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371.
Toru Sato 《Journal of Oceanography》2004,60(4):807-816
The direct injection of CO2 in the deep ocean is a promising way to mitigate global warming. One of the uncertainties in this method, however, is its
impact on marine organisms in the near field before CO2 is diluted widely in the ocean. Since field experiments cost enormously, computational simulations are expected to show detailed
information on the dilution process near injection points and its impact on marine organisms. In general, the LC50 concept
is widely applied for testing the acute impact of a toxic agent on organisms. As a biological impact model we therefore consider
mortality, which reflects recent laboratory experiments on zooplankton at various concentrations of CO2. Here we regard the sigmoid-transformed mortality as a linear function of time in the logarithmic scale, and not just of
the concentration of CO2 in the logarithmic scale. This model was installed in a computational simulation code for the reconstruction of small-scale
ocean turbulence. The results suggest that the biological effect is not significant when the ship speed is 4 knots and CO2 is injected at 0.1 ton/sec in the form of a spray through 100 nozzles provided vertically on a pipe at 10 m intervals. It
is therefore considered that the moving-ship method is effective for direct CO2 injection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
372.
Interpretation of landslide distribution triggered by the 2005 Northern Pakistan earthquake using SPOT 5 imagery 总被引:7,自引:4,他引:7
Hiroshi P. Sato Hiroyuki Hasegawa Satoshi Fujiwara Mikio Tobita Mamoru Koarai Hiroshi Une Junko Iwahashi 《Landslides》2007,4(2):113-122
The 2005 northern Pakistan earthquake (magnitude 7.6) of 8 October 2005 occurred in the northwestern part of the Himalayas.
We interpreted landslides triggered by the earthquake using black-and-white 2.5-m-resolution System Pour l’Observation de la Terre 5 (SPOT 5) stereo images. As a result, the counts of 2,424 landslides were identified in the study area of 55 by 51 km. About
79% or 1,925 of the landslides were small (less than 0.5 ha in area), whereas 207 of the landslides (about 9%) were large
(1 ha and more in area). Judging from our field survey, most of the small landslides are shallow rock falls and slides. However,
the resolution and whitish image in the photos prevented interpreting the movement type and geomorphologic features of the
landslide sites in detail. It is known that this earthquake took place along preexisting active reverse faults. The landslide
distribution was mapped and superimposed on the crustal deformation detected by the environmental satellite/synthetic aperture
radar (SAR) data, active faults map, geological map, and shuttle radar topography mission data. The landslide distribution
showed the following characteristics: (1) Most of the landslides occurred on the hanging-wall side of the Balakot–Garhi fault;
(2) greater than one third of the landslides occurred within 1 km from the active fault; (3) the greatest number of landslides
(1,147 counts), landslide density (3.2 counts/km2), and landslide area ratio (2.3 ha/km2) was found within Miocene sandstone and siltstone, Precambrian schist and quartzite, and Eocene and Paleocene limestone and
shale, respectively; (4) there was a slight trend that large landslides occurred on vertically convex slopes rather than on
concave slopes; furthermore, large landslides occurred on steeper (30° and more) slopes than on gentler slopes; (5) many large
landslides occurred on slopes facing S and SW directions, which is consistent with SAR-detected horizontal dominant direction
of crustal deformation on the hanging wall. 相似文献
373.
Yasumasa Ogawa Naotatsu Shikazono Daizo Ishiyama Hinako Sato Toshio Mizuta Takanori Nakano 《Mineralium Deposita》2007,42(3):219-233
The Sr, Ba, and rare earth elements (REEs) concentrations and Sr isotopic composition of anhydrite and gypsum have been determined
for samples from the Matsumine, Shakanai, and Hanaoka Kuroko-type massive sulfide–sulfate deposits of northern Japan to evaluate
the mechanisms of sekko (anhydrite and gypsum) ore formation. The Sr isotopic compositions of the samples fall in the range
of 0.7077–0.7087, intermediate between that for middle Miocene (13–15 Ma) seawater (0.7088) (Peterman et al., Geochim Cosmochim
Acta, 34:105–120, 1970) and that for country rocks (e.g., 0.7030–0.7050) (Shuto, Assn Geol Collab Japan Monograph 18:91–105, 1974). The Kuroko anhydrite samples exhibit two types of chondrite-normalized REE patterns: one with a decrease from light REEs
(LREEs) to heavy REEs (HREEs) (type I), and another with a LREE-depleted pattern (type II).
Based on the Sr content and isotopic ratio (assuming an Sr/Ca (mM/M) of 8.7 for seawater), anhydrite is considered to have
formed by mixing of preheated seawater with a hydrothermal solution of Sr/Ca (mM/M) = ca. 0.59–1.36 under the condition in
which the partition coefficient (Kd) ranges between ca. 0.5 and 0.7. This results in the formation of anhydrite with higher
Sr content with an Sr isotopic value close to that of seawater under seawater-dominant conditions.
Larger crystals of type II anhydrite are partly replaced by smaller ones, indicating that anhydrite dissolution and recrystallization
occurred after or during the formation of sekko ore. Gypsum, which partially replaces anhydrite in the Kuroko deposits, also
exhibits two distinct chondrite-normalized REE patterns. Because LREEs are likely to be more readily mobilized during dissolution
and recrystallization, it is hypothesized that LREEs are leached from type I anhydrite, resulting in the formation of type
II anhydrite with LREE-depleted profiles. 相似文献
374.
