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121.
The Iwate–Miyagi Nairiku Earthquake in 2008, whose seismic intensity was M. 7.2 in Japan Meteorological Agency (JMA) scale,
induced innumerable landslides on the southern flank of Mt. Kurikoma volcano allocated along the Ou Backbone Range in Northeast
Japan. Most landslides are detected in a hanging wall side of the seismic fault. Those landslides are classified into five
types: deep-seated slide, debris slide, shallow debris slide, secondary shallow debris slide, and debris flow. Most common
landslide types induced by the earthquake are shallow debris slides and subsequent debris flows. They are intensively distributed
along steep gorges incising a volcanic skirt of Mt. Kurikoma, consisting of welded ignimbrite of the Pleistocene age. Debris
flows are also distributed even along gentle river floors in the southern lower flank of the volcano. The area of densely
distributed debris slides, shallow debris slides, and debris flows is concordant with that of severe seismic tremor. Thus,
genetic processes of landslides induced by the Iwate–Miyagi Nairiku Earthquake in 2008 are attributed to multiple causative
factors such as geology, topography, and seismic force. 相似文献
122.
123.
Daisuke Hasegawa Jinyu Sheng David A. Greenberg Keith R. Thompson 《Ocean Dynamics》2011,61(11):1845-1868
The Bay of Fundy in eastern Canada has the highest tides in the world. Harnessing the tidal energy in the region has long
been considered. In this study, the effects of tidal in-stream energy extraction in the Minas Passage on the three-dimensional
(3D) tidal circulation in the Bay of Fundy (BoF) and the Gulf of Maine (GoM) are examined using a nested-grid coastal ocean
circulation model based on the Princeton Ocean Model (POM). The nested-grid model consists of a coarse-resolution (~4.5 km)
parent sub-model for the GoM and a high-resolution (~1.5 km) child sub-model for the BoF. The tidal in-stream energy extraction
in the model is parameterized in terms of nonlinear Rayleigh friction in the momentum equation. A suite of numerical experiments
are conducted to determine the ranges of extractable tidal in-stream energy and resulting effects on the 3D tidal circulation
over the Bay of Fundy and the Gulf of Maine (BoF-GoM) in terms of the Rayleigh friction coefficients. The 3D model results
suggest that the maximum energy extraction in the Minas Passage increases tidal elevations and tidal currents throughout the
GoM and reduces tidal elevations and circulation in the upper BoF, especially in the Minas Basin. The far-field effect of
tidal energy extraction in the Passage on the 3D tidal circulation in the BoF-GoM is examined in two cases of harnessing tidal
in-stream energy from (a) the entire water column and (b) the lower water column within 20 m above the bottom in the Passage.
The 3D model results demonstrate that tidal in-stream energy extraction from the lower water column has less impact on the
tidal elevations and circulation in the BoF-GoM than the energy extraction from the whole water column in the Minas Passage. 相似文献
124.
Nicolas C.M. Marty Jordi Cama Daisuke Chino Angelina Razafitianamaharavo Jocelyne Brendlé Josep M. Soler Christophe Tournassat 《Geochimica et cosmochimica acta》2011,75(20):5849-5864
The effect of pH and Gibbs energy on the dissolution rate of a synthetic Na-montmorillonite was investigated by means of flow-through experiments at 25 and 80 °C at pH of 7 and 9. The dissolution reaction took place stoichiometrically at 80 °C, whereas at 25 °C preferential release of Mg over Si and Al was observed. The TEM-EDX analyses (transmission electronic microscopy with quantitative chemical analysis) of the dissolved synthetic phase at 25 °C showed the presence of newly formed Si-rich phases, which accounts for the Si deficit. At low temperature, depletion of Si concentration was attributed to incongruent clay dissolution with the formation of detached Si tetrahedral sheets (i.e., alteration product) whereas the Al behaviour remains uncertain (e.g., possible incorporation into Al-rich phases). Hence, steady-state rates were based on the release of Mg. Ex situ AFM measurements were used to investigate the variations in reactive surface area. Accordingly, steady-state rates were normalized to the initial edge surface area (11.2 m2 g−1) and used to propose the dissolution rate law for the dissolution reactions as a function of ΔGr at 25 °C and pH∼9:
125.
Daisuke Shimozuru 《Bulletin of Volcanology》1994,56(3):217-219
The physical parameters that affect the formation of Pele's hair and Pele's tears during lava fountaining are discussed. Experiments on ink jets produced from a nozzle under different Weber number (We) and Reynolds number (Re) show the following results: if (Re) is relatively large compared with (We), an ink droplet is produced. However, if (Re) is relatively small and (We) is large, the spurting ink becomes thread-like. I define the Pele number (Pe) as (We)/(Re), which is expressed as v/0, where v is the spuring velocity from an erupting vent, and are viscosity and interfacial tension of the erupting magma, and and 0 are density of air and magma. The experimental results from ink jets suggest that Pele's hair will be produced for larger (Pe), while Pele's tears are very likely produced for relatively small (Pe). I conclude that Pele's hair could be produced when the spurting velocity of erupting magmas is high, and Pele's tears when it is relatively low. As an additional point of interest, the similarity of SEM photographs of the characteristic shape of Pele's hair to those of the failed products of commercial glass fibre are shown. 相似文献
126.
