Social Implementation of Tsunami Prediction System on Wakayama by Using DONET Information

High possibility of occurrence of earthquake with M9 or lager in the Nankai subduction zone was pointed out by Cabinet Office of Japanese government. Local governments along the area revised estimation of tsunami damages and attempt to reconstruct action plans for the disaster prevention. However, according to Cabinet office of Japanese government, the coastal area near the rupture zone receives huge tsunami within a few minutes after the earthquake happens. To take actions against the severe situation, we need a high-speed, and high-accurate tsunami prediction system. Baba et al. (2014) investigated the possibility for use of a concept of tsunami amplification in the early tsunami prediction. They computed tsunami waveforms at the twenty pressure gauges of dense ocean floor network system for earthquakes and tsunamis (DONET) and at prediction points near shore. They found clear correlations between them because tsunami height basically depends on the topography (bathymetry) during its propagation. In this study, an early tsunami prediction system using the concept of tsunami amplification was societally implemented in 6 regional areas in Wakayama Prefecture. We constructed a tsunami database that contains pre-computed tsunamis offshore and nearshore from 1506 earthquake scenarios may occur in the Nankai subduction zones. The new system detects first arrivals of earthquake and tsunami from DONET data in real time, and calculate average value of absolute observed pressure values among twenty DONET stations. The value is used to select an appropriate scenario from the tsunami database. Prediction accuracy of the system was also investigated by using cases of the 1944 Tonankai earthquake and the scenario earthquake provided by the Cabinet office. As a result, we found that predicted inundation area to be overestimated as the safety of the prediction.南海トラフの沈み込み帯において，M9クラス巨大地震とそれにともなう巨大津波の発生の可能性が内閣府により指摘されて久しい。この津波被害想定によると，地震域近傍の沿岸地域では地震発生から数分後に巨大な津波が到達してしまうため，津波防災に向けた行動計画の再構築や人的被害軽減のための迅速な対応策の検討が極めて重要になる。その対応策のひとつとして，高速かつ高精度な即時津波予測が有効と考えられる。本研究では，地震と津波観測に向けた稠密海底観測網(DONET)による沖合観測網を利用した即時津波予測システムを構築し，和歌山県沿岸6地域において実装を行い，その有効性の検討を行った。本システムにより，地震と津波の初動到達時間を即時評価できること，沿岸津波高や浸水域の即時予測が可能であることを示した。さらに，1944年昭和東南海地震の事例と内閣府のM9クラス巨大地震の波源シナリオを用いて本システムの予測精度を検証した。本システムで即時予測される沿岸津波高や浸水域面積はやや過大評価傾向にあるものの，おおむね安全側の予測結果となり，津波防災上有効なシステムであることを示した

Seismic Velocity Structure in and around the Japanese Island Arc Derived from Seismic Tomography Including NIED MOWLAS Hi-net and S-net Data

Japanese Islands are composed of four plates, with two oceanic plates subducting beneath the two continental plates. In 2016 the National Research Institute for Earth Science and Disaster Resilience (NIED) Seafloor Observation Network for Earthquakes and Tsunamis along the Japan Trench (S-net) started seismic observation of the offshore Hokkaido to Boso region in the Pacific Ocean, and Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) was transferred to NIED. We add the NIED S-net and DONET datasets to NIED high-sensitivity seismograph network (Hi-net) and full range seismograph network (F-net) datasets used in the previous study and obtain the three-dimensional seismic velocity structure beneath the Pacific Ocean as well as Japanese Islands. NIED S-net data dramatically improve the resolution beneath the Pacific Ocean at depths of 10–20 km because the seismic stations are located above the earthquakes and on the east side of the Japan Trench. We find a NS high-Vp zone at depths of 20–30 km. The 2018 Eastern Iburi earthquake occurred below the northern part of this high-V zone. The coseismic slip plane of the 2011 Tohoku-oki earthquake has low Vp/Vs, but its large slip region has high Vp. The broad low-Vp/Vs region may play a role in large earthquake occurrence

