Bioaccumulation of nitroarenes in bivalves at Osaka Bay, Japan     

Uno S  Tanaka H  Miki S  Kokushi E  Ito K  Yamamoto M  Koyama J 《Marine pollution bulletin》2011,63(5-12):477-481

This paper reports for the first time the detection and occurrence of nitroarenes (NPAHs) in marine organisms. Mussels and oysters collected from Osaka Bay, Japan, had total NPAHs concentrations that ranged from 2380 to 24,688 pg/g dry and 2672 to 25,961 pg/g dry, respectively. Relatively higher concentrations were detected in sampling sites located near the central district and suburbs of Osaka City implying that the most probable sources of NPAHs in the two bivalves are exhaust gases and smokes emitted by automobiles and industrial plants. Bivalves had relatively higher residues of 1-nitronaphthalene, 2-nitronaphthalene, 3-nitrophenanthrene, and 9-nitrophenanthrenes. Residues of 2-nitrofluorene, 1-nitropyrene, 4-nitropyrenes, and 6-nitrochrysene were much lower compared to nitronaphthalenes and nitrophenanthrenes. Inter-species differences was only observed for 2-nitronaphthalene with oysters exhibiting significantly higher residues than mussels.  相似文献   

Shaking Maps for Scenario Earthquakes by Applying the Upgraded Version of the Strong Ground Motion Prediction Method ��Recipe��     

Nobuyuki Morikawa  Shigeki Senna  Yuzuru Hayakawa  Hiroyuki Fujiwara 《Pure and Applied Geophysics》2011,168(3-4):645-657

The strong ground motion prediction method ??Recipe?? was published by the Headquarters for Earthquake Research Promotion (HERP) of Japan. HERP has applied this method to prepare shaking maps for scenario earthquakes in specific active faults. Recently, Recipe was updated following its verification by simulations of strong ground motions associated with the Mw?=?6.6 off-shore earthquake west of Fukuoka prefecture in 2005, which occurred in the northwest part of the Kego fault zone located in northern Kyushu, Japan. One of the prominent changes in the upgraded version of Recipe is the inclusion of a procedure to evaluate seismic intensities on the ground surface from waveforms of S-wave velocity of 400?m/s on the engineering bedrock. By applying the upgraded version of Recipe, we have made shaking-maps for earthquakes in the southeast part of the Kego fault zone, which is located directly below the mega-city of Fukuoka. We assume four source models for scenario earthquakes; the locations of the asperities and the hypocenters vary between the models. The results show that in all cases, disastrous seismic intensities can strike a wide area of Fukuoka city. Differences in the distributions of seismic intensities among the four cases can be clearly observed in the area located on the extension of the source fault. Furthermore, we construct a velocity-layer structure model on the engineering bedrock for the central area of Fukuoka city. We assess not only the distribution of seismic intensities but also waveforms on the ground by using an equivalent linear method for the central area of Fukuoka city.  相似文献   

A review of the NEMURO and NEMURO.FISH models and their application to marine ecosystem investigations     

Michio J. Kishi  Shin-ichi Ito  Bernard A. Megrey  Kenneth A. Rose  Francisco E. Werner 《Journal of Oceanography》2011,67(1):3-16

The evolution of the North Pacific Ecosystem Model for Understanding Regional Oceanography (NEMURO) family of models to study marine ecosystems is reviewed. Applications throughout the North Pacific have shown the models to be robust and to be able to reproduce 1D, 2D and 3D components of nutrient, carbon cycle and biogeochemical cycles as well as aspects of the lower trophic levels ecosystem (phyto- and zooplankton). NEMURO For Including Saury and Herring, an extension that includes higher trophic levels, can be run uncoupled or coupled to NEMURO. In the uncoupled mode, the growth and weight of an individual fish is computed using plankton densities simulated by NEMURO but with no feedback between fish consumption and plankton mortality. In the coupled mode, the feeding, growth and weight of a representative fish are computed, and prey removals due to feeding by fish appear as mortality terms on the prey. The NEMURO family of models continues to evolve, including effects of the microbial loop and iron limitation at lower trophic levels, and full life cycle, multi-species and multi-generational simulations at higher trophic levels. We outline perspectives for future end-to-end modeling efforts that can be used to study marine ecosystems in response to global environmental change.  相似文献   

