The 11 March 2011 East Japan Earthquake and Tsunami: Tsunami Effects on Coastal Infrastructure and Buildings     

Harry Yeh  Shinji Sato  Yoshimitsu Tajima 《Pure and Applied Geophysics》2013,170(6-8):1019-1031

The 11 March 2011 East Japan Earthquake and Tsunami caused unprecedented damage to well-engineered buildings and coastal structures. This report presents some notable field observations of structural damage based on our surveys conducted along the Sanriku coast in April and June 2011. Engineered reinforced concrete buildings failed by rotation due to the high-velocity and deep tsunami inundation: entrapped air in the buildings and soil liquefaction by ground shaking could have contributed to the failure. The spatial distribution pattern of destroyed and survived buildings indicates that the strength of tsunami was affected significantly by the locations of well-engineered sturdy buildings: weaker buildings in the shadow zone tended to survive while jet and wake formations behind the sturdy buildings enhanced the tsunami forces. We also found that buildings with breakaway walls or breakaway windows/doors remained standing even if the surrounding buildings were washed away or destroyed. Several failure patterns of coastal structures (seawalls) were observed. Flow-induced suction pressure near the seawall crown could have caused the failure of concrete panels that covered the infill. Remarkable destruction of upright solid-concrete type seawalls was closely related with the tsunami induced scour and soil instability. The rapid decrease in inundation depth during the return-flow phase caused soil fluidization down to a substantial depth. This mechanism explains severely undermined roads and foundations observed in the area of low flow velocities.  相似文献   

Near-infrared study of CIZA J1324.7-5736, the second richest cluster of galaxies in the Great Attractor     

T. Nagayama  P. A. Woudt  K. Wakamatsu  S. Nishiyama  C. Nagashima  D. Kato  T. Nagata  H. Nakaya  K. Sugitani  M. Tamura  S. Sato 《Monthly notices of the Royal Astronomical Society》2006,368(2):534-543

We present the result of a deep near-infrared survey of the newly identified X-ray luminous cluster of galaxies CIZA J1324.7-5736 in the Great Attractor (GA) region. In a 35 × 35 arcmin² region, 111 galaxy candidates with   r _{Ks 20} > arcsec  are identified. Comparison of the extinction-corrected   K _s   -band luminosity function of CIZA J1324.7-5736 with those of nearby clusters indicates that the richness class of CIZA J1324.7-5736 is almost the same as, or richer than, the Pavo, Centaurus and Hydra clusters but poorer than the Coma, Perseus and Norma clusters. CIZA J1324.7-5736 is possibly the second richest cluster in the GA region following the Norma cluster. The position of CIZA J1324.7-5736 [in the ( l , b , v ) space] is close to the Centaurus–Crux cluster and the agglomeration of galaxies detected by the Parkes H  i survey. CIZA J1324.7-5736, together with the Centaurus–Crux cluster and the H  i galaxy agglomeration, is most likely to be one of the richest local concentrations in the GA overdensity of galaxies.  相似文献   

Benefits of an impact mission to 3200 Phaethon: nature of the extinct comet and artificial meteor shower     

Toshihiro Kasuga  Jun-Ichi Watanabe  Mikiya Sato 《Monthly notices of the Royal Astronomical Society》2006,373(3):1107-1111

The asteroid 3200 Phaethon is suggested as a candidate for direct impact research. The object is considered to be an extinct comet and the parent of the Geminid meteor shower. One could say that this provides a possible argument for a space mission. Based on such a mission, this paper proposes to investigate the nature of the extinct comet and the additional interesting possibility of artificially generated meteor showers.
Dust trail theory can calculate the distribution of a bundle of trails and be used to show in which years artificial meteors would be expected. Results indicate that meteor showers will be seen on Earth about 200 yr after the event, on 2022 April 12.  相似文献   

Variable stars in the Magellanic Clouds – II. The data and infrared properties     

Yoshifusa Ita †  Toshihiko Tanabé  Noriyuki Matsunaga  Yasushi Nakajima  Chie Nagashima  Takahiro Nagayama  Daisuke Kato  Mikio Kurita  Tetsuya Nagata  Shuji Sato  Motohide Tamura  Hidehiko Nakaya  Yoshikazu Nakada 《Monthly notices of the Royal Astronomical Society》2004,353(3):705-712

  相似文献   

Gas stripping by radiation drag from an interstellar cloud     

Jun'ichi Sato  Masayuki Umemura  Keisuke Sawada  Shingo Matsuyama 《Monthly notices of the Royal Astronomical Society》2004,354(1):176-182

  相似文献   

Towards an integrated management framework for emerging disaster risks in Japan   总被引：2，自引：1，他引：1  

Saburo Ikeda  Teruko Sato  Teruki Fukuzono 《Natural Hazards》2008,44(2):267-280

An integrated framework for disaster risk management is presented to cope with the risk of low-probability high-consequence (LPHC) disasters in urban communities. Since the 2000 Tokai flood in Japan, there has been a shift in the management strategy from disaster prevention with a presumed zero risk to disaster reduction with an acceptable risk. The framework consists of: (i) integration of a different categories of risk reduction options in terms of structural and nonstructural measures, regulation and market-oriented measures, (ii) strengthening of the capacity of local communities to make their own management choices for LPHC-type disaster risks, and (iii) promoting the participation of stakeholders throughout the entire cycle of risk management. The interdisciplinary framework is discussed with reference to lessons learned from two recent major flood disasters (the 2000 Tokai flood and the 2004 Niigata flood). To implement the goals of the integrated framework, a participatory platform for disaster risk communication called “Pafrics” has been developed. Preliminary results of the pilot study of participation and risk communication supported by Pafrics are presented.  相似文献   

