m depth about 7 km off Hatsushima Island, Sagami Bay to monitor seismic activities and other geophysical phenomena. Video cameras monitored biological activities associated with tectonic activities. The observation system was renovated completely in 2000. An ocean bottom electromagnetic meter (OBEM), an ocean bottom differential pressure gauge (DPG) system, and an ocean bottom gravity meter (OBG) were installed January 2005; operations began in February of that year. An earthquake (M5.4) in April 2006, generated a submarine landslide that reached the Hatsushima Observatory, moving some sensors. The video camera took movies of mudflows; OBEM and other sensors detected distinctive changes occurring with the mudflow. Although the DPG and OBG were recovered in January 2008, the OBEM continues to obtain data. PMID:22291563

  4. A new solitary free-living species of the genus Sphenopus (Cnidaria, Anthozoa, Zoantharia, Sphenopidae) from Okinawa-jima Island, Japan.

    PubMed

    Fujii, Takuma; Reimer, James Davis

    2016-01-01

    A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and Sphenopus marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus. PMID:27551219

  5. A new solitary free-living species of the genus Sphenopus (Cnidaria, Anthozoa, Zoantharia, Sphenopidae) from Okinawa-jima Island, Japan

    PubMed Central

    Fujii, Takuma; Reimer, James Davis

    2016-01-01

    Abstract A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and Sphenopus marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus. PMID:27551219

  6. Trial of Multidisciplinary Observation at an Expandable Sub-Marine Cabled Station “Off-Hatsushima Island Observatory” in Sagami Bay, Japan

    PubMed Central

    Kasaya, Takafumi; Mitsuzawa, Kyohiko; Goto, Tada-nori; Iwase, Ryoichi; Sayanagi, Keizo; Araki, Eiichiro; Asakawa, Kenichi; Mikada, Hitoshi; Watanabe, Tomoki; Takahashi, Ichiro; Nagao, Toshiyasu

    2009-01-01

    Sagami Bay is an active tectonic area in Japan. In 1993, a real-time deep sea floor observatory was deployed at 1,175 m depth about 7 km off Hatsushima Island, Sagami Bay to monitor seismic activities and other geophysical phenomena. Video cameras monitored biological activities associated with tectonic activities. The observation system was renovated completely in 2000. An ocean bottom electromagnetic meter (OBEM), an ocean bottom differential pressure gauge (DPG) system, and an ocean bottom gravity meter (OBG) were installed January 2005; operations began in February of that year. An earthquake (M5.4) in April 2006, generated a submarine landslide that reached the Hatsushima Observatory, moving some sensors. The video camera took movies of mudflows; OBEM and other sensors detected distinctive changes occurring with the mudflow. Although the DPG and OBG were recovered in January 2008, the OBEM continues to obtain data. PMID:22291563

  7. Observations of Methane Plumes East of Oki Island in the Sea of Japan, Carried Out by Hyogo Prefecture Fisheries Research Vessel Tajima

    NASA Astrophysics Data System (ADS)

    Aoyama, D.; Aoyama, S.

    2012-12-01

    Twice in June and once in August of 2012, observations of gas plumes east of Oki Island in the Sea of Japan, at depths from 800m to 1500m, were carried out using the quantitative echo sounder (KFC3000, Kaijo) and the echo sounder (FCV1500L, Furuno), installed on the Hyogo Prefecture fisheries research vessel Tajima of 199 tons. At the same time, CTD observations of water temperature and quality, and observations of the ocean floor via underwater camera were carried out for confirmation. This is also a good fishing area for beni-zuwai crab, and although the relationship is unclear, there are often populations of beni-zuwai crab near methane hydrate deposits, so it is likely there are methane hydrate deposits in this area.

  8. Molecular characterization of Cryptosporidium parvum detected in Japanese black and Holstein calves in Iwate Prefecture and Tanegashima Island, Kagoshima Prefecture, Japan

    PubMed Central

    AITA, Junya; ICHIKAWA-SEKI, Madoka; KINAMI, Aiko; YAITA, Seiko; KUMAGAI, Yoshihiro; NISHIKAWA, Yoshifumi; ITAGAKI, Tadashi

    2015-01-01

    Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequences of the 18S rRNA gene. C. parvum oocyst-positive calves ranged in age from 6 to 13 days old and significantly have watery diarrhea (P<0.05). Sequences of the gene encoding the 60-kDa glycoprotein (GP60) in 43 Cryptosporidium oocyst-positive samples were identical to that of the zoonotic IIaA15G2R1 subtype. We therefore suggest that calves could be potential sources of C. parvum infections in humans. PMID:25819544

  9. A new analytical solution of water table response to tidal fluctuations and its application to estimate aquifer properties at the Niijima Island, Japan

    NASA Astrophysics Data System (ADS)

    Aichi, Masaatsu; Shiokari, Megumi; Tokunaga, Tomochika

    A perturbation solution of the Boussinesq equation under the boundary condition of multi-tide at the coast was derived for evaluating the hydraulic parameters of phreatic aquifer from tidally induced fluctuation of water table. Then, the solution was applied to estimate the hydraulic parameters of the Shiro-mama formation at the Niijima Island, Japan, by fitting the solution to the results of continuous measurements of water table fluctuations. The estimated hydraulic transmissivities from both the amplitude and the phase were comparable and consistent with the results of analyses based on Dupuit-Ghyben-Herzberg model, suggesting that the obtained values, i.e., 0.12-1.7 m2/s were reasonable.

  10. A new analytical approach to estimate the hydraulic parameters of a coastal phreatic aquifer from tidally induced water table fluctuations and its application at the Niijima Island, Japan

    NASA Astrophysics Data System (ADS)

    Aichi, M.; Shiokari, M.; Tokunaga, T.

    2010-12-01

    A new perturbation solution of the Boussinesq equation for tidally induced water table fluctuations in a coastal phreatic aquifer was derived under the condition of multiple tidal constituents. Then, the obtained solution was applied to estimate hydraulic parameters of the Shiro-mama formation at the Niijima Island, Japan, by fitting the solution to the results of continuous measurements of water table fluctuations in the frequency space. The estimated hydraulic transmissivities from both the amplitudes and the phase-shifts were comparable and consistent with the results of analyses based on the Dupuit-Ghyben-Herzberg model, suggesting that the proposed approach performed well and the obtained values, i.e., transmissivity to be 0.12-1.7 m2/s were reasonable.

  11. Molecular characterization of Cryptosporidium parvum detected in Japanese black and Holstein calves in Iwate Prefecture and Tanegashima Island, Kagoshima Prefecture, Japan.

    PubMed

    Aita, Junya; Ichikawa-Seki, Madoka; Kinami, Aiko; Yaita, Seiko; Kumagai, Yoshihiro; Nishikawa, Yoshifumi; Itagaki, Tadashi

    2015-08-01

    Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequences of the 18S rRNA gene. C. parvum oocyst-positive calves ranged in age from 6 to 13 days old and significantly have watery diarrhea (P<0.05). Sequences of the gene encoding the 60-kDa glycoprotein (GP60) in 43 Cryptosporidium oocyst-positive samples were identical to that of the zoonotic IIaA15G2R1 subtype. We therefore suggest that calves could be potential sources of C. parvum infections in humans. PMID:25819544

  12. High-resolution MIRU-VNTRs typing reveals the unique nature of Mycobacterium tuberculosis Beijing genotype in Okinawa, Japan.

    PubMed

    Millet, Julie; Miyagi-Shiohira, Chika; Yamane, Nobuhisa; Mokrousov, Igor; Rastogi, Nalin

    2012-06-01

    Mycobacterium tuberculosis Beijing lineage is highly prevalent in Japan. The aim of the present study was to describe the population structure of the Beijing lineage in this country based on 12-, 15-, and 21-loci MIRU-VNTR genotyping schemes. The MIRU-VNTR patterns of Beijing strains from Okinawa, Ryukyu Islands were compared to those recently published from the Osaka-Kobe megalopolis of the main island of Japan, Honshu (Wada et al., 2009). We also compared proportions of "modern/typical" vs. "ancient/atypical" Beijing strains as defined by structure of the NTF locus. Contrarily to the 12-loci Minimum Spanning Tree (MST), the 15- and 21-loci trees allowed the distinction of two groups of strains in Okinawa. A 12-loci MIRU-VNTR pattern (223325173533) corresponding to MIRU international type MIT17 was identified as the most prevalent Beijing genotype in Japan. In the SITVIT2 database, this pattern was found to be disseminated worldwide and corresponded to the most widely distributed Beijing profile in East Asia and former USSR countries. A comparison of 15- and 21-loci MIRU-VNTR patterns showed that two loci (QUB-4156 and Mtub21) were most polymorphic in our study, and could be potential candidates to distinguish between NTF locus based subclassification of Beijing strains. High-resolution VNTR typing using 15- and 21-loci underlined an evolutionarily distinct "ancient/atypical" subpopulation of the Beijing genotype in Okinawa as well as a subgroup of strains closely related to "modern/typical" Beijing strains observed in Osaka/Kobe. PMID:21723420

  13. Fecal DNA analysis for identifying species and sex of sympatric carnivores: a noninvasive method for conservation on the Tsushima Islands, Japan.

    PubMed

    Kurose, N; Masuda, R; Tatara, M

    2005-01-01

    Fecal analysis is a useful tool for the investigation of food habits and species identity in mammals. However, it is generally difficult to identify the species based on the morphological features and contents of feces deposited by mammals of similar body size. Therefore we developed noninvasive DNA analysis methods using fecal samples for identification of the species and sex of four small sympatric carnivores living on the Tsushima Islands of Japan: the leopard cat (Felis bengalensis), Japanese marten (Martes melampus), Siberian weasel (Mustela sibirica), and feral cat (Felis catus). Based on DNA sequence data from previous phylogenetic studies, we designed species-specific primers for polymerase chain reaction (PCR) amplification of the partial mitochondrial cytochrome b gene (112-347 bp) to identify the species and primers for the partial SRY gene (135 bp) to determine the sex. Due to the adjustment of PCR conditions, those specific DNA fragments were successfully amplified and then applied for species and sex identification. Nucleotide sequences obtained from the PCR products corresponded with cytochrome b sequences of the carnivore species expected. The protocol developed could be a valuable tool in the management and conservation of the four carnivore species occurring on the Tsushima Islands. PMID:16267168

  14. Trace element accumulation in short-tailed albatrosses (Diomedea albatrus) and black-footed albatrosses (Diomedea nigripes) from Torishima Island, Japan

    NASA Astrophysics Data System (ADS)

    Shinsuke, T.; Tokutaka, I.; Takashi, K.; Miyako, T.; Fumio, S.; Nariko, O.

    2003-05-01

    Concentrations of 19 trace elements (V, Cr, Mn, Co, Cu, Zn, Ga, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Hg, Tl, and Pb) were determined in liver, kidney, muscle, feather and stomach content of short-tailed albatross and feather of black-footed albatross from Torishima Island, Japan. For most of the elements, concentrations in liver and kidney were higher than those in muscle and feather, whereas concentrations of Ga, Sr and Ba were highest in feather of short-taled albatross. Metal concentrations in tissues of short-tailed albatross were within the range of those reported for albatrosses from other locations. Concentrations of Cr, Mn, Hg and Pb were relatively low in the tissues of short-tailed albatross, indicating less contamination by those metals in this species of Torishima Island. No significant differences were observed in metal concentrations in feather between short-tailed albatross and black-footed albatross. To our knowledge, this is the first report on the trace element accumulation in tissues of short-tailed albatross.

  15. Photochemical Formation of Fe(II) and Peroxides in Coastal Seawater Collected around Okinawa Island, Japan - Impact of Red Soil Pollution

    NASA Astrophysics Data System (ADS)

    Okada, K.; Nakajima, H.; Higuchi, T.; Fujimura, H.; Arakaki, T.; Taira, H.

    2003-12-01

    In a study to elucidate the impacts of red soil pollution on the oxidizing power of seawater, photochemical formation of Fe(II) and peroxides was studied in seawaters collected around Okinawa Island, Japan. The northern part of Okinawa Island suffers from red soil pollution which is caused mainly by land development such as pineapple farming and the construction of recreational facilities. We studied photochemical formation of peroxides and Fe(II) in the same seawater samples because the reaction between HOOH and Fe(II) forms hydroxyl radical (OH radical), the most potent environmental oxidant. Photochemical formation of Fe(II) was fast and reached steady-state in 30 minutes of simulated sunlight illumination and the steady-state Fe(II) concentrations were about 80% of total iron concentrations. Photochemical formation of peroxides was relatively slow and formation kinetics varied, depending on the initial peroxide concentrations. Because photochemical formation of peroxides was faster and total iron concentrations in the red soil polluted seawater were higher, red soil polluted seawater is expected to have greater oxidizing power than seawater that is not polluted with red soil.

  16. Asymmetric seasonal march from autumn to the next spring in East Asia (Toward interdisciplinary education on the climate systems and the "seasonal feeling" such as around the Japan Islands area)

    NASA Astrophysics Data System (ADS)

    Kato, Kuranoshin; Kato, Haruko; Sato, Sari; Akagi, Rikako; Haga, Yuichi; Miyake, Shoji

    2014-05-01

    There are many steps of seasonal transitions in East Asia, greatly influenced by the considerable phase differences of seasonal cycle among the Asian monsoon subsystems, resulting in the variety of "seasonal feeling" around the Japan Islands. For example, the "wintertime pressure pattern" begins to prevail already from November due to the seasonal development of the Siberian Air mass and the Siberian High, although the air temperature around the Japan Islands is still rather higher than in midwinter. On the other hand, since the southward retreat of the warm moist air mass in the western Pacific area delays rather greatly to the advances of those northern systems. Thus it would be interesting to re-examine the whole seasonal cycle around the Japan Islands at the view point of how the phase differences among seasonal marches of the Asian monsoon subsystems affect the variety of the seasonal cycle there, together with their effects on the "seasonal feeling". As such, the present study will examine the asymmetric seasonal march from autumn to the next spring through midwinter around the Japan Islands as an interesting example, and will also report the joint activity with music, and so on, toward the development of an interdisciplinary study plan on such topics for the students in junior high school, high school and the faculty of education of the university. The wintertime weather pattern, i.e., precipitation in the Japan Sea side and clear day in the Pacific side of the Japan Islands, prevails from early November to early March, reflected by the seasonal cycle of the Siberian Air Mass and the Siberian High. However, the air temperature shows the minimum from late January to early February around the Japan Islands. In other words, although the dominant weather patterns around November and in early March are nearly the same as each other, air temperature is still lower in early March (early spring). In spite of that, the solar radiation is rather stronger in early

  17. Spatial variations of the Kuroshio nutrient stream from the East China Sea to South of Japan

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao-Hua; Guo, Xinyu; Long, Yu; Li, Bo

    2013-04-01

    Based on velocity calculated from hydrographic data obtained from 39 cruises during from 2000 to 2009 and nitrate concentration data observed from 1964 to 2011, we calculated nitrate flux (the product of velocity and nitrate concentration) and nitrate transport (integration of flux over a section) through 5 sections along the Kuroshio path from the East China Sea (Sections PN and TK) to south of Japan (Sections ASUKA and 137E). In addition, Section OK east of the Ryukyu Islands was also examined. The nitrate flux showed a subsurface maximum core with a value of 9, 10, 6, 11 and 11 mol/m^2/s at Sections PN, TK, OK, ASUKA, 137E, respectively. The depth of subsurface maximum core changes at five sections and was about 400, 500, 800, 500, and 400 m at Sections PN, TK, OK, ASUKA, 137E, respectively. The eastward nitrate transport was 171, 167, 351, 942, 1444 k mol/s at Sections PN, TK, OK, ASUKA, 137E, respectively. The difference between nitrate transport through Section ASUKA and the sum of transports through Sections TK and OK, as well as the difference of nitrate transport between Sections ASUKA and 137E, suggest that the Kuroshio recirculation south of Shikoku can significantly intensify the eastward nitrate transport by the Kuroshio and therefore play an important role in the nitrate transport in the Kuroshio region.

  18. Sapporo, Hokkaido, Japan

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The city of Sapporo on the northernmost of the Japanese Home Island of Hokkaido (43.5N, 141.5E), host to the 1986 Winter Olympic Games is situated along the margin of a large valley which extends across the island from the Sea of Japan to the Pacific Ocean. The Valley is largely cultivated (the lighter green of the cultivated land distinguishes it from the gray urban development of Sapporo), but much of the island remains heavily forested.

  19. A 'Propagating' Active Across-Arc Normal Fault Shows Rupture Process of the Basement: the Case of the Southwestern Ryukyu Arc

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Shinjo, R.; Nakamura, M.; Kubo, A.; Doi, A.; Tamanaha, S.

    2011-12-01

    Ryukyu Arc is located on the southwestern extension of Japanese Island-arc towards the east of Taiwan Island along the margin of the Asian continent off China. The island-arc forms an arcuate trench-arc-backarc system. A NW-ward subduction of the Philippine Sea Plate (PSP)at a rate of 6-8 cm/y relative to the Eurasian Plate (EP) causes frequent earthquakes. The PSP is subducting almost normally in the north-central area and more obliquely around the southwestern area. Behind the arc-trench system, the Okinawa Trough (OT) was formed by back-arc rifting, where active hydrothermal vent systems have been discovered. Several across-arc submarine faults are located in the central and southern Ryukyu Arc. The East Ishigaki Fault (EIF) is one of the across-arc normal faults located in the southwestern Ryukyu Arc, ranging by 44km and extending from SE to NW. This fault was surveyed by SEABAT8160 multibeam echo sounder and by ROV Hyper-Dolphin in 2005 and 2008. The result shows that the main fault consists of five fault segments. A branched segment from the main fault was also observed. The southernmost segment is most mature (oldest but still active) and the northernmost one is most nascent. This suggests the north-westward propagation of the fault rupture corresponding to the rifting of the southwestern OT and the southward retreat of the arc-trench system. Considering that the fault is segmented and in some part branched, propagation might take place episodically rather than continuously from SE to NW. The ROV survey also revealed the rupture process of the limestone basement along this fault from the nascent stage to the mature stage. Most of the rock samples collected from the basement outcrop were limestone blocks (or calcareous sedimentary rocks). Limestone basement was observed to the west on the hanging wall far away from the main fault scarp. Then fine-grained sand with ripple marks was observed towards the main scarp. Limestone basement was observed on the main

  20. Nested Architecture of Pyroclastic Bedforms Generated by a Single Flow Event: Outcrop Examples from the Izu Volcanic Islands, Japan

    NASA Astrophysics Data System (ADS)

    Nemoto, Y.; Yoshida, S.

    2009-12-01

    We claim that compound bedforms, where small bedforms (e.g., dunes and antidunes) occur within and around the larger bedforms, are common in pyroclastic-flow deposits, using Quaternary-Holocene outcrop examples from the modern Izu volcanic island chain some 100-150 km SSW of Tokyo. The nested occurrence of bedforms have been well documented for siliciclastic deposits, as exemplified by compound dunes where small dunes (c. cm- dm thick) occur between the avalanche surfaces within larger dunes, indicating that these dunes of different sizes were produced simultaneously. However, compound dunes have rarely been reported from pyroclastic deposits. In contrast, we have discovered that compound dunes are common in pyroclastic flow deposits in the late Pleistocene & Holocene outcrops in Niijima and Oshima of the Izu volcanic island chain. Moreover, these outcrops contain abundant compound antidunes, which have been reported from neither siliciclastic or pyroclastic deposits. This is probably because flume studies, where most of published antidune studies are based, focus on small (c. cm-dm high) antidunes. In Niijima Island, we examined pyroclastic-flow deposits shed from Mt. Miyatsuka (14 ka) and Mt. Mukai (886 A.D.). Both groups of deposits contain abundant antidune stratifications, which commonly form nested structures in a two- or three-fold hierarchy, with subordinate crossbeddings originated from dune migrations. Each class of antidunes is characterized by multiple scour surfaces and vertical aggradations around mounds of lag deposits above erosion surfaces, and typically has both upstream and downstream accretion components with different proportions. The late Pleistocene pyroclastic outcrops of the nearby Oshima Island exhibit similar patterns. The geometry of the accretion surfaces vary significantly in the outcrops of both Niijima and Oshima. Whereas the antidunes dominated by upstream accretion are characterized by (1) gently inclined accretion surface and (2

  1. An extended magnetic viscous relaxation dating for calibrating an older age: an example of tsunamigenic coral boulders in Ishigaki Island, Japan

    NASA Astrophysics Data System (ADS)

    Sato, T.; Nakamura, N.; Goto, K.; Kumagai, Y.; Minoura, K.; Nagahama, H.

    2015-12-01

    A key to the understanding of past tsunami events is the ability to accurately date them. Analysis of past tsunami sediments is one of the most important tools for past tsunami reconstruction. A typical example of such tsunami sediment is tsunamigenic boulders. In Ishigaki Island, Japan, coral boulders that had been transported by tsunamis were distributed on the beach and land areas. Although the historical occurrences of several huge tsunamis were estimated based on large numbers of radiocarbon dating for coral boulders, radiocarbon dating can not determine a multiple rotational history by multiple tsunamis. A viscous remanet magnetization (VRM) dating method can be used to date any geological event that results in significant movements of a rock. Sato et al. (2014) applied VRM dating for comparing the radiocarbon age of these boulders. If a magnetic-mineral bearing rock is moved or re-oriented, the magnetism of the smaller magnetic grains re-aligns to the direction of the ambient magnetic field with time. This phenomenon is well known as Néel's (1949, 1955) single-domain (SD) relaxation theory. Pullaiah et al. (1975) derived a time-temperature (t-T relation) relation by assuming Néel's (1949, 1955) theory of magnetite. In principle, an experimental combination of short relaxation time and high temperature for removing VRM can determine the unknown relaxation time (tsunami age) at room temperature. We have been applied t-T relation to the coral boulders on Ishigaki Island, but their estimated ages showed older than radiocarbon dating. The longer relaxation time means that the observed magnetic relaxation is slower than the original Néel's theory. Such slow relaxation has been described by a stretched exponential function. The stretched exponential law provided a reasonable fit to the published experimental data. Thus, in this study, we revisit Néel's theory to provide a new t-T relation based on stretched exponential function.

  2. systematics of island arc crustal amphibolite migmatites from the Asago body of the Yakuno Ophiolite, Japan: a field evaluation of some model predictions

    NASA Astrophysics Data System (ADS)

    Pu, Xiaofei; Brophy, James G.; Tsujimori, Tatsuki

    2014-09-01

    The two most commonly invoked processes for generating silicic magmas in intra-oceanic arc environments are extended fractional crystallization of hydrous island arc basalt magma or dehydration melting of lower crustal amphibolite. Brophy (Contrib Mineral Petrol 156:337-357, 2008) has proposed on theoretical grounds that, for liquids >~65 wt% SiO2, dehydration melting should yield, among other features, a negative correlation between rare earth element (REE) abundances and increasing SiO2, while fractional crystallization should yield a positive correlation. If correct, the REE-SiO2 systematics of natural systems might be used to distinguish between the two processes. The Permian-age Asago body within the Yakuno Ophiolite, Japan, has amphibolite migmatites that contain felsic veins that are believed to have formed from dehydration melting, thus forming an appropriate location for field verification of the proposed REE-SiO2 systematics for such a process. In addition to a negative correlation between liquid SiO2 and REE abundance for liquids in excess of ~65 % SiO2, another important model feature is that, at very high SiO2 contents (75-76 %), all of the REE should have abundances less than that of the host rock. Assuming an initial source amphibolite that is slightly LREE-enriched relative to the host amphibolites, the observed REE abundances in the felsic veins fully support all theoretical predictions.

  3. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    NASA Astrophysics Data System (ADS)

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-01

    Radioactive fission product 131I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, 134Cs and 137Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m-3 in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of 134Cs and 137Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m-3) variation of stable cesium (133Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  4. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    SciTech Connect

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-15

    Radioactive fission product {sup 131}I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, {sup 134}Cs and {sup 137}Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m{sup -3} in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of {sup 134}Cs and {sup 137}Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m{sup -3}) variation of stable cesium ({sup 133}Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  5. Analysis of early bacterial communities on volcanic deposits on the island of Miyake (Miyake-jima), Japan: a 6-year study at a fixed site.

    PubMed

    Fujimura, Reiko; Sato, Yoshinori; Nishizawa, Tomoyasu; Nanba, Kenji; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Ohta, Hiroyuki

    2012-01-01

    Microbial colonization on new terrestrial substrates represents the initiation of new soil ecosystem formation. In this study, we analyzed early bacterial communities growing on volcanic ash deposits derived from the 2000 Mount Oyama eruption on the island of Miyake (Miyake-jima), Japan. A site was established in an unvegetated area near the summit and investigated over a 6-year period from 2003 to 2009. Collected samples were acidic (pH 3.0-3.6), did not utilize any organic substrates in ECO microplate assays (Biolog), and harbored around 106 cells (g dry weight)(-1) of autotrophic Fe(II) oxidizers by most-probable-number (MPN) counts. Acidithiobacillus ferrooxidans, Acidithiobacillus ferrivorans, and the Leptospirillum groups I, II and III were found to be abundant in the deposits by clone library analysis of bacterial 16S rRNA genes. The numerical dominance of Acidithiobacillus ferrooxidans was also supported by analysis of the gene coding for the large subunit of the form I ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO). Comparing the 16S rRNA gene clone libraries from samples differing in age, shifts in Fe(II)-oxidizing populations seemed to occur with deposit aging. The detection of known 16S rRNA gene sequences from Fe(III)-reducing acidophiles promoted us to propose the acidity-driven iron cycle for the early microbial ecosystem on the deposit. PMID:22075623

  6. Stable Isotope Anomalies and Low Chloride Concentrations in Pore Water of CH4-Rich Sediments at the Tanegashima Mud Volcano, Japan

    NASA Astrophysics Data System (ADS)

    Nakayama, N.; Tsunogai, U.; Ashi, J.; Gamo, T.

    2004-12-01

    Pore water from sediments collected at a Tanegashima mud volcano was analyzed for δ 13C (PDB) of dissolved CH4 together with other chemical components, Cl- and SO42-, and the δ 18O and δ D (SMOW). The Tanegashima mud volcanoes are located at the water depths from 1400 m to 1800 m, off Tanegashima island between Ryukyu trench and Ryukyu arc of Japan. It is situated at the end of south-western convergent plate boundary on Nankai-trough, which forms a part of Philippine Sea plate subducting under Eurasian plate. This cruise was conducted as a part of the JNOC (Japan National Oil Corporation) geochemical survey by R/V Hakurei-maru II. The concentrations of CH4 were generally higher than 100 micro-mol/kg. Its highest concentration (715 micro-mol/kg) was found in the crest core of a mud volcano. The δ 13C values ranged from -32 to -50 ‰ . C2H6 was detected only in the pore waters collected from the vicinity of the crest of the mud volcano. The highest δ 13C (around -22 ‰ ) and low C1/C2 concentration ratios (less than 100) were measured at the crest site, supporting the thermogenical production of methane. Other geochemical anomalies were also observed in the crest pore water. The concentrations of Cl- in the pore water at this site were extremely depleted to a minimum of 350 mmol/kg. The Cl- anomaly has not been previously reported for pore water from mud volcanoes around Japan. An endmember of isotopic composition of the fluid is estimated to be +12 ‰ for δ 18O and -40 ‰ for δ D. From these results we conclude that the most likely process to reduce pore water salinity is primarily the mixing of clay mineral dehydration water with seawater. The thermogenic methane found in the crest pore waters of the Tanegashima mud volcano may be brought from the depths of sediments due to the migration of fluid evolved by mineral the dehydration process.

  7. Structure of the tsunamigenic plate boundary and low-frequency earthquakes in the southern Ryukyu Trench

    PubMed Central

    Arai, Ryuta; Takahashi, Tsutomu; Kodaira, Shuichi; Kaiho, Yuka; Nakanishi, Ayako; Fujie, Gou; Nakamura, Yasuyuki; Yamamoto, Yojiro; Ishihara, Yasushi; Miura, Seiichi; Kaneda, Yoshiyuki

    2016-01-01

    It has been recognized that even weakly coupled subduction zones may cause large interplate earthquakes leading to destructive tsunamis. The Ryukyu Trench is one of the best fields to study this phenomenon, since various slow earthquakes and tsunamis have occurred; yet the fault structure and seismic activity there are poorly constrained. Here we present seismological evidence from marine observation for megathrust faults and low-frequency earthquakes (LFEs). On the basis of passive observation we find LFEs occur at 15–18 km depths along the plate interface and their distribution seems to bridge the gap between the shallow tsunamigenic zone and the deep slow slip region. This suggests that the southern Ryukyu Trench is dominated by slow earthquakes at any depths and lacks a typical locked zone. The plate interface is overlaid by a low-velocity wedge and is accompanied by polarity reversals of seismic reflections, indicating fluids exist at various depths along the plate interface. PMID:27447546

  8. Structure of the tsunamigenic plate boundary and low-frequency earthquakes in the southern Ryukyu Trench.

    PubMed

    Arai, Ryuta; Takahashi, Tsutomu; Kodaira, Shuichi; Kaiho, Yuka; Nakanishi, Ayako; Fujie, Gou; Nakamura, Yasuyuki; Yamamoto, Yojiro; Ishihara, Yasushi; Miura, Seiichi; Kaneda, Yoshiyuki

    2016-01-01

    It has been recognized that even weakly coupled subduction zones may cause large interplate earthquakes leading to destructive tsunamis. The Ryukyu Trench is one of the best fields to study this phenomenon, since various slow earthquakes and tsunamis have occurred; yet the fault structure and seismic activity there are poorly constrained. Here we present seismological evidence from marine observation for megathrust faults and low-frequency earthquakes (LFEs). On the basis of passive observation we find LFEs occur at 15-18 km depths along the plate interface and their distribution seems to bridge the gap between the shallow tsunamigenic zone and the deep slow slip region. This suggests that the southern Ryukyu Trench is dominated by slow earthquakes at any depths and lacks a typical locked zone. The plate interface is overlaid by a low-velocity wedge and is accompanied by polarity reversals of seismic reflections, indicating fluids exist at various depths along the plate interface. PMID:27447546

  9. Structure of the tsunamigenic plate boundary and low-frequency earthquakes in the southern Ryukyu Trench

    NASA Astrophysics Data System (ADS)

    Arai, Ryuta; Takahashi, Tsutomu; Kodaira, Shuichi; Kaiho, Yuka; Nakanishi, Ayako; Fujie, Gou; Nakamura, Yasuyuki; Yamamoto, Yojiro; Ishihara, Yasushi; Miura, Seiichi; Kaneda, Yoshiyuki

    2016-07-01

    It has been recognized that even weakly coupled subduction zones may cause large interplate earthquakes leading to destructive tsunamis. The Ryukyu Trench is one of the best fields to study this phenomenon, since various slow earthquakes and tsunamis have occurred; yet the fault structure and seismic activity there are poorly constrained. Here we present seismological evidence from marine observation for megathrust faults and low-frequency earthquakes (LFEs). On the basis of passive observation we find LFEs occur at 15-18 km depths along the plate interface and their distribution seems to bridge the gap between the shallow tsunamigenic zone and the deep slow slip region. This suggests that the southern Ryukyu Trench is dominated by slow earthquakes at any depths and lacks a typical locked zone. The plate interface is overlaid by a low-velocity wedge and is accompanied by polarity reversals of seismic reflections, indicating fluids exist at various depths along the plate interface.

  10. Very exceptional cases of VLF/LF ionospheric perturbations for deep oceanic earthquakes offshore the Japan island

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroki; Hayakawa, Masashi

    2015-12-01

    It is so far believed that ionospheric perturbations as detected by subionospheric VLF/LF (very low frequency/low frequency) propagation, are generated above and around the earthquake (EQ) epicenter. This paper presents very rare cases, which are in complete contrast to the above fact. We have found that in extremely rare cases when EQs happened (i) in the Pacific Ocean or (ii) offshore the Soya cape (Hokkaido) both with very large depths (300-400 km), corresponding ionospheric perturbations take place far away from the EQ epicenter and above the regions with considerable seismic intensity at the time of each EQ. Two EQs happened in the Torishima area of Izu islands (magnitude ∼7 and depth ∼400 km), and corresponding seismic intensity was observed in the Tokyo and Ibaraki districts. Our VLF data have indicated that the ionospheric perturbation takes place over such regions with high seismic intensity. Another group is two EQs (magnitude ∼5) offshore the Soya cape of Hokkaido, and the spatial distribution of seismic intensity at the time of each EQ is just around Aomori prefecture. VLF data have indicated the ionospheric perturbations taken place over the same Aomori area, which is in complete coincidence with the spatial distribution of seismic intensity. As a conclusion, these exceptional examples are, in principle, very similar to the concept of 'selectivity' (or sensitive zone) of geoelectric measurement by the Greek group, and we try to interpret these cases in the context of lithosphere-atmosphere-ionosphere coupling.

  11. Overwintering strategies of mosquitoes (Diptera:Culicidae) on warmer islands may predict impact of global warming on Kyushu, Japan.

    PubMed

    Mogi, M

    1996-05-01

    Mosquito overwintering was studied on Tanegashima and Yakushima, islands south of Kyushu, to predict the impact of global warming on northern Kyushu where mosquitoes overwinter in diapause. On Tanegashima and Yakushima, the following 5 types of overwintering strategies were recognized: (1) continued reproduction without diapause (2 Anopheles spp., 2 Culex spp., 2 Aedes spp.); (2) diapausing female adults but a few adults from late-developing larvae may emerge in midwinter (2 Anopheles spp. and 9 culex spp.); (3) diapausing eggs but a few adults may emerge in midwinter (5 Aedes spp.); (4) diapausing larvae (1 Orthopodomyia sp., 1 Aedes sp., 1 Armigeres sp., 1 Uranotaenia sp., 1 Toxorhynchites sp.); and (5) diapausing eggs and larvae (1 Tripteroides sp.). Few females of 4 aedine species were collected while seeking hosts in midwinter, but neither larvae nor adults of Culex tritaeniorhynchus Giles or southern house mosquito, Culex quinquefasciatus Say, were found during this survey. The 5 degrees C increase in the midwinter mean temperature in northern Kyushu probably will not produce serious mosquito problems directly, but the proximity of the subtropical regions may have significant effects through dispersal of adult mosquitoes. PMID:8667392

  12. In situ stress magnitudes at the toe of the Nankai Trough Accretionary Prism, offshore Shikoku Island, Japan

    NASA Astrophysics Data System (ADS)

    Huffman, K. A.; Saffer, D. M.

    2016-02-01

    Quantifying the orientation and magnitude of tectonic stresses is essential toward understanding deformation and faulting in subduction zones. However, constraints on in situ horizontal stress magnitudes (Shmin and SHmax) are rare. We estimate Shmin and SHmax at Ocean Drilling Program Site 808 at the toe of the Nankai accretionary prism offshore Japan, using coupled constraints from (1) the width of wellbore breakouts together with estimates of rock strength and a model describing stress redistribution at the borehole wall and (2) limits on regional differential stress defined by failure on preexisting faults. Our analysis extends from 175 to 915 m below seafloor (mbsf) and spans the active frontal thrust. For an upper bound on rock unconfined compressive strength (UCS) and assuming hydrostatic formation pore pressure, Shmin and SHmax (referenced to the seafloor) increase from 6.5 MPa at 175 mbsf to 17.4 MPa at 915 mbsf, with the stress state gradually transitioning from a thrust or strike-slip faulting regime above 800 mbsf to a normal faulting regime below. For cases with higher formation pore pressure, horizontal stresses are slightly lower but follow a similar pattern. We show that estimated Shmin and SHmax are strongly dependent on UCS, breakout width, and friction coefficient, all of which are characterized by uncertainty. Our results suggest that the prism is near thrust failure in the upper ~300 mbsf, but far from failure below. This may be reconciled with active thrusting if thrust faults are locally weaker than the surrounding rock or if SHmax fluctuates during the seismic cycle.