Tomoko Sato Hiroto Takada Takehiko Yagi Hirotada Gotou Taku Okada Daisuke Wakabayashi Nobumasa Funamori 《Physics and Chemistry of Minerals》2013,40(1):3-10
We have investigated the high-pressure behavior of cristobalite in helium by powder X-ray diffraction. Cristobalite transformed to a new phase at about 8 GPa. This phase is supposed to have a molar volume of about 30 % larger than cristobalite, suggesting the dissolution of helium atoms in its interstitial voids. On further compression, the new phase transformed to a different phase which showed an X-ray diffraction pattern similar to cristobalite X-I at about 21 GPa. On the other hand, when the new phase was decompressed, it transformed to another new phase at about 7 GPa, which is also supposed to have a molar volume of about 25 % larger than cristobalite. On further decompression, the second new phase transformed to cristobalite II at about 2 GPa. In contrast to cristobalite, quartz did not show anomalous behavior in helium. The behavior of cristobalite in helium was also consistent with that in other mediums up to about 8 GPa, where the volume of cristobalite became close to that of quartz. These results suggest that dissolution of helium may be controlled not only by the density (amount of voids) but also by the network structure of SiO4 tetrahedra (topology of voids). 相似文献
127.
The knowledge from the compression behavior of densified SiO2 glass suggests that SiO2 melt may behave as a single phase having a densified network structure (intermediate-range order) at the pressure condition of the Earth’s deep upper mantle, including the transition zone. A simple and easy-to-use equation of state of silicate melts which is applicable to a wide range of chemical composition at the pressure condition of the deep upper mantle is proposed based on the assumption that SiO2 component is in its densified state (or phase). The equation of state proposed in this study is consistent with all the available density data of silicate melts with an SiO2 content of about 35–55 mol% measured with large-volume presses at pressures between 8 and 22 GPa. The equations of state in previous studies differ considerably from each other. The main reason for the discrepancies seems to be that the compression behavior of multiple states (or phases) of silicate melts has been described in most cases with a single equation of state. It is necessary to consider that silicate melts are in their densified states (or phases) in the deep upper mantle. 相似文献
128.
Noriyuki Matsunaga Hinako Fukushi Yoshikazu Nakada Toshihiko Tanabé Michael W. Feast John W. Menzies Yoshifusa Ita Shogo Nishiyama Daisuke Baba Takahiro Naoi Hidehiko Nakaya Takahiro Kawadu Akika Ishihara Daisuke Kato 《Monthly notices of the Royal Astronomical Society》2006,370(4):1979-1990
We report the result of our near-infrared observations ( JHK s ) for type II Cepheids (including possible RV Tau stars) in galactic globular clusters. We detected variations of 46 variables in 26 clusters (10 new discoveries in seven clusters) and present their light curves. Their periods range from 1.2 d to over 80 d. They show a well-defined period–luminosity relation at each wavelength. Two type II Cepheids in NGC 6441 also obey the relation if we assume the horizontal branch stars in NGC 6441 are as bright as those in metal-poor globular clusters in spite of the high metallicity of the cluster. This result supports the high luminosity which has been suggested for the RR Lyr variables in this cluster. The period–luminosity relation can be reproduced using the pulsation equation assuming that all the stars have the same mass. Cluster RR Lyr variables were found to lie on an extrapolation of the period–luminosity relation. These results provide important constraints on the parameters of the variable stars.
Using Two Micron All-Sky Survey (2MASS) data, we show that the type II Cepheids in the Large Magellanic Cloud (LMC) fit our period–luminosity relation within the expected scatter at the shorter periods. However, at long periods ( P > 40 d, i.e. in the RV Tau star range) the LMC field variables are brighter by about one magnitude than those of similar periods in galactic globular clusters. The long-period cluster stars also differ from both these LMC stars and galactic field RV Tau stars in a colour–colour diagram. The reasons for these differences are discussed. 相似文献
Using Two Micron All-Sky Survey (2MASS) data, we show that the type II Cepheids in the Large Magellanic Cloud (LMC) fit our period–luminosity relation within the expected scatter at the shorter periods. However, at long periods ( P > 40 d, i.e. in the RV Tau star range) the LMC field variables are brighter by about one magnitude than those of similar periods in galactic globular clusters. The long-period cluster stars also differ from both these LMC stars and galactic field RV Tau stars in a colour–colour diagram. The reasons for these differences are discussed. 相似文献
129.