Magnetization Process of Kagome-Lattice Heisenberg Antiferromagnet

The magnetization process of the isotropic Heisenberg antiferromagnet on the kagome lattice is studied. Data obtained from the numerical-diagonalization method are reexamined from the viewpoint of the derivative of the magnetization with respect to the magnetic field. We find that the behavior of the derivative at approximately one-third of the height of the magnetization saturation is markedly different from that for the cases of typical magnetization plateaux. The magnetization process of the kagome-lattice antiferromagnet reveals a new phenomenon, which we call the "magnetization ramp".Comment: 4 pages, 5figures, accepted in J. Phys. Soc. Jpn

Crustal structure and growth of the Forearc region of Izu-Ogasawara arc

（独）海洋研究開発機構(JAMSTEC)では、2002年から伊豆・小笠原・マリアナ島弧において、大陸地殻の生成過程を明らかにすることを目的に構造調査を進め、現在の島弧地殻のボリュームより多くの玄武岩マグマが必要で島弧地殻を生成する過程でマフィックな島弧地殻の一部をマントル内に戻していること（Takahashi et al., 2007, 2008; Tatsumi et al., 2008）、火山フロントと背弧側の地殻の厚さ分布には相関があり過去のリフティングが検出されたこと（Kodaira et al., 2009）などがわかってきた。前弧域の地殻に関しては、厚い地殻と薄い地殻が存在すること（Takahashi et al., 2011）、地磁気異常から島弧的な構造があること（Yamazaki and Yuasa, 1998）がわかっているが、地殻構造から実証されていなかった。前弧域の地殻構造を求め、地殻進化の影響をどの程度受けているのか、前弧域の島弧成長を明らかにするために、（独）海洋研究開発機構の深海調査船「かいれい」を用いて人工地震探査を行った。 地震探査の測線は、新黒瀬からスミス海脚、第二東鳥島海丘、大町海山を通って、小笠原トラフに至る。得られた速度構造から前弧域は25km程度の地殻の厚い部分と10～15km程度の薄い部分があることが明らかになった。厚い地殻は、北緯32.5度付近、スミス海脚、第二東鳥島海丘、大町海山の下に分布する。新黒瀬側は厚い地殻を持たない。大町海山の内部には異常に厚い下部地殻が分布する。薄い地殻が分布するところでは、堆積層が厚く地殻の厚さの半分近くを占める。大町海山以外の地殻が厚く分布するところでは、P波速度6km/sの速度コンターが上に凸、7km/sの速度コンターが下に凸の形状を示す。火山フロントに沿った地殻構造では、むしろ6km/s以下の速度を持つ層が厚いことが示されている（Kodaira et al., 2007）。これは、前弧域下の島弧地殻は、火山フロント下と比較して未分化な物質を多く含むことを示唆おり、過去の掘削結果とも整合する（e.g., Taylor, 1992）。前弧海盆下の島弧地殻の分布は、地磁気異常の空間分布（Yamazaki and Yuasa, 1998）とよく合致する。新黒瀬周辺で見られる地磁気異常は、本研究から明らかになった地殻が薄く地殻全体が盛り上がっている形状と合致する。伊豆小笠原島弧の本州弧への衝突が新黒瀬の浅海部を作っているものと示唆される。SCG66-03発表要旨 / 日本地球惑星科学連合2012年大会（2012年5月20日～5月25日, 幕張メッセ国際会議場） / 日本惑星科学連合の許諾に基づき本文ファイルを掲