Gold Mineralization at the Agawa Prospect in Yamaguchi Prefecture,Southwestern Japan          下载免费PDF全文

Ryuya Sato  Osao Sawai  Yasushi Watanabe 《Resource Geology》2016,66(2):199-212

Agawa gold prospect, located in Yamaguchi Prefecture, southwestern Japan, is a small prospect, where placer gold has been explored and mined since the 17th century. We investigated the prospect to clarify the genesis of the deposit based on the geology, hydrothermal alteration, geochronology, and ore mineralogy. The main mineralized zone of the prospect has a horizontal and vertical extensions of 500 m and 100 m, respectively, and a width of less than 100 m. Gold mineralization in the prospect occurs as dissemination and stockwork veinlets in the intensely sericitized rocks at the apical part of the Agawa dioritic porphyry intrusion at 86.5–88.5 Ma. Mineralization is typified by at least three stages – an early stage characterized by the occurrence of pyrrhotite and native gold; a middle stage by chalcopyrite; and a late stage by pyrite–bornite. Mineral assemblage and fluid inclusion microthermometry estimation suggest a trend of decreasing temperatures from 400°C to 160°C at a constant sulfur fugacity. The mineralizing fluids formed by the mixing of a hypogene fluid of possibly magmatic origin with an external lower‐temperature and lower‐salinity fluid. The mixing process decreased the temperature and salinity of the fluid, resulting in the precipitation of sulfides, native gold and Bi–Te alloys and sulfosalts. The magnetite‐series signature of the Agawa porphyry and related molybdenite‐bearing mineralization indicate that the plutonism of the San‐in granitoids belt extends to the westernmost end of the Honshu Island. The compiled geochronology and distribution of the metallic deposits in the southwestern Japan arc show that transition from ilmenite‐series to magnetite‐series plutonism started earlier in the west, and shifted eastwards with time during the period from Late Cretaceous to Paleogene.  相似文献   

Groundwater geochemistry of a nitrate-contaminated agricultural site   总被引：1，自引：0，他引：1  

Hiroki Amano  Kei Nakagawa  Ronny Berndtsson 《Environmental Earth Sciences》2016,75(15):1145

  相似文献   

Decision-theoretic sensitivity analysis for reservoir development under uncertainty using multilevel quasi-Monte Carlo methods     

Takashi Goda  Daisuke Murakami  Kei Tanaka  Kozo Sato 《Computational Geosciences》2018,22(4):1009-1020

At various stages of petroleum reservoir development, we encounter a large degree of geological uncertainty under which a rational decision has to be made. In order to identify which parameter or group of parameters significantly affects the output of a decision model, we investigate decision-theoretic sensitivity analysis and its computational issues in this paper. In particular, we employ the so-called expected value of partial perfect information (EVPPI) as a sensitivity index and apply multilevel Monte Carlo (MLMC) methods to efficient estimation of EVPPI. In a recent paper by Giles and Goda, an antithetic MLMC estimator for EVPPI is proposed and its variance analysis is conducted under some assumptions on a decision model. In this paper, for an improvement on the performance of the MLMC estimator, we incorporate randomized quasi-Monte Carlo methods within the inner sampling, which results in an multilevel quasi-Monte Carlo (MLQMC) estimator. We apply both the antithetic MLMC and MLQMC estimators to a simple waterflooding decision problem under uncertainty on absolute permeability and relative permeability curves. Through numerical experiments, we compare the performances of the MLMC and MLQMC estimators and confirm a significant advantage of the MLQMC estimator.  相似文献   

Lagrangian observation of phytoplankton dynamics at an artificially enriched subsurface water in Sagami Bay,Japan     

Takako Masuda  Ken Furuya  Naoko Kohashi  Mitsuhide Sato  Shigenobu Takeda  Makoto Uchiyama  Naho Horimoto  Takashi Ishimaru 《Journal of Oceanography》2010,66(6):801-813

Phytoplankton dynamics in the lower euphotic zone were observed by tracking a subsurface water released at 20-m depth from Takumi, an artificial upwelling device. Takumi continually discharged seawater pumped up from a depth of 205 m: this water was mixed with 5-m depth water to adjust the density to that of 20-m depth water of Sagami Bay, Japan. The discharged water was pulse-labeled at Takumi with uranine and tracked for 63.9 h with a drifting buoy equipped with a drogue at 20-m depth. We present a simple model to estimate in situ phytoplankton net growth rates from temporal changes in phytoplankton abundance in the discharged water with correction for the influence of water exchange between the discharged water and neighboring layers. Lagrangian observation showed active growth of pico- and nanophytoplankton, especially cryptophytes and Synechococcus (Cyanobacteria), in the subsurface layer. In contrast, diatoms grew little in spite of micromolar concentrations of nutrients. The active growth of pico- and nanophytoplankton was in good agreement with shipboard serial dilution culture experiments. The low growth activity of diatoms was suggested to be related to low light availability in the subsurface layer.  相似文献