Distributed object‐based software environment for urban system integrated simulation under urban‐scale hazard—Part I: Infrastructure

In this paper, a distributed object‐based software environment (DOSE) has been developed to facilitate the integrated simulation of an urban system under the risk of urban‐scale hazards such as earthquakes. It is understood that individual simulation participants perform their simulation services in separate environments, bartering service exchange relationships to get what they need to resolve their part of the problem. This is the communication gap between the scientists on one side and the end users who need to understand knowledge and employ it on the other side. The authors envision a distributed simulation service software environment running in parallel with the activities of simulation participants. DOSE has lent itself to integrate interdisciplinary participants through an infrastructure that has three basic building blocks, namely: modularity, scalability, and interoperability. The modular, object‐based, design of DOSE architecture is described in terms of key functionalities of four distinct layers, namely: resource, core, domain, and interface layers. DOSE scalability in terms of urban system size and participant third‐party application complexity is enabled through the interface layer. A message passing model is developed using the Message Passing Interface standard and a control room is provided to schedule the interaction/communication among model processes. DOSE interoperability with the vulnerability analysis third‐party applications is enabled through the Industry Foundation Classes (IFC) standard. An adopted analogy between DOSE and construction industry is employed to provide interpretation and implementation for DOSE interoperability. While interfacing IFC object model to solve DOSE interoperability questions, an extension model for the structural view of IFC is proposed and accepted by the International Alliance for Interoperability. The DOSE application for real‐world urban systems is beyond the scope of this paper and is presented in an accompanying paper work. Copyright © 2007 John Wiley & Sons, Ltd.     

Structural seismic response analysis based on multiscale approach of computing fault–structure system

Structural safety for earthquake waves emitted from a nearby fault is a major concern. For a large complex structure, it might be desired to estimate its seismic response by analyzing a fault–structure system: a full three‐dimensional model in which a source fault and a target structure are modeled so that fault processes, wave propagation and amplification processes, and resulting dynamic responses of the structure can be computed numerically. To analyze this fault–structure system, this paper proposes an efficient approach based on multiscale analysis, i.e. waves emitted from the source fault are computed in the entire system in the geological length‐scale; then they are refined in a small part of the system that includes the structure, and the seismic response of the structure is accurately computed in the engineering length‐scale. Using a long highway tunnel as an example, this paper examines the validity of the proposed approach. The usefulness and applicability of the proposed approach to estimate the structural seismic responses are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

A nonlinear parametric model based on a power law relationship for predicting the coastal tsunami height

When a subduction-zone earthquake occurs, the tsunami height must be predicted to cope with the damage generated by the tsunami. Therefore, tsunami height prediction methods have been studied using simulation data acquired by large-scale calculations. In this research, we consider the existence of a nonlinear power law relationship between the water pressure gauge data observed by the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) and the coastal tsunami height. Using this relationship, we propose a nonlinear parametric model and conduct a prediction experiment to compare the accuracy of the proposed method with those of previous methods and implement particular improvements to the extrapolation accuracy.

     

日本南海弧前西端之下俯冲的九州—帕劳海岭的地震构造意义

作为菲律宾海板块残余岛弧的九州—帕劳海岭正沿着日本南海海槽的最西端俯冲于欧亚板块之下。沿走向布设的地震反射剖面显示出沿弧前增生楔前缘俯冲的九州—帕劳海岭70km宽的构造影像。地磁异常特征、海底地形特征、广角折射数据和陆地地貌证据等使得我们能够将俯冲海岭在弧前的延伸段一直追踪至九州岛的东部。正在俯冲的九州—帕劳海岭携带有大量冗余物质,可能具有相对较大浮力,因此在深部俯冲时与上覆板块的碰撞具有较大的抗性。有鉴于此,我们推测在俯冲海岭和上覆板块基底的接触区之间存在局部大应力构造。此局部大应力区人们已标出有历史冲断层型中等级别地震(6~7级)。当九州—帕劳海岭俯冲至深部时,漂浮的俯冲海岭其两侧的翼部更容易被撕裂而形成板块破裂。我们认为,俯冲的九州—帕劳海岭在深部不仅起到地震凹凸体的作用,而且产生板块破裂作为地震障碍体抑制邻近的日向段巨大逆冲地震的破裂传播。     