A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions 总被引:2,自引:0,他引:2
375.
J. Hansen M. Sato R. Ruedy P. Kharecha A. Lacis R. Miller L. Nazarenko K. Lo G. A. Schmidt G. Russell I. Aleinov S. Bauer E. Baum B. Cairns V. Canuto M. Chandler Y. Cheng A. Cohen A. Del Genio G. Faluvegi E. Fleming A. Friend T. Hall C. Jackman J. Jonas M. Kelley N. Y. Kiang D. Koch G. Labow J. Lerner S. Menon T. Novakov V. Oinas Ja. Perlwitz Ju. Perlwitz D. Rind A. Romanou R. Schmunk D. Shindell P. Stone S. Sun D. Streets N. Tausnev D. Thresher N. Unger M. Yao S. Zhang 《Climate Dynamics》2007,29(7-8):661-696
We carry out climate simulations for 1880–2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble
of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together.
We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among
model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all
forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are
notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations
of future climate change. By using a fixed well-documented model and accurately defining the 1880–2003 forcings, we aim to
provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested.
Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea
ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in
the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
376.
Tsutomu Sato Isao Machida Makoto Takahashi Taro Nakamura 《Pure and Applied Geophysics》2006,163(4):809-823
Water was sampled from eight springs and a lake in volcanic Miyakejima Island of Japan after the 2000 eruption. Major chemical
and isotopic compositions of the water were analyzed. Significant increases of sulfate ion are observed in several springs
where the thickness of ejecta exceeds 32 mm. A good relationship of Cl/S mole ratios between spring water and leachate of
the ejecta is observed. Sulfur isotopic compositions of the spring water become close to that of leachate of the ejecta as
time elapses after the eruption. Consequently the sources of the added sulfate ion in the spring water after the eruption
are interpreted to be anhydrite and adhered sulfur of the ejecta. 相似文献
377.
378.
Ana María Sato Hugo Tickyj Eduardo Jorge Llambías Miguel Angelo Stipp Basei Pablo Diego Gonzlez 《Gondwana Research》2004,7(4):1077-1087
The Las Matras Block in Central Argentina constitutes the southernmost part of the Cuyania terrane, which was accreted to the southwestern margin of Gondwana during the Early to Mid Ordovician Famatinian orogeny. The Grenville-aged rocks of the Las Matras Block are represented by the tonalitic to trondhjemitic Las Matras pluton. A new U-Pb conventional zircon age of 1244±42 Ma confirms previous Sm-Nd and Rb-Sr isochron ages of this pluton. Mineral composition data are consistent with the tonalitic-trondhjemitic character of the pluton, and constrain its emplacement level to 1.9 to 2.6 kb. This shallow level of emplacement and the undeformed character of the pluton are distinctive features of this southernmost basement. A regional comparison indicates that the igneous-metamorphic evolution of the Grenville-aged basement rocks of the Cuyania terrane occurred over a period of more than 200 million years, with ages older than 1200 Ma up to those close to 1000 Ma. The shallowest crustal level is found in Las Matras, suggesting a southward shallowing of the exposed level of basement. The deformation and metamorphism associated with the collisional Famatinian orogeny affect both the Cuyania terrane and the adjacent western margin of Gondwana, and the Gondwana margin was also the locus of the related arc magmatism, but the compressive effects of the collision decrease in intensity toward the south. The Famatinian metamorphism and magmatism continue even further south into the Patagonia region, but the southern continuity of the Cuyania terrane into this region remains uncertain. 相似文献
379.
The examination of fracturing process subjected to triaxial compression test in Inada granite 总被引:1,自引:0,他引:1
Takashi Nishiyama Youqing Chen Hiromu Kusuda Toshihide Ito Katsuhiko Kaneko Haruyuki Kita Toshinori Sato 《Engineering Geology》2002,66(3-4):257-269
The behavior of a granite subject to a triaxial compression test ranging from the prefailure stage to the postfailure stage was studied using a fluorescent technique from the geological point of view. Microscopic observations of the specimens at different stages showed changes in the failure process. The start of formation of new microcracks paralleled the compression direction through their propagation until the onset of faulting and ended with the failure of shear zones after the strength failure point. Pores chiefly identified in the feldspar increased in length and width in the early stages, but not in number. It seems that the effect of pore spaces did not have any effect of failure. The microcracks generated on angular edges of quartz or feldspar grains and around biotite grains with increasing compression force. The phenomenon appearing on the crystal boundaries among biotite and quartz or feldspar agrees with the result calculated based on the theory on stress fields with ellipsoidal inhomogeneity suggested by Eshelby. 相似文献
380.
Origin of calc-alkalic andesite in the Japanese Islands is reviewed on the basis of the recent trace element data and new experimental results. It is suggested that calc-alkalic andesites in the Japanese Islands have at least four different origins; (1) fractional crystallization with separation of magnetite of high-alumina basalt magma, (2) partial melting of hydrous upper mantle peridotite (for magnesian andesite), (3) fractional crystallization with separation of olivine and/or orthopyroxene of magnesian andesite magma and (4) mixing of dacitic and basaltic magmas. Emphasis is placed on the possible generation of primary magnesian calc-alkalic andesite magmas by direct partial melting of the upper mantle peridotite under hydrous conditions at depths between 40 and 60 km. 相似文献