Geometry of the Nojima Fault at Nojima-Hirabayashi, Japan – II. Microstructures and their Implications for Permeability and Strength     

Diane E. Moore  David A. Lockner  Hisao Ito  Riuji Ikeda  Hidemi Tanaka  Kentaro Omura 《Pure and Applied Geophysics》2009,166(10-11):1669-1691

Samples of damage-zone granodiorite and fault core from two drillholes into the active, strike-slip Nojima fault zone display microstructures and alteration features that explain their measured present-day strengths and permeabilities and provide insight on the evolution of these properties in the fault zone. The least deformed damage-zone rocks contain two sets of nearly perpendicular (60–90° angles), roughly vertical fractures that are concentrated in quartz-rich areas, with one set typically dominating over the other. With increasing intensity of deformation, which corresponds generally to increasing proximity to the core, zones of heavily fragmented rock, termed microbreccia zones, develop between prominent fractures of both sets. Granodiorite adjoining intersecting microbreccia zones in the active fault strands has been repeatedly fractured and locally brecciated, accompanied by the generation of millimeter-scale voids that are partly filled with secondary minerals. Minor shear bands overprint some of the heavily deformed areas, and small-scale shear zones form from the pairing of closely spaced shear bands. Strength and permeability measurements were made on core collected from the fault within a year after a major (Kobe) earthquake. Measured strengths of the samples decrease regularly with increasing fracturing and fragmentation, such that the gouge of the fault core and completely brecciated samples from the damage zone are the weakest. Permeability increases with increasing disruption, generally reaching a peak in heavily fractured but still more or less cohesive rock at the scale of the laboratory samples. Complete loss of cohesion, as in the gouge or the interiors of large microbreccia zones, is accompanied by a reduction of permeability by 1-2 orders of magnitude below the peak values. The core samples show abundant evidence of hydrothermal alteration and mineral precipitation. Permeability is thus expected to decrease and strength to increase somewhat in active fault strands between earthquakes, as mineral deposits progressively seal fractures and fill pore spaces.  相似文献   

Cross-shore variation of long-term average longshore current velocity in the nearshore zone     

Yoshiaki Kuriyama  Yoshimasa Ito  Shinichi Yanagishima 《Continental Shelf Research》2008

The cross-shore variation of long-term average longshore current velocity was investigated on the basis of a 15-year data set of longshore current, wave and wind. The longshore current velocities were measured once a day along a 427-m-long pier. The results show that the direction of the long-term average longshore current velocity away (>200 m) from the shore was the opposite to that near the shore. The southward current was dominant offshore, whereas the northward current was dominant near the shore. The cross-shore variation of the long-term average longshore current velocity was formed owing to a difference between the wave and wind conditions when the northward and southward currents developed. When the northward current developed, the offshore wave height was relatively small and the frequency of the southward wind velocity was almost equal to that of the northward one. As a result, the northward current developed only near the shore and decayed outside the narrow surf zone. On the other hand, when the southward current developed, the offshore wave height was relatively large and the southward wind velocity was predominant, which resulted in the southward current developing not only in the wide surf zone but also outside the surf zone. The superposition of the two cross-shore variations produced a cross-shore variation of the long-term average longshore current velocity with a northward velocity near the shore and a southward velocity away from the shore.  相似文献   