  13. Improving the seismic imaging in the southern Ryukyu subduction system by using multiple attenuation methods

    NASA Astrophysics Data System (ADS)

    Lyu, Ci-Jhu; Kuo-Chen, Hao; McIntosh, Kirk; Wu, Francis; Liu, Char-Shine

    2015-04-01

    The southern Ryukyu subduction system is at the boundary where the Philippine sea plate subducts northwestward beneath the Eurasian plate near the Taiwan orogen. In previous studies, the boundary where the PSP subducts northward beneath the EP have no clear answers due to a lack of high-resolution crustal-scale geophysical constraints. We want to know the Moho boundary. We analyze in this study the dynamics of SRA system with TAIGER program of 2009, multi-channel marine seismic reflection (MGL0906_23, MGL0906_28, MGL0906_26A, MGL0906_13, MGL0906_18N). Data area covers about 30,000 km2. Shots are spaced every 50 m, hydrophones are spaced every 12.5 m, and CDP spacing is 6.25 m. Recording length is 15 s. Signal of the source is low frequencies (20Hz~60Hz), which can penetrate the shallow sediments and reflex signal of the deep crust. Because multiple can affect the deep structure signals. Therefore, we use a variety of methods to remove multiple effects, and increase Moho signals. In this study, we use four ways to remove the multiple. (1) Increases CDP spacing. (2)Deconvolution. (3) Surface Related Multiple Elimination (SRME). (4)Radon Transform multiple attenuation. From the TAIGER marine reflection data. The shallow structure are Huatung Basin, Yeyama Accretionary Prism, Forearc Basin and Ryukyu Arc (from south to north), respectively. We discover a lot of transform fault zone, and account these stress related with shear zone of Ryukyu subduction system. The deep structure, the crust of PSP velocity is about 5~7 km/s, the PSP Moho velocity is 7.5 km/s. In multichannel reflection seismic, the PSP Moho deep is about 15~20 km under the seabed. Keywords: multiple; Moho boundary; subduction zone; southern Ryukyu Arc (SRA)

  14. Repeated magmatism at 34 Ma and 23-20 Ma producing high magnesian adakitic andesites and transitional basalts on southern Okushiri Island, NE Japan arc

    NASA Astrophysics Data System (ADS)

    Sato, Makoto; Shuto, Kenji; Nohara-Imanaka, Rikako; Takazawa, Eiichi; Osanai, Yasuhito; Nakano, Nobuhiko

    2014-09-01

    The southern part of Okushiri Island in the present-day back-arc margin of the NE Japan arc is one of the rare convergent plate boundaries where similar magma types (high-magnesian adakitic andesite (HMAA) and high-TiO2 basalt (HTB)) have been erupted concurrently at more than one time. Oligocene HMAA can be divided into two types: HMAA-I is characterized by high Sr/Y and low Y, and HMAA-II by relatively low Sr/Y and high Y. HMAA-I is primitive in terms of MgO (8.5 wt.%), Mg# (67), Ni (232 ppm) and Cr (613 ppm) contents, and the most Mg-rich olivine phenocrysts plot within the mantle olivine array in terms of Fo and NiO. The similar Cr versus Ni relations of types I and II HMAA indicate some interaction of slab-derived adakitic melts with mantle peridotite, whereas Ni contents are higher than those of most boninites derived by partial melting of mantle peridotite at a given Cr content. Types I and II HMAA have more enriched Sr and Nd isotopic compositions than N-MORB. The petrography and geochemistry of these rocks, combined with published results on the genesis of high-magnesian andesite (HMA) indicate that types I and II HMAA could be produced by interaction of slab (N-MORB and sediment)-derived adakitic melts with mantle peridotite. The comagmatism of HMAA and HTB is ascribed to the following model. A cool, less hydrous, adakite magma (spherical diapir) would rise from the subducting slab (Pacific Plate) and become more hydrous as a result of its interaction with overlying hydrous peridotite. This hydrated adakitic diapir further ascends and is heated on entering the overlying mantle wedge. Subsequently, the temperature and H2O gradients in the ascending adakitic diapir and surrounding mantle peridotite would have been established. The HTB magma segregated from the surrounding mantle peridotite region (high temperature and low H2O content) at a depth of 60 km or more, whereas the adakitic diapir (low temperature and high H2O content) continued to rise, with its

  15. Is heterostyly rare on oceanic islands?

    PubMed Central

    Watanabe, Kenta; Sugawara, Takashi

    2015-01-01

    Heterostyly has been considered rare or absent on oceanic islands. However, there has been no comprehensive review on this issue. Is heterostyly truly rare on oceanic islands? What makes heterostyly rare on such islands? To answer these questions, we review the reproductive studies on heterostyly on oceanic islands, with special emphasis on the heterostylous genus Psychotria in the Pacific Ocean as a model system. Overall, not many reproductive studies have been performed on heterostylous species on oceanic islands. In Hawaiian Psychotria, all 11 species are thought to have evolved dioecy from distyly. In the West Pacific, three species on the oceanic Bonin and Lanyu Islands are distylous (Psychotria homalosperma, P. boninensis and P. cephalophora), whereas three species on the continental Ryukyu Islands show various breeding systems, such as distyly (P. serpens), dioecy (P. rubra) and monoecy (P. manillensis). On some other Pacific oceanic islands, possibilities of monomorphy have been reported. For many Psychotria species, breeding systems are unknown, although recent studies indicate that heterostylous species may occur on some oceanic islands. A shift from heterostyly to other sexual systems may occur on some oceanic islands. This tendency may also contribute to the rarity of heterostyly, in addition to the difficulty in colonization/autochthonous evolution of heterostylous species on oceanic islands. Further investigation of reproductive systems of Psychotria on oceanic islands using robust phylogenetic frameworks would provide new insights into plant reproduction on oceanic islands. PMID:26199401

  16. Genetic differentiation and connectivity of morphological types of the broadcast-spawning coral Galaxea fascicularis in the Nansei Islands, Japan.

    PubMed

    Nakajima, Yuichi; Zayasu, Yuna; Shinzato, Chuya; Satoh, Noriyuki; Mitarai, Satoshi

    2016-03-01

    Population connectivity resulting from larval dispersal is essential for the maintenance or recovery of populations in marine ecosystems, including coral reefs. Studies of species diversity and genetic connectivity within species are essential for the conservation of corals and coral reef ecosystems. We analyzed mitochondrial DNA sequence types and microsatellite genotypes of the broadcast-spawning coral, Galaxea fascicularis, from four regions in the subtropical Nansei Islands in the northwestern Pacific Ocean. Two types (soft and hard types) of nematocyst morphology are known in G. fascicularis and are significantly correlated with the length of a mitochondrial DNA noncoding sequence (soft type: mt-L; hard type: mt-S type). Using microsatellites, significant genetic differentiation was detected between the mitochondrial DNA sequence types in all regions. We also found a third genetic cluster (mt-L+), and this unexpected type may be a cryptic species of Galaxea. High clonal diversity was detected in both mt-L and mt-S types. Significant genetic differentiation, which was found among regions within a given type (F ST = 0.009-0.024, all Ps ≤ 0.005 in mt-L; 0.009-0.032, all Ps ≤ 0.01 in mt-S), may result from the shorter larval development than in other broadcast-spawning corals, such as the genus Acropora. Nevertheless, intraspecific genetic diversity and connectivity have been maintained, and with both sexual and asexual reproduction, this species appears to have a potential for the recovery of populations after disturbance. PMID:27087925

  17. Photochemical age of air pollutants, ozone, and secondary organic aerosol in transboundary air observed on Fukue Island, Nagasaki, Japan

    NASA Astrophysics Data System (ADS)

    Irei, Satoshi; Takami, Akinori; Sadanaga, Yasuhiro; Nozoe, Susumu; Yonemura, Seiichiro; Bandow, Hiroshi; Yokouchi, Yoko

    2016-04-01

    To better understand the secondary air pollution in transboundary air over westernmost Japan, ground-based field measurements of the chemical composition of fine particulate matter ( ≤ 1 µm), mixing ratios of trace gas species (CO, O3, NOx, NOy, i-pentane, toluene, and ethyne), and meteorological elements were conducted with a suite of instrumentation. The CO mixing ratio dependence on wind direction showed that there was no significant influence from primary emission sources near the monitoring site, indicating long- and/or mid-range transport of the measured chemical species. Despite the considerably different atmospheric lifetimes of NOy and CO, these mixing ratios were correlated (r2 = 0.67). The photochemical age of the pollutants, t[OH] (the reaction time × the mean concentration of OH radical during the atmospheric transport), was calculated from both the NOx / NOy concentration ratio (NOx / NOy clock) and the toluene / ethyne concentration ratio (hydrocarbon clock). It was found that the toluene / ethyne concentration ratio was significantly influenced by dilution with background air containing 0.16 ppbv of ethyne, causing significant bias in the estimation of t[OH]. In contrast, the influence of the reaction of NOx with O3, a potentially biasing reaction channel on [NOx] / [NOy], was small. The t[OH] values obtained with the NOx / NOy clock ranged from 2.9 × 105 to 1.3 × 108 h molecule cm-3 and were compared with the fractional contribution of the m/z 44 signal to the total signal in the organic aerosol mass spectra (f44, a quantitative oxidation indicator of carboxylic acids) and O3 mixing ratio. The comparison of t[OH] with f44 showed evidence for a systematic increase of f44 as t[OH] increased, an indication of secondary organic aerosol (SOA) formation. To a first approximation, the f44 increase rate was (1.05 ± 0.03) × 10-9 × [OH] h-1, which is comparable to the background-corrected increase rate observed during the New England Air Quality

  18. Discovery of Seafloor Massive Sulfides in an Andesite-Dacite Knoll Caldera off Present-Day Volcanic Front, Izu-Ogasawara Island Arc, Japan

    NASA Astrophysics Data System (ADS)

    Iizasa, K.; Asada, A.; Lee, S.; Mizuno, K.; Katase, F.; Kojima, M.; Kurozawa, T.

    2015-12-01

    We report the discovery of sulfide mounds with 20 to 30 m high sulfide chimneys in the Higashi-Aogashima hydrothermal field of a Quaternary andesite-dacite knoll caldera at the frontal arc side off Quaternary volcanic front, Izu-Ogasawara island arc, Japan. The discovery was carried out based on the systematic survey method of geological technique and a developed acoustic device using AUV. The knoll caldera 12 km east of Aogashima volcanic island is the size 10 km to 9 km of its rim and 820 m deep at its deepest caldera floor. According to the results of heavy mineral analysis for caldera sediments by a gravity corer, at least two areas were inferred to sites of potential hydrothermal activity associated with seafloor massive sulfides. After the precise acoustic survey using AUV there are many mound-like structures in the both inferred areas on the floor. Two major hydrothermal fields among them so far, which are a conical sulfide mound on the southeast flank of the central cone and a ridge-like mound on the inferred caldera boundary fault in the southeast, were confirmed based on sulfide samples recovered by a gravity corer during the next survey stage. One of them occurs at the water depth of 760 m to 770 m. It has active sulfide chimneys (ca. 20 m high) on the conical sulfide mound of about 40 m in diameter with 20 m high. Samples from the mound are composed of major sphalerite with moderate galena and barite, and minor chalcopyrite and pyrite. Another mound associated with chimneys at the water depth ranging from 740m to 770m on the southeast caldera boundary fault forms a small, east-west trend ridge-like shape. The ridge sizes more than 100 m long with 10 m wide. Chimneys are more than 30 m high. It is inferred that the mound is composed of major sphalerite and moderate barite based on samples cored at the margin of the mound. These results indicate that more than several sulfide mounds would be confirmed in the caldera floor by ROV surveys this September.

  19. Paleoclimate Reconstruction during the 17th to 18th Century Using Fossil Coral Tsunami Boulders from Ishigaki Island, the Ryukyus, Japan

    NASA Astrophysics Data System (ADS)

    Tsuzuki, K.; Yokoyama, Y.; Seki, A.; Kawakubo, Y.; Araoka, D.; Suzuki, A.

    2014-12-01

    Little Ice Age (LIA) which lasted during approximately 1450 to 1850 (e.g. Grove, 1988) is known as naturally occurring climate fluctuation, so knowing LIA in detail is necessary to improve climate models. Instrumental records can only extend back to about 100 years in many areas, thus paleoclimate records are reconstructed using proxies in tree rings, sediments and so force. However there are differences in reconstructed timings and magnitudes of LIA occurred in each area (Overpack et al., 1997), and most of the records are based mainly on terrestrial proxies such as tree ring records, whereas only limited numbers of marine records are available (Mann et al., 2008). Coral skeletal climatology is a useful tool to reconstruct marine paleoclimate records in tropics and subtropics. Hermatypic corals, Porites spp. have aragonite skeletons and they have annual bands, which are suitable to reconstruct high-resolution paleoclimate in seasonal scale by measuring chemical compositions. Skeletal Sr/Ca ratio in Porites spp. has been widely used as a reliable proxy of SST (Sea Surface Temperature). However, corals grow for approximately several decades to 200 years, hence it is difficult to reconstruct LIA paleoclimate using living corals. Cobb et al. (2003) used fossil corals casted on shore by storms to reconstruct millennial scale paleoclimate. There are fossil coral boulders in the eastern coast of Ishigaki Island, Ryukyus, Japan. These fossil coral boulders were casted on shore by paleo Tsunami events, thus they are called "Tsunami boulders" (Araoka et al., 2010). Fossil corals used by Cobb et al. have 30-90-year records while some large Tsunami boulders have multi-centennial continuous records. In this study, we reconstruct paleo SST using the Tsunami boulder from Ishigaki Island. The boulder has 185 years of annual banding. U-series dating shows the boulder was moved on shore at Meiwa earthquake in 1771. We measure Sr/Ca ratio using LA-HR-ICPMS (Laser Ablation High

  20. Japan launches mission to Venus

    NASA Astrophysics Data System (ADS)

    Banks, Michael

    2010-06-01

    The Japanese space agency JAXA has launched its first mission to Venus. The Akatsuki craft, which means "dawn" in Japanese, took off last month from the Tanegashima Space Center on the island of Kagoshima, south-west of mainland Japan.

  1. Okinawa, Japan: Geologic Battleground

    NASA Astrophysics Data System (ADS)

    Waymack, S. W.; Carrington, M. P.; Harpp, K. S.

    2005-12-01

    One of our main goals as instructors, particularly in introductory courses, is to impart students with an appreciation of how geology has influenced the course of human events. Despite the apparent accessibility of such topics, communicating this in a lively, relevant, and effective way often proves difficult. We use a series of historical events, the Pacific island hopping campaign of WWII, to engage students in an active, guided inquiry exercise to explore how terrain and the underlying geology of an area can shape historical events. Teams of students are assigned the role of planning either the defense or occupation of Okinawa Island, in the Ryukyu arc, in a theoretical version of the 1945 conflict. Students are given a package of information, including geologic and topographic maps, a list of military resources available to them at the time, and some historical background. Students also have access to "reconnaissance" images, 360o digital panoramas of the landscape of Okinawa, keyed to their maps. Each team has a week to plan their strategies and carry out additional research, which they subsequently bring to the table in the form of a written battle plan. With an instructor as arbiter, teams alternate drawing their maneuvers on a map of the island, to which the other team then responds. This continues one move at a time, until the instructor declares a victor. Throughout the exercise, the instructor guides students through analysis of each strategic decision in light of the island's structure and topography, with an emphasis on the appropriate interpretation of the maps. Students soon realize that an understanding of the island's terrain literally meant the difference between life and death for civilians and military participants alike in 1945. The karst landscape of Okinawa posed unique obstacles to both the Japanese and the American forces, including difficult landing sites, networks of natural caves, and sequences of hills aligned perpendicular to the

  2. A pilot study of tele-anaesthesia by virtual private network between an island hospital and a mainland hospital in Japan.

    PubMed

    Miyashita, Tetsuya; Mizuno, Yusuke; Sugawara, Yo; Nagamine, Yusuka; Koyama, Yukihide; Miyazaki, Tomoyuki; Uchimoto, Kazuhiro; Iketani, Yasuhiro; Tojo, Kentaro; Goto, Takahisa

    2015-03-01

    We studied the use of tele-anaesthesia between Sado General Hospital (SGH) located on Sado Island and Yokohama City University Hospital (YCUH) located in mainland Japan. The two sites were connected via a virtual private network (VPN). We investigated the relationship between the bandwidth of the VPN and both the frame rate and the delay time of the tele-anaesthesia monitoring system. The tool used for communication between the two hospitals was free videoconferencing software (FaceTime), which can be used over Wi-Fi connections. We also investigated the accuracy of the commands given during teleanaesthesia: any commands from the anaesthetist at the YCUH that were not carried out for any reason, were recorded in the anaesthetic records at the SGH. The original frame rate and data rate at the SGH were 5 fps and approximately 18 Mbit/s, respectively. The frame rate at the transmission speeds of 1, 5 and 20 Mbit/s was 0.6, 1.6 and 5.0 fps, respectively. The corresponding delay time was 12.2, 4.9 and 0.7 s. Twenty-five adult patients were enrolled in the study and tele-anaesthesia was performed. The total duration of anaesthesia was 37 hours. All 888 anaesthetic commands were completed. There were 7 FaceTime disconnections, which lasted for 10 min altogether. Because no commands needed to be given during the FaceTime disconnection, the telephone was not used. The anaesthesia assistance system might form part of the solution to medical resource shortages. PMID:25488187

  3. A five-year observation of atmospheric metals on Ulleung Island in the East/Japan Sea: Temporal variability and source identification

    NASA Astrophysics Data System (ADS)

    Kang, Jeongwon; Choi, Man-Sik; Yi, Hi-Il; Song, Yun-Ho; Lee, Dongyup; Cho, Ju-Hye

    2011-08-01

    We investigated seasonal characteristics (concentration, enrichment factors, and correlation coefficients) of chemical constituents, including sources for sea salt-corrected metals (Al, Fe, K, Ca, Mg, S, As, Cd, Co, Cu, Li, Mn, Mo, Ni, Pb, Sn, Sr, Ti, V, and Zn), in 334 aerosol samples collected during October 2003-October 2008 at Ulleung Island in the southern East/Japan Sea. High Al concentrations were found in spring (geometric means of 1.23 and 1.28 μg m -3 in March and April, respectively) due to Asian dust (yellow sand) originating from northeastern China. The dust mineral transport by strong winds resulted in a change of metal composition showing soil-dominated condition. In the rainy period (June-September), the aerosol metal concentrations and composition were influenced largely by wet deposition and the summer monsoon, together with anthropogenic aerosol transport. The correlation coefficients in the summer period (July and August) showed a positive correlation of Al with K ( r = 0.74) and As ( r = 0.63), probably reflecting anthropogenic-originated Al coming from coal burning. In autumn (October and November) and winter (December and January), mixed sources of soil and anthropogenic-originated aerosols were pronounced by the development of northwesterly winds from the Asian continent. Especially, the soil-originated proportion was relatively higher in autumn than in winter when the anthropogenic-originated aerosols from heating fuels predominated. Anthropogenic As, Sn, Mo, Zn, Pb, and Cd between low- and high-dust periods that had similar air-mass movements in spring were at similar concentrations, but higher in the air masses including eastern China trajectories and/or slow movement at lower height during high-dust periods.

  4. Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan.

    PubMed

    Nakano, Takanori; Yokoo, Yoriko; Okumura, Masao; Jean, Seo-Ryong; Satake, Kenichi

    2012-11-01

    To elucidate the influence of airborne materials on the ecosystem of Japan's Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO(3) contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seawater, and distinct (87)Sr/(86)Sr ratios that depended on the bedrock type. The proportions of rain-derived cations in streamwater, estimated by assuming that Cl was derived from sea salt aerosols, averaged 81 % for Na, 83 % for Mg, 36 % for K, 32 % for Ca, and 33 % for Sr. The Sr value was comparable to the 28 % estimated by comparing Sr isotope ratios between rain and granite bedrock. The soils are depleted in Ca, Na, P, and Sr compared with the parent materials. At Yotsuse in the northwestern side, plants and the soil pool have (87)Sr/(86)Sr ratios similar to that of rainwater with a high sea salt component. In contrast, the Sr and Nd isotope ratios of soil minerals in the A and B horizons approach those of silicate minerals in northern China's loess soils. The soil Ca and P depletion results largely from chemical weathering of plagioclase and of small amounts of apatite and calcite in granitic rocks. This suggests that Yakushima's ecosystem is affected by large amounts of acidic precipitation with a high sea salt component, which leaches Ca and its proxy (Sr) from bedrock into streams, and by Asian dust-derived apatite, which is an important source of P in base cation-depleted soils. PMID:23136452

  5. Dense Community of Hyperthermophilic Sulfur-Dependent Heterotrophs in a Geothermally Heated Shallow Submarine Biotope near Kodakara-Jima Island, Kagoshima, Japan

    PubMed Central

    Hoaki, T.; Nishijima, M.; Miyashita, H.; Maruyama, T.

    1995-01-01

    Microbial communities in marine hydrothermal sediments (0 to 30 cm deep) in an inlet of Kodakara-Jima Island, Kagoshima, Japan, were studied with reference to environmental factors, especially the presence of amino acids. The study area was shallow, and the sea floor was covered with sand through which hot volcanic gas bubbled and geothermally heated water seeped out. The total bacterial density increased with depth in the sediments in parallel with a rise in the ambient temperature (80(deg)C at the surface and 104(deg)C at a depth of 30 cm in the sediments). As estimated by most-probable-number studies, hyperthermophilic sulfur-dependent heterotrophs growing at 90(deg)C dominated the microbial community (3 x 10(sup7) cells (middot) g of sediment(sup-1) at a depth of 30 cm in the sediments), followed in abundance by hyperthermophilic sulfur-dependent facultative autotrophs (3.3 x 10(sup2) cells (middot) g of sediment(sup-1)). The cooler sandy or rocky floor surrounding the hot spots was covered with white bacterial mats which consisted of large Beggiatoa-like filaments. Both the total organic carbon content, most of which was particulate (75% in the surface sediments), and the amino acid concentration in void seawater in the sediments decreased with depth. Amino acids, both hydrolyzable and free, constituted approximately 23% of the dissolved organic carbon in the surface sediments. These results indicate that a lower amino acid concentration is probably due to consumption by dense populations of hyperthermophilic sulfur-dependent heterotrophs, which require amino acids for their growth and thus create a gradient of amino acid concentration in the sediments. The role of primary producers, which supply essential amino acids to sustain this microbial community, is also discussed. PMID:16535029

  6. Rapid sedimentation of iron oxyhydroxides in an active hydrothermal shallow semi-enclosed bay at Satsuma Iwo-Jima Island, Kagoshima, Japan

    NASA Astrophysics Data System (ADS)

    Kiyokawa, Shoichi; Ueshiba, Takuya

    2015-04-01

    Hydrothermal activity is common in the fishing port of Nagahama Bay, a small semi-enclosed bay located on the southwest coast of Satsuma Iwo-Jima Island (38 km south of Kyushu Island, Japan). The bay contains red-brown iron oxyhydroxides and thick deposits of sediment. In this work, the high concentration and sedimentation rates of oxyhydroxide in this bay were studied and the sedimentary history was reconstructed. Since dredging work in 1998, a thickness of ~ 1.0-1.5 m of iron oxyhydroxide-rich sediments has accumulated on the floor of the bay. To estimate the volume of iron oxyhydroxide sediments and the amount discharged from hydrothermal vents, sediment traps were operated for several years and 13 sedimentary core samples were collected to reconstruct the 10-year sedimentary history of Nagahama Bay. To confirm the timing of sedimentary events, the core data were compared with meteorological records obtained on the island, and the ages of characteristic key beds were thus identified. The sedimentation rate of iron oxyhydroxide mud was calculated, after correcting for sediment input from other sources. The sediments in the 13 cores from Nagahama Bay consist mainly of iron oxyhydroxide mud, three thick tephra beds, and a topmost thick sandy mud bed. Heavy rainfall events in 2000, 2001, 2002, and 2004-2005 coincide with tephra beds, which were reworked from Iwo-Dake ash deposits to form tephra-rich sediment. Strong typhoon events with gigantic waves transported outer-ocean-floor sediments and supplied quartz, cristobalite, tridymite, and albite sands to Nagahama Bay. These materials were redeposited together with bay sediments as the sandy mud bed. Based on the results from the sediment traps and cores, it is estimated that the iron oxyhydroxide mud accumulated in the bay at the relatively rapid rate of 33.3 cm/year (from traps) and 2.8-4.9 cm/year (from cores). The pore water contents within the sediment trap and core sediments are 73%-82% and 47

  7. Tetrodotoxin and Its Analogues in the Pufferfish Arothron hispidus and A. nigropunctatus from the Solomon Islands: A Comparison of Their Toxin Profiles with the Same Species from Okinawa, Japan

    PubMed Central

    Gorapava Puilingi, Clyde; Kudo, Yuta; Cho, Yuko; Konoki, Keiichi; Yotsu-Yamashita, Mari

    2015-01-01

    Pufferfish poisoning has not been well documented in the South Pacific, although fish and other seafood are sources of protein in these island nations. In this study, tetrodotoxin (TTX) and its analogues in each organ of the pufferfish Arothron hispidus and A. nigropunctatus collected in the Solomon Islands were investigated using high resolution LC-MS. The toxin profiles of the same two species of pufferfish from Okinawa, Japan were also examined for comparison. TTXs concentrations were higher in the skin of both species from both regions, and relatively lower in the liver, ovary, testis, stomach, intestine, and flesh. Due to higher TTX concentrations (51.0 and 28.7 µg/g at highest) detected in the skin of the two species from the Solomon Islands (saxitoxin was <0.02 µg/g), these species should be banned from consumption. Similar results were obtained from fish collected in Okinawa, Japan: TTX in the skin of A. hispidus and A. nigropunctatus were 12.7 and 255 µg/g, respectively, at highest, and saxitoxin was also detected in the skin (2.80 µg/g at highest) and ovary of A. hispidus. TTX, 5,6,11-trideoxyTTX (with its 4-epi form), and its anhydro forms were the most abundant, and 11-oxoTTX was commonly detected in the skin. PMID:26343722

  8. Tetrodotoxin and Its Analogues in the Pufferfish Arothron hispidus and A. nigropunctatus from the Solomon Islands: A Comparison of Their Toxin Profiles with the Same Species from Okinawa, Japan.

    PubMed

    Puilingi, Clyde Gorapava; Kudo, Yuta; Cho, Yuko; Konoki, Keiichi; Yotsu-Yamashita, Mari

    2015-09-01

    Pufferfish poisoning has not been well documented in the South Pacific, although fish and other seafood are sources of protein in these island nations. In this study, tetrodotoxin (TTX) and its analogues in each organ of the pufferfish Arothron hispidus and A. nigropunctatus collected in the Solomon Islands were investigated using high resolution LC-MS. The toxin profiles of the same two species of pufferfish from Okinawa, Japan were also examined for comparison. TTXs concentrations were higher in the skin of both species from both regions, and relatively lower in the liver, ovary, testis, stomach, intestine, and flesh. Due to higher TTX concentrations (51.0 and 28.7 µg/g at highest) detected in the skin of the two species from the Solomon Islands (saxitoxin was <0.02 µg/g), these species should be banned from consumption. Similar results were obtained from fish collected in Okinawa, Japan: TTX in the skin of A. hispidus and A. nigropunctatus were 12.7 and 255 µg/g, respectively, at highest, and saxitoxin was also detected in the skin (2.80 µg/g at highest) and ovary of A. hispidus. TTX, 5,6,11-trideoxyTTX (with its 4-epi form), and its anhydro forms were the most abundant, and 11-oxoTTX was commonly detected in the skin. PMID:26343722

  9. Deep structure of the Beppu hydrothermal system, Kyushu, Japan

    SciTech Connect

    Yusa, Y.; Ohsawa, S.; Kitaoka, K.; Fukuda, Y.

    1995-12-31

    The central part of Kyushu Island, southwest Japan, is located at the junction of the Southwest Japan Arc and the Ryukyu Arc, where a graben (Beppu-Shimabara Graben) has been formed by the rifting tectonic movement. There are many Quaternary volcanoes and active geo- and hydro-thermal fields within the Graben. The Beppu hydrothermal system extends around the Tsurumi-Garandake volcanoes at the eastern end of the Graben. This report will deal with the hydrothermal system beneath the volcanoes specially focusing on Garandake. Modest or violent fumarolic activities are visible near the summit of Garandake (1045 m in height). The total water(steam) output is 1.4 kg/s and its heat output 3.8 MW, while the heat output from the ground surface of 5.5 x 10{sup 4} m{sup 2} is 19.5 MW estimated by a heat balance analysis based on infrared radiation measurements (Yuhara et al., 1987). Thus the main process of heat discharge from Garandake, totally 23.3 MW, is the radiation from the ground surface. The geothermal gradient observed in a well drilled near the summit indicates that the large heat output is caused by some special process different from conduction because the heat flow by conduction is estimated to be 0.03 MW, which is very small compared with the observed output. Allis and Yusa (1989) suggested that a two-phase flow system is developed in Garandake. The two-phase flow, steam rising and water failing, acts as a heat pipe, by which a large quantity of (latent) heat can be transported upwards. Applying the theory of two-phase flow (Yusa and Oishi, 1989) to the Garandake system, the upflow rate of steam is estimated to be 10.3 kg/s at 100{degrees}C; the temperature near the ground surface, A part of rising steam (1.4 kg/s) flows out through fumaroles, and the remnant condenses to flow downwards. If the system is vapor-dominated, the intrinsic permeability at the shallow part should be about 1 darcy.

  10. Detection and location of shallow very low frequency earthquakes along the Nankai trough and the Ryukyu trench

    NASA Astrophysics Data System (ADS)

    Asano, Y.; Matsuzawa, T.; Obara, K.

    2013-12-01

    We have investigated spatiotemporal distribution of shallow very low frequency earthquakes (VLFEs) along the Nankai trough and the Ryukyu trench. Three component seismograms recorded at broadband stations of the NIED F-net were analyzed by using waveform-correlation and back-projection techniques after processing a band-pass filter (0.02 to 0.05 Hz). Here we used known VLFEs and regular interplate earthquakes near the trench axis as template events. Time series of cross-correlation function (CC) at each station was calculated from continuous waveform data and triggered seismograms of template events with a length of 180 s. Assuming surface wave propagation with a velocity of 3.8 km/s, CCs are back-propagated onto possible origin times and horizontal locations. We obtained VLFE epicenters by performing a grid search in time and space domains with spacing of 1 s and 0.025 degrees, respectively, to maximize the averaged CCs from all stations. At first, we choose grid points with averaged CCs larger than 0.5. If these grid points have similar origin times within 180 s, we assume that these grid points reflect a same event and choose the VLFE candidate having the largest averaged CC. If some grid points are detected in the same time window from different template events, we choose the VLFE candidate with the largest averaged CC from grid points located within 100 km from the template event. VLFEs were finally identified by removing regular earthquakes listed in the JMA catalogue from all candidates. As a result of the analysis for data from October, 2009 to February, 2010, two episodes of VLFE activity were detected. One episode was located east of the M6.8 interplate earthquake which occurred on October 30, 2009 along the Ryukyu trench. The VLFE seismicity was quite active just after the M6.8 earthquake and had been smoothly decreasing with the elapsed time. Such time dependent seismicity may be related to the post-seismic slip following the M6.8 earthquake. Another

  11. A new species of fiddler crab from the Ogasawara (Bonin) Islands, Japan, separated from the widely-distributed sister species Uca (Paraleptuca) crassipes (White, 1847) (Crustacea: Decapoda: Brachyura: Ocypodidae).

    PubMed

    Shih, Hsi-Te; Komai, Tomoyuki; Liu, Min-Yun

    2013-01-01

    A new species of fiddler crab (Brachyura: Ocypodidae), Uca boninensis sp. nov., is described from the Ogasawara (Bonin) Islands, Japan. The new species has previously been identified with the widely distributed U. crassipes (White, 1847), from which it differs by having a slightly differently shaped carapace, and relatively stouter male first gonopods (G1). The recognition of the new species is also supported by differences in the mitochondrial cytochrome oxidase I (COI) and control region (CR) genes. U. boninensis sp. nov., appears to be endemic to the Ogasawara Islands, and as the only known population is small, urgent conservation measures are needed for its protection. Our study brings the total number of the Japanese fiddler crab species to 12. PMID:25113474

  12. Spatial Variation of the Tectonic Stress Field along the Ryukyu-Taiwan-Luzon Convergent Margin

    NASA Astrophysics Data System (ADS)

    Wu, W.; Kao, H.; Hsu, S.

    2008-12-01

    We apply a recently developed damped stress inversion method to a large dataset consisting of high-quality focal mechanism solutions from global and regional moment tensor catalogs to invert the detailed crustal stress field along the western convergent margin of the Philippine Sea plate (PSP), namely the Ryukyu- Taiwan-Luzon system. The transition from oblique subduction to regional collision is best characterized by significant variations in the direction of the maximum compressional axis (£m1). In the Ryukyu subduction zone, £m1 is generally consistent with the relative plate motion between PSP and Eurasia plate, except the southernmost segment near the Gagua Ridge where £m1 turns to almost N-S. The azimuth of extensional axis (£m3) is mainly perpendicular to the local strike of the Ryukyu Trench in the outer-rise region, and shows a NNW-SSE direction in the Okinawa Trough. This observation is consistent with the local extensional processes reported previously. A clear stress boundary trending NW-SE is identified in northeast Taiwan separating the stress regime associated with the Ryukyu subduction system from the collision system in Taiwan. For most part of Taiwan, £m1 agrees with the plate convergent direction, rather than shows a fan- shape pattern as earlier suggested. It is interesting to note that £m1 exhibits prominent clockwise and counterclockwise rotations to the north of the Lukang Magnetization High (LMH) and to the south of the Paikang High (PH), respectively. Such patterns suggest that not only the PH but also the LMH may play important roles in dominating the tectonic stress field of Taiwan. Counterclockwise rotation of the £m1 axis appears to extend to the south along the Luzon Arc until ~20°N. No significant deviation from the predicted plate convergent direction can be found farther south, marking the 20°N line as the incipient point of the stress regime associated with the Luzon arc-Taiwan collision.

  13. An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan.

    PubMed

    Igawa, Takeshi; Sugawara, Hirotaka; Tado, Miyuki; Nishitani, Takuma; Kurabayashi, Atsushi; Islam, Mohammed Mafizul; Oumi, Shohei; Katsuren, Seiki; Fujii, Tamotsu; Sumida, Masayuki

    2013-01-01

    Anderson's crocodile newt (Echinotriton andersoni) is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4%) became normal tailbud embryos, 274 (72.5%) hatched normally, 213 (56.3%) metamorphosed normally, and 141 (37.3%) became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live Tubifex. Metamorphosed newts were transferred to plastic containers containing wet sponges kept in a temperature-controlled incubator at 22.5 °C and fed a cricket diet to promote healthy growth. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species and can be applied to the preservation of other similarly wild and endangered species such as E. chinhaiensis. PMID:26479528

  14. Intraplate volcanism influenced by distal subduction tectonics at Jeju Island, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Brenna, Marco; Cronin, Shane J.; Kereszturi, Gábor; Sohn, Young Kwan; Smith, Ian E. M.; Wijbrans, Jan

    2015-01-01

    The drivers behind the inception of, and the variable, pulsatory eruption rates at distributed intraplate volcanic fields are not well understood. Such broad areas of monogenetic volcanism cover vast areas of the world and are often heavily populated. Reliable models to unravel their behaviour require robust spatio-temporal frameworks within the fields, but an analysis of the potential proximal and distal regional volcano-tectonic processes is also needed. Jeju Island (Republic of Korea) is a volcanic field that has been extensively drilled and dated. It is also located near one of the world's best-studied tectonic plate boundaries: the subduction zone in southwestern Japan, which generates the Ryukyu and SW Japan arcs. A new set of 40Ar/39Ar ages collected from cores penetrating the entire Jeju eruptive pile, along with geochemical information, is used to construct a temporal and volumetric model for the volcano's growth. The overall pattern indicates inception of volcanism at ~1.7 Ma, with an initial 1.2 Myr of low-rate activity, followed by over an order of magnitude rise over the last 0.5 Myr. The magma flux at Jeju correlates well with increased extension rates in the arc/backarc region. In particular, we infer that the increased trenchward mantle flow, caused by the greater rollback of the Philippine Sea Plate, activated pre-existing shear weaknesses in the mantle beneath Jeju, resulting in mantle upwelling and decompression melting that caused a change in compositions and an increase in eruption rates at Jeju. Thus, the volcanic activity of an intraplate field system can be modulated by regional subduction processes occurring more than 650 km away. This model may explain the frequent observation of pulsatory behaviour seen in many monogenetic volcanic fields worldwide that lie within 1,000 km of subduction zones.

  15. A tear fault boundary between the Taiwan orogen and the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Lallemand, Serge E.; Liu, Char-Shine; Font, Yvonne

    1997-06-01

    More than twenty seismic lines were analysed across the intersection of the Taiwan orogen and the Ryukyu arc-forearc system. The main results of this study concern the recognition of two superposed sedimentary basins that were previously unknown. We have named the recent one the Hoping Basin and the older, tectonized one the Suao Basin. The Suao Basin, containing sediments more than 3 km thick, records subsidence of about 3 km on its southwestern portion after being shortened in the direction of plate convergence. On the basis of seismicity, gravity, present-day plate kinematics as well as seismic reflection data, we relate the dramatic subsidence of the Suao Basin to the initiation of a WNW-trending tear fault within the Philippine Sea plate. This tear fault decouples the subducting Philippine Sea plate to the northeast and the apparent overthrusting Philippine Sea plate in the Coastal Range to the southwest. Back-arc rifting may thus occur in the westernmost section of the Okinawa trough above the sinking Philippine Sea slab while lithospheric shortening prevails south of Hualien. As a consequence, the triangular area located southwest of the tear fault, between the Taiwan coastline and the toe of the Yaeyama ridge, no longer belongs to the Ryukyu forearc. It is now passively transported with the non-subducting portion of the Philippine Sea plate. We propose an evolutionary model for the relative chronology of tectono-sedimentary events in this region over the last 5 m.y.

  16. The influence of the Kuril Islands on the penetration of tsunamis into the Sea of Okhotsk (on the example of the Japan tsunami on March 11, 2011)

    NASA Astrophysics Data System (ADS)

    Kostenko, I. S.; Kurkin, A. A.; Pelinovsky, E. N.; Yalciner, A.

    2016-01-01

    The features of the propagation of the tsunami of March 11, 2011 in the northeastern Pacific have been studied with the aim of revealing the degree of influence of the Kuril Islands on the penetration of the tsunami in the Sea of Okhotsk. For this, a series of computational experiments have been performed within the shallow water theory using bathymetry (1) with and (2) without the Kuril Islands. The wave heights calculated have been analyzed, and the tsunami's magnitude and intensity in the Sea of Okhotsk have been estimated. The computational experiments performed allow assessment of a decrease in the tsunami intensity while passing the Kuril Islands.