Long-term (36-year) observations on the dynamics of the fish-killing raphidophyte Chattonella in Harima-Nada,eastern Seto Inland Sea,Japan

Long-term changes of the fish-killing raphidophyte Chattonella spp. (Chattonella antiqua, Chattonella marina and Chattonella ovata) were examined in relation to environmental factors at 19 sampling stations in Harima-Nada, eastern Seto Inland Sea, Japan, for 36 years from 1973 to 2008. Long-term trends in the dynamics of Chattonella populations were considered to relate to environmental factors such as nutrient concentrations and water temperature. High nutrient levels during the period from the 1970s to the early 1980s have contributed to the high cell density and large-scale red tides of Chattonella spp. in Harima-Nada. However, nutrient levels exhibited a decreasing trend thereafter, and it is thought that Chattonella spp. cannot form large-scale blooms under the present conditions. After the mid-1990s, the occurrence period of vegetative cells of Chattonella spp. has been several weeks or 1 month earlier than that of the 1970s and early 1980s, and the appearance frequency of Chattonella spp. has increased in the northern coastal area, although the cell density and the spatial scale of the distribution have become lower and smaller than those in the previous decades. It is suggested that the timing of germination of Chattonella cysts has become earlier as a result of the increase in water temperature, and the chances of vegetative growth have also increased, especially at the northern coast where most of large rivers discharge into the Harima-Nada. In addition, the present results revealed that fewer diatoms were also one of the significant factors for the high abundance of Chattonella spp. in Harima-Nada.     

江豚的分娩及相关行为观察

于１９９３年４月１０日,在日本江之岛水族馆,江豚顺利分娩,对其分娩过程,以及与之相关的呼吸,活动行为进行较详细的观察和研究,结果表明,母豚将小母豚发尾部生以占分娩的绝大部分时间,分娩后期段平均呼吸频率减缓,游动速度放慢,水面活动增多,并趋于单独活动,此外,还记录到母豚的喷水,跳水,收腹,摆尾,转游等分娩时的特殊行为及出生后幼豚的行为。     

Seismological monitoring on the 2003 Tokachi-oki earthquake, derived from off Kushiro permanent cabled OBSs and land-based observations

Japan Marine Science and Technology Center installed a cabled geophysical observatory system off Kushiro, Hokkaido Island in July 1999. This observatory system comprises three ocean bottom seismographs (OBSs), two tsunami gauges, and a geophysical/geochemical monitoring system. 4 years and 2 months after the installation, a megathrust earthquake (the 2003 Tokachi-Oki earthquake, 26th September in Japan Standard Time (JST), M_JMA 8.0) occurred along a plate boundary underneath a forearc basin where the system is located. The system recorded clear unsaturated seismograms just at 28.6 km from the epicenter. This paper demonstrates advantages brought by the cabled observatory to record the megathrust earthquake showing how earthquake detectability is improved dramatically combining permanent OBS and land-based observations around the region, and importance of the in situ monitoring on the seismogenic zone. In the present study, processing OBSs and land-based network together, and comparing magnitudes of common observed earthquakes with national authorized network, event detection level improved down to M 1.5, which is much lower than the previously designed as down to M  2. Comparing detection level before and after installing OBSs, we found dramatic improvement of the earthquake detection level in the interesting region. Real-time continuous observations of microearthquakes since 1999 have brought us tremendous findings. First, a seismic quiescence started about 10 days before the 2003 Tokachi-Oki earthquake. Second, aftershock distribution is not uniform over the focal area and can be divided into several sub-regions, which might indicate an existence of several asperities. We think that the geophysical observations helped to understand the initiation process of the rupture of the 2003 Tokachi-Oki earthquake and that observations including seismological, geodynamic, hydrogeological, and the other multidisciplinary observations would provide a clue to future understanding of seismogenic processes at subduction zones.     