構造研究に基づく南海トラフ（西部）地震発生帯のプレート形状および速度構造の3次元モデル

Great interplate earthquakes have repeatedly occurred in pairs along the Nankai Trough. In order to reduce a great deal of damage to coastal area from both strong ground motion and tsunami generation, it is necessary to understand rupture synchronization and segmentation of the Nankai megathrust earthquake. For a precise estimate of the rupture zone of the Nankai megathrust event based on the knowledge of realistic earthquake cycles and variations of magnitude, it is important to know the geometry and property of the plate boundary of the subduction seismogenic zone. To improve a physical model of the Nankai Trough seismogenic zone, the large-scale high-resolution wide-angle and reflection (MCS) seismic studies, and long-term observation have been conducted since 2008. Marine active source seismic data have been acquired along grid two-dimensional profiles having the total length of ~800km per year. A three-dimensional seismic tomography using active and passive seismic data observed both land and ocean bottom stations have been also performed. This study is part of 'Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. The seismic survey was conducted off the Tokai area including the onshore survey across the eastern Kii Peninsula in 2012, the final year of this project. Compiling those studies provides a three-dimensional plate geometry and velocity structure models of the western Nankai Trough at the moment. Although their reliability and resolution should be evaluated, these models can be applied to a numerical simulation to examine if the observed rupture zone of the historical event can be reproduced. We will also try to construct more fine-scale model for the entire Nankai Trough area.SSS31-P15ポスター要旨 / 日本地球惑星科学連合2013年大会（2013年5月19日～5月24日, 幕張メッセ国際会議場） / 日本惑星科学連合の許諾に基づき本文ファイルを掲載http://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr10-11/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr11-09/

Association of plasma thioredoxin-1 with renal tubular damage and cardiac prognosis in patients with chronic heart failure

AbstractBackgroundThioredoxin-1 (Trx-1) is an abundant 12.5kDa redox protein expressed in almost all eukaryotic cells that protect against the development of heart failure and kidney dysfunction. Plasma Trx-1 levels are considered as a reliable marker for oxidative stress. However, it remains to be determined whether plasma Trx-1 levels can predict cardiac prognosis in patients with chronic heart failure (CHF).Methods and resultsWe measured plasma Trx-1 levels and urinary β2-microglobulin–creatinine ratio (UBCR), a marker for renal tubular damage, in 156 consecutive patients with CHF and 17 control subjects. The patients were prospectively followed for a median follow-up period of 627 days and 46 cardiac events were observed. The patients with cardiac events had significantly higher plasma Trx-1 levels and UBCR levels than the cardiac event-free patients. Multivariate Cox proportional hazard analysis revealed that an elevated Trx-1 level was independently associated with poor outcome in patients with CHF after adjustment for confounding factors (hazard ratio, 1.74; 95% confidence interval, 1.33–2.29; p<0.0001). UBCR was increased with higher plasma Trx-1 levels. Kaplan–Meier analysis demonstrated that the highest Trx-1 tertile was associated with the highest risk of cardiac events.ConclusionPlasma Trx-1 level was associated with renal tubular damage and cardiac prognosis, suggesting that it could be a useful marker to identify patients at high risk for comorbid heart failure and renal tubular damage

Enabling Secured Traceability of Fishery Products Using 2D Code and Digital Encryption

Technologies that enable traceability for fishery products are increasing their demands. Recently proposed technologies are mainly based on disposal RF(IC) tags which are able to record information directly onto them. However, the current systems based on RF tags have problems of expensive price of tags, and weakness of reading information if applied onto surface of products containing much water, which prevents to construct practically feasible systems using the RF tags. To provide a traceability system that uses much inexpensive media and that assures as high security as the RF tags, we propose a system based on a combination of printed 2D codes and internet connection, with security control similar to on-line electronic transactions. The proposed system identifies a fishery product by giving it a unique serial ID, which is issued by a database server, and printed in 2D code onto a paper or a plastic plate, which is directly put on the product. All the trace information sent from client (producer, transporters, and retailer) via internet is associated to the ID and stored to the server. Since 2D code is able to be read by such as mobile phones with built-in camera, a consumer is able to get history of the product with a single scanning operation. For the weakness of printed codes against duplication by copying, we propose a method to identify its validity by digital encryption, along with identification by weight information. The system is assured its usability by a series of experiments conducted for the distribution of cultured flounder in Hakodate, Japan.Keywords: Mobile Phone, Fisheries Economics, Falsification, Brand Fish, 2D Code, Fish Processing, Marketing, And Consumption, TraceabilityKeywords: Mobile Phone, Fisheries Economics, Falsification, Brand Fish, 2D Code, Fish Processing, Marketing, And Consumption, Traceabilit

Size-selective encapsulation property of unimolecular reverse micelle consisting of hyperbranched D-glucan core and L-leucine ethyl ether shell