  17. Discovery of a bird-parasitic fly, Carnus orientalis (Diptera: Carnidae), in Japan, with bionomic remarks and a key to Carnus species.

    PubMed

    Iwasa, Mitsuhiro; Sakamoto, Hironori; Asahi, Kento

    2014-03-01

    A bird-parasitic fly, Carnus orientalis Maa, 1968, is recorded for the first time from Japan, and it is taxonomically reexamined on the basis of specimens collected in Okinawa Prefecture. Adult flies were found from nestlings of Ryukyu scops owl (Otus elegans Cassin, 1852), which is a new host for C. orientalis. Bionomic remarks regarding C. orientalis are presented, and akey to the world species of Carnus is also provided. PMID:24724300

  18. Origin of Japanese White-Eyes and Brown-Eared Bulbuls on the Volcano Islands.

    PubMed

    Sugita, Norimasa; Kawakami, Kazuto; Nishiumi, Isao

    2016-04-01

    The Ogasawara Archipelago comprises two groups of oceanic islands: the Bonin Islands, formed in the Paleogene, and the Volcano Islands, formed in the Quaternary. These groups are located within a moderate distance (ca. 160-270 km) of one another; thus, most land bird species are not distinguished as different subspecies. Two land birds, however, show unusual distribution. The Japanese white-eyes Zosterops japonicus originally inhabited only the Volcano Islands, but has been introduced to the Bonin Islands. The brown-eared bulbuls Hypsipetes amaurotis are distributed as a different subspecies. We investigated their genetic differences and divergences in the Ogasawara Archipelago using mitochondria DNA. The Volcano population of white-eyes had four endemic haplotypes that were divergent from one another, except for the Bonin population, which shared three haplotypes with the Volcano, Izu, and Ryukyu Islands and did not have any endemic haplotype. This is the first genetic suggestion that the Bonin population is a hybrid of introduced populations. With respect to bulbuls, the Volcano and Bonin Islands each had a single endemic haplotype. The Volcano haplotype is closest to a haplotype shared with Izu, the Japanese mainland, Daito and Ryukyu, whereas the Bonin haplotype is closest to one endemic to the south Ryukyu Islands. This indicates that the sources of the two bulbul populations can be geologically and temporally distinguished. The populations of the two species in the Ogasawara Archipelago are irreplaceable, owing to their genetic differences and should be regarded as evolutionarily significant units. In order to prevent introgression between the two populations, we must restrict interisland transfers. PMID:27032679

  19. Comparative genomic analysis of eight Leptospira strains from Japan and the Philippines revealing the existence of four putative novel genomic islands/islets in L. interrogans serovar Lai strain 56601.

    PubMed

    Youn, Jung-Ho; Hayashida, Kyoko; Koizumi, Nobuo; Ohnishi, Makoto; Sugimoto, Chihiro

    2014-12-01

    Leptospirosis is one of the most widespread zoonotic diseases worldwide and can be considered an emerging health problem to both human and animal. Despite the importance of the disease, complete genome sequences are currently available for only three Leptospira interrogans strains: 56601, Fiocruz L1-130, and IPAV. Therefore, intra- and inter-species comparative genomic analyses of Leptospira are limited. Here, to advance current knowledge of the genomic differences within Leptospira species, next-generation sequencing technology was used to examine the genomes of eight L. interrogans strains belonging to six different serogroups isolated from humans and dogs in Japan and the Philippines. The genomic sequences were mapped to that of the reference strain, L. interrogans serovar Lai strain 56601. The results revealed the presence of four novel genomic islands/islets (GIs) in strain 56601. This study provides a deeper insight into the molecular basis and evolutionary perspective of the virulence of leptospires. PMID:25449997

  20. Elucidation of Environmental Fate of Artificial Sweetener, Aspartame by Determining Bimolecular Rate Constants with Hydroxyl Radical at Various pH and Temperature Conditions and Reaction By-Products Presentation type:Poster Section:Ocean Sciences Session:General Contribution Authors:Takashi Teraji (1) Takemitsu Arakaki (2) AGU# 10173629 (1) Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru Nishihara-cho, Okinawa, 903-0123, Japan (a4269bj@yahoo.co.jp), (2) Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru Nishihara-cho, Okinawa, 903-0123, Japan (arakakit@sci.u-ryukyu.ac.jp)

    NASA Astrophysics Data System (ADS)

    Teraji, T.; Arakaki, T.

    2011-12-01

    Use of artificial sweeteners in drinks and food has been rapidly increasing because of their non-calorie nature. In Japan, aspartame, acesulfame K and sucralose are among the most widely used artificial sweeteners. Because the artificial sweeteners are not metabolized in human bodies, they are directly excreted into the environment without chemical transformations. We initiated a study to better understand the fate of artificial sweeteners in the marine environment. In particular, we focused on the fate of aspartame by determining its bimolecular rate constants with hydroxyl radicals at various pH and temperature conditions and reaction by-products. The hydroxyl radical (OH), the most potent reactive oxygen species, reacts with various compounds and determines the environmental oxidation capacity and the life-time of many compounds. The steady-state OH concentration and the reaction rate constants between the compound and OH are used to estimate the life-time of the compound. In this study, we determine the bimolecular rate constants between aspartame and OH at various pH and temperature conditions using a competition kinetics technique. We use hydrogen peroxide as a photochemical source of OH. Bimolecular rate constant we obtained so far was (2.6±1.2)×109 M-1 s-1 at pH = 3.0. Little effect was seen by changing the temperatures between 15 and 40 °C. Activation energy (Ea) was calculated to be -1.0 kJ mol-1 at pH = 3.0, which could be regarded as zero. We will report reaction rate constants at different pHs and reaction by-products which will be analyzed by GC-MS. We will further discuss the fate of aspartame in the coastal environment.

  1. Interdisciplinary approaches to better understand the past tsunamis -Case study of the 1771 Meiwa Tsunami, Japan-

    NASA Astrophysics Data System (ADS)

    Goto, K.

    2012-12-01

    It is important to know frequency and magnitude of past tsunamis over hundred to thousand years to better understand the risk from low-frequency large tsunamis. Historical documents, archeological evidence, and sediments laid down by tsunamis in coastal environments are useful for understanding the past tsunamis. Among them, tsunami geology has become a subject of great interest since the March 11, 2011 Tohoku-oki tsunami, Japan. This is because the 2011 tsunami was suspected as a recurrence of the AD869 Jogan tsunami, which was well known based on the geological and historical evidence. Our newly acquired geological data on the 2011 tsunami however, suggest that previous estimates of the Jogan tsunami have probably been underestimated [Goto et al., 2011]. This suggests that more interdisciplinary research is needed to better understand the historical and prehistoric tsunamis. As an example of the interdisciplinary research to better understand the past tsunami, here I review the studies of the AD1771 Meiwa Tsunami and its predecessors that struck the southern Ryukyu Islands, Japan. Reliable historical documents suggest run-up heights of up to 30 m for this tsunami [e.g. Goto et al., 2010], which are well supported by the archeological evidence as well as local traditions. Moreover, the displacement of specific coral boulders by the tsunami is also described in detail. Geological studies and numerical modeling of the boulder transport by the tsunami further revealed that many coral boulders of several hundred tons were deposited by the tsunami [e.g. Goto et al., 2010]. Based on such researches, the source model for the tsunami was estimated by the high-resolution numerical modeling, although it remains still controversial. Our study suggests that all available historical, geological, and archaeological data should be collected to better estimate the historical and prehistoric tsunami source model. The field evidences are still increasing for the 1771 Meiwa Tsunami

  2. Species-Specific Responses of Corals to Bleaching Events on Anthropogenically Turbid Reefs on Okinawa Island, Japan, over a 15-year Period (1995–2009)

    PubMed Central

    Hongo, Chuki; Yamano, Hiroya

    2013-01-01

    Coral bleaching, triggered by elevated sea-surface temperatures (SSTs) has caused a decline in coral cover and changes in the abundances of corals on reefs worldwide. Coral decline can be exacerbated by the effects of local stressors like turbidity, yet some reefs with a natural history of turbidity can support healthy and resilient coral communities. However, little is known about responses of coral communities to bleaching events on anthropogenically turbid reefs as a result of recent (post World War II) terrestrial runoff. Analysis of region-scale coral cover and species abundance at 17–20 sites on the turbid reefs of Okinawa Island (total of 79 species, 30 genera, and 13 families) from 1995 to 2009 indicates that coral cover decreased drastically, from 24.4% to 7.5% (1.1%/year), subsequent to bleaching events in 1998 and 2001. This dramatic decrease in coral cover corresponded to the demise of Acropora species (e.g., A. digitifera) by 2009, when Acropora had mostly disappeared from turbid reefs on Okinawa Island. In contrast, Merulinidae species (e.g., Dipsastraea pallida/speciosa/favus) and Porites species (e.g., P. lutea/australiensis), which are characterized by tolerance to thermal stress, survived on turbid reefs of Okinawa Island throughout the period. Our results suggest that high turbidity, influenced by recent terrestrial runoff, could have caused a reduction in resilience of Acropora species to severe thermal stress events, because the corals could not have adapted to a relatively recent decline in water quality. The coral reef ecosystems of Okinawa Island will be severely impoverished if Acropora species fail to recover. PMID:23565291

  3. Diatoms from Lake Kushu: A pilot study to test the potential of a Late Quaternary palaeoenvironmental archive from Rebun Island (Hokkaido Region, Japan)

    NASA Astrophysics Data System (ADS)

    Schmidt, Mareike; Tarasov, Pavel E.; Hoelzmann, Philipp; Meyer, Hanno; Leipe, Christian

    2016-05-01

    Rebun Island is a key research area for the Baikal-Hokkaido Archaeology Project to better understand the dynamics of the Neolithic hunter-gatherers in the NW Pacific region. Hence, the ca. 19.5 m sediment core RK12 spanning the last ca. 16.6 cal. kyr BP was obtained from Lake Kushu. Our aim is to test its potential as a high-resolution multi-proxy archive. Here, we used diatoms to investigate the modern ecosystem of Lake Kushu and its surrounding area on Rebun Island and of Hime-numa Pond on Rishiri Island and selected core samples for comparison. Modern diatom and stable isotope analyses show well-mixed freshwater bodies with eutrophic, alkaline conditions. The fossil diatom and geochemical sediment analyses display three phases that represent major changes in the lake development: (i) a marshy phase (ca. 16.6-10 cal. kyr BP); (ii) a brackish water lagoon phase (ca. 10-6.6 cal. kyr BP); and (iii) a freshwater lake phase (since ca. 6.6 cal. kyr BP). This shows the major role of the post-glacial climate amelioration, global sea-level rise and marine transgression in the development of this landscape. Further analyses will provide a palaeolimnological record at (sub-)decadal resolution that will facilitate the interpretation of the hunter-gatherer dynamics.

  4. Application of Satellite Geodesy in Analyzing the Accelerated Movement of the Back-arc Rifting in the Izu Bonin Islands, Japan

    NASA Astrophysics Data System (ADS)

    Arisa, D.; Heki, K.

    2014-12-01

    The Izu-Bonin islands lies along the convergent boundary between the subducting Pacific plate (PA) and the overriding Philippine Sea plate (PH) in the western Pacific. Nishimura (2011) found that the back-arc rifting goes on behind the Izu arc by studying the horizontal velocities of GNSS stations on the Izu islands. Here we show that this rifting has accelerated in 2004 using GNSS data at Aogashima, Hachijoujima, and Mikurajima stations. The back-arc rifting behind the Izu islands can be seen as the increasing distance between stations in the Izu-Bonin islands and stations located in the stable part of PH. We found that their movement showed clear acceleration around the third quarter of 2004. Obtaining the Euler vector of the PH is necessary to analyzed the movement of each stations relative to the other stations on the same plate. The analyzing of GPS timeseries leads us to one initial conclusion that some accelerated movement started to occur in the third quarter of 2004. This event was closely related to the earthquake on May 29, 2004 in Nankai Trough and September 5, 2004 earthquake near the triple junction of Sagami Trough. The analyzing process help us to understand that this accelerated movement was not the afterslip of any of these earthquakes, but it was triggering these area to move faster and further than it was. We first rule out the best possible cause by constraining the onset time of the accelerated movement, and correlating it with the earthquakes. May 29, 2004 earthquake (M6.5) at the PA-PH boundary clearly lacked the jump which should mark the onset of the eastward slow movement. Moreover, additional velocity vectors do not converge to the epicenter, and onset time that minimizes the post-fit residual is significantly later than May. We therefore conclude that accelerated movement started in 2004 was not due to the afterslip of interplate earthquake in May 29. On the next step we found that the onset time coincides with the occurrence of

  5. Coral-reef front migration in the Ryukyu Arc: responses of high latitude coral reefs to Quaternary climatic changes in North Western Pacific

    NASA Astrophysics Data System (ADS)

    Matsuda, H.; Iryu, Y.; Machiyama, H.

    2003-04-01

    Coral reefs are tropic to subtropic coastal ecosystems comprising very diverse organisms. Their community structure and geographic and local distribution are highly controlled by various environmental factors. Thus, their ancient counterparts, reef deposits, provide important, high-resolution records of geoscientific events in tropic to subtropic shallow waters, such as vertical and lateral tectonic movements, sea-level fluctuations, paleoclimatic changes, and paleoceanographic variations. In order to clarify relationships between reef formation and geoscientific events, it is necessary to investigate the reef deposits at relatively higher latitudes within reef provinces, because such reefs were considered to be more sensitive to the environmental changes than those in proximal areas. It can be, therefore, considered that the northern or southern limit of reef formation, herein termed the 'coral-reef front', may have migrated to higher and lower latitudes, respectively, responding to Pleistocene global warming and cooling associated with rapid, cyclic changes in climate and oceanographic conditions and with glacioeustatic sea-level rises and falls. Thus, this study mainly aims (1) to depict paleoeclimatic and paleoceanographic fluctuations in tropic to subtropic shallow-waters in details by reconstructing the coral-reef front migration, (2) how and to what extent the reefs responded to rapid environmental changes, and (3) to evaluate a role of coral reefs in a global carbon cycle. To resolve the problems described above, the Ryukyu Islands are one of the best fields. In this proposal, we will insist that the multiple drilling that covers submarine (IODP) and land (ICDP) areas is the only way to complete our purposes.

  6. Explaining unusual winter lightning in Japan

    NASA Astrophysics Data System (ADS)

    Shindo, Takatoshi; Ishii, Masaru; Williams, Earle

    2011-11-01

    Third International Symposium on Winter Lightning; Sapporo, Japan, 15-16 June 2011 Japan's meteorological setting in winter is unusual: It is an island in a relatively warm sea frequently overswept by colder air from Siberia. This sets up appreciable atmospheric instability in the fringe of the land adjacent to the Sea of Japan. Heavy snowstorms overlap the edge of the island and produce extraordinarily energetic lightning flashes that initiate from points on the ground (known as ground-to-cloud (GC) strokes) and wreak havoc on power lines and, more recently, wind turbines. These troublesome and costly conditions set the stage for the third in a series of conferences on winter lightning.

  7. An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan

    PubMed Central

    Igawa, Takeshi; Sugawara, Hirotaka; Tado, Miyuki; Nishitani, Takuma; Kurabayashi, Atsushi; Islam, Mohammed Mafizul; Oumi, Shohei; Katsuren, Seiki; Fujii, Tamotsu; Sumida, Masayuki

    2013-01-01

    Simple Summary We naturally bred the endangered Anderson’s crocodile newt (Echinotriton andersoni) and tested a laboratory farming technique using near-biotopic breeding cages with several male and female pairs collected from Okinawa, Amami, and Tokunoshima Islands. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species, and can be applied to the preservation of other similarly wild and endangered species. Abstract Anderson’s crocodile newt (Echinotriton andersoni) is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4%) became normal tailbud embryos, 274 (72.5%) hatched normally, 213 (56.3%) metamorphosed normally, and 141 (37.3%) became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live

  8. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone

    PubMed Central

    Nagaya, Takayoshi; Walker, Andrew M.; Wookey, James; Wallis, Simon R.; Ishii, Kazuhiko; Kendall, J. -Michael

    2016-01-01

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed. PMID:27436676

  9. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone.

    PubMed

    Nagaya, Takayoshi; Walker, Andrew M; Wookey, James; Wallis, Simon R; Ishii, Kazuhiko; Kendall, J-Michael

    2016-01-01

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed. PMID:27436676

  10. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Nagaya, Takayoshi; Walker, Andrew M.; Wookey, James; Wallis, Simon R.; Ishii, Kazuhiko; Kendall, J.-Michael

    2016-07-01

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed.

  11. Tokyo, Japan

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Tokyo, (35.5N, 140.0E) the capital city of Japan, Tokyo Bay and the neighboring cities of Yokohama, Kawasaki and Chiba are seen in this view of Japan. This great international seaport facility covers almost all of the bayfront and is home to over thirty million people.

  12. Dutch surgery in Japan.

    PubMed

    van Gulik, Thomas M; Nimura, Yuji

    2005-01-01

    An isolation policy was adopted in feudal Japan from 1639 to 1853 owing to the fear of foreign influence. During those 200 years of isolation, all foreigners were withheld from the country with the exception of the Dutch, who were permitted to establish a trading post on a small island in the Bay of Nagasaki, called Decima. Western culture and science reached the Japanese exclusively through the Dutch on Decima. Health care on Decima was provided by Dutch barber-surgeons, who introduced Western surgical practice in Japan. Official interpreters were the only Japanese allowed on Decima. It was from among these interpreters that the first Japanese surgeons arose who, having mastered the Dutch language, translated several Dutch anatomic and surgical texts. Genpaku Sugita translated a Dutch anatomy textbook into Japanese, which was completed in 1774. This book, entitled Kaitai Shinsho [New Book on Anatomy], was the first Western scientific monograph to be translated entirely into Japanese. Several Dutch surgical schools were founded through which Dutch surgery, known in Japan as "surgery of the red-haired" was propagated. According to the custom of the surgical guilds in Holland, certificates were granted to Japanese apprentices who had completed their training in Dutch surgery. About 60 Dutch surgeons had served on Decima up to 1850, providing the basis for surgery to develop in Japan. Among them, Philipp Franz von Siebold was an exceptional scholar who also had a great impact in making Japanese culture known to the Western world. PMID:15599736

  13. Helicobacter pylori infection in Japan

    PubMed Central

    Shiota, Seiji; Murakawi, Kazunari; Suzuki, Rumiko; Fujioka, Toshio; Yamaoka, Yoshio

    2013-01-01

    The prevalence of Helicobacter pylori infection is gradually decreasing in Japan. On the main island of Japan, nearly all H. pylori isolates possess cagA and vacA with strong virulence. However, less virulent H. pylori strains are frequently found in Okinawa where cases of gastric cancer are the lowest in Japan. Eradication therapy for peptic ulcer, idiopathic thrombocytopenic purpura, gastric mucosa-associated lymphoid tissue lymphoma and early gastric cancer after endoscopic resection has been approved by the Japanese national health insurance system. However, the Japanese Society for Helicobacter Research recently stated that all ‘H. pylori infection’ was considered as the indication for eradication irrespective of the background diseases. To eliminate H. pylori in Japan, the Japanese health insurance system should approve the eradication of all H. pylori infections. PMID:23265147

  14. A model for the termination of the Ryukyu subduction zone against Taiwan: A junction of collision, subduction/separation, and subduction boundaries

    USGS Publications Warehouse

    Wu, F.T.; Liang, W.-T.; Lee, J.-C.; Benz, H.; Villasenor, A.

    2009-01-01

    The NW moving Philippine Sea plate (PSP) collides with the Eurasian plate (EUP) in the vicinity of Taiwan, and at the same time, it subducts toward the north along SW Ryukyu. The Ryukyu subduction zone terminates against eastern Taiwan. While the Ryukyu Trench is a linear bathym??trie low about 100 km east of Taiwan, closer to Taiwan, it cannot be clearly identified bathymetrically owing to the deformation related to the collision, making the location of the intersection of the Ryukyu with Taiwan difficult to decipher. We propose a model for this complex of boundaries on the basis of seismicity and 3-D velocity structures. In this model the intersection is placed at the latitude of about 23.7??N, placing the northern part of the Coastal Range on EUP. As PSP gets deeper along the subduction zone it collides with EUP on the Taiwan side only where they are in direct contact. Thus, the Eurasian plate on the Taiwan side is being pushed and compressed by the NW moving Philippine Sea plate, at increasing depth toward the north. Offshore of northeastern Taiwan the wedge-shaped EUP on top of the Ryukyu subducting plate is connected to the EUP on the Ryukyu side and coupled to the NW moving PSP by friction at the plate interface. The two sides of the EUP above the western end of the subduction zone are not subjected to the same forces, and a difference in motions can be expected. The deformation of Taiwan as revealed by continuous GPS measurements, geodetic movement along the east coast of Taiwan, and the formation of the Hoping Basin can be understood in terms of the proposed model. Copyright 2009 by the American Geophysical Union.

  15. First records of interstitial leptocytherids (Crustacea, Ostracoda): two new species and a redescription of Callistocythere ventricostata Ruan & Hao, 1988 collected from the Okinawa Islands, southern Japan.

    PubMed

    Ha, Tran Manh; Tsukagoshi, Akira

    2015-01-01

    Two new and one known species belonging to the genus Callistocythere of the family Leptocytheridae from interstitial environments of the Okinawa Islands are fully described. Callistocythere intermedia sp. nov. is regarded as belonging to the C. japonica group, and Callistocythere ryukyuensis sp. nov. belongs to the C. minor group (these groups were established by Hanai 1957 based on carapace morphology). The redescribed Callistocythere ventricostata Ruan & Hao, 1988 clearly differs from known leptocytherid species in the morphologies of the carapace and the male copulatory organ. The habitats of C. intermedia sp. nov. and C. ryukyuensis sp. nov. are found along the shoreline zone and the mid to high tide levels of the littoral zone, respectively, and C. ventricostata is found from the shoreline to the sub-tidal zone. These species are the first global records of interstitial leptocytherids. PMID:26623759

  16. Detection of microwave emission due to rock fracture as a new tool for geophysics: A field test at a volcano in Miyake Island, Japan

    NASA Astrophysics Data System (ADS)

    Takano, Tadashi; Maeda, Takashi; Miki, Yoji; Akatsuka, Sayo; Hattori, Katsumi; Nishihashi, Masahide; Kaida, Daishi; Hirano, Takuya

    2013-07-01

    This paper describes a field test to verify a newly discovered phenomenon of microwave emission due to rock fracture in a volcano. The field test was carried out on Miyake Island, 150 km south of Tokyo. The main objective of the test was to investigate the applicability of the phenomenon to the study of geophysics, volcanology, and seismology by extending observations of this phenomenological occurrence from the laboratory to the natural field. We installed measuring systems for 300 MHz, 2 GHz, and 18 GHz-bands on the mountain top and mountain foot in order to discriminate local events from regional and global events. The systems include deliberate data subsystems that store slowly sampled data in the long term, and fast sampled data when triggered. We successfully obtained data from January to February 2008. During this period, characteristic microwave pulses were intermittently detected at 300 MHz. Two photographs taken before and after this period revealed that a considerably large-scale collapse occurred on the crater cliff. Moreover, seismograms obtained by nearby observatories strongly suggest that the crater subsidence occurred simultaneously with microwave signals on the same day during the observation period. For confirmation of the microwave emission caused by rock fracture, these microwave signals must be clearly discriminated from noise, interferences, and other disturbances. We carefully discriminated the microwave data taken at the mountaintop and foot, checked the lightning strike data around the island, and consequently concluded that these microwave signals could not be attributed to lightning. Artificial interferences were discriminated by the nature of their waveforms. Thus, we inferred that the signals detected at 300 MHz were due to rock fractures during cliff collapses. This result may provide a useful new tool for geoscientists and for the mitigation of natural hazards.

  17. Rifting Process and Geomorphic Development of the Okinawa Tough, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Sato, T.; Arai, K.; Inoue, T.; Matsumoto, D.

    2012-12-01

    The Ryukyu Island Arc extends from Kyushu to Taiwan, a distance of 1,200 km, along the Ryukyu Trench where the Philippine Sea Plate is subducting beneath the Eurasian Plate. The Okinawa Trough, a back arc basin has formed behind the Ryukyu Island Arc in late Pliocene to early Pleistocene. The research cruises of GH11 (from 14 July to 15 August, 2011) and GH12 (from 20 to 30 July, 2012) were carried out around the Okinawa Trough. More than 3,600 miles multi channel high-resolution seismic profiles were acquired during these cruises by the GI-gun (Generator 250 cu inch and Injector 105 cu. inch) systems with 16ch digital streamer cable. As a result, two unconformities and three depositional sequence divided by the unconformities are recognized in the trough. The lower and the midlle sequence are tilted and blocked by many normal faults, on the other hand the upper one is not tilted and shows the pattern of onlap fill. From this result, the upper sequence started to deposit after start of the rifting. Additionally, internal reflection of the upper sequence shows the cyclic activities of the rifting. The position of the rifting axis was revealed based on dip of the normal faults. As a result, rifting axis shows echelon arrangement and the displacement of the faults are varied with the segment of the arrangement. The location of the segment boundaries is correlated with geometrical boundary of the adjacent slope. Steep slope with incised valley is distributed in southwestern part where the displacement of the normal fault is large, on the other hand, gentle slope without incised valley is distributed in northeastern part where the displacement is small. This difference of the displacement strongly controls the geometry of the adjacent slope.

  18. Japan Smoke

    Atmospheric Science Data Center

    2013-04-16

    article title:  Smoke Plume from Industrial Fires in Miyagi Prefecture, Japan     ... 2011, and its subsequent tsunami, several oil refineries and industrial complexes caught fire, including facilities in the Port of Sendai ...

  19. Morphometric comparisons of plant-mimetic juvenile fish associated with plant debris observed in the coastal subtropical waters around Kuchierabu-jima Island, southern Japan.

    PubMed

    de Queiroz, Alexya Cunha; Sakai, Yoichi; Vallinoto, Marcelo; Barros, Breno

    2016-01-01

    The general morphological shape of plant-resembling fish and plant parts were compared using a geometric morphometrics approach. Three plant-mimetic fish species, Lobotes surinamensis (Lobotidae), Platax orbicularis (Ephippidae) and Canthidermis maculata (Balistidae), were compared during their early developmental stages with accompanying plant debris (i.e., leaves of several taxa) in the coastal subtropical waters around Kuchierabu-jima Island, closely facing the Kuroshio Current. The degree of similarity shared between the plant parts and co-occurring fish species was quantified, however fish remained morphologically distinct from their plant models. Such similarities were corroborated by analysis of covariance and linear discriminant analysis, in which relative body areas of fish were strongly related to plant models. Our results strengthen the paradigm that morphological clues can lead to ecological evidence to allow predictions of behavioural and habitat choice by mimetic fish, according to the degree of similarity shared with their respective models. The resemblance to plant parts detected in the three fish species may provide fitness advantages via convergent evolutionary effects. PMID:27547571

  20. Morphometric comparisons of plant-mimetic juvenile fish associated with plant debris observed in the coastal subtropical waters around Kuchierabu-jima Island, southern Japan

    PubMed Central

    2016-01-01

    The general morphological shape of plant-resembling fish and plant parts were compared using a geometric morphometrics approach. Three plant-mimetic fish species, Lobotes surinamensis (Lobotidae), Platax orbicularis (Ephippidae) and Canthidermis maculata (Balistidae), were compared during their early developmental stages with accompanying plant debris (i.e., leaves of several taxa) in the coastal subtropical waters around Kuchierabu-jima Island, closely facing the Kuroshio Current. The degree of similarity shared between the plant parts and co-occurring fish species was quantified, however fish remained morphologically distinct from their plant models. Such similarities were corroborated by analysis of covariance and linear discriminant analysis, in which relative body areas of fish were strongly related to plant models. Our results strengthen the paradigm that morphological clues can lead to ecological evidence to allow predictions of behavioural and habitat choice by mimetic fish, according to the degree of similarity shared with their respective models. The resemblance to plant parts detected in the three fish species may provide fitness advantages via convergent evolutionary effects. PMID:27547571

  1. Genetic diversity and differentiation of the Ryukyu endemic frog Babina holsti as revealed by mitochondrial DNA.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Nakata, Katsushi

    2014-02-01

    We surveyed the genetic diversity and genetic differentiation of an endangered frog, Babina holsti, endemic to Okinawajima and Tokashikijima Islands of the Ryukyus, to elucidate its divergence history and obtain basic data for its conservation. Genetic differentiation between the two island lineages is moderate (3.1% p-distance in the cyt b gene). This result suggests that the two island lineages have been isolated between the late Pliocene and the middle Pleistocene and have never migrated between the current northern part of Okinawajima and Tokashikijima Islands, which were once connected in the late Pleistocene glacial age. On Okinawajima Island, the southernmost sample was constituted by a unique haplotype, without considerable genetic distance from haplotypes detected from northern samples. This unique haplotype composition in the southernmost sample would have resulted from the restricted gene flow between the southernmost population and the other populations in Okinawajima Island. Furthermore, the absence of genetic diversity within the southernmost sample indicates that this population has recently experienced population size reduction, possibly by predation pressure from an introduced mongoose, which is more abundant in the southern part than in the northern part of the island. Lower genetic diversity in the Tokashikijima sample implies a small effective population size for mitochondrial DNA (mtDNA) in B. holsti on the island. Immediate conservation measures should be taken for the populations from the southernmost range in Okinawajima and Tokashikijima. PMID:24521314

  2. Shallow repeating slow-slip-events along the convergent block boundary in northern Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Heki, K.; Kimura, T.

    2015-12-01

    The Japanese Islands are divided into several crustal blocks [e.g. Loveless and Meade, 2010 JGR]. In the Northern Hokkaido, the boundary between the Amurian and the North American Plates run north-south between 44.0N and 45.4N. The east-west block convergence is considered to be as fast as ~1 cm/year there, but few large earthquakes are known to have occurred along this boundary. Recently, a slow slip event (SSE) is reported to have occurred in a segment at ~45.0N over a 4 months period from 2012 summer to the early 2013 [Ohzono et al., 2014 GJI]. The maximum surface movements was about 15 mm, and the moment magnitude of the SSE would not exceed 6.0 (fault slip is estimated as 10 cm). This suggests that plate convergence takes place as episodic SSEs in this block boundary. In this research, we looked for signatures of repeating SSEs along this block boundary using continuous GNSS data of the dense array GEONET in Japan. In order to detect faint signatures of SSEs in the coordinate time series, we adopted the method using AIC (Akaike's Information Criterion) similar to Nishimura et al. [2013 JGR] and Nishimura [2014 PEPS]. As a result, we were able to find numbers of SSE signals in various segments along the boundary. The detected SSEs are all fairly small, and surface movements did not exceed a few millimeters (except the 2012-2013 SSE reported in Ohzono et al. [2014]). We also searched earthquakes that may have triggered these SSEs. Although the 2012 SSE seems to have been triggered by a deep earthquake beneath Sakhalin on Aug. 14, 2012, no clear triggering earthquakes were identified for other SSEs. SSEs in subduction zones are known to recur fairly regularly, e.g. biannually repeating SSE in the SW part of the Ryukyu Arc [Heki and Kataoka, 2008 JGR]. However, shallow SSEs along the block boundary in the northern Hokkaido did not show such regular occurrences. We plan to confirm these SSE occurrences by comparing GNSS data with the Hi-Net tiltmeter records.

  3. P-wave velocity structure of the southern Ryukyu margin east of Taiwan: Results from the ACTS wide-angle seismic experiment

    NASA Astrophysics Data System (ADS)

    Klingelhoefer, F.; Berthet, T.; Lallemand, S.; Schnurle, P.; Lee, C.-S.; Liu, C.-S.; McIntosh, K.; Theunissen, T.

    2012-11-01

    An active seismic experiment has been conducted across the southern Ryukyu margin east of Taiwan over the whole trench-arc-backarc system in May 2009. Twenty-four ocean bottom seismometers (OBS) were deployed from the Ryukyu trench to the southern Okinawa trough over the Ryukyu arc and forearc. Wide angle seismic data were recorded by the OBS array while coincident reflection seismic data were acquired using a 6 km long streamer and a 6600 cubic inch seismic airgun array. Results from tomographic inversion of 21091 travel time picks along this line allowed us to image crustal structures of the Ryukyu margin down to a depth of 25 km. The transect has been designed to provide a better seismic velocity structure of the subduction zone in a highly deformed area that has produced an M8 earthquake in 1920. The line crosses a seismic cluster of earthquakes which source mechanisms are still poorly understood. The subducting oceanic crust of the Huatung Basin is about 5-6 km thick. The underlying mantle exhibits low seismic velocities around 7.8 km/s suggesting some hydrothermal alterations or alteration of the upper mantle through faults generated by the flexure of the subducting plate as it enters the subduction. Low velocities, up to 4.5 km/s, associated with the accretionary wedge are well imaged from the trench back to the Nanao forearc. A major result concerns the abrupt termination of the buttress at the rear of the accretionary wedge. Despite the low resolution of the tomographic inversion near the subduction interface, several lines of evidence supporting the presence of a low velocity zone beneath the toe of the forearc buttress could be established. The Moho beneath the Ryukyu non-volcanic arc is located at a depth around 25 km depth.

  4. Tidal triggering of shallow very-low-frequency earthquakes in the Ryukyu Trenc

    NASA Astrophysics Data System (ADS)

    Nakamura, M.; Kakazu, K.

    2015-12-01

    We analyzed tidal response of shallow very-low-frequency earthquakes (VLFEs), which occur in Ryukyu Trench (RT), and showed that the activity of VLFEs responds to ocean tide loading. We used the epicenter catalog of the VLFEs from 2002-2014, the epicenter determination procedure of which is the same as that described by Nakamura & Sunagawa [2015]. The minimum magnitude of the used events was 3.4, which was determined from the magnitude-frequency relationship. We computed the tidal sensitivity and phase lag between the occurrence of VLFEs and the ocean tide for each point along the RT. We then predicted the fault normal stress (FNS) and updip shear stress (UDSS) on the plate interface and compared them with the excess value (Nex) of the VLFEs. The stress components at a depth of 15 km were predicted using Earth tide strain [Matsumoto et al., 2001] and ocean tide [Matsumoto et al., 2000]. The distribution of tidal sensitivity shows that the sensitivity and phase change gradually from northeast to southwest along the RT. High sensitivity (0.20-0.42) is evident at central RT, but the sensitivity is < 0.2 at southwestern RT. The Nex in the FNS ranges 0.22-0.28 at central RT and 0.04-0.11 at southwestern RT. The Nex in the UDSS ranges 0.17-0.22 at central RT and 0.04-0.11 at southwestern RT. The comparison of Nex with stress components shows that the VLFEs are activated by the thrust-encouraging shear stress or maximum extensional normal stress of the ocean tide corresponding to the low-tide period. The tidal sensitivity is highest in the central portion of the RT, where the thin sediment layer is subducting, whereas it is lowest in the southwestern portion of the RT, where a thick sediment layer exists and an accretionary prism is developed. Differences in the sediment-rock properties of the overriding plate, which cause lateral heterogeneity in the extremely high pore-fluid pressure in the plate interface, would control the sensitivity of the VLFEs to ocean tides.

  5. Tsunami Recurrences in the Ryukyu Arc-trench System: Geological Records in the Jinshan Coastal Plain of North Taiwan

    NASA Astrophysics Data System (ADS)

    Yu, N. T.; Yen, J. Y.; Lin, L. H.; Liu, J. H.

    2014-12-01

    Active continental margin like the Ryukyu arc-trench system poses high tsunami risk, which however remains poorly assessed due to the sparse historic records and geological studies. In order to better understand the tsunami risk in northern Taiwan of the southernmost Ryukyu active margin, borehole cores of the Jinshan Coastal Plain were investigated for the tsunami deposits of 1867 event and possibly its precursors. Based on facies characteristics, two decimeter-thick marine event sand beds are identified intercalated with the fluvial gravelly deposit that has been accumulated in a microtidal barred estuary over the past millennium. Distributed all over the coastal plain except the coastal sand spits, the fluvial deposit are predominantly sourced from the Pleistocene arc andesite, and thus commonly reddish in color due to the high iron content. The marine beds are rich in quartz sand and granule, whitish gray in color, and rounded to subangular in grain shape, indicating a sediment source from the coastal sand spits which receive longshore drift from the nearby rocky coasts dominated by the Oligocene and Miocene quartzose sandstone and mudstone. The facies succession of marine bed is characterized by erosion base, planar lamination, normal grading, soft-sediment deformation, and variations in magnetic susceptibility, Si, K, Ti, and Fe. The succession reflects the sedimentary processes from incoming wave erosion, rapid marine deposition, backflow reworking, and suspension fall-out. The marine beds are traceable landward based on the facies characteristics and C14 dating over a distance up to two kilometers before thinning out and grading into carbonaceous mud. According to the C14 dating, the two marine beds are linked to the 1867 tsunami and an earlier event in the late 17th century. Based on their ages and distributions, the two event beds further suggest two marine incursions of similar extant in an approximate recurrence interval of ~170 yr.

  6. Japan: Land of the Rising Sun. A Twelve Day Unit of Study for Fourth Grade Students.

    ERIC Educational Resources Information Center

    Craycraft, Kenneth; Winters, Norm

    This unit of study on Japan contains the following content areas: Unit Focus/Motivation; Islands of Japan; Living on an Island; Buildings; Economics; Transportation; and Culminating Activities. The objectives of the unit include knowledge, skills, and attitudes. Suggested activities for each of the content areas are offered and explained to assist…

  7. Cenozoic rift tectonics of the Japan Sea

    SciTech Connect

    Kimura, K.