Origin of cyclicity in Triassic-Jurassic radiolarian bedded cherts of the Mino accretionary complex from Japan

Abstract The abundance of magnetic microspherules in a Triassic-Jurassic continuous sequence of alternating chert and shale beds in the Mino accretionary complex, central Japan, was measured systematically. Depending on time, the magnetic microspherules extracted from shale beds change in abundance considerably from the minimum 0.9ppm/cm³ at latest Triassic ( ca 208Ma) and the maximum 75ppm/cm³ at late Early Jurassic ( ca 187Ma); however, the abundance is always higher approximately 10–100 (average 70) times than those from adjacent chert bed at any stratigraphic horizon. Such systematic difference reveals the origin of radiolarian bedded chert as cyclic-rapid accumulation of biogenic SiO₂ under extremely slow accumulative environments of shale with probable aeolian dust in origin. The accumulation data for individual shale and chert beds were obtained based on the microspherule abundance and radiolarian biostratigraphy, i.e., ca 0.018g/cm²Ka for lower Jurassic shale beds and ca 1.9g/cm²Ka for adjacent chert beds.
Duration time to make a chert-shale couplet corresponds to a dominantly 15–20Ka interval (average 23 Ka) in Upper Triassic bedded cherts with a low paleolatitude, whereas a 40–45 Ka interval (average 42 Ka) in Lower Jurassic ones which may been formed in higher latitude than Triassics before the final accretion to the Asian continental margin. Depending on paleolatitude, the cyclicity of 23 and 42 Ka may correspond to Milankovitch cycles which have been well documented in deep-sea sediments.     

Cold air formation and advection over Eurasia during “dzud” cold disaster winters in Mongolia

Large negative temperature anomalies due to cold air advection have been observed over the Eurasian continent in recent years. During the 2009/2010 winter, a large amount of snow accumulated across Central Asia and China, which along with a strong cold air outbreak, resulted in extremely high livestock mortality in Mongolia. The present study examined the surface inversion development over the Eurasian continent in terms of the cold air advection, accumulation, and breaking processes at ground level. Meteorological analyses shown trends toward earlier onsets of snow and subsequent cold air advection from the Arctic through western Siberia during the last decade, which is a possible driver of the persistent enhanced surface cooling observed in mid-winter in Mongolia. Cyclones are shown to be drivers of early snowfall onset at the beginning of winter and the subsequent migration of cold air from the Arctic, and are thus the key to understanding and predicting the frequency and intensity of persistent surface cooling, which is a substantial physical precursor for the cold disaster in Mongolia “dzud.”     

Analysis software for upper atmospheric data developed by the IUGONET project and its application to polar science

To comprehensively understand the Arctic and Antarctic upper atmosphere, it is often crucial to analyze various data that are obtained from many regions. Infrastructure that promotes such interdisciplinary studies on the upper atmosphere has been developed by a Japanese inter-university project called the Inter-university Upper atmosphere Global Observation Network （1UGONET）. The objective of this paper is to describe the infrastructure and tools developed by IUGONET. We focus on the data analysis software. It is written in Interactive Data Language （IDL） and is a plug-in for the THEMIS Data Analysis Software suite （TDAS）, which is a set of IDL libraries used to visualize and analyze satellite- and ground-based data. We present plots of upper atmospheric data provided by IUGONET as examples of applications, and verify the usefulness of the software in the study of polar science. We discuss IUGONET＇s new and unique developments, i.e., an executable file of TDAS that can run on the IDL Virtual Machine, IDL routines to retrieve metadata from the IUGONET database, and an archive of 3-D simulation data that uses the Common Data Format so that it can easily be used with TDAS.