金沢大学理工研究域自然システム学系The synthesis of a unimolecular reverse micelle (3) consisting of hyper-branched D-glucan as the core and L-leucine ethyl ester as the shell was accomplished through the carbamation reaction of the hyperbranched D-glucan (1) with the N-carbonyl L-leucine ethyl ester (2) in pyridine at 100 °C. The polymer 3 was soluble in a large variety of organic solvents, such as methanol, acetone, chloroform, and ethyl acetate, and insoluble in water, which remarkably differed from the solubility of 1. The solubilities of 3 were also changed by the substitution degrees of the L-leucine moiety. The encapsulation ability of 3 toward water-soluble dyes has been investigated. These results indicated that 3 was a unimolecular reverse micelle with an encapsulation ability toward hydrophilic dye molecules. In addition, 3 showed an molecular size-selective encapsulation ability. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Velocity structure of the fore-arc region of the Ogasawara Ridge and distribution of horizons

小笠原海嶺はフィリピン海プレート上の島弧地殻としては、もっとも古い島弧の一つとして島弧生成時の地殻を含む地殻が分布すると知られている（例えば、Ishizsuka et al., 2006）。これらのことは、これまでに行われてきた構造探査結果からも示唆されている。海嶺を横断する調査からは、P 波速度6.4-6.6 km/s の上部地殻とP 波速度7.0-7.2 km/s の下部地殻が同定された（Takahashi et al., 2009）。しかし、海嶺軸に沿った方向の調査からは、海洋性地殻と同等の薄い地殻の分布が明らかになり、海嶺の最浅部近傍の狭いエリアに薄い地殻が存在することが明らかになっている（Kodaira et al., 2012）。しかもその厚さは、海嶺に沿った方向に大きく変化する。一方、しんかい6500 を用いた海底観察からは、boninite、fore-arc basalt、gabbro、peridotite が分布していることが明らかになっており（Ishizuka et al.,2006）、オフィオライトの構造、つまり島弧生成前の古い海洋性地殻が存在しているのではないか、と議論された。太平洋プレート上の構造との共通的な特徴が地震学的に確認できるかどうか、この層序の海嶺の前弧域直下への連続性を確認するため、2011 年に構造探査を実施した。これらの構造は島弧の初期生成の鍵になるため、IODP の掘削提案も提出された。紹介する調査は、このIODP 掘削提案の事前調査の一環として行われた。調査は（独）海洋研究開発機構の深海調査船「かいれい」を用いて行われた。マルチチャンネル反射法探査データのみならず（444channels, 25 m group interval）、海底地震計を用いた屈折法探査データも取得した。使用したエアガンは総容量7800 cu.in.のAPG ガンで、反射法探査向けには50 m、屈折法探査向けには200 m 間隔で発振した。測線長は約250 kmで、海底地震計43 台を5 km 間隔で設置した。得られた反射断面は非常に複雑な様相を呈する。少なくとも測線全体に渡って連続する反射面は見当たらない。いくつかの小海山があるが、これらの海山はなだらかな傾斜をしており、また火山フロント上の海山で見られるようなすそ野に広がる厚い堆積物も見られない。海底地震計の記録も、海底地震計直上から40?60 km の範囲でしか初動が読み取れず、複雑な速度構造が分布していることを示唆している。peridotite が広く存在していれば、8 km/s 前後の見かけ速度の走時が読み取れるはずだが、そのような部分は、測線の中央部付近の海嶺の一部に限定された。また、初動走時が不連続でジャンプするような低速度層の分布を示唆する記録も得られた。浅部の構造は深部と比較して均質であり、5.0-5.5 km/s、6.0-7.0 km/s の層が広範囲に分布している。以前の調査結果によれば、上盤側の地殻と海洋性地殻が接している場所に本発表の測線があり、部分的に上盤側のperidotite 層がこの測線直下に分布しているものと思われる。海底から約4 秒のところには、比較的明瞭な反射波が読み取れた。本発表では、トモグラフィックインバージョンによる暫定的に決定した速度構造と反射面の分布を紹介する。また、反射記録断面から上盤側の反射面と沈み込む太平洋プレート上面からの反射波を同定し、オフィオライト構造を確認するために、得られた速度構造と海洋性地殻の類似性、相違性を確認する。B21-12発表要旨, 日本地震学会2012年度秋季大会（2012年10月16日～19日, 北海道函館市