    1988-08-01

    The Japan Sea is one of the back-arc basins in trench-arc systems bordering the western Pacific. Recent paleomagnetic works suggest the Japan Sea opened during early to middle Miocene. Radiometric and microfossil ages of the Cenozoic onland sequences in the Japanese Islands elucidate the rift tectonics of the Japan Sea. The rifting history is summarized as follows: nonmarine volcanic formations of prerift stage before 50 Ma, rift-onset unconformity at 40 Ma, nonmarine volcanic formations of synrift stage 20-33 Ma, breakup unconformity 19 Ma showing the opening of the Japan Sea, marine volcanic and sedimentary formations of synrift stage 14.5-18 Ma, beginning of regional subsidence 14.5 Ma corresponding to the end of the Japan Sea opening, marine sedimentary formations of postdrift stage after 14.5 Ma. Rifting is not limited to the synrift stage but is continued to the syndrift stage. Rifting led to a horst-and-graben structure. Thus, the Cenozoic onland sequences in the Japanese Islands are suited for a study of rift tectonics because the sequences were subaerially exposed by the late Miocene-Holocene island-arc tectonics. Rift tectonics cannot be studied as easily in most Atlantic-type passive margins.

  8. Hokkaido, Japan

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Cities mingle with rugged hills and a dormant volcano in this image of Hokkaido, Japan. This three-dimensional image comes from observations made by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite on July 23, 2006. The view is toward the north and slightly east. Green indicates vegetation; beige and gray indicate bare ground, paved surfaces, or buildings; and dark blue indicates water. The water body at the top of the image is the Pacific Ocean. Now dormant, Mount Yotei is a stratovolcano--a symmetrical cone composed of alternating layers of hardened lava, solidified ash, and volcanic rocks ejected in previous eruptions. It reaches a height of 1,898 meters (6,227 feet), and its summit sports a 700-meter- (2,297-foot-) wide crater. Snow often caps this volcano, but in this summertime shot, the volcano's summit is snow-free. The volcano is also known as Ezo-Fuji for its resemblance to Mount Fuji. As angular patches of gray and beige indicate, urban areas surround the volcano, most notably the city of Kutchan to the northwest. Even when volcanoes remain active, people often settle close to them, drawn by benefits of good soil and mild climates that appear to outweigh the risks. NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  9. The Flores Island tsunamis

    NASA Astrophysics Data System (ADS)

    Yeh, Harry; Imamura, Fumihiko; Synolakis, Costas; Tsuji, Yoshinobu; Liu, Philip; Shi, Shaozhong

    On December 12, 1992, at 5:30 A.M. GMT, an earthquake of magnitude Ms 7.5 struck the eastern region of Flores Island, Indonesia (Figure 1), a volcanic island located just at the transition between the Sunda and Banda Island arc systems. The local newspaper reported that 25-m high tsunamis struck the town of Maumere, causing substantial casualties and property damage. On December 16, television reports broadcast in Japan via satellite reported that 1000 people had been killed in Maumere and twothirds of the population of Babi Island had been swept away by the tsunamis.The current toll of the Flores earthquake is 2080 deaths and 2144 injuries, approximately 50% of which are attributed to the tsunamis. A tsunami survey plan was initiated within 3 days of the earthquake, and a cooperative international survey team was formed with four scientists from Indonesia, nine from Japan, three from the United States, one from the United Kingdom, and one from Korea.

  10. Boron isotopic composition of fumarolic condensates from some volcanoes in Japanese island arcs

    NASA Astrophysics Data System (ADS)

    Nomura, Masao; Kanzaki, Tadao; Ozawa, Takejiro; Okamoto, Makoto; Kakihana, Hidetake

    1982-11-01

    Boron samples from 40 fumarolic condensates from volcanoes in the Ryukyu arc (Satsuma Iwo-jima and Shiratori Iwo-yama) and the North-east Japan arc (Usu-shinzan, Showa-shinzan, Esan and Issaikyo-yama) all have 11B /10B ratios close to 4.07. Higher values, from 4.09 to 4.13, were only observed in condensates from volcanoes in the southernmost end of the North-east Japan arc (Nasu-dake), the northern part of the Izu-Bonin arc (Hakone), and the North Mariana arc (Ogasawara Iwo-jima). These higher values suggest geological interaction of the magmas with sea-water enriched in 11B.

  11. Ryukyuan Culture.

    ERIC Educational Resources Information Center

    Trafton, Terry

    The Ryukyu Islands of Japan, of which Okinawa is the best known, possess a lengthy history and a sophisticated cultural background, an exploration of which helps to shed light on this area and on mainland Japan. This document is an exposition of Ryukuan culture. Divided into eight sections, the areas covered include: (1) Historical perspective;…

  12. Shallow very low frequency earthquakes off the Pacific coast of Tohoku, Japan

    NASA Astrophysics Data System (ADS)

    Matsuzawa, T.; Asano, Y.; Obara, K.

    2012-12-01

    Activities of shallow very low frequency earthquakes (VLFEs) have been reported around the trench axis of the off-Tokachi region, and the Nankai and the Ryukyu subduction zone around the Japan Islands (e.g., Obara and Ito, 2005; Asano et al., 2008; Ando et al., 2012). In NIED, epicenters of seismic sources including VLFEs are routinely located by an array analysis technique using Hi-net high-sensitivity accelerometers (Asano et al., 2008). Some of the epicenters are also located off the Pacific coast of Tohoku, Japan. However, these events are not fully examined, as most of these sources have been thought to arise from regular earthquakes and microseisms, and the number of events is much smaller than those in the previously reported region. In this study, we aim to detect VLFEs in the off-Tohoku region with a waveform correlation analysis. We examined waveforms of the events detected by the array analysis in the off-Tohoku region. Some of events are very similar to pre-known shallow VLFEs, which are dominant around the frequency of 0.05 Hz and have no clear signals in the high frequency band (above 1 Hz). We successfully estimated CMT solutions of some of these events, using F-net broadband seismometers and Hi-net high-sensitivity accelerometers. The result shows that these events are reverse-fault-type Mw~3.5 earthquakes, and located around the depth of the subducting plate interface. As a typical dominant frequency of regular earthquakes with similar magnitude and close hypocenter is several Hz, these events are considered as shallow VLFEs. To reveal the activity of the off-Tohoku VLFEs, other VLFEs were detected by a waveform correlation analysis using a template event. We selected two VLFEs as template events in the central and southern off-Tohoku region. Averaged cross correlation values for template events were calculated using broadband seismograms at surrounding F-net stations which are bandpass-filtered between 0.02 to 0.1 Hz. Finally, we visually checked

  13. Revisiting the Metaphor of the Island: Challenging "World Culture" from an Island Misunderstood

    ERIC Educational Resources Information Center

    Rappleye, Jeremy

    2015-01-01

    This article revisits the newly "discovered" island that world culture theorists have repeatedly utilised to explain their theoretical stance, conceptual preferences and methodological approach. Yet, it seeks to (re)connect world culture with the real world by replacing their imagined atoll with a real one--the island-nation of Japan. In…

  14. American Influence on Okinawan Culture before 1972.

    ERIC Educational Resources Information Center

    Trafton, Terry

    The Ryukyu Islands form a chain stretching from the southernmost point of mainland Japan to the northern tip of Taiwan. The largest and most important of these islands is Okinawa. This paper documents the influence of other nations and cultures upon the Okinawan culture, and focuses upon U.S. cultural influence. In the mid-nineteenth century,…

  15. Phylogeny and Differentiation of Wide-Ranging Ryukyu Kajika Frog Buergeria japonica (Amphibia: Rhacophoridae): Geographic Genetic Pattern Not Simply Explained by Vicariance Through Strait Formation.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Eto, Koshiro; Ota, Hidetoshi

    2015-06-01

    To investigate geographic genetic structures and taxonomic relationships among isolated populations of Buergeria japonica, occurring very widely in various habitats of the Ryukyu Archipelago and Taiwan, we conducted phylogenetic and demographic analyses among individuals from various localities, representing their entire distributional ranges. Buergeria japonica is genetically greatly differentiated and comprises three major clades (the Southern Taiwan [ST] clade, the Northern Taiwan + Southern Ryukyu [NT/SR] clade, and the Central + Northern Ryukyu [CR/NR] clade), each of which seems to represent independent species. The first divergence in the species is estimated to have occurred in the middle to late Miocene in areas of current Taiwan, then eastern periphery of the Asian continent. Split of the ST and the remaining clades, and subsequent divergence between the NT/SR and the CR/NR clades in the latter, indicate consecutive south to north vicariant diversifications. However, these vicariances are not always associated with formation of significant barriers such as deep straits. Less but still prominently diverged subclades (the Amami + Tokara [AM/TK] and the Okinawa [ON] subclades) in the CR/NR clade were recognized in spite of the absence of an intervening deep strait. Contrariwise, individuals from Amami and Tokara Groups formed the AM/TK subclade in spite of the presence of the intervening Tokara Gap (a long-standing deep tectonic strait). Furthermore, in the AM/TK subclade, low but definite genetic divergence was found between the Northern Amami + Tokara (NAM/TK) lineage and the Southern Amami (SAM) lineage. Estimated divergence time and gene flow rate within the NAM/TK lineage indicate that this species reached northern Tokara from the south by overseas dispersal over the Tokara Gap long after its formation, but not by more recent artificial transportation. This overseas dispersal would have been facilitated by its more frequent occurrence around coastal

  16. Intraspecific variations in carbon-isotope and oxygen-isotope compositions of a brachiopod Basiliola lucida collected off Okinawa-jima, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Takayanagi, Hideko; Asami, Ryuji; Abe, Osamu; Miyajima, Toshihiro; Kitagawa, Hiroyuki; Sasaki, Keiichi; Iryu, Yasufumi

    2013-08-01

    This study presents intraspecific variations in carbon-isotope (δ13C) and oxygen-isotope (δ18O) compositions of nine specimens of a subtropical brachiopod, Basiliola lucida, collected west of Okinawa-jima, Ryukyu Islands, southwestern Japan. The δ13C values of samples collected along the maximum growth axis (ontogenetic samples) from two modern and seven older (pre-1945 cal AD) shells show no seasonal changes. The modern shells, which were collected from comparable depths, have similar δ13C values that fall within the range of calcite precipitated in isotopic equilibrium with ambient seawater (equilibrium calcite) (δ13CEC values), and their mean δ13C values are ˜1.1-1.6‰ less than those from the older shells. This decrease in δ13C values is similar in magnitude to the decreases in atmospheric CO2 and the oceanic dissolved inorganic carbon at the sea surface in recent years (13C Suess effect), suggesting that the effect can even be detected at water depths of 200-300 m in the subtropical northwestern Pacific Ocean. The δ18O values fluctuate within a narrow range (0.26-0.41‰) with no seasonal changes, and they exhibit small (0.14-0.51‰) offsets from those of equilibrium calcite (δ18OEC values). A statistically significant negative linear relationship is established between seawater temperature and mean δ18O values of the nine shells, but the slope (-0.31‰/°C) is steeper than those of equilibrium calcite (-0.23‰/°C) and other calcareous organisms (-0.15‰ to -0.26‰/°C). The cross-plots of the δ13C and δ18O values suggest that the degree of the vital effect varies among individuals in this species. The δ13C and δ18O values of B. lucida are potentially useful for reconstructing the δ13C and δ18O evolution of ancient oceans, because both values show small intraspecific variations, the former is identical to the δ13CEC values, and the latter shows small within-shell variations and small, nearly constant offsets from the δ18OEC values.

  17. Seismology in Ryukyu arc, Japan reveals the distribution and orientation of serpentine minerals suggesting convection and low viscosity of forearc mantle

    NASA Astrophysics Data System (ADS)

    Nagaya, T.; Walker, A.; Wookey, J. M.; Kendall, M.; Wallis, S.

    2014-12-01

    Refining available estimates of the amount, distribution and alignment of serpentinite in the forearc wedge is needed to develop a better understanding of the seismic anisotropy, strength and fluid transport in this region. Mantle dominantly consists of olivine. However, petrological studies and thermal modeling of convergent margins predict that olivine will be replaced by hydrous mineral phases in fluid-rich and relatively cold forearc mantle. The dominant hydrous mineral will be antigorite. Lower seismic velocities (Vp < ~8 km/s and Vs < ~4 km/s) and higher Vp/Vs values (> ~1.8) of serpentine minerals than those of olivine are commonly used as to detect the distribution of antigorite and estimate its proportion compared to olivine. However, antigorite is highly anisotropic and this anisotropy can disguise the presence of antigorite in seismic tomography; the apparent Vp/Vs ratio of antigorite can vary from 1.2-3.4 (Vp = 5.6-8.9 km/s and Vs = 2.5-5.1 km/s) depending on the propagation path of the seismic wave relative to the crystal orientation. Here, we take advantage of this anisotropy and perform an analysis of seismic anisotropy that takes into account ray path measured above the forearc mantle of the Rykuyu arc subduction zone. The measured shear wave splitting delay time above this subduction zone is very large, suggesting the presence of aligned antigorite. Comparing the results of modeling to observed shear wave splitting for both local-S and teleseismic SKS phases, we conclude that the mantle wedge consists of 65 % antigorite and that the antigorite must be aligned along the subducting slab in the deepest part of the wedge but aligned vertically at intermediate depths. This distribution of different orientations strongly suggests the presence of convective mantle flow in the forearc mantle. Physical modeling of the dynamics of the mantle wedge shows that a bulk long-term viscosity of less than 1019 Pa s is required to maintain this large-scale flow. This analysis reveals the presence of otherwise invisible antigorite bearing domains, allows an estimate of the volume percent of serpentinite in the forearc mantle to be made and indicates the pattern of large scale induced flow in this domain.

  18. Introductory Overview of Stone Heritages in Japan

    NASA Astrophysics Data System (ADS)

    Kato, Hirokazu; Oikawa, Teruki; Fujita, Masayo; Yokoyama, Shunji

    2013-04-01

    As one contribution to 'Global Heritage Stone Resources' (GHSR), some stone heritages in Japan, which are nominated in the interim list, are briefly introduced. The geology of Japanese Islands where are the one of the most active areas in the history of the Earth, is very complicated. Therefore Japanese Islands consist of various kinds of minerals and rocks. Some of them were used to make stone implements and accessories. Japanese people also used to the best possible advantage to built tombstone, gate, pavement ,and the basement and wall of the large building such as temples, shrines, castles and modern buildings. 1. Stone Heritages of Pre-historical age: In the late Pleistocene and the early Holocene, ancient Japanese used obsidian cooled rapidly from rhyolitic magma.to make small implements and accessories. For example, Shirataki, Hokkaido (north island) is the largest place producing obsidian in Japan where Paleolithic people made arrowhead, knives and so on. Another example, Jade yielded in Itoigawa City, Japan Sea coast of central Japan, was made in the metamorphic rock about five hundred million years ago. Itoigawa area is only one place where jade is abundantly produced in Japan. Ancient people had been already collected and processed to ornaments although it is very hard and traded in wide area more than several thousand years ago. 2. Stone Heritages of Historical age: 2.1 Archaeological remains: In the Kofun (old mound) period (250 to 538 AD), stone burial chambers were used for old mounds to preserve against the putrefaction and to protect from the theft. For example, Ishibutai Kofun ("ishi" means "stone" and "butai" means "stage") in Nara old capital city, southwest Japan, is the largest known megalithic structure made of granite in Japan. 2.2 Stone walls of some typical castles Stones used is because of not only the rich reserves of rocks but also restriction of transportation. Osaka (second biggest city) castle, are composed of Cretaceous granite

  19. Academic Libraries in Japan

    ERIC Educational Resources Information Center

    Cullen, Rowena; Nagata, Haruki

    2008-01-01

    Academic libraries in Japan are well resourced by international standards, and support Japan's internationally recognized research capability well, but there are also ways in which they reflect Japan's strong bureaucratic culture. Recent changes to the status of national university libraries have seen a new interest in customer service, and…

  20. Shallow earthquake swarms in southern Ryukyu area: manifestation of dynamics of fluid and/or magma plumbing system revealed by teleseismic and regional datasets

    NASA Astrophysics Data System (ADS)

    Špičák, Aleš; Vaněk, Jiří

    2016-06-01

    Earthquake swarm occurrence beneath volcanic domains is one of the indicators of current magmatic activity in the Earth's crust. Repeated occurrence of teleseismically recorded earthquake swarms has been observed in the lithospheric wedge of the southern Ryukyu area above the subducting slab of the Philippine Sea Plate. The swarms were analyzed using the EHB, ISC and JMA catalogs of hypocenter parameters. The swarm earthquakes are shallow (1-60 km), in the body-wave magnitude range up to 5.8. The swarms are distributed beneath the seafloor, parallel to the Ryukyu Trench along a belt connecting active subaerial volcanoes Io-Torishima north-east and Kueishantao west of the investigated area. Epicentral zones of the swarms often coincide with distinct elevations at the seafloor—seamounts and seamount ranges. The top of the subducting slab reaches a depth of about 100 km beneath the zones of earthquake swarm occurrence, which is an average depth of a slab beneath volcanoes in general. The repeated occurrence of relatively strong, teleseismically recorded earthquake swarms thus probably reflects fluid and/or magma migration in the plumbing system of the volcanic arc and points to brittle character of the lithospheric wedge at respective depths. In addition to the factual results, this study documents the high accuracy of hypocenter parameter determinations published by the International Seismological Centre and the usefulness of the EHB relocation procedure.

  1. Intraspecific Variation of Eysarcoris guttigerus (Hemiptera: Pentatomidae) in Japanese Southwest Population Based on Mitochondrial DNA.

    PubMed

    Yamaji, Takuya; Ishikawa, Tadashi; Nomura, Masashi

    2016-01-01

    The white-spotted globular bug Eysarcoris guttigerus (Thunberg) (Hemiptera: Pentatomidae) is widely distributed in East Asia and the Pacific region. In Japan, the species is found in grassy or composite weeds in the western area of the main islands and Ryukyu Islands of Japan. One notable characteristic of the Eysarcoris genus is the two white spots on the scutellum. This is not the case with the Ishigaki Island population, however, which sports red spots instead of white, suggesting that intraspecific variation exists in the species. Therefore, we investigated intraspecific variation in E. guttigerus using mitochondrial NADH dehydrogenase subunit 2 (ND2), cytochrome oxidase subunit 1 (CO1), cytochrome b (Cytb), tRNA-Serine (tRNA(ser)), NADH dehydrogenase subunit 1 (ND1), and 16S ribosomal RNA (16SrRNA) genes from 13 populations of Japan. The obtained maximum likelihood phylogenetic tree was divided into three groups--Group 1: Mainland, Group 2: Central Ryukyu Islands (Okinawa-Amamioshima Islands), and Group 3: South Ryukyu Islands (Ishigaki Island). The Ishigaki population was significantly separated from the other populations with consistent differences in spot color. The estimated period of divergence between the Ishigaki population and the other populations was consistent with the period of formation of the Kerama Gap in the Ryukyu arc. Thus, the process of formation of the Kerama Gap may have influenced the intraspecific variation of E. guttigerus. PMID:26798143

  2. Intraspecific Variation of Eysarcoris guttigerus (Hemiptera: Pentatomidae) in Japanese Southwest Population Based on Mitochondrial DNA

    PubMed Central

    Yamaji, Takuya; Ishikawa, Tadashi; Nomura, Masashi

    2016-01-01

    The white-spotted globular bug Eysarcoris guttigerus (Thunberg) (Hemiptera: Pentatomidae) is widely distributed in East Asia and the Pacific region. In Japan, the species is found in grassy or composite weeds in the western area of the main islands and Ryukyu Islands of Japan. One notable characteristic of the Eysarcoris genus is the two white spots on the scutellum. This is not the case with the Ishigaki Island population, however, which sports red spots instead of white, suggesting that intraspecific variation exists in the species. Therefore, we investigated intraspecific variation in E. guttigerus using mitochondrial NADH dehydrogenase subunit 2 (ND2), cytochrome oxidase subunit 1 (CO1), cytochrome b (Cytb), tRNA-Serine (tRNAser), NADH dehydrogenase subunit 1 (ND1), and 16S ribosomal RNA (16SrRNA) genes from 13 populations of Japan. The obtained maximum likelihood phylogenetic tree was divided into three groups—Group 1: Mainland, Group 2: Central Ryukyu Islands (Okinawa-Amamioshima Islands), and Group 3: South Ryukyu Islands (Ishigaki Island). The Ishigaki population was significantly separated from the other populations with consistent differences in spot color. The estimated period of divergence between the Ishigaki population and the other populations was consistent with the period of formation of the Kerama Gap in the Ryukyu arc. Thus, the process of formation of the Kerama Gap may have influenced the intraspecific variation of E. guttigerus. PMID:26798143

  3. Galapagos Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  4. Can GRACE detect winter snows in Japan?

    NASA Astrophysics Data System (ADS)

    Heki, Kosuke

    2010-05-01

    Current spatial resolution of the GRACE (Gravity Recovery and Climate Experiment) satellites is 300-400 km, and so its hydrological applications have been limited to continents and large islands. The Japanese Islands have width slightly smaller than this spatial resolution, but are known to show large amplitude seasonal changes in surface masses due mainly to winter snow. Such loads are responsible for seasonal crustal deformation observed with GEONET, a dense array of GPS (Global Positioning System) receivers in Japan (Heki, 2001). There is also a dense network of surface meteorological sensors for, e.g. snow depths, atmospheric pressures, etc. Heki (2004) showed that combined effects of surface loads, i.e. snow (predominant), atmosphere, soil moisture, dam impoundment, can explain seasonal crustal deformation observed by GPS to a large extent. The total weight of the winter snow in the Japanese Islands in its peak season may reach ~50 Gt. This is comparable to the annual loss of mountain glaciers in the Asian high mountains (Matsuo & Heki, 2010), and is above the detection level of GRACE. In this study, I use GRACE Level-2 Release-4 data from CSR, Univ. Texas, up to 2009 November, and evaluated seasonal changes in surface loads in and around the Japanese Islands. After applying a 350 km Gaussian filter and a de-striping filter, the peak-to-peak change of the water depth becomes ~4 cm in northern Japan. The maximum value is achieved in February-March. The region of large winter load spans from Hokkaido, Japan, to northeastern Honshu, which roughly coincides with the region of deep snow in Japan. Next I compiled snow depth data from surface meteorological observations, and converted them to loads using time-dependent snow density due to compaction. By applying the same spatial filter as the GRACE data, its spatial pattern becomes similar to the GRACE results. The present study suggests that GRACE is capable of detecting seasonal mass changes in an island arc not

  5. Skin cancer screening in Okinawa, Japan.

    PubMed

    Nagano, T; Ueda, M; Suzuki, T; Naruse, K; Nakamura, T; Taguchi, M; Araki, K; Nakagawa, K; Nagai, H; Hayashi, K; Watanabe, S; Ichihashi, M

    1999-04-01

    Depletion of the ozone layer has been observed on a global scale. Ozone depletion increases the amount of biologically harmful solar ultraviolet radiation (UV) that reaches the surface of the Earth, leading to an increased incidence of skin cancer. We previously reported the prevalence and incidence of actinic keratosis (AK) in Kasai City, which is located almost at the center of Japan. To evaluate the effects of different ambient annual UV doses on the prevalence and incidence of non-melanoma skin cancer and AK in Japan, we screened for skin cancer on Ie Island in Okinawa at the southern end of Japan, where the annual cumulative dose of UV is assumed to be the highest in Japan. The island had a population of 5562 in 1993. A prospective 4-year population-based study on the prevalence and incidence of cutaneous neoplasms was conducted by examining the sun-exposed skin of people over 40 years of age living on Ie Island. In 1993 1996, 86 cases of AK, nine of basal cell carcinoma (BCC), and two of squamous cell carcinoma were identified. The annual prevalence of AK on Ie Island was 1159.4 in 1993, 572.8 in 1994, 1014.3 in 1995 and 988.9 per 100000 Japanese in 1996. These values were significantly higher than those in Kasai City. The annual age-adjusted odds ratios for AK of Ie Island to Kasai City were 2.79, 1.38, 2.45 and 2.39, respectively. The incidences of AK on Ie Island per 100,000 were 637.0 in 1995 and 625.5 in 1996, which were also significantly higher than those in Kasai City (223.6 in 1993 and 171.2 in 1994). The prevalence of BCC was 123.6 and the incidence was 26.1. Together with our previous reports, the present results show a possible inverse relationship between the prevalence and incidence of AK and latitude among Japanese people. PMID:10215187

  6. Akpatok Island

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

  7. Strawberry Species of Iturup and Sakhalin Islands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A plant collecting expedition to Iturup (known in Japan as Etorofu) and Sakhalin Islands, Sakhalin Territory, Russian Federation, occurred between 21 July and 12 September 2003. Strawberries, Fragaria L., were observed and collected. Japanese and Russian flora have described two diploid (2n = 2x = ...

  8. Island Hopping

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2009-01-01

    At some institutions, it may feel as though faculty live on one island and advancement staff on another. The islands form part of an archipelago, and they exchange ambassadors and send emissaries occasionally, but interactions are limited. It may even seem as though the two groups speak different languages, deal in different currencies, and abide…

  9. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth

    PubMed Central

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed. PMID:26859569

  10. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth.

    PubMed

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed. PMID:26859569

  11. Game Development Toolkit for Business People in Japan

    ERIC Educational Resources Information Center

    Shirai, Hiroaki; Tanabu, Motonari; Terano, Takao; Kuno, Yasushi; Suzuki, Hisatoshi; Tsuda, Kazuhiko

    2003-01-01

    This article describes the authors' experience of developing a business gaming course for business people in Japan. The course that was developed consists of (a) simple gaming experiments among multiple students using ALEXANDER ISLANDS, a tiny business game on the World Wide Web; (b) lectures to make the students understand the core concepts of…

  12. Seismicity of the Earth 1900-2007, Japan and Vicinity

    USGS Publications Warehouse

    Rhea, Susan; Tarr, Arthur C.; Hayes, Gavin P.; Villaseñor, Antonio; Benz, Harley

    2010-01-01

    This map shows details of Japan and vicinity not visible in an earlier publication, U.S. Geological Survey Scientific Investigations Map 3064. Japan and its island possessions lie across four major tectonic plates: Pacific plate, North America plate; Eurasia plate; and Philippine Sea plate. The Pacific plate is subducted into the mantle, beneath Hokkaido and northern Honshu, along the eastern margin of the Okhotsk microplate, a proposed subdivision of the North America plate (Bird, 2003). Farther south, the pacific plate is subducted beneath volcanic islands along the eastern margin of the Philippine Sea plate. This 2,200 km-long zone of subduction of the Pacific plate is responsible for the creation of the deep offshore Ogasawara and Japan trenches as well as parallel chains of islands and volcanoes, typical of the Circumpacific island arcs. Similarly, the Philippine Sea plate is itself subducting under the Eurasia plate along a zone, extending from Taiwan to southern Honshu, that comprises the Ryuku Islands and the Nansei-Shonto trench.

  13. Subducting oceanic high causes compressional faulting in southernmost Ryukyu forearc as revealed by hypocentral determinations of earthquakes and reflection/refraction seismic data

    NASA Astrophysics Data System (ADS)

    Font, Yvonne; Lallemand, Serge

    2009-03-01

    Absolute earthquake hypocenter locations have been determined in the area offshore eastern Taiwan, at the Southernmost Ryukyu subduction zone. Location process is run within a 3D velocity model by combining the Taiwanese and neighboring Japanese networks and using the 3D MAXI technique. The study focuses on the most active seismic cluster in the Taiwan region that occurs in the forearc domain offshore eastern Taiwan. Earthquakes distribute mainly along 2 active planes. The first one aligns along the subduction interface and the second one, shallower affects the overriding margin. Focal mechanisms within the shallow group indicate that nodal planes are either compatible with high-angle back-thrusts or low-angle thrusts. The active seismic deformation exclusively indicates reverse faulting revealing that the forearc basement undergoes trench-perpendicular strong compression. By integrating the seismological image into the regional context, we favor the hypothesis in which the dense seismicity occurring offshore marks the activity of en-échelon high-angle reverse faults accommodating the uplift of a broken piece of Ryukyu Arc basement, called Hoping Basement Rise. The uplift is inferred to be caused by the subduction of an oceanic relief, either exotic block, seamount or oceanic crust sliver. Our favored solution satisfies the narrowness of epicenter's cluster along the Hoping Canyon, and the observation of high-angle active faults on seismic lines crossing the area. Furthermore, this solution is compatible with the active uplift of the Hoping Rise demonstrated from morphological and sedimentological data. We do not exclude the branching of the high-angle reverse faults system onto a splay fault connected with the subduction interface but further investigations are needed to map precisely the 3D distribution of active faults that break the margin.

  14. Journey to Japan

    ERIC Educational Resources Information Center

    Godfrey, Lorraine

    1978-01-01

    Create a variety of activities related to the country you are studying--Japan, for example--and arrange them by such subjects as art, games, creative writing, maps, dress and greetings. These activities can be tied in with classroom learning centers or stations. Here students make passports, learn about traditional styles of dress in Japan, learn…

  15. TWELVE DOORS TO JAPAN.

    ERIC Educational Resources Information Center

    BEARDSLEY, RICHARD K.; HALL, JOHN WHITNEY

    THE TWELVE DOORS OF THIS COLLEGE-LEVEL TEXT ARE TWELVE CHAPTERS ON ASPECTS OF JAPAN AND JAPANESE CULTURE AS TREATED BY VARIOUS ACADEMIC DISCIPLINES. THE AUTHORS' PURPOSE IN CHOOSING THIS FORMAT WAS TO PRESENT INTRODUCTORY INFORMATION ABOUT JAPAN AND TO ACQUAINT STUDENTS WITH THE AIMS, MATERIALS, AND METHODS OF DISCIPLINES OTHER THAN THE ONE THEY…

  16. Teaching English in Japan.

    ERIC Educational Resources Information Center

    Kitao, Kenji, Ed.; And Others

    English language instruction, which is considered very important in Japan, is offered in 90 percent of all secondary schools and is studied by almost all students, even though it is an elective subject. English is considered a cultural and commercial link with the western world and has been taught in Japan since the mid-nineteenth century. Most…

  17. Rehabilitation in Japan, 1988.

    ERIC Educational Resources Information Center

    Japanese Society for Rehabilitation of the Disabled, Tokyo.

    The scope of Japan's rehabilitation services for persons with disabilities is reviewed and discussed from the perspective of social and demographic change in that country. An introductory chapter on the current situation in Japan looks at characteristics of the land, the people, the government, industry and the economy, and the culture. The second…

  18. Volcano-Hydrothermal Systems of the Central and Northern Kuril Island Arc - a Review

    NASA Astrophysics Data System (ADS)

    Kalacheva, E.; Taran, Y.; Voloshina, E.; Ptashinsky, L.

    2015-12-01

    More than 20 active volcanoes with historical eruptions are known on 17 islands composing the Central and Northern part of the Kurilian Arc. Six islands - Paramushir, Shiashkotan, Rasshua, Ushishir, Ketoy and Simushir - are characterized by hydrothermal activity, complementary to the fumarolic activity in their craters. There are several types of volcano-hydrothermal systems on the islands. At Paramushir, Shiashkotan and Ketoy the thermal manifestations are acidic to ultra-acidic water discharges associated with hydrothermal aquifers inside volcano edifices and formed as the result of the absorption of magmatic gases by ground waters. A closest known analogue of such activity is Satsuma-Iwojima volcano-island at the Ryukyu Arc. Another type of hydrothermal activity are wide spread coastal hot springs (Shiashkotan, Rasshua), situated as a rule within tide zones and formed by mixing of the heated seawater with cold groundwater or, in opposite, by mixing of the steam- or conductively heated groundwater with seawater. This type of thermal manifestation is similar to that reported for other volcanic islands of the world (Satsuma Iwojima, Monserrat, Ischia, Socorro). Ushishir volcano-hydrothermal system is formed by the absorption of magmatic gases by seawater. Only Ketoy Island hosts a permanent acidic crater lake. At Ebeko volcano (Paramushir) rapidly disappearing small acidic lakes (formed after phreatic eruptions) have been reported. The main hydrothermal manifestation of Simushir is the Zavaritsky caldera lake with numerous coastal thermal springs and weak steam vents. The last time measured temperatures of fumaroles at the islands are: >500ºC at Pallas Peak (Ketoy), 480ºC at Kuntamintar volcano (Shiashkotan), variable and fast changing temperatures from 120º C to 500ºC at Ebeko volcano (Paramushir), 150ºC in the Rasshua crater, and > 300ºC in the Chirpoy crater (Black Brothers islands). The magmatic and rock-forming solute output by the Kurilian volcano

  19. Siberian Islands

    Atmospheric Science Data Center

    2013-04-16

    ... Distinguishing Clouds from Ice over the East Siberian Sea, Russia     View Larger Image ... clouds from snow and ice. The central portion of Russia's East Siberian Sea, including one of the New Siberian Islands, Novaya ...

  20. Current status of atopic dermatitis in Japan.

    PubMed

    Furue, Masutaka; Chiba, Takahito; Takeuchi, Satoshi

    2011-07-01

    Atopic dermatitis (AD) is a common, chronic or chronically relapsing, severely pruritic, eczematous skin disease. AD is the second most frequently observed skin disease in dermatology clinics in Japan. Prevalence of childhood AD is 12-13% in mainland Japan; however, it is only half that (about 6%) in children from Ishigaki Island, Okinawa. Topical steroids and tacrolimus are the mainstay of treatment. However, the adverse effects and emotional fear of long-term use of topical steroids have induced a "topical steroid phobia" in patients throughout the world. Undertreatment can exacerbate facial/periocular lesions and lead to the development of atopic cataract and retinal detachment due to repeated scratching/rubbing/patting. Overcoming topical steroid phobia is a key issue for the successful treatment of AD through education, understanding and cooperation of patients and their guardians. PMID:22053299

  1. Current status of atopic dermatitis in Japan

    PubMed Central

    Chiba, Takahito; Takeuchi, Satoshi

    2011-01-01

    Atopic dermatitis (AD) is a common, chronic or chronically relapsing, severely pruritic, eczematous skin disease. AD is the second most frequently observed skin disease in dermatology clinics in Japan. Prevalence of childhood AD is 12-13% in mainland Japan; however, it is only half that (about 6%) in children from Ishigaki Island, Okinawa. Topical steroids and tacrolimus are the mainstay of treatment. However, the adverse effects and emotional fear of long-term use of topical steroids have induced a "topical steroid phobia" in patients throughout the world. Undertreatment can exacerbate facial/periocular lesions and lead to the development of atopic cataract and retinal detachment due to repeated scratching/rubbing/patting. Overcoming topical steroid phobia is a key issue for the successful treatment of AD through education, understanding and cooperation of patients and their guardians. PMID:22053299

  2. Diurnal variations in H2O2, O3, PAN, HNO3 and aldehyde concentrations and NO/NO2 ratios at Rishiri Island, Japan: potential influence from iodine chemistry.

    PubMed

    Kanaya, Yugo; Tanimoto, Hiroshi; Matsumoto, Jun; Furutani, Hiroshi; Hashimoto, Shigeru; Komazaki, Yuichi; Tanaka, Shigeru; Yokouchi, Yoko; Kato, Shungo; Kajii, Yoshizumi; Akimoto, Hajime

    2007-04-15

    The presence of iodine chemistry, hypothesized due to the overprediction of HO(2) levels by a photochemical box model at Rishiri Island in June 2000, was quantitatively tested against the observed NO/NO(2) ratios and the net production rates of ozone. The observed NO/NO(2) ratios were reproduced reasonably well by considering the conversion of NO to NO(2) by IO, whose amount was calculated so as to reproduce the observed HO(2) levels. However, the net production rates of ozone were calculated to be negative when such high mixing ratios of IO were considered, which was inconsistent with the observed buildup of ozone during daytime. These results suggest that iodine chemistry may not be the sole mechanism for the reduced mixing ratios of HO(2), or that "hot spots" for iodine chemistry were present. Diurnal variations in the mixing ratios of HCHO, CH(3)CHO, peroxy acetyl nitrate (PAN) and HNO(3) observed during the study are presented along with the simulated ones. The box model simulations suggest that the effect of iodine chemistry on these concentrations is small and that important sources of CH(3)CHO and sinks of PAN are probably missing from our current understanding of the tropospheric chemistry mechanism. PMID:17306859

  3. Groundwater contamination in Japan

    NASA Astrophysics Data System (ADS)

    Tase, Norio

    1992-07-01

    Problems on groundwater contamination in Japan are briefly summarized in this paper. Although normal physical conditions in Japan restrict the possibilities of groundwater contamination, human activities are threatening groundwater resources. A survey by the Environment Agency of Japan showed nationwide spreading of organic substances, such as trichloroethylene as well as nitrogen compounds. Synthetic detergents have also been detected even in rural areas and in deep confined aquifers, although their concentrations are not as high. Public awareness of agrichemical or pesticides abuse, especially from golf courses, is apparent. Other problems such as nitrate-nitrogen, leachate from landfills, and the leaking of underground storage tanks are also discussed.

  4. Shaded Relief Mosaic of Umnak Island, Aleutian Islands, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is a shaded relief mosaic of Umnak Island in Alaska's Aleutian Islands.

    It was created with Airsar data that was geocoded and combined into this mosaic as part of a NASA-funded Alaska Digital Elevation Model Project at the Alaska Synthetic Aperture Radar Facility (ASF) at the University of Alaska Geophysical Institute in Fairbanks, Alaska.