Solar radiation management and ecosystem functional responses     

Akihiko Ito 《Climatic change》2017,142(1-2):53-66

Geoengineering such as solar radiation management (SRM) can be an emergent option to avoid devastating climatic warming, but its ramifications are barely understood. The perturbation of the Earth’s energy balance, atmospheric dynamics, and hydrological cycling may exert unexpected influences on natural and human systems. In this study, I evaluate the impacts of SRM deployment on terrestrial ecosystem functions using a process-based ecosystem model (the Vegetation Integrative Simulator for Trace gases, VISIT) driven by the climate projections by multiple climate models. In the SRM-oriented climate projections, massive injection of sulphate aerosols into the stratosphere lead to increased scattering of solar radiation and delayed anthropogenic climate warming. The VISIT simulations show that canopy light absorption and gross primary production are enhanced in subtropics in spite of the slight decrease of total incident solar radiation. The retarded temperature rise during the deployment period leads to lower respiration, and consequently, an additional net terrestrial ecosystem carbon uptake by about 20%. After the SRM termination, however, along with the temperature rise, this carbon is released rapidly to the atmosphere. As a result of altered precipitation and radiation budget, simulated runoff discharge is suppressed mainly in the tropics. These SRM-induced influences on terrestrial ecosystems occurr heterogeneously over the land surface and differed among the ecosystem functions. These responses of terrestrial functions should be taken into account when discussing the costs and benefits of geoengineering.  相似文献   

Thermodynamic properties of MgSiO3 ilmenite from vibrational spectra     

Anne M. Hofmeister  Eiji Ito 《Physics and Chemistry of Minerals》1992,18(7):423-432

Unpolarized infrared (IR) reflectance spectra for MgSiO₃ ilmenite taken from a single-crystal and from a densly packed polycrystalline sample possessed all eight peaks mandated by symmetry between 337 and 850 cm^?1. Polarizations were inferred from intensity differences between the two samples. IR peak positions differ by up to 250 cm^?1 from recent calculations, but on average are within 11%. Heat capacity C _p calculated from these data by using a Kieffer-type model are within the experimental uncertainty of calorimetric measurements from 170 to 700 K. Outside this range, calculated C _p is probably accurate within a few percent, based on recent results for garnets. Calculated entropy is only slightly less accurate, giving S ⁰ (298.15 K) as 54.1 ±0.5 J/ mol-K, which is 10% lower than recent estimates based on phase equilibria. The slope of the phase boundary between ilmenite and perovskite is used to predict S ⁰ (298.15 K) of perovskite as 58.7 ±1.4 J/mol-K, which is 10% lower than previous values.  相似文献   

Standing Crops of Planktonic Ciliates and Copepod Nauplii in the Subarctic North Pacific and the Bering Sea in Summer     

Hiroshi Ito  Akira Taniguchi 《Journal of Oceanography》2001,57(3):333-339

Abundances and biomasses of planktonic ciliates and copepod nauplii, major components of the microzooplankton community, were investigated in the subarctic North Pacific and the Bering Sea in summer of 1997. Their regional variation was illustrated by demarcating the entire area into five regions. Ciliates always predominated both in abundance (>94%) and biomass (>78%) over nauplii. Regional means of ciliates in the water column were higher in the Alaskan Gyre (120 × 10⁶ cells/m²) and the Western Subarctic Gyre (110 × 10⁶ cells/m²) in terms of abundance, and rich in the Bering Sea Gyre (360 mgC/m²) and the Western Subarctic Gyre (340 mgC/m²) in terms of biomass. By contrast, standing crops of ciliates were poor in the Oyashio Region (67 × 10⁶ cells/m²; 170 mgC/m²) and the Transition Region (64 × 10⁶ cells/m²; 160 mgC/m²). The values of biomass reported here are generally in agreement with the values reported previously from the Bering Sea Gyre and the Alaskan Gyre but are considerably higher than the previous value found in the Western Subarctic Gyre. No significant correlations could be found between chlorophyll a crop and standing crops of ciliates and copepod nauplii over the entire subarctic North Pacific and the Bering Sea during this summer.  相似文献