    Airsar collected the Alaska data as part of its PacRim 2000 Mission, which took the instrument to French Polynesia, American and Western Samoa, Fiji, New Zealand, Australia, New Guinea, Indonesia, Malaysia, Cambodia, Philippines, Taiwan, South Korea, Japan, Northern Marianas, Guam, Palau, Hawaii and Alaska. Airsar, part of NASA's Airborne Science Program, is managed for NASA's Earth Science Enterprise by JPL. JPL is a division of the California Institute of Technology in Pasadena.

  5. GPM Arrives in Japan

    NASA Video Gallery

    An international satellite that will set a new standard for global precipitation measurements from space has completed a 7,300-mile journey from the United States to Japan, where it now will underg...

  6. Space communications in Japan

    NASA Astrophysics Data System (ADS)

    Mori, T.

    This paper outlines some of the planned satellite comunication projects in Japan over the next 5-7 years. In addition, Japanese space development policies are set out along with a historic review of the development of artificial satellites.

  7. IMPACTS OF DIOXIN EMISSIONS FROM THE SHINKAMPO INCINERATOR TO THE U.S. NAVAL AIR FACILITY AT ATSUGI, JAPAN

    EPA Science Inventory

    The United States Naval Air Facility at Atsugi, Japan (NAF Atsugi) is located in the Kanto Plain area on the island of Honshu, Japan. Directly to the south of the facility, in the Tade River Valley, was the Shinkampo Incinerator Complex (SIC). The Incinerator is no longer in op...

  8. Unzen Volcano, Japan

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This is a space radar image of the area around the Unzen volcano, on the west coast of Kyushu Island in southwestern Japan. Unzen, which appears in this image as a large triangular peak with a white flank near the center of the peninsula, has been continuously active since a series of powerful eruptions began in 1991. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 93rd orbit on April 15, 1994. The image shows an area 41.5 kilometers by 32.8 kilometers (25.7 miles by 20.3 miles) that is centered at 32.75 degrees north latitude and 130.15 degrees east longitude. North is toward the upper left of the image. The radar illumination is from the top of the image. The colors in this image were obtained using the following radar channels: red represents the L-band (vertically transmitted and received); green represents the average of L-band and C-band (vertically transmitted and received); blue represents the C-band (vertically transmitted and received). Unzen is one of 15 'Decade' volcanoes identified by the scientific community as posing significant potential threats to large local populations. The city of Shimabara sits along the coast at the foot of Unzen on its east and northeast sides. At the summit of Unzen a dome of thick lava has been growing continuously since 1991. Collapses of the sides of this dome have generated deadly avalanches of hot gas and rock known as pyroclastic flows. Volcanologists can use radar image data to monitor the growth of lava domes, to better understand and predict potentially hazardous collapses.

    Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The

  9. Devon Island

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mars Researchers Rendezvous on Remote Arctic Island   ... equipment and technology that may be deployed during a human mission to Mars. One of the many objectives of the project scientists is to ... Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's ...

  10. Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multiangle Imaging Spectro-Radiometer (MISR) image of five Hawaiian Islands was acquired by the instrument's vertical- viewing (nadir) camera on June 3, 2000. The image shows the islands of Oahu, Molokai, Lanai, Maui, and Kahoolawe. The prevailing Pacific trade winds bring higher levels of rainfall to the eastern slopes of the islands, leading to a greater abundance of vegetation on the windward coasts. The small change in observation angle across the nadir camera's field-of- view causes the right-hand portion of the image to be more affected by Sun glint, making the ocean surface appear brighter. Oahu is the westernmost of the islands seen in this image. Waikiki Beach and the city of Honolulu are located on the southern shore, to the west of Diamond Head caldera. MISR is one of several Earth-observing instruments on the Terra satellite, launched in December 1999. The Terra spacecraft, the flagship of a fleet of satellites dedicated to understanding our global environment, is part of NASA's Earth Sciences Enterprise, a long-term research program dedicated to understanding how human-induced and natural changes affect our world. Image courtesy NASA/GSFC/JPL, MISR Team

  11. Anatahan Island

    Atmospheric Science Data Center

    2013-04-19

    ... Snorkelers around this island are likely to encounter the fish Achilles Tang and the Moorish Idol (Acanthurus achilles and Zanclus ... Terra circles the Earth in the same orbit as Landsat 7, flying at an altitude of about 700 kilometers above the Earth's surface. ...

  12. The influence of Ryukyu subduction on magma genesis in the Northern Taiwan Volcanic Zone and Middle Okinawa Trough - Evidence from boron isotopes

    NASA Astrophysics Data System (ADS)

    Pi, Ju-Lien; You, Chen-Feng; Wang, Kuo-Lung

    2016-09-01

    Boron (B) is an excellent geochemical tracer for investigating crustal recycling processes at convergent margins, due to its high fluid mobility under high P-T conditions, distinct elemental abundances and isotopic compositions in the mantle wedge and subducting slabs. The Northern Taiwan Volcanic Zone (NTVZ), wherein the nature of magma genesis has long been a topic of debate, is located at the rear side of the Okinawa Trough (OT), an atypical back-arc rift in the Ryukyu subduction system. In this study, B and B isotopes (δ11B) were measured in 19 volcanic rocks collected from the NTVZ and the middle Okinawa Trough (MOT) to assess the influence of the Ryukyu subduction system on magma genesis. The B concentrations in the MOT and NTVZ volcanic rocks are 5.8 to 13.6 mg/L and 2.2 to 48.6 mg/L, respectively. The large B abundances variation in the NTVZ was caused mainly by variable degrees of partial melting. The Nb/B and δ11B in the MOT have small ranges of 0.5 to 0.6 and - 2.7‰ to 0.2‰, respectively, whereas they range widely from 0.4 to 2.5 and from - 8.6‰ to 2.4‰, respectively in the NTVZ. These Nb/B values suggest that the magma contains a smaller subduction component than that normally observed in arcs, although this component is still more substantial than in a typical back-arc setting. The δ11B results indicate insignificant influence of the subducting Philippine Sea Plate at 2.6 Ma, but it becomes more substantial later in the NTVZ. The mixing proportions of sediment derived fluids in onshore volcanoes in the NTVZ imply a rather heterogeneous mantle wedge near the plate boundary, most likely due to either a heterogeneous source of slab derived fluids or more complicated mantle flow. A substantial B flux from the subducting slab in the incipient back-arc rifting in the MOT and NTVZ may reflect characteristics of a cold, steep and fast subducting slab, which may be capable of carrying volatiles efficiently into greater depth in subduction zones. The

  13. Phylogeny, hybridization, and life history evolution of Rhinogobius gobies in Japan, inferred from multiple nuclear gene sequences.

    PubMed

    Yamasaki, Yo Y; Nishida, Mutsumi; Suzuki, Toshiyuki; Mukai, Takahiko; Watanabe, Katsutoshi

    2015-09-01

    Rhinogobius fishes (Gobiidae) are distributed widely in East and Southeast Asia, and represent the most species-rich group of freshwater gobies with diversified life histories (i.e., amphidromous, fluvial, and lentic). To reveal their phylogenetic relationships and life history evolution patterns, we sequenced six nuclear and three mitochondrial DNA (mtDNA) loci from 18 species, mainly from the mainland of Japan and the Ryukyu Archipelago. Our phylogenetic tree based on nuclear genes resolved three major clades, including several distinct subclades. The mtDNA and nuclear DNA phylogenies showed large discordance, which strongly suggested mitochondrial introgression through large-scale interspecific hybridization in these regions. On the basis of the molecular dating using geological data as calibration points, the hybridization occurred in the early to middle Pleistocene. Reconstruction of the ancestral states of life history traits based on nuclear DNA phylogeny suggests that the evolutionary change from amphidromous to freshwater life, accompanied by egg size change, occurred independently in at least three lineages. One of these lineages showed two life history alterations, i.e., from amphidromous (small egg) to fluvial (large egg) to lentic (small egg). Although more inclusive analysis using species outside Japan should be further conducted, the present results suggest the importance of the life history evolution associated with high adaptability to freshwater environments in the remarkable species diversification in this group. Such life history divergences may have contributed to the development of reproductive isolation. PMID:25929788

  14. A new insight on magma generation environment beneath Jeju (Cheju) volcanic island

    NASA Astrophysics Data System (ADS)

    Shin, Y.; CHOI, K.; Koh, J.; Yun, S.; Nakamura, E.; Na, S.

    2011-12-01

    We present a Moho undulation model from gravity inversion that gives a new insight on the magma generation environment beneath Jeju (Cheju) volcanic island, Korea. The island is an intra-plate volcanic island located behind Ryukyu Trench, the collisional boundary between Eurasian plate and Philippine plate. Jeju island is a symmetrical shield volcano of oval shape (74 km by 32 km) whose peak is Hallasan (Mt. Halla: 1950m). The landform, which is closely related to the volcanism, can be divided topographically into the lava plateau, the shield-shaped Halla volcanic edifice and the monogenetic cinder cones, which numbers over 365. The basement rock mainly consists of Precambrian gneiss, Mesozoic granite and volcanic rocks. Unconsolidated sedimentary rock is found between basement rock and lava. The lava plateau is composed of voluminous basaltic lava flows, which extend to the coast region with a gentle slope. Based on volcanic stratigraphy, paleontology and geochronology, the Jeju basalts range from the early Pleistocene to Holocene in age. The mean density of the island is estimated to be very low, 2390 kg/cubic cm from gravity data analysis, which reflects the abundant unconsolidated pyroclastic sediments below the surface lava. The mean Moho depth is estimated to be 29.5 km from power spectral density of gravity anomaly, which means it has continental crust. It is noticeable that the gravity inversion indicates the island is developed above and along a swelled-up belt (ridge), several hundred meters higher than the surrounding area. The structure is also shows positive correlation with high magnetic anomaly distribution that could indicate existence of volcanic rocks. We interpret the Moho structure has a key to the magma generation: 1) the high gravity anomaly belt is formed by folding/buckling process under compressional environment, 2) it causes decrease of pressure beneath the lithosphere along the belt, and 3) it accelerates melting of basaltic magma in

  15. Space robotics in Japan

    NASA Astrophysics Data System (ADS)

    Whittaker, William; Lowrie, James W.; McCain, Harry; Bejczy, Antal; Sheridan, Tom; Kanade, Takeo; Allen, Peter

    1994-03-01

    Japan has been one of the most successful countries in the world in the realm of terrestrial robot applications. The panel found that Japan has in place a broad base of robotics research and development, ranging from components to working systems for manufacturing, construction, and human service industries. From this base, Japan looks to the use of robotics in space applications and has funded work in space robotics since the mid-1980's. The Japanese are focusing on a clear image of what they hope to achieve through three objectives for the 1990's: developing long-reach manipulation for tending experiments on Space Station Freedom, capturing satellites using a free-flying manipulator, and surveying part of the moon with a mobile robot. This focus and a sound robotics infrastructure is enabling the young Japanese space program to develop relevant systems for extraterrestrial robotics applications.

  16. Space robotics in Japan

    NASA Technical Reports Server (NTRS)

    Whittaker, William; Lowrie, James W.; Mccain, Harry; Bejczy, Antal; Sheridan, Tom; Kanade, Takeo; Allen, Peter

    1994-01-01

    Japan has been one of the most successful countries in the world in the realm of terrestrial robot applications. The panel found that Japan has in place a broad base of robotics research and development, ranging from components to working systems for manufacturing, construction, and human service industries. From this base, Japan looks to the use of robotics in space applications and has funded work in space robotics since the mid-1980's. The Japanese are focusing on a clear image of what they hope to achieve through three objectives for the 1990's: developing long-reach manipulation for tending experiments on Space Station Freedom, capturing satellites using a free-flying manipulator, and surveying part of the moon with a mobile robot. This focus and a sound robotics infrastructure is enabling the young Japanese space program to develop relevant systems for extraterrestrial robotics applications.

  17. Cultural Astronomy in Japan

    NASA Astrophysics Data System (ADS)

    Renshaw, Steven L.

    While Japan is known more for its contributions to modern astronomy than its archaeoastronomical sites, there is still much about the culture's heritage that is of interest in the study of cultural astronomy. This case study provides an overview of historical considerations necessary to understand the place of astronomy in Japanese society as well as methodological considerations that highlight traditional approaches that have at times been a barrier to interdisciplinary research. Some specific areas of study in the cultural astronomy of Japan are discussed including examples of contemporary research based on interdisciplinary approaches. Japan provides a fascinating background for scholars who are willing to go beyond their curiosity for sites of alignment and approach the culture with a desire to place astronomical iconography in social context.

  18. Occupational asthma in Japan.

    PubMed

    Dobashi, Kunio

    2012-07-01

    Research into occupational asthma (OA) in Japan has been led by the Japanese Society of Occupational and Environmental Allergy. The first report about allergic OA identified konjac asthma. After that, many kinds of OA have been reported. Cases of some types of OA, such as konjac asthma and sea squirt asthma, have been dramatically reduced by the efforts of medical personnel. Recently, with the development of new technologies, chemical antigen-induced asthma has increased in Japan. Due to advances in anti-asthma medication, control by medical treatment tends to be emphasized and the search for causative antigens seems to be neglected. Furthermore, we do not have a Japanese guideline for diagnosis and management of OA. This article discusses the current state of OA in Japan. PMID:22872819

  19. Streamlined Island

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-514, 15 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a streamlined island in Marte Vallis, a large outflow channel system that crosses the 180oW meridian between the Elysium and Amazonis regions of Mars. The flow patterns on the floor of Marte Vallis might be the remains of lava flows or mud flows. Marte is the Spanish word for Mars. Most of the largest valleys on the red planet are named for 'Mars' in various languages. This island is located near 21.8oN, 175.3oW. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  20. Signs of continental rifting in the southwestern Japanese Island Arc

    NASA Astrophysics Data System (ADS)

    Chernysheva, E. A.; Eroshenko, D. V.

    2016-03-01

    The southwestern margin of the Japan Arc evolved in the geodynamic regime of continental rifting during the Miocene-Pleistocene. This has been verified by broad manifestations of metasomatosis of mantle peridotites that underlie the lithosphere of the Japan Islands and by episodes of deep magmatism (kimberlites and melilitites) in the region. The high enrichment of deep melts in incompatible rare and rare earth elements is partially preserved in melts of regional basalts from smaller depths. In contrast, spreading basalts of the Sea of Japan and subduction basalts from the Nankai trench at the boundary with the Philippine Plate are extremely depleted in rare elements.

  1. Phylogeographic Study of Whip Scorpions (Chelicerata: Arachnida: Thelyphonida) in Japan and Taiwan.

    PubMed

    Karasawa, Shigenori; Nagata, Satomi; Aoki, Jun-ichi; Yahata, Kensuke; Honda, Masanao

    2015-08-01

    Whip scorpions (Thelyphonida), comprising an order in the class Arachnida, are distributed from tropical to temperate zones. Two species occur exclusively in Japan and Taiwan, but the border of their distributional ranges is ambiguous in the Central Ryukyus (Japan). We collected new specimens from the Central Ryukyus and revealed that the border of distribution of the two species lies between the Central and Southern Ryukyus, i.e., the Kerama Gap. Moreover, the estimated divergence time (15.8 Mya) of the two species, based on the mitochondrial COI gene, was older than the recently estimated time (1.55 Mya) of formation of the Kerama Gap. These results highlight the risks of a priori assumption solely on the basis of geological data for applying it as a calibration point to some terrestrial animals in this region. Typopeltis stimpsonii was genetically divided into four lineages, two of which turned out to be endemic to the Okinawa Islands. All specimens from the main island of Japan and Shikoku were in one lineage, which was also found in the Amami Islands and Hachijojima Island. This suggests that these specimens may have been dispersed by human activity. Typopeltis crucifer included five genetic lineages. Species collected from Ishigakijima and Iriomotejima Islands were genetically diversified not between the borders of these islands but within Ishigakijima Island. This study also suggests that phylogenetic diversity of the species in the Southern Ryukyus have increased through two times of invasions from Taiwan. PMID:26245222

  2. A morphological review of the Cuora flavomarginata complex (Testudines: Geoemydidae)

    USGS Publications Warehouse

    Ernst, C.H.; Laemmerzahl, A.F.; Lovich, J.E.

    2008-01-01

    A reevaluation of the morphometric and color pattern differences within the Asiatic box turtle, Cuora flavomarginata sensu latu, was conducted in view of determining the taxonomic position of the three currently recognized subspecies: C. f. flavomarginata (Taiwan), C. f. sinensis (southern mainland China), and C. f. evelynae (Ryukyu Islands, Japan). Recent analyses indicate that the allopatric population of C. f. evelynae is the most divergent of the three taxa and shares little possibility for gene exchange with the other two populations. In contrast, the populations of C. f. flavomarginata and C. f. sinensis share many characters. We recommend the recognition of the Ryukyu population as a full species, C. evelynae.

  3. Classifying Pacific islands

    NASA Astrophysics Data System (ADS)

    Nunn, Patrick D.; Kumar, Lalit; Eliot, Ian; McLean, Roger F.

    2016-12-01

    An earth-science-based classification of islands within the Pacific Basin resulted from the preparation of a database describing the location, area, and type of 1779 islands, where island type is determined as a function of the prevailing lithology and maximum elevation of each island, with an island defined as a discrete landmass composed of a contiguous land area ≥1 ha (0.01 km2) above mean high-water level. Reefs lacking islands and short-lived (<20 years) transient islands are not included. The principal aim of the classification is to assess the spatial diversity of the geologic and geomorphic attributes of Pacific islands. It is intended to be valid at a regional scale and based on two attributes: five types of lithology (volcanic, limestone, composite, continental, surficial) and a distinction between high and low islands. These attributes yielded eight island types: volcanic high and low islands; limestone high and low islands; composite high and low islands; reef (including all unconsolidated) islands; and continental islands. Most common are reef islands (36 %) and volcanic high islands (31 %), whereas the least common are composite low islands (1 %). Continental islands, 18 of the 1779 islands examined, are not included in maps showing the distribution of island attributes and types. Rationale for the spatial distributions of the various island attributes is drawn from the available literature and canvassed in the text. With exception of the few continental islands, the distribution of island types is broadly interpretable from the proximity of island-forming processes. It is anticipated the classification will become the basis for more focused investigation of spatial variability of the climate and ocean setting as well as the biological attributes of Pacific islands. It may also be used in spatial assessments of second-order phenomena associated with the islands, such as their vulnerability to various disasters, coastal erosion, or ocean pollution as

  4. Black brant from Alaska staging and wintering in Japan

    USGS Publications Warehouse

    Derksen, Dirk V.; Bollinger, K.S.; Ward, David H.; Sedinger, J.S.; Miyabayashi, Y.

    1996-01-01

    Black brant (Branta bernicla nigricans) nest in colonies in arctic Canada, Alaska, and Russia (Derksen and Ward 1993, Sedinger et al. 1993). Virtually the entire population stages in fall at Izembek Lagoon near the tip of the Alaska Peninsula (Bellrose 1976) before southward migration (Dau 1992) to winter habitats in British Columbia, Washington, Oregon, California, and Baja California (Subcommittee on Black Brant 1992). A small number of black brant winter in Japan, Korea, and China (Owen 1980). In Japan 3,000–5,000 brant of unknown origin stop over in fall, and a declining population (<1,000) of birds winter here, primarily in the northern islands (Brazil 1991, Miyabayashi et al. 1994). Here, we report sightings of brant in Japan that were marked in Alaska and propose a migration route based on historical and recent observations and weather patterns.

  5. Display of historical and hypothetical tsunami on the coast of Sakhalin Island

    NASA Astrophysics Data System (ADS)

    Kostenko, Irina; Zaytsev, Andrey; Kurkin, Andrey; Yalciner, Ahmet

    2014-05-01

    Tsunami waves achieve the coast of the Sakhalin Island and their sources are located in the Japan Sea, in the Okhotsk Sea, in Kuril Islands region and in the Pacific Ocean. Study of tsunami generation characteristics and its propagation allows studying display of the tsunami on the various parts of the island coast. For this purpose the series of computational experiments of some historical tsunamis was carried out. Their sources located in Japan Sea and Kuril Islands region. The simulation results are compared with the observations. Analysis of all recorded historical tsunami on coast of Sakhalin Island was done. To identify the possible display of the tsunami on the coast of Sakhalin Island the series of computational experiments of hypothetical tsunamis was carried out. Their sources located in the Japan Sea and in the Okhotsk Sea. There were used hydrodynamic sources. There were used different parameters of sources (length, width, height, raising and lowering of sea level), which correspond to earthquakes of various magnitudes. The analysis of the results was carried out. Pictures of the distribution of maximum amplitudes from each tsunami were done. Areas of Okhotsk Sea, Japan Sea and offshore strip of Sakhalin Island with maximum tsunami amplitudes were defined. Graphs of the distribution of maximum tsunami wave heights along the coast of the Sakhalin Island were plotted. Based on shallow-water equation tsunami numerical code NAMI DANCE was used for numerical simulations. This work was supported by ASTARTE project.

  6. "Hands on" Japan.

    ERIC Educational Resources Information Center

    Borries, Richard

    Cultural learning kits designed by Evansville, Indiana teachers, supervisors, and community advisory groups were compiled to provide information about Japan to community organizations and students. This document provides a key to the contents of the kits. The kits contain teaching materials and information about food, school materials, language…

  7. Advanced composites in Japan

    NASA Technical Reports Server (NTRS)

    Diefendorf, R. Judd; Hillig, William G.; Grisaffe, Salvatore J.; Pipes, R. Byron; Perepezko, John H.; Sheehan, James E.

    1994-01-01

    The JTEC Panel on Advanced Composites surveyed the status and future directions of Japanese high-performance ceramic and carbon fibers and their composites in metal, intermetallic, ceramic, and carbon matrices. Because of a strong carbon and fiber industry, Japan is the leader in carbon fiber technology. Japan has initiated an oxidation-resistant carbon/carbon composite program. With its outstanding technical base in carbon technology, Japan should be able to match present technology in the U.S. and introduce lower-cost manufacturing methods. However, the panel did not see any innovative approaches to oxidation protection. Ceramic and especially intermetallic matrix composites were not yet receiving much attention at the time of the panel's visit. There was a high level of monolithic ceramic research and development activity. High temperature monolithic intermetallic research was just starting, but notable products in titanium aluminides had already appeared. Matrixless ceramic composites was one novel approach noted. Technologies for high temperature composites fabrication existed, but large numbers of panels or parts had not been produced. The Japanese have selected aerospace as an important future industry. Because materials are an enabling technology for a strong aerospace industry, Japan initiated an ambitious long-term program to develop high temperature composites. Although just starting, its progress should be closely monitored in the U.S.

  8. Japan's electronic packaging technologies

    NASA Technical Reports Server (NTRS)

    Tummala, Rao R.; Pecht, Michael

    1995-01-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  9. Political Corruption in Japan.

    ERIC Educational Resources Information Center

    Reed, Steven R.; And Others

    1996-01-01

    Provides an overview of political corruption and its place in Japanese culture and society. Discusses recent scandals and efforts at political reform. These efforts are moving Japan from a "boss-patronage" system to a "civic-culture." Includes a table of post-war Japanese prime ministers and corruption scandals. (MJP)

  10. [Films: China and Japan].

    ERIC Educational Resources Information Center

    Gumport, Roberta H.

    The history of filmmaking in China and Japan and film usage in teaching are considered in this document. Pointing out how films describe historical context and culture, the document also describes various techniques of film making. Films in China were heavily influenced by western models and have tended to be tools of the power structure, as…

  11. Photovoltaics in Japan

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1985-01-01

    Report surveys status of research and development on photovoltaics in Japan. Report based on literature searches, private communications, and visits by author to Japanese facilities. Included in survey are Sunshine Project, national program to develop energy sources; industrial development at private firms; and work at academic institutions.

  12. Japan's electronic packaging technologies

    NASA Astrophysics Data System (ADS)

    Tummala, Rao R.; Pecht, Michael

    1995-02-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  13. Country Profiles. Japan.

    ERIC Educational Resources Information Center

    Muramatsu, Minoru

    This occasional paper on Japan is one of a series setting forth the nature, scope, and accomplishments of population activities in specified countries. Here, an overview is given of population characteristics and growth patterns, the relationship of population growth to socioeconomic development, and the history of population concerns and…

  14. Japan: Tsunami Flooding

    Atmospheric Science Data Center

    2013-04-16

    ... of 41 kilometers (25 miles) by 89 kilometers (55 miles). Flooding extending about 2 kilometers (1.2 miles) inland is visible just north ... March 18, 2005 and March 19, 2011 - Before and after tsunami flooding along Japan's eastern coast. project:  MISR ...

  15. Language Testing in Japan.

    ERIC Educational Resources Information Center

    Brown, James Dean, Ed.; Yamashita, Sayoko Okada, Ed.

    Papers on second language testing in Japan include: "Differences Between Norm-Referenced and Criterion-Referenced Tests" (James Dean Brown); "Criterion-Referenced Test Construction and Evaluation" (Dale T. Griffe); "Behavioral Learning Objectives as an Evaluation Tool" (Judith A. Johnson); "Developing Norm- Referenced Tests for Program-Level…

  16. Nuclear Power in Japan.

    ERIC Educational Resources Information Center

    Powell, John W.

    1983-01-01

    Energy consumption in Japan has grown at a faster rate than in any other major industrial country. To maintain continued prosperity, the government has embarked on a crash program for nuclear power. Current progress and issues/reactions to the plan are discussed. (JN)

  17. Lifelong Learning Facilities in Japan.

    ERIC Educational Resources Information Center

    Hirai, Akishige

    1997-01-01

    Examines Japan's educational system and the role of national policy and local government in fostering lifelong learning. Reasons why Japan is building a lifelong learning society are examined, as are the opportunities available in Japan for learning beyond traditional education, the national and local government's role, access to facilities,…

  18. Globalization and Education in Japan

    ERIC Educational Resources Information Center

    Ohkura, Kentaro; Shibata, Masako

    2009-01-01

    In this paper, the authors contend that globalization in Japan is the gradual process in which Japan's positioning of "self" within international relations, which had formerly been dominated by the West, has changed. Accordingly, Japan's relationships with the West and the rest of the world, for example, Asia, have also been reviewed and modified.…

  19. Solomon Islands.

    PubMed

    1988-06-01

    The Solomon Islands, which form an archipelago in the Southwest Pacific about 1900 km northeast of Australia, are described. Included are brief descriptions about such points as geography, people, history, type of government, political conditions, economy, and foreign relations. In 1987 the population was 301,180 (49% under age 14); the annual growth rate was 3.67%. The infant mortality rate is 46/1000; the life expectancy, 54 years. Health conditions in the Solomons generally are adequate, and the country does not suffer from serious endemic diseases other than malaria, in both the vivax and falsiparum strains. Hospitals and pharmacies are limited to population centers and missions. PMID:12177986

  20. New observations at Iwo-Jima caldera, Volcano Islands, Japan

    NASA Astrophysics Data System (ADS)

    Ukawa, U. M.; Fujita, E.; Hill, D.; Kobayashi, T.; Lowenstern, J.; Newhall, C.

    2003-04-01

    Small phreatic eruptions on opposite sides of Iwo-Jima in September and October 2001 marked the beginning of several changes in this largely submarine caldera and trapdoor resurgence of its floor. The northern part of Motoyama, roughly the center of the caldera floor, has risen >120 m in the past 420 years at an average rate of ˜25 cm/y; uplift in the past year has been substantially faster. The main cause of uplift at Iwo-Jima is fresh, episodic(?) magma influx into a reservoir whose top is ˜ 2 km below the caldera floor. Despite roughly 10 million m3/y apparent magma influx, degassing seems to minimize magmatic eruptions.

  1. Scientific ballooning in Japan

    NASA Astrophysics Data System (ADS)

    Makino, Fumiyoshi

    Activities in scientific ballooning in Japan during 1998-1999 are reported. The total number of scientific balloons flown in Japan in 1998 and 1999 was sixteen, eight flights in each year. The scientific objectives were observations of high energy cosmic electrons, air samplings at various altitudes, monitoring of atmospheric ozone density, Galactic infrared observations, and test flights of new type balloons. Balloon expeditions were conducted in Antarctica by the National Institute of Polar Research, in Russia, in Canada and in India in collaboration with foreign countries' institutes to investigate cosmic rays, Galactic infrared radiation, and Earth's atmosphere. There were three flights in Antarctica, four flights in Russia, three flights in Canada and two flights in India. Four test balloons were flown for balloon technology, which included pumpkin-type super-pressure balloon and a balloon made with ultra-thin polyethylene film of 3.4 μm thickness.

  2. [Gambling disorder in Japan].

    PubMed

    Tanabe, Hitoshi

    2015-09-01

    Gambling disorder is a psychiatric disorder characterized by persistent and recurrent problematic gambling behavior, associated with impaired functioning, reduced quality of life, and frequent divorce and bankruptcy. Gambling disorder is reclassified in the category Substance-Related and Addictive Disorders in the DSM-5 because its clinical features closely resemble those of substance use disorders, and gambling activates the reward system in brain in much the same way drugs do. Prevalence of gambling disorder in Japan is high rate because of slot machines and pachinko game are very popular in Japan. The author recommend group psychotherapy and self-help group (Gamblers Anonymous), because group dynamics make them accept their wrongdoings related to gambling and believe that they can enjoy their lives without gambling. PMID:26394523

  3. Numerical earthquake model of the 20 April 2015 southern Ryukyu subduction zone M6.4 event and its impact on seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Lee, Shiann-Jong

    2015-10-01

    The M6.4 earthquake that took place on the 20 April 2015 off the shore of eastern Taiwan was the largest event in the vicinity of Taiwan during 2015. The mainshock was located in the southern Ryukyu subduction zone, which is the interface between the Philippine Sea Plate and the Eurasian Plate. People in Taipei experienced strong ground shaking for more than 40 s, even though the epicenter was located more than 150 km away. In order to understand the origin of ground motions from this earthquake and how it caused such strong shaking in Taipei, a numerical earthquake model is analyzed, including models of source rupture and wave propagation. First, a joint source inversion was performed using teleseismic body wave and local ground motion data. Source inversion results show that a large slip occurred near the hypocenter, which rapidly released seismic energy in the first 2 s. Then, the rupture propagated toward the shallow fault plane. A large amount of seismic energy was released during this rupture stage that slipped for more than 8 s before the end of the rupture. The estimated stress drop is 2.48 MPa, which is consistent with values for subduction zone earthquakes. Forward simulation using this inverted source rupture model and a 3D seismic velocity model based on the spectral-element method was then performed. Results indicate that the strong ground motion in Taipei resulted from two factors: (1) the Taipei basin amplification effect and (2) the specific source radiation pattern. The results of this numerical earthquake model imply that future subduction zone events that occur in offshore eastern Taiwan are likely to cause relatively strong ground shaking in northern Taiwan, especially in the Taipei metropolitan area.

  4. Psychology in Japan.

    PubMed

    Imada, Hiroshi; Tanaka-Matsumi, Junko

    2016-06-01

    The purpose of this article is to provide information about Japan and its psychology in advance of the 31st International Congress of Psychology (ICP), to be held in Yokohama, Japan, in 2016. The article begins with the introduction of the Japanese Psychological Association (JPA), the hosting organization of the ICP 2016, and the Japanese Union of Psychological Associations consisting of 51 associations/societies, of which the JPA is a member. This is followed by a brief description of a history of psychology of Japan, with emphasis on the variation in our approach to psychology in three different periods, that is, the pre- and post-Pacific War periods, and the post-1960 period. Next, the international contributions of Japanese psychology/psychologists are discussed from the point of view of their visibility. Education and training in psychology in Japanese universities is discussed with a final positive remark about the long-awaited enactment of the Accredited Psychologist Law in September, 2015. PMID:26892102

  5. Island Formation: Constructing a Coral Island

    ERIC Educational Resources Information Center

    Austin, Heather; Edd, Amelia

    2009-01-01

    The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

  6. Native fruit tree genetic resources in Japan.

    PubMed

    Iketani, Hiroyuki

    2016-01-01

    The diversity of climate, from subarctic to subtropical, and the complex geological history of Japan have produced a rich biodiversity. The flora includes several hundred species of native woody plants with edible fleshy fruits or nuts. People have eaten them from prehistoric times until about a half century ago. In Hokkaidō and the Ryūkyū Islands nut species had an important role in the diet, but fleshy fruits were also eaten until recently. Only Castanea crenata and a few minor species became domesticated as edible fruit trees in pre-modern times. Recently, Vitis coignetiae, Lonicera caerulea, Akebia quinata, Akebia trifoliata, Stauntonia hexaphylla, and Actinidia arguta have entered small-scale cultivation. The conservation of the germplasm of many of these native species, both in situ and ex situ, is precarious. PMID:27069393

  7. Native fruit tree genetic resources in Japan

    PubMed Central

    Iketani, Hiroyuki

    2016-01-01

    The diversity of climate, from subarctic to subtropical, and the complex geological history of Japan have produced a rich biodiversity. The flora includes several hundred species of native woody plants with edible fleshy fruits or nuts. People have eaten them from prehistoric times until about a half century ago. In Hokkaidō and the Ryūkyū Islands nut species had an important role in the diet, but fleshy fruits were also eaten until recently. Only Castanea crenata and a few minor species became domesticated as edible fruit trees in pre-modern times. Recently, Vitis coignetiae, Lonicera caerulea, Akebia quinata, Akebia trifoliata, Stauntonia hexaphylla, and Actinidia arguta have entered small-scale cultivation. The conservation of the germplasm of many of these native species, both in situ and ex situ, is precarious. PMID:27069393

  8. 2012/13 abnormal cold winter in Japan associated with Large-scale Atmospheric Circulation and Local Sea Surface Temperature over the Sea of Japan

    NASA Astrophysics Data System (ADS)

    Ando, Y.; Ogi, M.; Tachibana, Y.

    2013-12-01

    On Japan, wintertime cold wave has social, economic, psychological and political impacts because of the lack of atomic power stations in the era of post Fukushima world. The colder winter is the more electricity is needed. Wintertime weather of Japan and its prediction has come under the world spotlight. The winter of 2012/13 in Japan was abnormally cold, and such a cold winter has persisted for 3 years. Wintertime climate of Japan is governed by some dominant modes of the large-scale atmospheric circulations. Yasunaka and Hanawa (2008) demonstrated that the two dominant modes - Arctic Oscillation (AO) and Western Pacific (WP) pattern - account for about 65% of the interannual variation of the wintertime mean surface air temperature of Japan. A negative AO brings about cold winter in Japan. In addition, a negative WP also brings about cold winter in Japan. Looking back to the winter of 2012/13, both the negative AO and negative WP continued from October through December. If the previous studies were correct, it would have been extremely very cold from October through December. In fact, in December, in accordance with previous studies, it was colder than normal. Contrary to the expectation, in October and November, it was, however, warmer than normal. This discrepancy signifies that an additional hidden circumstance that heats Japan overwhelms these large-scale atmospheric circulations that cool Japan. In this study, we therefore seek an additional cause of wintertime climate of Japan particularly focusing 2012 as well as the AO and WP. We found that anomalously warm oceanic temperature surrounding Japan overwhelmed influences of the AO or WP. Unlike the inland climate, the island climate can be strongly influenced by surrounding ocean temperature, suggesting that large-scale atmospheric patterns alone do not determine the climate of islands. (a) Time series of a 5-day running mean AO index (blue) as defined by Ogi et al., (2004), who called it the SVNAM index. For

  9. Proceedings of US-Japan heliotron-stellarator workshop: Volume 4

    SciTech Connect

    Not Available

    1987-01-01

    This paper is the fourth of four volumes on the US-Japan Heliotron-Stellarator workshop. It contains talks on the following: Compact torsatron studies; Low aspect ratio torsatron design; Optimized small stellarator designs; Currents in ATF; Computations of 3-D equilibria with islands; and Magnetic surface mapping studies. (LSP)

  10. Hawaiian Island Archipelago

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The entire Hawaiian Island Archipelago (21.5N, 158.0W) is seen in this single view. The islands are a favorite international resort and tourist attraction drawing visitors from all over the world to enjoy the tropical climate, year round beaches and lush island flora. Being volcanic in origin, the islands' offer a rugged landscape and on the big island of Hawaii, there is still an occasional volcanic eruption of lava flows and steam vents.

  11. Ijime in Japan.

    PubMed

    Ogura, Masayoshi; Okada, Kaori; Hamada, Shoko; Asaga, Reiko; Honjo, Shuji

    2012-01-01

    This paper reviews the problem of ijime in Japan from a variety of perspectives, primarily through studies conducted in this country. The term ijime is not uniform in concept, open to different interpretations given the disparity in definitions among different circles, making precise assessment of the actual conditions difficult. Such being the case, what is needed is further study on the mechanisms and actual state of ijime accounting for the flow of the times, and compilation of research to enable the creation of ever more effective modes of prevention and intervention. PMID:22909914

  12. Astrogeodetic geoid of Japan

    NASA Technical Reports Server (NTRS)

    Ganeko, Y.

    1976-01-01

    Three kinds of astrogeodetic geoid maps for Japan are presented: one referred to the global (18, 18) geoid of the 1973 Smithsonian Standard Earth (III) (SE III), referred to the best-fitting ellipsoid of SE III, and one referred to the reference ellipsoid of the Tokyo datum. Interpolations of the deflection of the vertical are carried out by a least squares estimation method. The geoid height differences obtained are compared with solutions of satellite-derived station positions. Good agreement is found in a comparison with Doppler tracking stations.

  13. Discovery of the genus Leptophion Cameron, 1901, from Japan and the Palaearctic region, with description of two new species (Hymenoptera: Ichneumonidae: Ophioninae).

    PubMed

    Shimizu, So; Watanabe, Kyohei

    2015-01-01

    The genus Leptophion Cameron, 1901, which belongs to the subfamily Ophioninae Shuckard, 1840, is recorded from Japan and the Palaearctic region for the first time based on two new species, L. parvus sp. nov. from Amamioshima Island and L. septentrionis sp. nov. from Yakushima and Amamioshima Island. A key to the Japanese and Taiwanese species is also provided. PMID:26623604

  14. Overview of DRAGON-Japan in 2012

    NASA Astrophysics Data System (ADS)

    Sano, I.; Holben, B. N.; Mukai, S.; Sugimoto, N.; Hatakeyama, S.; Schafer, J. S.; Eck, T. F.; Nishizawa, T.; Takemura, T.; Takamura, T.; Teruyuki, N.; Nakajima, T. Y.; Takami, A.; Kaneyasu, N.; Goto, M.; Hiraki, T.; Iguchi, N.; Kenny, P.; Kouzai, K.; Kuji, M.; Muramatsu, K.; Nakata, M.; Okada, Y.; Sadanaga, Y.; Sorokin, M.; Tohno, S.; Toyazaki, Y.; Kim, J.; Li, Z.

    2012-12-01

    The AERONET (AErosol RObotic NETwork) is an on-going project since early 1990s. The 400 sun/sky radiometers are sparsely deployed and provide us with the information of aerosol properties over the world. In summer of 2011, the first DRAGON field campaign was made in Washington, D.C./Baltimore metropolitan area, where about 40 AERONET Cimel instruments were set according to small square grid boxes. Thus it has been shown that the detail scale observations are useful to investigate the local influence of aerosols and validation of high resolution satellite product such as newly developed 3 km x 3 km aerosol product from MODIS. The second DRAGON project is done in East Asia because this region emits huge amount of anthropogenic gases and aerosols. The emission influences not only local atmosphere near the origin but also out of Asian continent by long range transportation. The aim of DRAGON-Japan is as follows: 1: retrieval of optical properties of trans-boundary aerosols, 2: detection of aerosols over megacity, 3: investigation of the influence to local aerosols by inbound aerosols from continent. During the DRAGON-Asia (March-May, 2012), AERONET instruments were set sparsely from Fukue Island (in the East China Sea) to Osaka (in the middle of Japan) as well as 2ch-LIDAR system. As for megacity region, dense sun/sky radiometer network was made by using nine instruments at Mt. Rokko (840 m/asl.), Mt. Ikoma (640 m/asl.), Kobe, North-Osaka, South-Osaka, Central-Osaka, East-Osaka (simply named by Osaka in AERONET web), Nara, and Kyoto. The following results on AOT (Aerosol optical thickness at a wavelength of 500 nm: AERONET Level 1.5) have been driven from the measurements : 1: Fukue Island provides the highest value as 0.56, 2: in respect of urban cities; 0.42 at Fukuoka, 0.42~0.47 over Osaka area, and 0.39 at Kyoto or Nara, 3: in the remote place; 0.33~0.35 at Nishiharima, Noto or Shirahama, 4: the difference between AOT values at mountain (ex. Mt. Rokko, Mt. Ikoma

  15. Legalized Abortion in Japan

    PubMed Central

    Hart, Thomas M.

    1967-01-01

    The enactment of the Eugenic Protection Act in Japan was followed by many changes. The population explosion was stemmed, the birth rate was halved, and while the marriage rate remained steady the divorce rate declined. The annual total of abortions increased until 1955 and then slowly declined. The highest incidence of abortions in families is in the 30 to 34 age group when there are four children in the family. As elsewhere abortion in advanced stages of pregnancy is associated with high morbidity and mortality. There is little consensus as to the number of criminal abortions. Reasons for criminal abortions can be found in the legal restrictions concerning abortion: Licensing of the abortionist, certification of hospitals, taxation of operations and the requirement that abortion be reported. Other factors are price competition and the patient's desire for secrecy. Contraception is relatively ineffective as a birth control method in Japan. Oral contraceptives are not yet government approved. In 1958 alone 1.1 per cent of married women were sterilized and the incidence of sterilization was increasing. PMID:6062283

  16. Legalized abortion in Japan.

    PubMed

    Hart, T M

    1967-10-01

    The enactment of the Eugenic Protection Act in Japan was followed by many changes. The population explosion was stemmed, the birth rate was halved, and while the marriage rate remained steady the divorce rate declined. The annual total of abortions increased until 1955 and then slowly declined. The highest incidence of abortions in families is in the 30 to 34 age group when there are four children in the family. As elsewhere abortion in advanced stages of pregnancy is associated with high morbidity and mortality. There is little consensus as to the number of criminal abortions. Reasons for criminal abortions can be found in the legal restrictions concerning abortion: Licensing of the abortionist, certification of hospitals, taxation of operations and the requirement that abortion be reported. Other factors are price competition and the patient's desire for secrecy. Contraception is relatively ineffective as a birth control method in Japan. Oral contraceptives are not yet government approved. In 1958 alone 1.1 per cent of married women were sterilized and the incidence of sterilization was increasing. PMID:6062283

  17. Model analysis of seasonal variation of PM2.5 across Japan and its reginal-scale transport in East Asia

    NASA Astrophysics Data System (ADS)

    Ikeda, Kohei; Yamaji, Kazuyo; Kanaya, Yugo; Taketani, Fumikazu; Pan, Xiaole; Komazaki, Yuichi; Kurokawa, Jun-ichi; Ohara, Toshimasa

    2013-04-01

    In Japan, an atmospheric environmental standard for PM2.5 was newly introduced in September 2009. According to one year of data observed at ambient air quality monitoring stations in Japan main islands in fiscal 2010, PM2.5 concentrations exceed the environmental standard at the large part of monitoring stations. In particular, concentration levels at almost all the monitoring stations in the western part of Japan exceed the standard value. Besides Japan main islands, PM2.5 concentrations monitored at Fukue Island, a remote island in the most western part of Japan and close to the Asian continent, clearly exceeds the short-term standard value. These results suggest that regional-scale transport in East Asia affects the spatial and temporal variations of PM2.5 across Japan. To investigate seasonal variations of PM2.5 and estimate the influence of trans-boundary air pollution in East Asia, we performed emission sensitivity simulations for the full year 2010 by using a chemical transport model (Weather Research and Forecasting model /Community Multi-scale Air Quality model). The source regions in East Asia were divided into six areas: Japan, Korean Peninsula, northeast China, central north China, central south China, and south China. In each sensitivity simulation, the anthropogenic emission was reduced by 20% in each source region. The sensitivity of each source region was obtained by taking the difference of simulated PM2.5 concentration between each sensitivity and base run. The model generally well reproduces the seasonal variation pattern of PM2.5 concentrations across Japan; in the western part of Japan, PM2.5 concentration decreases in summer, whereas it increases during summer in the eastern part of Japan. However, the absolute concentrations were underestimated by the model in the entire Japan throughout the year. We estimated the relative contributions from each source region to annual mean PM2.5 concentrations in Japan. The contribution of domestic

  18. Teaching Elementary Students about Japan

    ERIC Educational Resources Information Center

    Fitzhugh, William P.

    This paper presents a study unit on Japan for elementary students which can be adapted for any level. Lessons include: (1) "Video Traveling Activities To Accompany Students on Their Journey to Japan"; (2) "Travel Brochure"; (3) "Discovering Culture by Using a Realia Kit"; (4) "Comparative Geography Using the Five Fundamental Themes of Geography";…

  19. Higher Education Studies in Japan

    ERIC Educational Resources Information Center

    Kaneko, Motohisa

    2010-01-01

    The rapid development of higher education in the postwar period has given rise to various problems, and higher education studies in Japan have developed in response to them. What have been the major issues, and how did academic research respond to them, in postwar Japan? This article delineates an outline of higher education studies in general,…

  20. China and Japan (Theme Issue).

    ERIC Educational Resources Information Center

    Kiernan, Henry, Ed.; Pyne, John, Ed.

    1993-01-01

    This serial issue is devoted to the theme "China and Japan" and contains six articles that focus on educational, political, and cultural issues in the two Asian countries. In the first article, "China and Japan: A New Era in Relations with the United States," Henry Kiernan and John Pyne provide a brief overview of the history of United States'…

  1. Japan to increase coal imports

    SciTech Connect

    Griffin, S.

    1982-04-01

    Imports of coal into Japan are expected to increase next year. One major company is buying into a Canadian mine to obtain a long-term supply contract, and other companies are expected to follow. A feasibility study on production of methanol-coal slurry and its transportation by pipeline in Alberta, Canada (conducted by Japan and Canada) has been completed.

  2. Generic antibiotics in Japan.

    PubMed

    Fujimura, Shigeru; Watanabe, Akira

    2012-08-01

    Generic drugs have been used extensively in many developed countries, although their use in Japan has been limited. Generic drugs reduce drug expenses and thereby national medical expenditure. Because generic drugs provide advantages for both public administration and consumers, it is expected that they will be more widely used in the future. However, the diffusion rate of generic drugs in Japan is quite low compared with that of other developed countries. An investigation on generic drugs conducted by the Ministry of Health, Labour and Welfare in Japan revealed that 17.2 % of doctors and 37.2 % of patients had not used generic drugs. The major reasons for this low use rate included distrust of off-patent products and lower drug price margin compared with the brand name drug. The generic drugs available in the market include external drugs such as wet packs, antihypertensive agents, analgesics, anticancer drugs, and antibiotics. Among them, antibiotics are frequently used in cases of acute infectious diseases. When the treatment of these infections is delayed, the infection might be aggravated rapidly. The pharmacokinetics-pharmacodynamics (PK-PD) theory has been adopted in recent chemotherapy, and in many cases, the most appropriate dosage and administration of antibiotics are determined for individual patients considering renal function; high-dosage antibiotics are used preferably for a short duration. Therefore, a highly detailed antimicrobial agent is necessary. However, some of the generic antibiotics have less antibacterial potency or solubility than the brand name products. We showed that the potency of the generic products of vancomycin and teicoplanin is lower than that of the branded drugs by 14.6 % and 17.3 %, respectively. Furthermore, we confirmed that a generic meropenem drug for injection required about 82 s to solubilize in saline, whereas the brand product required only about 21 s. It was thought that the cause may be the difference in size of bulk

  3. [Buddhist mummies in Japan].

    PubMed

    Morimoto, I

    1993-08-01

    The mummy of priest Kochi (preserved at Saishoji Temple, Teradomari, Niigata Pref.) has become famous, since it appeared in the book "Snow Country Tales" written by Bokushi Suzuki in 1841 (Fig. 1). In a country of high humidity, such as Japan, the belief that mummification could not, and did not, exist would not be altogether unfounded, but rather more a matter of common sense. There are two dozen Buddhist mummies in this country. It was not known until 1961 that a reliable source of artificial mummification has existed in Japan. The Japanese Buddhist mummies, apart from those of the Fujiwara family, a powerful clan of northeast Japan in the 12th century, dated mostly from the 17th to the 19th century as given in Table 1. Three principal types of mummification described by Vreeland, Jr. and Cockburn (1980) could be identified in the Japanese Buddhist mummies: type I, natural mummification; type II, intentional natural; and type III, artificial. Matsumoto (1990) classified the mummies into four groups, based on their ideological backgrounds: group A, mummies of the priests having faith in the Amitabha (the Supreme Buddha presiding over the Pure Land in the West); group B, sokushin-butsu mummies of the priests belonging to the Shingon sect of Japanese Buddhism founded by Kukai (Kobo-daishi); group C, nyujo mummies of the priests having faith in the Maitreya (the Buddha presiding over the Pure Land in the North, or the Buddha of the future); and group D, other mummies. These mummies of groups A, B, C and D are respectively listed in Table 2. Previous papers have shown that the mummies of the groups A, C and D belonged to the mummification of type I (natural mummification) or type II (intentional natural), whereas those of only the group B were of type III (artificial). The mummies of groups A to D were given as follows. a) Mummies of group A. The four mummies of the Fujiwara family in the Amitabha faith (preserved at Chusonji Temple, Hiraizumi, Iwate Pref.), which

  4. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Japan wax. 186.1555 Section 186.1555 Food and....1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan tallow or sumac wax, is a..., India, and Japan). Japan wax is soluble in hot alcohol, benzene, and naphtha, and insoluble in water...

  5. Nature of the Moho in Japan and Kamchatka

    NASA Astrophysics Data System (ADS)

    Iwasaki, Takaya; Levin, Vadim; Nikulin, Alex; Iidaka, Takashi

    2013-04-01

    The Kamchatka peninsula and the islands of Japan are located along the eastern margin of the Asian continent. The natures of the Moho in these areas have been studied for decades, with a variety of geophysical methods, including active and passive seismic methods, gravity and other techniques. The Moho and the upper mantle structures in the NE Japan and SE Japan Arcs have been investigated well both from active and passive seismic source studies. The Moho depth in the NE Japan is ranging from 30 to 40 km. Almost parallel to the present volcanic front, there exists a belt of deep Moho (34-36 km) with a lower Pn velocity (7.5-7.7 km/s). Amplitude analysis of the PmP phase indicates that the Moho beneath the NE Japan Arc is not a simple velocity contrast, but rather a gradual transition. Toward the backarc side, remarkable crustal thinning is recognized. Actually, the Moho depth decreases from 35 km beneath the central part of NE Japan to 18 km beneath the Sea of Japan. This thinning is evident in the upper crust, while the lower crust remains constant in thickness. This may be explained by the continuous magmatic underplating beneath the rifted crust or deformation under a simple shear mode, allowing the lower crustal thickness to remain unchanged. The Moho in the SW Japan Arc is also at a depth of 30-40 km. The Pn velocity is 7.7-7.8 km/s, slightly higher than that in the NE Japan, although this value was mostly sampled in the eastern half of the SW Japan Arc where the recent volcanic activity has been less effective. Fluids expelled from the subducted oceanic lithosphere (the PHS plate) play an important role in controlling the structure of the mantle wedge. As these fluids leak into the mantle wedge they induce serpentinization there, transforming original mantle materials to those of lower velocity and higher Vp/Vs. The crustal thinning of the SW Japan Arc is characterized by notable decrease in upper crustal thickness, which is similar to the case of the NE

  6. Aeromagnetic surveys in the seas around Japan in 1980

    NASA Astrophysics Data System (ADS)

    Utashiro, S.; Oshima, S.; Kaneko, T.

    1984-07-01

    Aeromagnetic surveys in the seas around Japan were carried out in 1979 to 1980 by a YS-11 aircraft of the Maritime Safety Agency of Japan using a new type of airborne magnetometer system. The new type of airborne magnetometer system consists of a ring-core type three-component fluxgate magnetometer, an inertial sensing system, a fish-eye camera to measure the true north, an 8-bit microcomputer and a proton magnetometer. The VLF/OMEGA system is used to fix the position of the aircraft. Tracks extended to about 600 nautical miles off the coast of the Japanese islands in the Sea of Japan and the North-West Pacific Ocean. Average spacing between tracks was about 80 miles. The flights were carried out at an altitude of 9500 feet. From the survey results, magnetic charts of the seven geomagnetic elements for 1980 over the sea around Japan were compiled by the method of least squares using a polynomial. Also, the contour charts of secular variation in 1980 were compiled.

  7. Constraints on the Moho in Japan and Kamchatka

    NASA Astrophysics Data System (ADS)

    Iwasaki, Takaya; Levin, Vadim; Nikulin, Alex; Iidaka, Takashi

    2013-12-01

    This review collects and systematizes in one place a variety of results which offer constraints on the depth and the nature of the Moho beneath the Kamchatka peninsula and the islands of Japan. We also include studies of the Izu-Bonin volcanic arc. All results have already been published separately in a variety of venues, and the primary goal of the present review is to describe them in the same language and in comparable terms. For both regions we include studies using artificial and natural seismic sources, such as refraction and reflection profiling, detection and interpretation of converted-mode body waves (receiver functions), surface wave dispersion studies (in Kamchatka) and tomographic imaging (in Japan). The amount of work done in Japan is significantly larger than in Kamchatka, and resulting constraints on the properties of the crust and the uppermost mantle are more detailed. Japan and Kamchatka display a number of similarities in their crustal structure, most notably the average crustal thickness in excess of 30 km (typical of continental regions), and the generally gradational nature of the crust-mantle transition where volcanic arcs are presently active.

  8. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  9. Use of microbial analysis to evaluate denitrification in the karstic aquifer of Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Yasumoto, J.

    2014-12-01

    Denitrification, a microbial process in the nitrogen cycle, is a facultative respiratory pathway in which nitrate (NO3-), nitrite (NO2-), nitric oxide (NO), and nitrous oxide (N2O), successively, are reduced to nitrogen gas (N2). This study explores the use of microbial analysis to evaluate the processes involved in nitrate attenuation in groundwater. Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) is used to identify denitrifiers based only on their 16SrRNA gene sequences, and Real-Time PCR analysis is used to quantify nitrite reducing genes (nirK and nirS), this suggest that a new methods for detecting denitrification activity by comparing the gene dosage that has been detected by RT-PCR and the value of the δ15NNO3- and δ18ONO3-. This study focuses on a zone of significant NO3- attenuation occurring at underground dam catchment area in the karstic Ryukyu limestone aquifer, which is located southern part of Okinawa, Japan. As a result of microbial analysis, the bacteria were detected at all observation points which have been reported to have denitrification ability. And it has been confirmed that the bacteria has a gene nirS which is related to denitrification. In addition, many bacteria related to denitrification have been extracted from suspended solids more than from groundwater in the aquifer. And, the correlation was high between nirK /nirS gene dosage that has been detected by RT-PCR and the value of the δ15N and δ18O; therefore, this study demonstrates the effectiveness of using Real-Time PCR analysis for providing insights into the processes affecting nitrate attenuation in ground water.

  10. Falkland Islands, UK

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view of the Falkland Islands (52.0S, 58.5W) was taken with a dual camera mount. Compare this scene with STS048-109-043 to analyze the unique properties of each film type. Seldom seen cloud free, the Falkland Islands lie off the southern coast of Argentina. The cold Falklands Ocean Current keeps the islands chilly, ideal for sheep herding and fishing, the two main industries. Colonies of seals and penguins also thrive on the islands.

  11. Arctic ice islands

    SciTech Connect

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  12. Diomede Islands, Bering Straight

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations.

    The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  13. The Social Sciences in Japan

    ERIC Educational Resources Information Center

    Watanuki, Joji

    1975-01-01

    This article relates a brief historical background of social sciences in Japan, the institutional framework of social science education and research, and major issues and perspectives for the development of the social scinces. (ND)

  14. Japan's launch vehicles

    NASA Astrophysics Data System (ADS)

    Kuroda, Y.; Hara, N.

    The development of Japan's Mu series scientific research launch vehicles, and N and H series practical applications vehicles, is described. The three-stage M-3C features a second-stage radio inertial guidance system. The evolution to the M-3S includes a first-stage TVC and Solid Motor Roll Control device, and eight 310-m strap-on boosters (SOB's). The M-3SII developed to launch an interplanetary satellite for the 1986 Halley's Comet apparition, employs two 735-mm SOB's and a microprocessor digitalized flight control system, and can put a 770 kg satellite into low earth orbit. The N-1 is a three-stage radio-guided vehicle using first and second stage liquid engines, a solid motor third stage, three SOB's, and having the capability to launch a 145 kg geostationary satellite. N-II improvements include a 350 kg geostationary payload capacity, nine SOB's, and an inertial guidance system. The H-1 planned for 1987 has a 550 kg geostationary payload capacity and a domestically developed cryogenic engine. The H-II planned for 1992 will be capable of launching a two-ton geostationary satellite, or LOX/LH2 plural satellites simultaneously. It will be powered by a single 95-ton thrust LE-7 main engine.

  15. Whistleblowing in Japan.

    PubMed

    Davis, Anne J; Konishi, Emiko

    2007-03-01

    This article, written from research data, focuses on the possible meaning of the data rather than on detailed statistical reporting. It defines whistleblowing as an act of the international nursing ethical ideal of advocacy, and places it in the larger context of professional responsibility. The experiences, actions, and ethical positions of 24 Japanese nurses regarding whistleblowing or reporting a colleague for wrongdoing provide the data. Of these respondents, similar in age, educational level and clinical experience, 10 had previously reported another nurse and 12 had reported a physician for a wrongful act. These data raise questions about overt actions to expose a colleague in a culture that values group loyalty and saving face. Additional research is needed for an in-depth understanding of whistleblowing, patient advocacy and professional responsibility across cultures, especially those that value group loyalty, saving face and similar concepts to the Japanese Ishin Denshin, where the value is on implicit understanding requiring indirect communication. Usually, being direct and openly discussing sensitive topics is not valued in Japan because such behavior disrupts the most fundamental value, harmony (wa). PMID:17425148

  16. Fusion Studies in Japan

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi

    2016-05-01

    A new strategic energy plan decided by the Japanese Cabinet in 2014 strongly supports the steady promotion of nuclear fusion development activities, including the ITER project and the Broader Approach activities from the long-term viewpoint. Atomic Energy Commission (AEC) in Japan formulated the Third Phase Basic Program so as to promote an experimental fusion reactor project. In 2005 AEC has reviewed this Program, and discussed on selection and concentration among many projects of fusion reactor development. In addition to the promotion of ITER project, advanced tokamak research by JT-60SA, helical plasma experiment by LHD, FIREX project in laser fusion research and fusion engineering by IFMIF were highly prioritized. Although the basic concept is quite different between tokamak, helical and laser fusion researches, there exist a lot of common features such as plasma physics on 3-D magnetic geometry, high power heat load on plasma facing component and so on. Therefore, a synergetic scenario on fusion reactor development among various plasma confinement concepts would be important.

  17. [Geobotanical studies on the island of Tanegashima (affinity of world property island Yakushima)].

    PubMed

    Satake, M; Kaburagi, K; Seki, T; Nozaki, T; Lee, I; Katsuki, S

    1999-01-01

    A list was drawn up of wild plants growing on Tanegashiama island that were identified in our field work, and the list was compared with the flora of the rest of Japan and the flora of Taiwan. There were 166 families and 1,218 species consisting of 23 families and 159 species of Pteridophyta, 4 families and 7 species of Gymnosperma, 113 families and 700 species of the dicotyledous Angiosperma, and 26 families and 353 species of monocotyledous Angiosperma. There are 229 families and 5,500 species of plants in Japan, 196 families and 3,019 species in Kyushu, and 228 families and 3,477 species in Taiwan. There are 11 species of endemic plants on Tanegashima and Yakushima, and the best known of them is Pinus armandii Francht. var. amamiana Hatsushima. There are 181 species of flora of flora limited to the northern element, including several important medicinal plants, such as Akebia quinata Decaisne and Zanthoxylum piperitum DC. The 69 species of flora limited to the southern element include several important tropical plants, such as Messerschmidia argentea Johnston and Clerodendrum inerme Gaertn. Most of these plants are distributed on both island, but some of are distributed only Tanegashima. We concluded that one of the temperate borderlines of Japanese flora in the temperate zone is the islands of Tokara. The flora of Tanegashima and Yakushima are having a closely affinity of plant species and having the rich plant species. PMID:10859935

  18. High definition systems in Japan

    NASA Astrophysics Data System (ADS)

    Elkus, Richard J., Jr.; Cohen, Robert B.; Dayton, Birney D.; Messerschmitt, David G.; Schreiber, William F.; Tannas, Lawrence E., Jr.; Shelton, Duane

    1991-02-01

    The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems.

  19. High definition systems in Japan

    NASA Technical Reports Server (NTRS)

    Elkus, Richard J., Jr.; Cohen, Robert B.; Dayton, Birney D.; Messerschmitt, David G.; Schreiber, William F.; Tannas, Lawrence E., Jr.; Shelton, Duane

    1991-01-01

    The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems.

  20. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Japan wax. 186.1555 Section 186.1555 Food and Drugs... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  1. Mt. Fuji, Japan

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] Click on image to view the movie

    The nearly perfectly conical profile of Fuji soars 3,776 meters (12,388 feet) above sea level on southern Honshu, near Tokyo. The highest mountain in Japan, Fuji is the country's most familiar symbol. The summit of this graceful, dormant volcano is broken by a crater 610 meters (2,000 feet) in diameter. The crater is ringed by eight jagged peaks. The five Fuji Lakes lie on the northern slopes of the mountain, all formed in the wake of lava flows. Mirrored in the still waters of Kawaguchi-ko, the most beautiful of the five lakes, is a reflection of Fuji. Part of Fuji-Hakone-Izu National Park, Fuji last erupted for a two-month period starting in November 1707, covering Tokyo, some 100 kilometers (60 miles) away, with a layer of ash. According to legend, Fuji arose from the plain during a single night in 286 BC. Geologically, the mountain is much older than this.

    Considered sacred by many, Fuji is surrounded by temples and shrines. Thousands of pilgrims climb the mountain each year as part of their religious practice, hoping to reach the summit by dawn to watch the sunrise. This animated fly-by was created by draping visible and near infrared image data over a digital topography model, created from ASTER's stereo bands. The spatial resolution of both the image and topography is 15 m. The image is centered at 35.3 degrees north latitude, 138.7 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  2. Quo Vadis, Japan. [Status of Japan's Nuclear Power Program

    SciTech Connect

    Not Available

    1993-08-01

    A pile of plutonium - 1.4 tonnes in all - was on board Japanese nuclear transport ship Akatsuki Maru when it left France on November 8, 1992 for Japan. Alongside it were Greenpeace's hostile and ever-vigilant boats and the great swells of public protest from around the world. Transports like this are likely to follow. But more to the tune of 30 to 40 tonnes of plutonium cargo is expected from the Japanese spent fuel that is separated at European reprocessing plants. Both Japanese utilities and governmental agencies have agreed that plutonium is to be fabricated into mixed oxide fuel (MOX) before being returned to Japan. But in the meantime, critics are accusing Japan of being one of the greatest threats to international safety. After the Akatsuki Maru spectacle, the Japanese civil nuclear program is awash in criticism and can not escape the watchful eye of the international community. Now, with Japan's parliamentary elections over and a review of its nuclear program just around the corner, the question is: Quo vadis, Japan

  3. Plate tectonics and crustal deformation around the Japanese Islands

    NASA Technical Reports Server (NTRS)

    Hashimoto, Manabu; Jackson, David D.

    1993-01-01

    We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Geodetic data are used to obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N deg 69 +/- 2 deg W at about 80 +/- 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.

  4. Ainu as a Heritage Language of Japan: History, Current State and Future of Ainu Language Policy and Education

    ERIC Educational Resources Information Center

    Teeter, Jennifer Louise; Okazaki, Takayuki

    2011-01-01

    Ainu is the heritage language of the indigenous people of present-day southern Sakhalin, the Kurile Islands, present-day Hokkaido, and northeastern Honshu (mainland Japan). The UNESCO Interactive Atlas of the World's Languages in Danger (2009) considered the Ainu language critically endangered with only 15 speakers remaining. This article…

  5. Psychotropic dose equivalence in Japan.

    PubMed

    Inada, Toshiya; Inagaki, Ataru

    2015-08-01

    Psychotropic dose equivalence is an important concept when estimating the approximate psychotropic doses patients receive, and deciding on the approximate titration dose when switching from one psychotropic agent to another. It is also useful from a research viewpoint when defining and extracting specific subgroups of subjects. Unification of various agents into a single standard agent facilitates easier analytical comparisons. On the basis of differences in psychopharmacological prescription features, those of available psychotropic agents and their approved doses, and racial differences between Japan and other countries, psychotropic dose equivalency tables designed specifically for Japanese patients have been widely used in Japan since 1998. Here we introduce dose equivalency tables for: (i) antipsychotics; (ii) antiparkinsonian agents; (iii) antidepressants; and (iv) anxiolytics, sedatives and hypnotics available in Japan. Equivalent doses for the therapeutic effects of individual psychotropic compounds were determined principally on the basis of randomized controlled trials conducted in Japan and consensus among dose equivalency tables reported previously by psychopharmacological experts. As these tables are intended to merely suggest approximate standard values, physicians should use them with discretion. Updated information of psychotropic dose equivalence in Japan is available at http://www.jsprs.org/en/equivalence.tables/. [Correction added on 8 July 2015, after first online publication: A link to the updated information has been added.]. PMID:25601291

  6. Hi-net: High sensitivity seismograph network, Japan

    NASA Astrophysics Data System (ADS)

    Obara, Kazushige

    The high sensitivity seismograph network in Japan (Hi-net), composed of around 600 seismic stations, is a part of the project made by ‘The Headquarter for Earthquake Research Promotion’ after 1995 Hyogoken-nanbu Earthquake and has been constructed and operated by National Research Institute for Earth Science and Disaster Prevention (NIED). Seismic stations are distributed homogeneously covering whole Japan Islands with an average spacing of 20 30 km. Three-component short period velocity seismometers are installed at the bottom of boreholes with depth of 100 m or deeper. Seismic data are digitized by 24-bit A/D converter and decimated to 27bit data with the sampling frequency of 100Hz. Stations are connected to the Hi-net data center, NIED in Tsukuba by a frame relay network service. TCP/IP and SNMP are used for data transmission and network management, respectively. The data are continuously transmitted to the data center and local offices of Japan Meteorological Agency for routine monitoring of seismic activity. The data receiving, monitoring, processing, and archiving system is controlled by a database management system in the data center. Event detection, phase picking, hypocentral determination, spectra analyses, and extracting waveform parameters are processed automatically. Event information and continuous waveform data are available through the world-wide-web.

  7. Y chromosomal DNA variation and the peopling of Japan.

    PubMed Central

    Hammer, M F; Horai, S

    1995-01-01

    Four loci mapping to the nonrecombining portion of the Y chromosome were genotyped in Japanese populations from Okinawa, the southernmost island of Japan; Shizuoka and Aomori on the main island of Honshu; and a small sample of Taiwanese. The Y Alu polymorphic (YAP) element is present in 42% of the Japanese and absent in the Taiwanese, confirming the irregular distribution of this polymorphism in Asia. Data from the four loci were used to determine genetic distances among populations, construct Y chromosome haplotypes, and estimate the degree of genetic diversity in each population and on different Y chromosome haplotypes. Evolutionary analysis of Y haplotypes suggests that polymorphisms at the YAP (DYS287) and DXYS5Y loci originated a single time, whereas restriction patterns at the DYS1 locus and microsatellite alleles at the DYS19 locus arose more than once. Genetic distance analysis indicated that the Okinawans are differentiated from Japanese living on Honshu. The data support the hypotheses that modern Japanese populations have resulted from distinctive genetic contributions involving the ancient Jomon people and Yayoi immigrants from Korea or mainland China, with Okinawans experiencing the least amount of admixture with the Yayoi. It is suggested that YAP+ chromosomes migrated to Japan with the Jomon people > 10,000 years ago and that a large infusion of YAP- chromosomes entered Japan with the Yayoi migration starting 2,300 years ago. Different degrees of genetic diversity carried by these two ancient chromosomal lineages may be explained by the different life-styles (hunter-gatherer versus agriculturalist). of the migrant groups, the size of the founding populations, and the antiquities of the founding events. Images Figure 1 PMID:7717406

  8. Y chromosomal DNA variation and the peopling of Japan.

    PubMed

    Hammer, M F; Horai, S

    1995-04-01

    Four loci mapping to the nonrecombining portion of the Y chromosome were genotyped in Japanese populations from Okinawa, the southernmost island of Japan; Shizuoka and Aomori on the main island of Honshu; and a small sample of Taiwanese. The Y Alu polymorphic (YAP) element is present in 42% of the Japanese and absent in the Taiwanese, confirming the irregular distribution of this polymorphism in Asia. Data from the four loci were used to determine genetic distances among populations, construct Y chromosome haplotypes, and estimate the degree of genetic diversity in each population and on different Y chromosome haplotypes. Evolutionary analysis of Y haplotypes suggests that polymorphisms at the YAP (DYS287) and DXYS5Y loci originated a single time, whereas restriction patterns at the DYS1 locus and microsatellite alleles at the DYS19 locus arose more than once. Genetic distance analysis indicated that the Okinawans are differentiated from Japanese living on Honshu. The data support the hypotheses that modern Japanese populations have resulted from distinctive genetic contributions involving the ancient Jomon people and Yayoi immigrants from Korea or mainland China, with Okinawans experiencing the least amount of admixture with the Yayoi. It is suggested that YAP+ chromosomes migrated to Japan with the Jomon people > 10,000 years ago and that a large infusion of YAP- chromosomes entered Japan with the Yayoi migration starting 2,300 years ago. Different degrees of genetic diversity carried by these two ancient chromosomal lineages may be explained by the different life-styles (hunter-gatherer versus agriculturalist). of the migrant groups, the size of the founding populations, and the antiquities of the founding events. PMID:7717406

  9. Ober's Island, One of the Review Islands on Rainy Lake, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  10. Back-arc Mantle Evolution inferred from Peridotite Xenotlishs from the Japan Sea

    NASA Astrophysics Data System (ADS)

    Morishita, T.; Ichiyama, Y.; Tamura, A.; Arai, S.

    2014-12-01

    Peridotite xenoliths are recovered in basaltic to andesitic lavas from several localities in the Japan Sea, a Miocene back-arc basin of the Western Pacific region. These peridotites are classified into two groups: two-pyroxene peridotitess and dunite-wehrlite groups. Although slight chemical modifications are observed in these peridotite samples, two-pyroxene peridotite group has retained their original residual mantle geochemical signatures left after partial melting. The dunite-wehrlite group is, on the other hand, probably formed by extensive interaction of the two-pyroxene peridotite group. We examined trace element characteristics of clinopyroxene in these xenoliths. Light REE-depleted clinopyroxenes that are usually interpreted as a simple residual mantle after anhydrous partial melting are similar to those of abyssal peridotite recovered from mid-ocean ridges and back-arc basins. Other samples show LREE-enriched patterns that are residues after influx melting caused by hydrous melt/supercritical fluids released from the subducted slab at high pressure conditions. The geotectonic and geochemical variations of the peridotite xenoliths from the Japan Sea (Shirabeshi Seamount, Seifu Seamount and Oshima-Oshima Island) suggest that the mantle beneath the Japan Sea are suffered from hydrous to anhydrous melting as the Japan Sea forms. This is consistent with the geochemical and isotopic results from Miocene basaltic rocks formed during opening of the Japan Sea (Sato et al., Jour. Petrol., 2013). The Japan Sea peridotite xenoliths also shed lights on the origin of ophiolites.

  11. FBIS report. Science and technology: Japan, April 10, 1996

    SciTech Connect

    1996-04-10

    ;Partial Contents: Biotechnology (Japan: Japan`s RITE Introduces Biotech Projects, Japan: Pharmacia Biotech Develops Detection Method for Point Mutation); Energy (Japan: New Catalyst for Synthesis Gas Reduces Energy Needs, Japan: Major Company Activities for Promotion of Wind Power Generation, Japan: Waste Power Generation System in Saitama Draws Much Attention); Environment (Japan: AIST`s NIMC To Develop Efficient Decomposition Method for Waste Using Super-Critial Water, Japan: Kyoei Co. Develops High Temperature Fusion Furnace for Industrial Waste Treatment, Japan: Air Dry Cleaning for Recycling Chemically Contaminated Plastic Sheets); Microelectronics (Japan: Toshiba Corp. DEC To jointly Develop LSI for ATM); Science and Technology Policy (Japan`s MITI To Begin Electronic Commerce Experiment Project); Technology Transfer (Japan: Nissho Iwai Delivers Cleaner Plant to Russia`s Energiya, Japan: Energy Agency Transfers Coal Fired Power Generation Technology to Indonesia); Telecommunications (Japan`s MPT Releases Study Report on Advanced Information Technologies).

  12. The educational system in Japan

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1986-01-01

    The rapid economic growth of Japan since World War II has resulted in Japan becoming a reference point for developing nations and the West. This remarkable growth results from a combination of factors, one of which has been unyielding attention to education in order to cultivate the human talent necessary to provide the productivity for economic growth. The Japanese education system emphasizes quality of instruction and rewards hard work. Some of the principles of the system are outlined together with a summary of the content of the curriculum, the quantity and quality of instruction, and the influence of culture and environment.

  13. Geothermal Field Developments in Japan

    SciTech Connect

    Hirakawa, Seiichi

    1983-12-15

    The present situation of the geothermal field developments in Japan is such that eight geothermal power stations are being operated, while there are sill many geothermal areas to be explored. Up to this day, the target of geothermal exploration has mainly been the areas by surface geological survey and the existing geothermal reservoirs are located not deeper than 1,500m depth. Recent geothermal energy development shows a trend from the study on vapor dominated of liquid dominated hydrothermal resources in shallow zones to that on hydrothermal resources in deeper zones. Exploration wells of 3,000m depth class have been drilled in Japan.

  14. A small island Taiwan makes a remote typhoon turn

    NASA Astrophysics Data System (ADS)

    Nakata, K.; Tachibana, Y.; Komatsu, K.; Hara, M.; Yamazaki, K.; Kodera, K.

    2015-12-01

    Typhoon (TC) Talas (2011), which caused Japan catastrophic disaster, landed the western part of Japan. The TC suddenly turned northwestward, and then landed on Japan. A reason for the occurrence of the disaster is that Japan Meteorological Agency (JMA) failed to predict the TC's sudden left turn, JMA predicted that the TC would not turn northwestward but would move northeastward. The actual course was opposite to the JMA numerical weather prediction. The timing when the TC started to turn northwestward was the same as another TC, Nanmadol, crossed Taiwan Island. Here we find that whether TC Nanmadol landed Taiwan Island or not determines whether the TC Talas turned left or not. If Nanmadol had not landed on Taiwan, Talas would not have landed on Japan. A small island controls the course of a remote TC. Therefore, the presence of the Island of Taiwan is important for the determination of the course of a typhoon. The utilization of two-way Weather Research and Forecasting (WRF) simulation with moving nesting, which allows the influence of a TC upon surrounding environmental large-scale atmospheric flow in comparison with one-way moving nesting shows that Talas remotely strengthened the subtropical high located to the east of Talas. This strengthened subtropical high somewhat blocked the eastward movement of Talas. In addition, Nanmadol remotely strengthened the high pressure system that was between Talas and Nanmadol. This strengthened high blocked westward movement of the Talas. The WRF showed that the deeper the typhoon developed, the stronger the high pressure system. When Nanmadol landed Taiwan, this remote strengthening of the high suddenly weakened because of decay of landed Nanmadol. The weakened high no longer blocked the westward movement of Talas. Therefore, Talas started to turn westward when Nanmadol landed on Taiwan. In some WRF members without landed on Taiwan, neither Nanmadol nor the high between Talas and Nanmadol did weakened. Also, Talas did not

  15. Geology of Northeast Part of Fukue Island, Goto Islands, Nagasaki Prefecture

    NASA Astrophysics Data System (ADS)

    Hasegawa, T.; Kiyokawa, S.; Yamamoto, A.; Hasebe, N.

    2007-12-01

    The Goto islands situated in the western part of Japan expose after Lower to Middle Miocene sedimentary and igneous rocks. The geologic evidences in this area are very important to identify relation between the north west of Kyushu and the Asian continent. We examined stratigraphy and geological structure of the Fukue Island of the southwest part of the Goto islands. Stritigraphy: In The Fukue Island, three lithofacies, Goto Group, Goto granite intrusion and Fukue Rhyolite are observed. Lower Goto Group consists of green colored volcaniclastics and massive tuff, based on the petrographic observation, there are very rounded quartz, siltstone listhic fragments and volcanic rock fragments. Upper Goto Group consists of alternation of sandstone and mudstone with upward grading structure, which is considered fluvial-lacustrine. And these were intruded by granitic dike. The Fukue Rhyolite is reported that the age is 12.4 ± 0.6Ma. Deformation: In center of the Fukue Island, there are about 10-20 degree plunges into north NE-SW trending fold, which is called "Goto central fold". In the northwest side of the fold hinge, high angle dipping beds and asymmetric fold are observed. On the other hand, in the southeast side of the fold hinge, dipping to east gentle bedding structure is observed. In the Fukue Island, the following three structures can be recognized. D1-a; NE-SW trending normal fault and fault related fold; The Goto center fold, which is one of the main structure in the deformation. D1-b; NE-SW trending west dipping normal fault and right lateral strike-slip fault. In the southwest region, the high angle bed formed by D1-a is bended from NE-SW trend to N-S by D1-b. D2; NW-SE trending normal fault and left lateral strike-slip fault. The trend of this structure is vertical to NE-SE trending of The Goto islands. Because of the cross cutting relationship, we consider that D1-a and D1-b were formed from 15 to 7 Ma, and D2 was formed in later 7Ma. Based on age data and

  16. Channel Islands rare plants

    USGS Publications Warehouse

    McEachern, K.

    1999-01-01

    Database contains information on 65 rare plant taxa on six islands from archive searches and field surveys, including population location, size and extent 1920-1999, population and habitat conditions, census data, phenological information, associated species. USGS-BRD, Channel Islands Field Station, Ventura, CA.

  17. Pine Island Bay

    Atmospheric Science Data Center

    2013-04-16

    ... article title:  Birth of a Large Iceberg in Pine Island Bay, Antarctica     View ... iceberg (42 kilometers x 17 kilometers) broke off Pine Island Glacier, West Antarctica (75°S latitude, 102°W longitude) sometime ...

  18. Marine and Island Ecology.

    ERIC Educational Resources Information Center

    Stephens, Lawrence J.; And Others

    1988-01-01

    Describes an ecology course which provides students with an opportunity to observe aquatic and terrestrial life in the Bahamas. States that students learn scientific methodology by measuring physical and chemical aspects of the island habitats. Provides information on the island, course description and objectives, transportation, facilities, and…

  19. Basaltic island sand provenance

    SciTech Connect

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  20. Back to Treasure Island

    ERIC Educational Resources Information Center

    Shriki, Atara

    2011-01-01

    In this article, the author presents the Treasure Island problem and some inquiry activities derived from the problem. Trying to find where pirates buried a treasure leads to a surprising answer, multiple solutions, and a discussion of problem solving. The Treasure Island problem is an example of an inquiry activity that can be implemented in…

  1. Island Natural Science School.

    ERIC Educational Resources Information Center

    Toronto Board of Education (Ontario).

    Prepared for students in grade six attending the Island Natural Science School, Toronto, Ontario, Canada, this booklet offers information and suggests activities in the areas of ecology, conservation, natural resources, and outdoor recreation. Introductory material describes island lore, its formation and significant features, followed by units of…

  2. Chloroplast DNA phylogeography of Photinia glabra (Rosaceae) in Japan.

    PubMed

    Aoki, Kyoko; Matsumura, Toshikazu; Hattori, Tamotsu; Murakami, Noriaki

    2006-12-01

    Climate changes during glacial periods have had significant effects on the present geographic distribution of plant species. To elucidate the evolutionary history of a plant species with a disjunctive distribution, we investigated the geographic distribution patterns of cpDNA haplotypes in Photinia glabra (Rosaceae) growing in broadleaved evergreen forests in Japan. We examined cpDNA in 42 populations of P. glabra sampled over a geographic range that included Kinki and its surrounding areas and the disjunctive regions in the Amakusa Islands. Both areas had unique cpDNA haplotypes. Moreover, the AMOVA revealed that a large proportion of the total variance (51%, P < 0.001) could be explained by differences among these regions. These results suggest a past fragmentation of this plant species into two separate refugia: southwestern Kyushu and Kinki, including the surrounding area, during the Quaternary glacial periods. A particularly interesting result was that in the southern disjunct distribution in the Amakusa Islands, the genetic subdivision (Φ(CT) = 1.00, P < 0.001) appears to lie between the populations from nearly contiguous islands located across a fairway only approximately 80 to 150 m in width. PMID:21642130

  3. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan tallow or sumac wax, is a pale yellow vegetable tallow, containing glycerides of the C19-C23...

  4. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan tallow or sumac wax, is a pale yellow vegetable tallow, containing glycerides of the C19-C23...

  5. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan tallow or sumac wax, is a pale yellow vegetable tallow, containing glycerides of the C19-C23...

  6. School Broadcast Utilization in Japan.

    ERIC Educational Resources Information Center

    Akiyama, Takashiro

    A school broadcast utilization survey was conducted between September and November 1975 from a total of 73,048 kindergartens, nurseries, primary schools, junior high schools, senior high schools, and special schools in Japan. Survey questions focused on the usage rates of TV, radio, and VTR as well as utilization of NHK's TV and radio school…

  7. How Japan Supports Novice Teachers

    ERIC Educational Resources Information Center

    Ahn, Ruth

    2014-01-01

    When U.S. educators first hear that Japanese teacher preparation programs require only four weeks of formal student teaching at the end of the credential program, they're appalled: How can this be? More surprising still, few new teachers in Japan (1.35 percent) leave the profession during their first year. So where are these beginning…

  8. Japan Studies Association Journal, 1998.

    ERIC Educational Resources Information Center

    Speaker, Richard B., Jr., Ed.; Kawada, Louise Myers, Ed.

    1998-01-01

    This journal presents new perspectives and materials on Japan that are engaging, relatively jargon-free, and shaped so that their usefulness in a college classroom is readily apparent. The journal represents an example of the potential for genuine scholarship that lies within interdisciplinary studies. Articles are divided among three thematic…

  9. Innovative shotcreting system in Japan

    SciTech Connect

    Okada, Takashi

    1995-12-31

    Robotization of shotcreting has advanced remarkably in Japan in a short span of time for the purpose of avoiding exposure of human workers to adverse conditions. This paper provides an overview of various devices used in shotcreting and discusses the development of improved systems which ensure higher safety and larger productivity.

  10. AERIAL MEASURING SYSTEM IN JAPAN

    SciTech Connect

    Lyons, Craig; Colton, David

    2012-01-01

    The U.S. Department of Energy National Nuclear Security Agency’s Aerial Measuring System deployed personnel and equipment to partner with the U.S. Air Force in Japan to conduct multiple aerial radiological surveys. These were the first and most comprehensive sources of actionable information for U.S. interests in Japan and provided early confirmation to the government of Japan as to the extent of the release from the Fukushima Daiichi Nuclear Power Generation Station. Many challenges were overcome quickly during the first 48 hours; including installation and operation of Aerial Measuring System equipment on multiple U.S. Air Force Japan aircraft, flying over difficult terrain, and flying with talented pilots who were unfamiliar with the Aerial Measuring System flight patterns. These all combined to make for a dynamic and non-textbook situation. In addition, the data challenges of the multiple and on-going releases, and integration with the Japanese government to provide valid aerial radiological survey products that both military and civilian customers could use to make informed decisions, was extremely complicated. The Aerial Measuring System Fukushima response provided insight in addressing these challenges and gave way to an opportunity for the expansion of the Aerial Measuring System’s mission beyond the borders of the US.

  11. Direct Broadcasting Satellites in Japan.

    ERIC Educational Resources Information Center

    Maeda, Jiro

    The development and use of broadcasting satellites in Japan are discussed in this paper. The paper describes the medium-scale experimental broadcasting satellite, YURI, launched by NASA in 1978, and reports that experiments with YURI in the areas of basic technologies in the broadcasting satellite system, experiments on satellite control…

  12. Teaching and Learning in Japan.

    ERIC Educational Resources Information Center

    Rohlen, Thomas P., Ed.; LeTendre, Gerald K., Ed.

    The essays gathered in this volume are united by the common goal of understanding teaching and learning in Japan as it actually occurs. The essays seek to answer questions about the actual conduct of learning in different settings and at different points in the life cycle. This volume explores the expectations and associations found in specific…

  13. Japan's Eco-School Programme

    ERIC Educational Resources Information Center

    Mori, Masayuki

    2007-01-01

    Since 1997, several ministries in Japan have collaborated on an eco-school programme, which applies to both newly constructed and renovated school buildings, in an effort to make its schools more environmentally friendly. The programme equips school buildings with ecological features such as photovoltaic cells, solar thermal collectors, other new…

  14. Japan: Images of a People.

    ERIC Educational Resources Information Center

    Smigielski, Alan; Casey, Douglas, Ed.

    1997-01-01

    This issue of "Art to Zoo" focuses on Japanese art and is adapted from materials developed by the education department of the Smithsonian Institution's Freer Gallery of Art and the Arthur M. Sackler Gallery. After learning how to look at paintings, students make paper screens that resemble Japanese screens. Background essays about Japan place the…

  15. The Japan of Today, 1982.

    ERIC Educational Resources Information Center

    Ministry of Foreign Affairs, Tokyo (Japan).

    Following an introduction which discusses the history and geography of Japan, this book focuses on topics related to this country's government, economy, social conditions, and cultural life. Topics related to government include: constitution and emperor; legislature; executive power; judiciary system; foreign relations; and defense. Topics related…

  16. Modernization of Education in Japan.

    ERIC Educational Resources Information Center

    National Inst. for Educational Research, Tokyo (Japan).

    The document traces the development of education in Japan from the 17th century to the present. It is presented in four chapters. Chapter one discusses the Tokugawa Period (1603-1867). Principal forms of schooling were hanko for the Samurai class and terakoya for the commoners. The hanko were established for the benefit of the fiefs; objectives of…

  17. Zoonotic filariasis caused by Onchocerca dewittei japonica in a resident of Hiroshima Prefecture, Honshu, Japan.

    PubMed

    Uni, Shigehiko; Boda, Tomoyuki; Daisaku, Koichi; Ikura, Yoshihiro; Maruyama, Haruhiko; Hasegawa, Hideo; Fukuda, Masako; Takaoka, Hiroyuki; Bain, Odile

    2010-09-01

    A female of Onchocerca sp. was found to be the probable causative agent of a subcutaneous nodule in the left knee of a 70-year-old man in a rural area of Hiroshima Prefecture, Honshu, the main island of Japan. We compared the characteristics of the agent with the features of the four previously suspected species found in cattle and horses in various parts of the world, as well as O. lupi and O. jakutensis that were suspected or proved, respectively, in zoonotic cases in Europe. In addition, the morphologic characteristics of this parasite were compared with those of the four Onchocerca species found in wild animals in Japan. Based on such characteristics as the large triangle ridges, the considerable distance between any two adjacent ridges, and the absence of inner cuticular striae in the longitudinal sections, we found the causative agent in the present case to be identical to the female of Onchocerca dewittei japonica. All five previous cases of zoonotic onchocerciasis in Japan had been found in Oita, Kyushu, the main southern island. This human case caused by O. dewittei japonica suggests that zoonotic onchocerciasis is liable to occur in rural areas in Japan where wild boar, Simulium vectors, and humans overlap. PMID:20561913

  18. 75 FR 38119 - Polychloroprene Rubber From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... from Japan (38 FR 33593). Following five-year reviews by the Department of Commerce (``Commerce'') and... imports of polychloroprene rubber from Japan (64 FR 47765, September 1, 1999). Following second five-year... antidumping duty finding on imports of polychloroprene rubber from Japan (70 FR 44893). The Commission is...

  19. Teaching about Japan: Lessons and Resources.

    ERIC Educational Resources Information Center

    Bernson, Mary Hammond, Ed.; Wojtan, Linda S., Ed.

    This document is a revised and updated version of two publications: "Modern Japan: An Idea Book for K-12 Teachers" and "Resources for Teaching About Japan." These lesson plans were developed by teachers who participated in a summer institute on Japan, sponsored by the East Asia Resource Center at the Jackson School of International Studies,…

  20. Historical Characteristics of Adult Education in Japan.

    ERIC Educational Resources Information Center

    Miyasaka, Kosaku

    In its modern sense, adult education in Japan began after the Meiji Restoration in 1868. Until 1945, adult education functioned as an agent to indoctrinate the nationalistic and military ideology. Since World War II, Japan has adopted the democratic social system and has become a capitalist society like the West. In Japan, social education is the…

  1. The US Occupation and Japan's New Democracy

    ERIC Educational Resources Information Center

    Kumano, Ruriko

    2007-01-01

    During the US Occupation of Japan (1945-1952), a victorious America attempted to reform Japanese education by replacing Japan's tradition system of values with one that promoted American democratic values. The United States had considered the source of Japan's militarism to lie in the selfless loyalty and love of country that many older Japanese…

  2. FBIS report. Science and technology: Japan, March 3, 1997

    SciTech Connect

    1997-03-03

    Partial Contents: JAPAN: Sumitomo Electric Industries Develops Exhaust Purification Equipment for Buses; JAPAN: Matsushita Battery to Market Next Generation Thin Film Solar Batteries by 2000; JAPAN: Hitachi, Toshiba Use Computer Networks to Build Nuclear Power Plants; JAPAN: Monju Incident Scars Not Yet Healed; JAPAN: Encryption Key Management Debate; and JAPAN: Military Infrared R&D Reviewed.

  3. Ober's Island: The Mallard Ober's Island, One of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island: The Mallard - Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  4. Japan`s nuclear weapons options and U.S. security interests

    SciTech Connect

    Sharman, C.H.

    1998-06-01

    Japan is a virtual nuclear weapons power. It has the scientific and technical ability to produce hundreds or even thousands of nuclear weapons, but has chosen not to do so for political reasons. This thesis examines the historical development of Japan`s nuclear energy and aerospace programs since the mid-1950s and considers the possibility that at various points in its history, Japan used these programs as a cover to insure that its nuclear weapons options remained open. This thesis analyzes internal and external factors that may have influenced Japan`s nuclear policies. External factors include regional threats, international pressures to join the Non-Proliferation Treaty, and distrust of US commitments to provide for Japan`s defense. Internal factors include Japan`s historical tradition of a strong military state and Japan`s unique nuclear allergy. While both external and internal factors have influenced the path of Japans nuclear energy and aerospace programs, internal factors will drive Japan to maintain its plutonium-based energy program and will allow Japan to remain a virtual nuclear power well into the twenty-first century.

  5. Impact of Historical Deforestation and Urbanization on Regional Climate in North Japan

    NASA Astrophysics Data System (ADS)

    Sato, T.; Sasaki, T.

    2011-12-01

    The Hokkaido Island located in North Japan has been experienced historical land use change since 150 years ago when Japanese began to develop. The original boreal forest in Hokkaido Island has been replaced by cropland, paddy field, and urban areas. This study aims to evaluate the impact of the historical land use/ land cover change on regional climate in Hokkaido area. Although the impact of deforestation on regional climate has been studied in many previous works, our knowledge on high-latitude areas with snow cover is still limited. Motivated with this fact, we conducted a dynamical downscaling experiment using regional climate model with two different vegetation map, namely original land cover and current land cover. Results in numerical experiments with different land cover maps indicate that difference in annual mean temperature is very small when it is averaged over whole island area. However, the prominent temperature differences are found over urban areas. The difference in annual mean temperature for urban area is 1.1 K due to the deforestation and urbanization effect which is very similar to those estimated using the observed trend. Therefore, we conclude that the recent urbanization in North Japan is a primary factor as well as large-scale climate change to cause rapid warming in big cities in Hokkaido Island.

  6. Threatened Pollination Systems in Native Flora of the Ogasawara (Bonin) Islands

    PubMed Central

    ABE, TETSUTO

    2006-01-01

    • Background and Aims Various alien species have been introduced to the Ogasawara Islands (Japan). A survey was made investigating whether the native pollination systems fit an ‘island syndrome’ (biasing the flora to dioecy, with subdued, inconspicuous flowers) and whether alien species have disrupted the native pollination network. • Methods Flower visitors and floral traits were determined in the field (12 islands) and from the literature. Associations among floral traits such as sexual expression, flower colour and flower shape were tested. • Key Results Among the 269 native flowering plants, 74·7 % are hermaphroditic, 13·0 % are dioecious and 7·1 % are monoecious. Classification by flower colour revealed that 36·0 % were white, 21·6 % green and 13·8 % yellow. Woody species (trees and shrubs) comprised 36·5 % of the flora and were associated with dioecy and white flowers. Solitary, endemic small bees were the dominant flower visitors and visited 66·7 % of the observed species on satellite islands where the native pollination networks are preserved. In contrast to the situation on the satellite islands, introduced honeybees were the most dominant pollinator (visiting 60·1 % of observed species) on the two main islands, Chichi-jima and Haha-jima, and had spread to satellite islands near Chichi-jima Island. • Conclusions The island syndrome for pollination systems in the Ogasawara Islands was evident in a high percentage of dioecious species, the subdued colour of the native flora and solitary flower visitors on satellite islands. The shape and colour adaptations of several flowers suggested native pollination niches for long-proboscis moths and carpenter bees. However, the domination and expansion of introduced honeybees have the potential for disruption of the native pollination network in the two main, and several satellite, islands of the Ogasawara Islands. PMID:16790463

  7. Cognitive Constraints and Island Effects

    ERIC Educational Resources Information Center

    Hofmeister, Philip; Sag, Ivan A.

    2010-01-01

    Competence-based theories of island effects play a central role in generative grammar, yet the graded nature of many syntactic islands has never been properly accounted for. Categorical syntactic accounts of island effects have persisted in spite of a wealth of data suggesting that island effects are not categorical in nature and that…

  8. Seismic-induced water waves by the March 2011 Japan earthquake

    NASA Astrophysics Data System (ADS)

    Lin, L.; Liang, W.; Liang, M.; Huang, N.

    2011-12-01

    On March 11, 2011, the Mw 9.0 Tohoku earthquake caused unusual water waves in many harbors. After about 10 minutes, significant changes in sea level were observed in the coastal regions of Taiwan. The event also induced seismic surface waves of ~7 cm displacement. The effects of earthquake on water bodies were examined in Taiwan, Japan and Russia. Results show the effect is more amplified at the islands than in the continental area. Other dominant features from this analysis are the roughly 20-40 cm amplitude, period of 2-5 minutes oscillations and ~20 cm amplitude of tsunami waves at the Orchid island of Taiwan. The superposition of two waves estimates the amplitude of roughly 40 cm at the island but has two different source mechanisms. Therefore, the real tsunami is overestimate and the arrival time for tsunami wave groups need to be adjusted. This study will focus on the forced waves caused by the passing of seismic waves.

  9. Water resources in the Japanese Islands

    NASA Astrophysics Data System (ADS)

    Takagi, T.

    2005-12-01

    Due to its limited land area and limited range of natural resources (particularly fuel), Japan has developed a highly efficient economy in terms of resource utilization. This also applies to water resources. For sustainable use of water resources in the Japanese Islands, integrated and unified analyses of the data of groundwater by the nation and local governments have been needed. Land area of the Japanese Islands is 377,000 square kilometers, which is equivalent to the area of the state of Montana, but extends for 3,600 kilometers along the margin of the Eurasian continent. Mountainous areas separated by isolated, narrow plains make up 80 % of the land area. Due to the topography of Japan, rivers are generally short with steep grades, the longest being only 367 kilometers in length. Average annual precipitation is 1,600 millimeters but is highly seasonal. The annual water demand was approximately 87 billion cubic meters during the past 25 years, which represents 21 % of the total usable water. The water demand for agriculture makes up 66 % of the total water demand, and 96 % of the water for agricultural uses is used for the irrigation of rice paddies. Municipal and industrial uses make up 15.4 and 18.9 % of the demand, respectively (as of 2000). Nearly 80 % of the water used by industry in recycled. Approximately 87 % of the water demand is supplied from surface water with the rest from ground water. Because of its mountainous topography, the extent of individual aquifers is far smaller than in United States. Groundwater basins in the Japanese Islands are classified into the following six types: plain type (thick Quaternary strata); basin type (intermontane terraces and fans; hill type (highly eroded old volcanoes); volcano type (permeable lava and pyroclasitc flows comprising Quaternary strato volcanoes); pyroclastic type (thick tuff associated with large caldera formations); and limestone type (limestone blocks with karsts). Of the above types, the only major

  10. DUPAL anomaly in the Sea of Japan: Pb, Nd, and Sr isotopic variations at the eastern Eurasian continental margin

    USGS Publications Warehouse

    Tatsumoto, M.; Nakamura, Y.

    1991-01-01

    Volcanic rocks from the eastern Eurasian plate margin (southwestern Japan, the Sea of Japan, and northeastern China) show enriched (EMI) component signatures. Volcanic rocks from the Ulreung and Dog Islands in the Sea of Japan show typical DUPAL anomaly characteristics with extremely high ??208/204 Pb (up to 143) and enriched Nd and Sr isotopic compositions (??{lunate}Nd = -3 to -5, 87Sr 86Sr = ~0.705). The ??208/204 Pb values are similar to those associated with the DUPAL anomaly (up to 140) in the southern hemisphere. Because the EMI characteristics of basalts from the Sea of Japan are more extreme than those of southwestern Japan and inland China basalts, we propose that old mantle lithosphere was metasomatized early (prior to the Proterozoic) with subduction-related fluids (not present subduction system) so that it has been slightly enriched in incompatible elements and has had a high Th/U for a long time. The results of this study support the idea that the old subcontinental mantle lithosphere is the source for EMI of oceanic basalts, and that EMI does not need to be stored at the core/ mantle boundary layer for a long time. Dredged samples from seamounts and knolls from the Yamato Basin Ridge in the Sea of Japan show similar isotopic characteristics to basalts from the Mariana arc, supporting the idea that the Yamato Basin Ridge is a spreading center causing separation of the northeast Japan Arc from Eurasia. ?? 1991.

  11. Japan's research on gaseous flames

    NASA Technical Reports Server (NTRS)

    Niioka, Takashi

    1995-01-01

    Although research studies on gaseous flames in microgravity in Japan have not been one-sided, they have been limited, for the most part, to comparatively fundamental studies. At present it is only possible to achieve a microgravity field by the use of drop towers, as far as gaseous flames are concerned. Compared with experiments on droplets, including droplet arrays, which have been vigorously performed in Japan, studies on gaseous flames have just begun. Experiments on ignition of gaseous fuel, flammability limits, flame stability, effect of magnetic field on flames, and carbon formation from gaseous flames are currently being carried out in microgravity. Seven subjects related to these topics are introduced and discussed herein.

  12. Fruit harvesting robots in Japan.

    PubMed

    Kondo, N; Monta, M; Fujiura, T

    1996-01-01

    We have developed harvesting robots for tomato, petty-tomato, cucumber and grape in Japan. These robots mainly consist of manipulators, end-effectors, visual sensors and traveling devices. These mechanisms of the robot components were developed based on the physical properties of the work objects. The robots must work automatically by themselves in greenhouses or fields, since we are considering for one operator to tend several robots in the production system. The system is modeled after Japanese agriculture which is commonly seen to produce many kinds of crops in greenhouses and in many small fields intensively. Bioproduction in space is somewhat similar to the agricultural system in Japan, because few operators have to work in a small space. Employing robots for bioproduction in space is considered desirable in near future. The following is a description of the harvesting robots. PMID:11538961

  13. Belcher Islands, Canada

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Belcher Islands are an archipelago in Hudson Bay in Canada, belonging to the territory of Nunavit. The hamlet of Sanikiluaq is on the north coast of Flaherty Island. Over 1500 islands make up the archipelago. The folded sedimentary and volcanic rocks making up the islands are Proterozoic in age between 0.5 and 2.5 billion years old.

    The image mosaic was acquired 18 September 2006, covers an area of 45.7 x 113.3 km, and is located near 56.1 degrees north latitude, 79.4 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  14. Lost island found

    NASA Astrophysics Data System (ADS)

    An abandoned ll-by-5-km kidney-shaped chunk of freshwater ice, used as a research station for 25 years, was rediscovered after the National Oceanic and Atmospheric Administration (NOAA) lost track of the island for 6 months. The recent find may foreshadow another loss, however: The island is drifting through the Greenland Sea and into the North Atlantic where it should melt within several months and d u m p its cargo of oil drums, equipment, and a wrecked plane into the ocean.Known as Fletcher's Ice Island—after Joseph O. Fletcher, a member of the first team of researchers to inhabit the island and a recently retired NOAA climate researcher—the ice chunk has already melted to a third of its original 49 m thickness. A pilot flying over the area to measure annual pollution buildup in the Arctic located the drifting island 242 km from the North Pole near the International Date Line.

  15. The Island Approach.

    ERIC Educational Resources Information Center

    Schroder, Peter C.

    1994-01-01

    Proposes the study of islands to develop a method of integrating sustainable development with sound resource management that can be extrapolated to more complex, highly populated continental coastal areas. (MDH)

  16. Island Watershed Activity.

    ERIC Educational Resources Information Center

    Benson, Rod

    2003-01-01

    Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

  17. Small islands adrift

    NASA Astrophysics Data System (ADS)

    Petherick, Anna

    2015-07-01

    With the charismatic former president of the Maldives, Mohamed Nasheed, behind bars on a widely derided terrorism charge, Anna Petherick asks whether small island states can really make themselves heard in Paris.

  18. Commencement of Geoparks, Geology day and International Earth Science Olympiad, IYPE in Japan

    NASA Astrophysics Data System (ADS)

    Tsukuda, Eikichi; Kodama, Kisaburo; Miyazaki, Teruki

    2010-05-01

    The GSJ is the main supporting organization of IYPE Japan, which is an implementation body of IYPE in Japan, serving as its secretariat. During the IYPE triennial activity, the GSJ has been supporting development of Geparks, establishment of "the Geology Day" and the Earth Science Olympiad activities with some academic societies, and has distributed geological maps with IYPE logo. The GSJ also established an outreach network "Geo-networks Tsukuba" as a local legacy of the IYPE, and has managed it with a local government, research organizations, nonprofit corporations and local media to increase geological and environmental literacy of public, especially among young people. The GSJ-AIST has also contributed internationally to IYPE by joining two international projects, OneGeology and the CCOP Book project. Geoparks in Japan are characterized by following features. The Japanese Islands and the surrounding seas are situated in the area of unique geologic features; the place where several tectonic plates meet and collide. This causes earthquakes and volcanic activities, and makes Japan one of most dynamic areas on the earth. The dynamics of the earth bring about not only geological hazards but also a lot of blessings. In August of 2009, three Geoparks, the Toya Caldera and Usu Volcano Geopark, the Itoigawa Geopark and the Unzen Volcanic Area Geopark, were accepted to join the Global Geopark Network from Japan for the first time. Since its launch in 2006, the GSJ has been playing a major role in promoting Geoparks in Japan together with Geological Society of Japan. The GSJ hosts the Japan Geopark Committee (JGC) for quality evaluation, serving as the information center of Geoparks in Japan. The Geology Day of Japan (10th of May) has been set up by the academic societies for geology in Japan and GSJ in 2007. The Geology Day is expected to provide the chances for the public to enjoy field trips and excursions and to understand the importance of geo-diversity. The Day

  19. Relationship of the crustal structure and its deformation from arc to back-arc basin in the eastern Japan Sea deduced from the seismic survey

    NASA Astrophysics Data System (ADS)

    Sato, Takeshi; No, Tetsuo; Miura, Seiichi; Kodaira, Shuichi; Sato, Hiroshi

    2015-04-01

    The Japan Sea is a back-arc basin in the northwestern Pacific. Based on geophysical, geological, and petrological results, it is suggested that the opening of the Japan Sea was initiated by crustal rifting and the separation of Japan Island arcs from the Asian continent in the Early Oligocene, followed by the ocean floor spreading in the Late Oligocene (e.g., Tamaki et al., 1992). After 3.5 Ma, the crustal shortening by a strong compression occurred in the eastern margin (e.g., Sato, 1994). In the eastern margin, because of the extension associated with the opening of the Japan Sea and this shortening, the deformation such as active faults and folds formed have developed and large earthquakes with magnitudes-7 class repeatedly occurred (e.g., Okamura et al., 2007). The Japan Sea has a unique setting in terms of the connection between the back-arc basin opening and the crustal deformation. However, we have little information concerning with a crustal structure formed by the back-arc opening in the margin and the deformation. To obtain the information, we have been carrying out active-source seismic surveys using ocean bottom seismographs (OBSs) and multi-channel streamer system (MCS) to cover the eastern margin of the Japan Sea. The obtained results show a difference in crustal structures between the northern and the southern parts of the eastern Japan Sea. In the northern part from the arc to the back-arc basin, the crust is divided into three types; the rifted island arc crust, the thicker oceanic crust and the oceanic crust, based on the comparison of the P-wave velocity distribution and the crustal thickness of a typical oceanic crust (White et al., 1992) and of the northeastern Japan Island arc crust (Iwasaki et al., 2001). On the other hand, the southern part from the arc to the back-arc basin has two crustal types, which are the rifted island arc crust and the thicker oceanic crust. In the northern part, the deformation is distributed in a structural boundary

  20. Melville Island, Australia

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Melville Island, just off the coast of Darwin, Northern Territory, Australia (11.5S, 131.0E) is a sparsely inhabited tropical island with heavy woodland concentrations. The widespread and prominant smoke plumes were most likely set to renew pasture under open canopy woodland. Soil erosion is almost non- existant as can be seen by the clear and clean river flow. The offshore sediments are coastal current borne deposits from King Sound to the west.

  1. Investigations of The Structure of Mesoscale Convective Systems Over The Sea of Japan

    NASA Astrophysics Data System (ADS)

    Mezrin, M. Yu.; Starokoltsev, E. V.; Fujiyoshi, Yasushi

    Under the Joint Research Agreement between the Central Aerological Observatory of the Russian Federal Service for Hydrometeorology and Environmental Monitoring, Russia (CAO) and Japan Science and Technology Corporation, Japan (JST), investigations of the structure and formation/development mechanisms of mesoscale convective systems in the Sea of Japan area were carried out in January- February 2001 from board a Russian research aircraft IL-18. The aircraft was equipped with navigation and research instruments to investigate diverse atmospheric and cloud parameters, including instrumentation to study turbulent transport of moisture, heat, etc. The meteorological situation was characterized by a surge of cold, dry continental air to the rear of a cold front (i.e., from Siberia to the open surface of the Sea of Japan). Horizontal measurements were made during flights at altitudes of 100, 500, 1500, and 3000 m, between Vladivistok, Russia, and Sado Island of Japan. As a result of the investigations of turbulent moisture transport at a 100-m level, mesostructure features of the transport were observed having a horizontal scale of about 30 km and an amplitude of about 0.100 g/m2s. The shape and magnitude of such features repeated at a 500-m level, their position shifting windward with time. This phenomenon was evidently caused by cylindrical convection, whose spatial structure showed in the arrangement of cloud streets formed at a 1500-m level. Satellite pictures of the cloud streets were used.

  2. Bathymetry Mapping Using Hyperspectral Data: a Case Study of Yamada Bay, Northeast Japan

    NASA Astrophysics Data System (ADS)

    Ariyasu, E.; Kakuta, S.; Takeda, T.

    2016-06-01

    This study aims to examine if the inversion method using hyperspectral data is applicable in Japan. Nowadays, overseas researchers are mainly applied an inversion method for accurately estimating water depth. It is able to gain not only water depth, but also benthic spectral reflection and inherent optical properties (IOPs) at the same time, based on physics-based radiative transfer theory for hyperspectral data. It is highly significant to understand the possibility to develop the application in future for coastal zone of main island, which is a common water quality in Japan, but there is not any case study applied this method in Japan. The study site of Yamada bay in Iwate Prefecture is located in northeast of Japan. An existed analytical model was optimized for mapping water depth in Yamada bay using airborne hyperspectral image and ground survey data which were simultaneously acquired in December, 2015. The retrieved remote-sensing reflectance (Rrs) is basically qualitatively appropriate result. However, when compared with all ground survey points, the retrieved water depth showed low correlation, even though ground points which are selected sand bottom indicates high relationship. Overall, we could understand the inversion method is applicable in Japan. However, it needs to challenge to improve solving error-caused problems.

  3. Polymer composites technology in Japan

    SciTech Connect

    Karbhari, V.M.; Kukich, D.S. . Center for Composite Materials)

    1993-08-01

    In 1992, the National Science Foundation, Department of Energy, Army Research Office, and Air Force Office of Scientific Research convened a panel to assess advanced manufacturing technology for polymer composite structures in Japan. The panel was charged with comparing the levels of the technology and the industry in both the United States and Japan. The Panel on Advanced Polymer Composites Manufacturing Technology of the Japanese Technology Evaluation Center visited approximately twenty Japanese organizations over a ten-day period in December 1992. Their findings cover seven areas: aerospace, sporting goods, automotive, civil engineering, materials, manufacturing science, and product and process development methods. This report reflects the views of the authors, not necessarily those of the entire panel. The panel observed five emerging techno-paradigm shifts in Japan, previously identified by Kodama: Manufacturing companies; Business dynamics; R and D activities; Technology development; and Technology diffusion. Thus, what the panel observed in the specific area of advanced materials really reflects the overall Japanese approach to technology development. Their primary focus is on finding innovative new applications for existing materials, processes, and technologies, and on using these market opportunities to drive new development.

  4. FBIS report. Science and technology: Japan, December 10, 1996

    SciTech Connect

    1996-12-10

    Contents (partial): Japan: Fabrication of Diamond Single Crystal Thin Film by Ion Beam Deposition; Japan: Hitachi Metal Develops New Semi Solid Metal Processing Technology; Japan: NTT Develops Fuel Cell System That Uses Both City Gas, LPG; Japan: Daihatsu Motor Completes Prototype EV; Japan: NIRIM Announces Success With Synthetic Bone Development; Japan: Sandoz Pharmaceuticals Plans Clinical Trials of Gene Therapy to Cerebral Tumor in Japan; Japan: MITI To Provide Aid for Residential Solar Power Generation Systems; Japan: MELCO To Provide Satellite Solar Cell Panel for SSL, USA; Japan: Japan Atomic Energy Research Institute Leads Nuclear Research; Japan: Kobe Steel`s Superconducting Magnet Ready to Go Fast; Japan: MPT To Begin Validation Test for Electric Money Implementation; and Japan: Defense Agency to Send ASDF`s Pilots to Russia for Training.

  5. FBIS report. Science and technology: Japan, December 3, 1996

    SciTech Connect

    1996-12-03

    Contents (selected articles): Japan: Nissan To Use Nickel-Hydrogen Battery in EV; Japan: Takii To Commercialize Cauliflower-Broccoli Hybrid; Japan: Kawasaki Steel Improves Recovery of Metals from Furnace Residue; Japan: Japan`s NEC Corp. To Develop Cost-Effective Photodection Chip; Japan: Japanese Companies Establish Research Association to Develop 16-gigabit DRAMS; Japan: Safe Operation of Nuclear Power Plants, Actual Achievements; Japan: Future for Nuclear Fuel Recycle as a Result of Monju Accident; Japan: Superconducting Magnet System Using No Liquid Helium; Japan: Hitachi`s MULTI Network Security Technologies; Japan: Defense Bureau Chief Tokita Interviewed; Japan: DRC Executive on GSDF, High Technology; and Japan: Retired Admiral on Post-Cold War MSDF Strategy.

  6. FBIS report. Science and technology: Japan, May 7, 1996

    SciTech Connect

    1996-05-07

    ;Partial Contents: Japan: FH1 Aerospace Division Executive on UAV R&D; JapaN: MHI Delivers First F-2 Flight Test Model; Nuclear Technologies; Japan: Nuclear Material Research in Cross-Over Research Project; Japan: MITI To Subsidize Development of Cryptography; Defense Industries; Japan: JADI Announces FY96 Major Events Schedule; Japan: Rollout Ceremony Held for First OH-X Flight Test Model; and Japan: KHI Weapons Designer OH-X Development.

  7. Late Cretaceous and Eocene volcanism in the southern Line Islands and implications for hotspot theory

    NASA Astrophysics Data System (ADS)

    Haggerty, Janet A.; Schlanger, Seymour O.; Premoli Silva, Isabella

    1982-08-01

    Rocks dredged from a seamount 100 km northwest of Caroline Island, at the southern end of the Line Islands chain, contain Late Cretaceous fossils associated with volcanic debris. This association is evidence for the existence of a reef-bearing volcanic edifice with a minimum age of Late Cretaceous, 70 to 75 m.y., near Caroline Island. With the discovery of this seamount, the known occurrences of Late Cretaceous, reef-capped, volcanic edifices now extend a distance of 2,500 km, from Deep Sea Drilling Project Site 165 to 100 km northwest of Caroline Island. The apparent synchroneity of Late Cretaceous volcanism over this distance argues against the proposition that a single hotspot of the Hawaiian-Emperor type produced the Line Islands chain. Biochronologic data from the Line Islands indicate that the chain is not the temporal equivalent of the Emperor chain. Volcanic edifices of Cretaceous age are now known to extend from the Line Islands through the Mid-Pacific Mountains to the Marshall Islands and the western margin of the Pacific plate from Japan to the Marianas. A volcanic event occurred in the southern Line Islands during middle Eocene time; Eocene sediments were engulfed and altered by a volcanic eruption. The occurrence of both Cretaceous and Eocene volcanism in the southern Line Islands indicates that the history of the Line Islands is similar to that of the Marshall Islands. *Present addresses: (Haggerty) Department of Geosciences, University of Tulsa, Tulsa, Oklahoma 74104; (Schlanger) Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201

  8. Impact Materials of Takamatsu Crater in Japan

    NASA Astrophysics Data System (ADS)

    Miura, Y.; Okamoto, M.; Fukuchi, T.

    1995-09-01

    Shocked quartz materials have been found in Japanese K.T boundary (Hokkaido) and mountains of middle main-islands of Japan, though there are few direct evidence of "natural circular structure" on the surface in Japan. However circular structure has been recently found as a buried crater(up to 150m deep) [1] which is ca. 4km in diameter with -10 mgal of Bouguer gravity anomaly from surrounding Rhyoke granitic region of the southern part of Takamatsu City, Kagawa Prefecture, northeast Shikoku, Japan [1,2,3]. Two boring cores of 300m deep near small mountains inside the crater could not reach the bottom of the crater so far. From model calculation of the negative gravity anomaly, the Takamatsu crater shows deep basin structure up to 1.4km. If the Takamatsu crater is considered to be only impact crater, it is difficult to discuss only surface materials on the crater. But anomalous minerals are found only around small volcanic intrusions inside the crater, which the mixed minerals are clearly different with those of other volcanic intrusions of the Yashima and Goshikidai outside the crater [1,2,3]. The small volcanic intrusions are not origin of large Takamatsu crater, because the small volcanic intrusions are found on whole areas of Kagawa Prefecture. Major different activity of the small intrusions inside the crater is to bring the brecciated materials of the interior (esp. crater sediments). The xenolith materials around only volcanic intrusion of andesite are divided into the following four major mineral materials:(a) round pebble fragments from the Rhyoke granitic basement (Sampling No.15), (b) rock fragments from intruded biotite andesites (Nos. 2,15), (c) impact-induced fragments of shocked Quartz grains (Nos. 2,3,6,15), diaplectic feldspars (Nos. 2,3,6,15), silica glasses (Nos. 2,15) and small Fe-Ni metallic grains (No.15), and (d) small sedimentary fragments of halite and mordenite, as listed in Table 1. Table I, showing the characterization of surface samples

  9. Impacts of Long-Range Transport of Metals from East Asia in Bulk Aerosols Collected at the Okinawa Archipelago, Japan

    NASA Astrophysics Data System (ADS)

    A, Sotaro; S, Yuka; I, Moriaki; N, Fumiya; H, Daishi; A, Takemitsu; T, Akira

    2010-05-01

    Economy of East Asia has been growing rapidly, and atmospheric aerosols discharged from this region have been transported to Japan. Okinawa island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km of south Korea. Its location in Asian is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air mass which has been affected by anthropogenic activities. Therefore, Okinawa region is suitable area for studying impacts of air pollutants from East Asia. We simultaneously collected bulk aerosol samples by using the same type of high volume air samplers at Cape Hedo Atmospheric Aerosol Monitoring Station (CHAAMS, Okinawa island), Kume island (ca. 160 km south-west of CHAAMS), and Minami-Daitou island (ca. 320 km south-east of CHAAMS). We determined the concentrations of acid-digested metals using atomic absorption spectrometer and inductively-coupled plasma mass spectrometry (ICP-MS). We report and discuss spatial and temporal distribution of metals in the bulk atmospheric aerosols collected at CHAAMS, Kume island and Minami-Daitou island during June, 2008 to June 2009. We also determined 'background' concentration of metals in Okinawa archipelago. We then compare each chemical component among CHAAMS, Kume island and Minami-Daitou island to elucidate the influence of the transport processes and distances from Asian continent on metal concentrations.

  10. Upwelling process of mantle helium in northeast Japan

    NASA Astrophysics Data System (ADS)

    Horiguchi, K.; Kazahaya, K.; Tsukamoto, H.; Morikawa, N.; Ohwada, M.; Nakama, A.

    2014-12-01

    Northeast Japan has an island arc structure where the Pacific plate subducts from the east. The helium isotope ratio is a good indicator to discriminate the origin of fluid carring helium, because the ratios in the mantle and crust are clearly different from each other. We performed a detailed study of helium isotope ratios in northeast Japan, and clarified the boundaries of the higher and lower helium isotope ratio distributions. The crustal components are dominant in the fore-arc region, whereas the mantle components dominate along the volcanic front and in the back-arc region. It is suggested that the clear contrast of the helium isotope ratio between the fore-arc and back-arc regions is due to the difference in whether helium isotope ratio of the wedge mantle or radiogenic helium-4 production rate in the crust. Specifically, we found the following characteristics; 1) comparison of the distribution between helium isotope ratios and faults revealed that the area along faults shows higher helium isotope ratios, 2) distribution of the helium isotope ratios is correlated with that of Li/Cl ratios which is the indicator of slab-derived water or magmatic water, suggesting that the mantle helium is transported by the slab-derived aqueous fluid. Important constraints on mantle helium upwelling are concluded as follows; a) the slab-derived water as the carrier of mantle helium, b) the faults, tectonic lines and volcanoes as the flow paths of slab-derived water, and c) crustal helium-4 contamination during upwelling process. *This research project has been conducted as the regulatory supporting research funded by the Secretariat of Nuclear Regulation Authority (Secretariat of NRA), Japan.

  11. Us-Japan cooperation on safeguards

    SciTech Connect

    Beddingfield, David H; Menlove, Howard O; Hori, Masato; Kawakubo, Yoko; Mcclelland - Kerr, J

    2009-01-01

    There is a long history of collaborative safeguards development between the United States and Japan. Japan has built, and continues to expand, the largest civil nuclear fuel cycle under full-scope IAEA safeguards in world. This development has posed unique challenges to the international safeguards system. Safeguards developments made through the US-Japan cooperation to address these unique challenges have significantly impacted the technologies deployed for international safeguards applications around the world.

  12. Heron Island, Australia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

  13. Spatial heterogeneities of deviatoric stress and pore-pressure in Kyushu, Japan, and their implication for seismic activity

    NASA Astrophysics Data System (ADS)

    Matsumoto, Satoshi; Chikura, Hiromi; Ohkura, Takahiro; Miyazaki, Masahiro; Shimizu, Hiroshi; Abe, Yuki; Inoue, Hiroyuki; Yoshikawa, Shin; Yamashita, Yusuke

    2013-04-01

    We investigated the spatial variation in stress fields and pore fluid pressures on Kyushu Island, southwestern Japan. High seismic activity is found not only along active faults in Kyushu Island (southwestern Japan) but also in the central area of the island where there are active volcanoes. We consider the focal mechanisms of the shallow earthquakes on Kyushu Island to determine the relative deviatoric stress field and pore fluid factor. Generally, the stress field corresponds to a strike slip regime in this area. A decline in the maximum principal compressional stress is found in the western part of the high seismicity area, in the middle of Kyushu Island; this may be caused by a thickening of the seismogenic zone, as estimated from D90 analysis. At thin seismogenic layer, strike slip faulting dominates and strain rate from GPS study is high. In the active fault zone, seismic activity along the fault is high, and the pore pressure within the zone is higher than the values observed elsewhere, suggesting a mechanism explained by the fault valve model of Sibson [1992]. The pore pressure in the high seismic area with scattered hypocenter distribution in the middle part is lower than that in the active fault zones.

  14. Children in Japan and multimedia.

    PubMed

    Shimauchi, Y

    1999-01-01

    Many parents in Japan today are very concerned and have daily problems with their children over the following kind of issues concerning video games, multimedia, and similar devices. 1) Is children's enthusiasm for video games actually harming their growth (physically or mentally)? 2) Is there any way that video games can help children in the future? For example, will playing these games help children learn to use computers or develop their power of thought? 3) Will excessive enthusiasm for TV games undermine our basic lifestyle? Is the time they spend studying at home or playing outside actually decreasing? 4) Will the methods of communication brought about by computers, pagers, and cellular phones weaken human relations among children? 5) Will being immersed in a virtual world created by computers result in a diminished sense of reality? The causes of this uneasiness may be traced to parents' own anxieties and concerns about the exceedingly rapid growth of the "information society" of today, together with the fact that their children are directly caught up in the deluge of this information and multimedia society. The development of media has coincided with the growth of today's adults, but children are immersed in a media-filled environment from the day they are born. In Japan, there are now children who can play video games before even learning to write. No one can predict what kind of adults these children will grow to be in the future, and it is fair to say that the most parents and children in Japan are being tossed about on the waves of this information explosion. At this international symposium, we hope to hear the many views that are held around the world concerning children and multimedia. PMID:10770069

  15. Recent cryocooler progress in Japan

    NASA Astrophysics Data System (ADS)

    Matsubara, Y.

    1985-05-01

    The progress of cryocoolers and related devices in Japan is reviewed. The Japanese National Railways has developed the light weight 4 K on-board refrigerators since 1977 as part of the MAGLEV train program. Superconducting and cryogenic fundamental technology was examined which included high performance cryocooler, magnetic refrigerator and superfluid refrigeration. Space cryogenics such as the cooling systems of IR-detectors was studied. Cryocooler for special applications such as cryopump, NMR-CT and JJ devices was investigated. Compact heat exchangers, high performance regenerators and reliable compressors are investigated as a critical component technology.

  16. Solid waste management in Japan

    SciTech Connect

    Naito, S.

    1995-09-01

    On Friday 17 June 1994, as the invited speaker of the International Congress of IWM/ISWA at Torbay, UK the author presented a paper of {open_quotes}A framework for success: the role of legislation{close_quotes}. THis was to introduce the amendment of Waste Disposal Cleansing Law and the Basic Environment Law in 1991, but the combination of the two amended laws has enforced promoting and assisting the fulfillment of the responsibilities of corporations and citizens. In addition to such presentation, the author pointed out a new manner of solid waste management (SWM) in Japan.

  17. Maintenance of biodiversity on islands.

    PubMed

    Chisholm, Ryan A; Fung, Tak; Chimalakonda, Deepthi; O'Dwyer, James P

    2016-04-27

    MacArthur and Wilson's theory of island biogeography predicts that island species richness should increase with island area. This prediction generally holds among large islands, but among small islands species richness often varies independently of island area, producing the so-called 'small-island effect' and an overall biphasic species-area relationship (SAR). Here, we develop a unified theory that explains the biphasic island SAR. Our theory's key postulate is that as island area increases, the total number of immigrants increases faster than niche diversity. A parsimonious mechanistic model approximating these processes reproduces a biphasic SAR and provides excellent fits to 100 archipelago datasets. In the light of our theory, the biphasic island SAR can be interpreted as arising from a transition from a niche-structured regime on small islands to a colonization-extinction balance regime on large islands. The first regime is characteristic of classic deterministic niche theories; the second regime is characteristic of stochastic theories including the theory of island biogeography and neutral theory. The data furthermore confirm our theory's key prediction that the transition between the two SAR regimes should occur at smaller areas, where immigration is stronger (i.e. for taxa that are better dispersers and for archipelagos that are less isolated). PMID:27122558

  18. The taxonomic position and the unexpected divergence of the Habu viper, Protobothrops among Japanese subtropical islands.

    PubMed

    Shibata, Hiroki; Chijiwa, Takahito; Hattori, Shosaku; Terada, Koki; Ohno, Motonori; Fukumaki, Yasuyuki

    2016-08-01

    There are four Habu species currently recognized in Japan: Protobothrops flavoviridis from the Amami Islands and the Okinawa Islands, P. tokarensis from the Tokara Islands, P. elegans from the Yaeyama Islands and Ovophis okinabvensis from the Amami Islands and the Okinawa Islands. To clarify their taxonomic positions, we determined the complete mitochondria genome sequence (approx. 17kb) from two specimens from two different islands each for P. flavoviridis, P. tokarensis and P. elegans as well as one specimen of O. okinavensis and reconstructed the molecular phylogeny of Protobothrops using the published sequences of related species. The maximum likelihood tree showed four major species groups within Protbothrops: Group I consisting of P. cornutus, P. dabieshanensis, P. jerdonii and P. xiangchengensis; Group II consisting of P. flavoviridis and P. tokarensis; Group III consisting of P. maolensis, P. mucrosquamatus and P. elegans; Group IV consisting of P. himalayanus and P. kaubacki. Since we observed an unexpected divergence and the paraphyly of the two samples of P. flavoviridis collected from different islands, Amami-Oshima and Okinawajima within the Group II, we expanded the analysis by increasing the number of P. flavoviridis and P. tokarensis collected from 10 islands: Amami-Oshima (5 specimens), Kakeromajima (4) and Tokunoshima (4) from the Amami Islands, Okinawajima (4), Iheyajima (4), Iejima (4), Tokashikijima (4) and Kumejima (4) from the Okinawa Islands, Kodakarajima (P. tokarensis) (4) and Takarajima (P. tokarensis) (4) from the Tokara Islands. The maximum likelihood tree of the 44 samples replicated the significant divergence of P. flavoviridis between the Amami Clade including Amami-Oshima, Kakeromajima and Tokunoshima and the Okinawa Clade including Okinawajima, Iheyajima, Iejima, Tokashikijima and Kumejima. The Amami Clade also include all specimens from the Tokara Islands currently known as an independent species, P. tokarensis, suggesting the

  19. Unexpected monophyletic origin of Ephoron shigae unisexual reproduction strains and their rapid expansion across Japan

    PubMed Central

    Sekiné, K.; Hayashi, F.; Tojo, K.

    2015-01-01

    The burrowing polymitarcyid mayfly Ephoron shigae is distributed across Japan, Korea, northeast China and far east Russia. Some populations are bisexual, and others are unisexual, i.e. geographically parthenogenetic throughout Japan. In general, parthenogenetic organisms are often found in harsh environments, such as at high latitudes and altitudes, in xeric as opposed to mesic conditions, in isolated habitats such as islands and island-like areas, and at the peripheral regions of the taxon's range. In E. shigae, however, the distributions of bisexual and unisexual populations overlap broadly in their respective geographical ranges. In the analysis of mitochondrial 16S rRNA and COI, we revealed that unisexual populations were of monophyletic origin and recently differentiated somewhere in western Japan. In the nuclear DNA EFI-α analysis, parthenogenetic strains had two genotypes, i.e. the heterozygous genotype of E1/E3 and the homozygous genotype of E1/E1 or E3/E3, while specimens of bisexual lineage had 20 genotypes. These results are consistent with an automixis mode of reproduction for the parthenogenetic strains, and also support the monophyletic origin of the parthenogenetic strains. Furthermore, there would be no gene flow between the specimens of the bisexual lineage and those of the parthenogenetic strain. PMID:26543584

  20. Teachers' Unions and the Politics of Education in Japan. SUNY Series on Japan in Transition.

    ERIC Educational Resources Information Center

    Aspinall, Robert W.

    In 1989, the Japan Teachers' Union, Nikkyoso, split into two unions after 2 years of factional infighting. Japan has two political camps, the governing conservative Liberal Democratic Party and the left-wing Japan Socialist Party. The teachers' union is a powerful member in the camp of the latter. This book incorporates studies of the links…

  1. Spatial heterogeneities in tectonic stress in Kyushu, Japan and their relation to a major shear zone

    NASA Astrophysics Data System (ADS)

    Matsumoto, Satoshi; Nakao, Shigeru; Ohkura, Takahiro; Miyazaki, Masahiro; Shimizu, Hiroshi; Abe, Yuki; Inoue, Hiroyuki; Nakamoto, Manami; Yoshikawa, Shin; Yamashita, Yusuke

    2015-10-01

    We investigated the spatial variation in the stress fields of Kyushu Island, southwestern Japan. Kyushu Island is characterized by active volcanoes (Aso, Unzen, Kirishima, and Sakurajima) and a shear zone (western extension of the median tectonic line). Shallow earthquakes frequently occur not only along active faults but also in the central region of the island, which is characterized by active volcanoes. We evaluated the focal mechanisms of the shallow earthquakes on Kyushu Island to determine the relative deviatoric stress field. Generally, the stress field was estimated by using the method proposed by Hardebeck and Michael (2006) for the strike-slip regime in this area. The minimum principal compression stress ( σ3), with its near north-south trend, is dominant throughout the entire region. However, the σ 3 axes around the shear zone are rotated normal to the zone. This result is indicative of shear stress reduction at the zone and is consistent with the right-lateral fault behavior along the zone detected by a strain-rate field analysis with global positioning system data. Conversely, the stress field of the normal fault is dominant in the Beppu-Shimabara area, which is located in the central part of the island. This result and the direction of σ3 are consistent with the formation of a graben structure in the area.

  2. A revision of the Australian species of Trimma (Actinopterygii, Gobiidae), with descriptions of six new species and redescriptions of twenty-three valid species.

    PubMed

    Winterbottom, Richard; Hoese, Douglass F

    2015-01-01

    The gobiid genus Trimma currently contains 75 valid species, with another 20-30 known but undescribed species. There are 29 species in Australian waters (six undescribed). This paper describes the six new species, and provides redescriptions of most of the 23 previously described species known from the region, as well as a key for all the species. The six new species are: T. insularum (endemic to Cocos (Keeling) Islands), T. kitrinum (Fiji to Great Barrier Reef), T. meristum (Cape York to the Bismark Archipelago and Fiji), T. pentherum (Great Barrier Reef to Fiji and the South-West Islands of Palau), T. readerae (Australia to Japan), and T. xanthum (Palau to Fiji, Great Barrier Reef to Christmas Island). The following 23 species have been recorded from Australian waters, and most are redescribed here: T. anaima (Comores to Fiji), T. annosum (Maldives to the Phoenix Islands, Taiwan to the southern Great Barrier Reef), T. benjamini (southern Vietnam to the Marshall Islands, Samoa and southern Barrier Reef), T. caesiura (Ryukyus through the Marshall Islands to Samoa and Elizabeth Reef on the Lord Howe Rise), T. capostriatum (New Caledonia to eastern Australia and Papua New Guinea), T. maiandros (Java to the Ryukyus, Marshalls to Great Barrier Reef), T. emeryi (Comores to Ryukyus and Samoa), T. fangi (western South China Sea through to the Solomons), T. flavatrum (Ryukyu Islands to Western Australia and Samoa), T. hoesei (Chagos Archipelago, central Indian Ocean to Palau and Solomons), T. lantana (Australia, Solomons, northern New Guinea, South-West Islands of Palau), T. macrophthalmus (Ryukyu Islands to Cocos (Keeling) Islands and Samoa), T. milta (Taiwan to Western Australia, Society Islands and Hawaii), T. nasa (Sumbawa, Indonesia to Fiji), T. necopinum (northern tip of Cape York to Sydney), T. nomurai (Japan to northern Australia and New Caledonia), T. okinawae (western Thailand to Japan and the Phoenix Islands, north-west Australia to the Great Barrier Reef), T

  3. A new species of the genus Paracypria (Crustacea: Ostracoda: Cypridoidea) from the Fiji Islands.

    PubMed

    Chand, Prerna; Kamiya, Takahiro

    2016-01-01

    A new marine species of the genus Paracypria (Paracypria fijiensis n. sp.) is reported from the Fiji Islands, a small island archipelago in the South Pacific Ocean. This is the first report of a Paracypria species from the Fiji Islands. Descriptions of soft parts and valves of Paracypria fijiensis n. sp. are presented herein, and morphological comparisons are made with existing Paracypria species from Australia, Japan and New Caledonia. Although eight coastal sites were sampled across the Fiji Islands, the new Paracypria species was found at only three sites. Large numbers of P. fijiensis n. sp. were recorded from intertidal flats, indicating it to be highly tolerant of the dynamic intertidal zone conditions. PMID:27615895

  4. Archaeoastronomy of Easter Island

    NASA Astrophysics Data System (ADS)

    Edwards, Edmundo

    Astronomer priests or "skywatchers" on Easter Island lived in stone towers that were used as observatories and built stone markers in the periphery that indicated the heliacal rising of certain stars that served to indicate the arrival of marine birds, turtles, the offshore fishing season, and times for planting and harvest. Petroglyphs related to such sites depict outriggers, fishhooks, pelagic fish, and turtles and supposedly represented a star map. In this chapter, we analyze a set of such skywatchers dwellings, and stone markers located upon the North coast of Easter Island that have astronomic orientations, its related petroglyphs, and the relations between these directions with their yearly activities and their ritual calendar.

  5. Sakhalin Island terrain intelligence

    USGS Publications Warehouse

    U.S. Geological Survey Military Geology Branch

    1943-01-01

    This folio of maps and explanatory tables outlines the principal terrain features of Sakhalin Island. Each map and table is devoted to a specialized set of problems; together they cover the subjects of terrain appreciation, climate, rivers, water supply, construction materials, suitability for roads, suitability for airfields, fuels and other mineral resources, and geology. In most cases, the map of the island is divided into two parts: N. of latitude 50° N., Russian Sakhalin, and south of latitude 50° N., Japanese Sakhalin or Karafuto. These maps and data were compiled by the United States Geological Survey during the period from March to September, 1943.

  6. Long Island Solar Farm

    SciTech Connect

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  7. Controlling summer heat islands: Proceedings

    SciTech Connect

    Garbesi, K.; Akbari, H.; Martien, P.

    1989-11-01

    A workshop was held on the energy and pollution implications of summertime urban heat islands and the potential to control them. The presentations, papers, and discussions fell into four broad categories: (1) the potential to conserve energy, reduce atmospheric pollution, and slow global warming by reducing summer heat islands; (2) the use of computer models to understand and simulate the heat island phenomenon; (3) measurements of heat islands; and (4) the design and implementation of heat island mitigation strategies. On the afternoon of the second day of the workshop, the participants divided into three workgroups. Group 1 discussed research needs to better quantify the effect of heat island mitigation on energy use. Group 2 discussed future research on the characterization and modeling of heat islands. And Group 3 discussed the development of a manual that would present to policy makers our current knowledge of techniques to mitigate heat islands and thereby save energy. This Proceedings documents the presentations and outcome of the Workshop.

  8. Transformer Efficiency Assessment - Okinawa, Japan

    SciTech Connect

    Thomas L. Baldwin; Robert J. Turk; Kurt S. Myers; Jake P. Gentle; Jason W. Bush

    2012-05-01

    The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.

  9. Transformer Efficiency Assessment - Okinawa, Japan

    SciTech Connect

    Thomas L. Baldwin; Robert J. Turk; Kurt S. Myers; Jake P. Gentle; Jason W. Bush

    2012-08-01

    The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.

  10. On earthquake prediction in Japan.

    PubMed

    Uyeda, Seiya

    2013-01-01

    Japan's National Project for Earthquake Prediction has been conducted since 1965 without success. An earthquake prediction should be a short-term prediction based on observable physical phenomena or precursors. The main reason of no success is the failure to capture precursors. Most of the financial resources and manpower of the National Project have been devoted to strengthening the seismographs networks, which are not generally effective for detecting precursors since many of precursors are non-seismic. The precursor research has never been supported appropriately because the project has always been run by a group of seismologists who, in the present author's view, are mainly interested in securing funds for seismology - on pretense of prediction. After the 1995 Kobe disaster, the project decided to give up short-term prediction and this decision has been further fortified by the 2011 M9 Tohoku Mega-quake. On top of the National Project, there are other government projects, not formally but vaguely related to earthquake prediction, that consume many orders of magnitude more funds. They are also un-interested in short-term prediction. Financially, they are giants and the National Project is a dwarf. Thus, in Japan now, there is practically no support for short-term prediction research. Recently, however, substantial progress has been made in real short-term prediction by scientists of diverse disciplines. Some promising signs are also arising even from cooperation with private sectors. PMID:24213204

  11. Genetic variation and population structure of hair crab (Erimacrus isenbeckii ) in Japan inferred from mitochondrial DNA sequence analysis.

    PubMed

    Azuma, Noriko; Kunihiro, Yasushi; Sasaki, Jun; Mihara, Eiji; Mihara, Yukio; Yasunaga, Tomoaki; Jin, Deuk-Hee; Abe, Syuiti

    2008-01-01

    Genetic variation and population structure of hair crab (Erimacrus isenbeckii) were examined using nucleotide sequence analysis of 580 base pairs (bp) in the 3' portion of the mitochondrial cytochrome c oxidase subunit I gene (COI) of 20 samples collected from 16 locales in Japan (the Hokkaido and Honshu Islands) and one in Korea. A total of 27 haplotypes was defined by 23 variable nucleotide sites in the examined COI region. Pairwise population F (ST) estimates and neighbor-joining tree inferred distinct genetic differentiation between the representative samples from the Pacific Ocean off the Eastern Hokkaido Island and the Sea of Japan, while others were intermediate between these two groups. AMOVA also showed a weak but significant differentiation among these three groups. The present results suggest a moderate population structure of hair crab, probably influenced by high gene flow between regional populations due to sea current dependent larval dispersal of this species. PMID:17955293

  12. A review of the role of mosquitos in the transmission of malayan and bancroftian filariasis in Japan*

    PubMed Central

    Omori, Nanzaburo

    1962-01-01

    Malayan filariasis is found in Japan only on the small island of Hachijo-koshima and is transmitted there by Aëdes togoi and probably by Culex pipiens pallens. Bancroftian filariasis is widely distributed in the three main islands, and is of particularly high endemicity in the south. Of the ten mosquito species proved experimentally susceptible to Wuchereria bancrofti, only Aëdes togoi and Culex p. pallens seem to be responsible for transmission of the disease. The former species is of importance only in fishing villages situated on a rocky seashore with many tidal pools or in villages engaged in the processing of dried sardines. Culex p. pallens is domestic in habit, highly anthropophilic and highly susceptible to W. bancrofti infection, and must be considered the most important vector of this disease in Japan. PMID:13940117

  13. Great East Japan Earthquake Tsunami

    NASA Astrophysics Data System (ADS)

    Iijima, Y.; Minoura, K.; Hirano, S.; Yamada, T.

    2011-12-01

    The 11 March 2011, Mw 9.0 Great East Japan Earthquake, already among the most destructive earthquakes in modern history, emanated from a fault rupture that extended an estimated 500 km along the Pacific coast of Honshu. This earthquake is the fourth among five of the strongest temblors since AD 1900 and the largest in Japan since modern instrumental recordings began 130 years ago. The earthquake triggered a huge tsunami, which invaded the seaside areas of the Pacific coast of East Japan, causing devastating damages on the coast. Artificial structures were destroyed and planted forests were thoroughly eroded. Inrush of turbulent flows washed backshore areas and dunes. Coastal materials including beach sand were transported onto inland areas by going-up currents. Just after the occurrence of the tsunami, we started field investigation of measuring thickness and distribution of sediment layers by the tsunami and the inundation depth of water in Sendai plain. Ripple marks showing direction of sediment transport were the important object of observation. We used a soil auger for collecting sediments in the field, and sediment samples were submitted for analyzing grain size and interstitial water chemistry. Satellite images and aerial photographs are very useful for estimating the hydrogeological effects of tsunami inundation. We checked the correspondence of micro-topography, vegetation and sediment covering between before and after the tsunami. The most conspicuous phenomenon is the damage of pine forests planted in the purpose of preventing sand shifting. About ninety-five percent of vegetation coverage was lost during the period of rapid currents changed from first wave. The landward slopes of seawalls were mostly damaged and destroyed. Some aerial photographs leave detailed records of wave destruction just behind seawalls, which shows the occurrence of supercritical flows. The large-scale erosion of backshore behind seawalls is interpreted to have been caused by

  14. Improved Gravimetric Geoid Model for Japan From Terrestrial Data and Altimetric Gravity Model

    NASA Astrophysics Data System (ADS)

    Kuroishi, Y.

    2003-12-01

    An improved gravimetric geoid model for Japan is developed by combining an altimetric gravity model, KMS02 with terrestrial gravity data. Additional terrestrial gravity data were newly obtained in some data gaps for previous geoid models: ship data in the western part of Seto Inland Sea and land gravity data in south and east Hokkaido, where the latest gravimetric geoid model for Japan, JGEOID2000 shows relatively large errors at short wavelengths. In addition, medium wavelength signals of gravity from KMS02 are retrieved and combined by filtering based on wavelets. The combination significantly reduces systematic errors of JGEOID2000 gravity/geoid models derived from ship data, at medium wavelengths around Hokkaido Island. Moreover, recently-released global geopotential models from the GRACE mission, EIGEN-GRACE01S by GFZ and GGM01 by CSR are used as a foundation for 1D-FFT computation of Stokes integral in a remove-restore manner. Those models themselves show improved performance over the Japanese islands in terms of geoid heights when compared with GPS/leveling geoid heights throughout the islands. When we change the maximum degree of the spherical harmonics used and merge them with higher degree harmonics of EGM96 (up to degree and order 360), those geopotential models seem to work best at degree 90. Resulting geoid models are compared and evaluated with GPS/leveling geoid heights.

  15. Distribution patterns of Babesia gibsoni infection in hunting dogs from nine Japanese islands.

    PubMed

    El-Dakhly, Khaled Mohamed; Goto, Minami; Noishiki, Kaori; El-Nahass, El-Shaymaa; Sakai, Hiroki; Yanai, Tokuma; Takashima, Yasuhiro

    2015-04-01

    Canine babesiosis constitutes a major global veterinary medical problem caused by tick-borne hemoparasites Babesia gibsoni and Babesia canis. Babesia gibsoni induces more severe clinical signs and is mainly transmitted by the ixodid Haemaphysalis longicornis. In Japan, B. gibsoni is primarily found in the western districts, with few records in the eastern parts. The aim of the current investigation was to evaluate distribution patterns of B. gibsoni infection in 9 Japanese islands and peninsulas using direct microscopy and PCR. Therefore, 196 hunting dogs were randomly sampled during the period from March to September 2011. Ages and sexes of dogs were identified. Direct microscopy of Giemsa-stained blood smear revealed pear-shaped piroplasms of B. gibsoni in 3 (1.6%) dogs. PCR was done initially with the universal primer set (B18S-F and B18S-R) amplifying the 1,665-bp portion of the 18S rRNA gene, followed by the specific primer set (Bg18F1 and Bg18R2) amplifying 2,363-bp fragments of the same gene. Accordingly, 84 (42.9%) and 8 (4.1%) dogs were positive, respectively. The current investigation shows that canine babesiosis was recorded in all islands except for Sado Island, Atsumi Peninsula, and Tanegashima Island. The highest infection rate was detected in the main island of Okinawa, while the lowest was on Ishigaki Island. Both sexes were non-significantly infected. However, the diversity of infection in islands was significantly different (P < 0.05). Although B. gibsoni has been previously found in western and eastern Japan, the present work highlights the prevalence of infection in many Japanese districts, including islands and peninsulas, giving realistic data that can facilitate treatment and control. PMID:25419881

  16. Crustal architecture of the eastern margin of Japan Sea: back-arc basin opening and contraction

    NASA Astrophysics Data System (ADS)

    No, T.; Sato, T.; Takahashi, N.; Kodaira, S.; Kaneda, Y.; Ishiyama, T.; Sato, H.

    2012-12-01

    Although large earthquakes such as the 1964 Niigata earthquake (M 7.5), 1983 Nihonkai-Chubu earthquake (M 7.8), and 1993 Hokkaido Nansei-Oki earthquake (M 7.8) have caused large amounts of damage to the eastern margin of the Japan Sea, a substantial number of seismic studies have been conducted for the seismogenic zone on the Pacific Ocean side of Japan. In addition, the detail of the source fault model for the eastern margin of the Japan Sea is not well defined for all cases. This highlights the need for further studies to investigate seismic imaging. Therefore, we have collaborated with other Japanese research institutions for a project titled "Priority Investigations of Strain Concentration Areas" (which is funded by Special Coordination Funds for Promoting Science and Technology, Japan). This project has conducted seismic surveys from 2009 to 2012 using the deep-sea research vessel, Kairei, from the Japan Agency for Marine-Earth Science and Technology. There is a strain concentration area in the eastern part of the survey area (Okamura et al., 1995). The western part of the survey area includes the Yamato Basin and Japan Basin. It is very important to study the crustal structure in the seismotectonic studies of the eastern margin of the Japan Sea. We conducted a marine seismic survey by using a multichannel seismic (MCS) system and ocean bottom seismographs (OBSs) along the eastern margin of the Japan Sea. Seismic data were acquired along 42 lines with a total length of approximately 9,000 km. The following results were obtained from seismic imaging. On the basis of the results of the MCS imaging, active reverse faults and folds were observed in the margin of the Toyama Trough; however, the sedimentary layers in the trough were flat. In the sedimentary layers and crusts of the Sado Ridge, Mogami Trough, and source area of the 1964 Niigata earthquake located north of the Sado Island, greater deformation was observed. The deformation weakened toward the Yamato

  17. HEAT ISLAND REDUCTION STRATEGIES GUIDEBOOK

    EPA Science Inventory

    This heat island reduction strategies guidebook provides an overview of urban heat islands and steps communities can take to reduce them. In particular, this guidebook provides background basics and answers the questions: “What is a heat island?” “What are its impacts?" "What ar...

  18. Mitochondrial genomes and divergence times of crocodile newts: inter-islands distribution of Echinotriton andersoni and the origin of a unique repetitive sequence found in Tylototriton mt genomes.

    PubMed

    Kurabayashi, Atsushi; Nishitani, Takuma; Katsuren, Seiki; Oumi, Shohei; Sumida, Masayuki

    2012-01-01

    Crocodile newts, which constitute the genera Echinotriton and Tylototriton, are known as living fossils, and these genera comprise many endangered species. To identify mitochondrial (mt) genes suitable for future population genetic analyses for endangered taxa, we determined the complete nucleotide sequences of the mt genomes of the Japanese crocodile newt Echinotriton andersoni and Himalayan crocodile newt Tylototriton verrucosus. Although the control region (CR) is known as the most variable mtDNA region in many animal taxa, the CRs of crocodile newts are highly conservative. Rather, the genes of NADH dehydrogenase subunits and ATPase subunit 6 were found to have high sequence divergences and to be usable for population genetics studies. To estimate the inter-population divergence ages of E. andersoni endemic to the Ryukyu Islands, we performed molecular dating analysis using whole and partial mt genomic data. The estimated divergence ages of the inter-island individuals are older than the paleogeographic segmentation ages of the islands, suggesting that the lineage splits of E. andersoni populations were not caused by vicariant events. Our phylogenetic analysis with partial mt sequence data also suggests the existence of at least two more undescribed species in the genus Tylototriton. We also found unusual repeat sequences containing the 3' region of cytochrome apoenzyme b gene, whole tRNA-Thr gene, and a noncoding region (the T-P noncoding region characteristic in caudate mtDNAs) from T. verrucosus mtDNA. Similar repeat sequences were found in two other Tylototriton species. The Tylototriton taxa with the repeats become a monophyletic group, indicating a single origin of the repeat sequences. The intra-and inter-specific comparisons of the repeat sequences suggest the occurrences of homologous recombination-based concerted evolution among the repeat sequences. PMID:22531793

  19. Linguistic Minorities and Education in Japan.

    ERIC Educational Resources Information Center

    Maher, John

    1997-01-01

    The ideology of a monolingual and monoracial Japan is being challenged by increasing language diversity in communities where Ainu, Ryukyuan, Chinese, English, Japanese Sign Language, Korean, and other languages are spoken. Government policies and school textbooks still resist the notion of a multilingual Japan. (SK)

  20. 75 FR 57980 - Polychloroprene Rubber From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... interested parties did not participate in this sunset review * * *.'' (75 FR 51981). Accordingly, pursuant to... COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION... whether revocation of the antidumping duty finding on polychloroprene rubber from Japan would be likely...