JCOPE-FGO: an eddy-resolving quasi-global ocean reanalysis product     

Kido  Shoichiro  Nonaka  Masami  Miyazawa  Yasumasa 《Ocean Dynamics》2022,72(8):599-619

  相似文献   

2021年日本福岛县冲地震的震源破裂过程分析基于采用经验格林函数方法的波形反演          下载免费PDF全文

吴双兰  野津厚  長坂陽介 《世界地震工程》2021,(2):001-12

利用中小震作为经验格林函数,选取0.2~2.0 Hz频段的强震数据进行波形反演,获得了2021年福岛县冲地震的破裂过程。结果表明:该地震的破裂主要集中在断层面距离震源约25 km的区域内,沿震源向东北延伸约5 km,向西南延伸约20 km;在该区域内,识别出两个滑动量集中的区域,均分布在距离震源约15 km西南侧,主要滑动量集中区域最大滑动量约3.2 m,深度基本与震源一致;次要滑动量集中区域略比主要滑动量集中区域浅约18 km。该震源模型对应矩震级M_w7.3,破裂速度为2.4 km/s。通过选择不同的中小震组合进行波形反演,结果对该震源模型特性无显著影响,揭示了该震源模型的稳健性;基于该震源模型合成反演分析中未使用的强震观测台站强震动,获得的合成波形与观测波形有很好的相关性,充分证明了该震源模型时空特征的可靠性。  相似文献   

Editorial—the 5th International workshop on modeling the ocean (IWMO 2013)   总被引：2，自引：2，他引：0  

Jarle Berntsen  Lie-Yauw Oey  Tal Ezer  Richard Greatbatch  Huijie Xue  Yasumasa Miyazawa 《Ocean Dynamics》2014,64(10):1531-1534

  相似文献   

Presence of high nitrate to phosphate ratio subsurface water in the Tsushima Strait during summer     

Taketoshi Kodama  Akihiko Morimoto  Tetsutaro Takikawa  Masashi Ito  Yosuke Igeta  Shoko Abe  Ken-Ichi Fukudome  Naoto Honda  Osamu Katoh 《Journal of Oceanography》2017,73(6):759-769

To identify water with an excess nitrate concentration to phosphate ratio and its potential source, the nutrient concentrations in the Tsushima Strait (TSS) were investigated over ten cruises in August and September 2007–2014, excluding 2010. On the basis of the Redfield ratio, water with an excess nitrate concentration of >1 μM (positive ExNOx water) was identified below the surface mixed layer during four cruises in 2011–2013. Positive ExNOx water was present mainly in less-saline (<34) waters with a density of 22–25 σ _θ , and 25–75 m depth. However, in August 2012, positive ExNOx was detected in dense (25–25.5 σ _θ ) and deep (50–110 m depth) waters near the salinity maximum, although the salinity during this period was significantly lower than that in other years. The horizontal length of positive ExNOx water was >100 km across the TSS during two cruises in August 2012 and September 2013, respectively. According to multi-regression analysis conducted on the silicate concentration, temperature, and salinity, the silicate concentration was increased in the less-saline subsurface water. The required amount of original freshwater was 10^8–9 m³ day^?1 based on the excess nitrate concentration. This evidence indicates that the positive ExNOx water originated from large river waters such as the Changjiang. Thus, discharged water from the rivers of the East Asia is contributing to the increased N:P ratio in the Tsushima Warm Current, southern Japan Sea.  相似文献   

Fifteen years progress of the TRITON array in the Western Pacific and Eastern Indian Oceans     

Kentaro Ando  Yoshifumi Kuroda  Yosuke Fujii  Tatsuya Fukuda  Takuya Hasegawa  Takanori Horii  Yasuhisa Ishihara  Yuji Kashino  Yukio Masumoto  Keisuke Mizuno  Motoki Nagura  Iwao Ueki 《Journal of Oceanography》2017,73(4):403-426

The Triangle Trans‐Ocean Buoy Network (TRITON) project by the Japan Agency for Marine-Earth Science and Technology began with deployment in the western tropical Pacific Ocean in 1998 and has shifted to steady, long-term observations since 1999. After on-site inter-comparison with the Autonomous Temperature Line Acquisition System mooring system of the Tropical Atmosphere and Ocean (TAO) array by the National Oceanic and Atmospheric Administration, the TRITON array became the international TAO/TRITON array in 2000 as a key component of the Global Ocean and Climate Observing Systems. The TAO/TRITON array took over from the TAO array, which was developed during the Tropical Ocean and Global Atmosphere program (1985–1994), and replaced the western part of TAO with new additional real-time measurements of salinity and ocean currents. In 2001, two TRITON moorings were deployed in the eastern Indian Ocean for capturing the eastern pole of the Indian Ocean Dipole. From this initiative, the Indian Ocean Observing System (IndOOS) was designed, and the Indian Ocean mooring array (Research Moored Array for Africa–Asian–Australian Monsoon Analysis and Prediction) was developed as a key component of IndOOS. In this paper, 15 years of progress in the TRITON project in the western Pacific and eastern Indian Oceans is reviewed with regards to scientific outcomes, technological development, and collaborations with international and domestic partners. Future directions for sustainable observation in the Pacific and Indian Oceans are also discussed.  相似文献   

Evidence for a Tang-Song Dynasty great earthquake along the Longmen Shan Thrust Belt prior to the 2008 <Emphasis Type="Italic">M</Emphasis><Subscript>w</Subscript> 7.9 Wenchuan earthquake,China     

Aiming Lin  Zhikun Ren  Dong Jia  Yosuke Miyairi 《Journal of Seismology》2010,14(3):615-628

The magnitude (M _w) 7.9 Wenchuan earthquake occurred on 12 May 2008 in the Longmen Shan region of China, the transition zone between the Tibetan Plateau and the Sichuan Basin, resulting in widespread damage throughout central and western China. The steep, high-relief eastern margin of the Tibetan Plateau has undergone rapid Cenozoic uplift and denudation accompanied by folding and thrusting, yet no large thrust earthquakes are known prior to the 2008 M _w 7.9 Wenchuan earthquake. Field and excavation investigations reveal that a great historical earthquake occurred in the Sichuan region that ruptured a >200-km-long thrust fault within the Longmen Shan Thrust Belt, China, which also triggered the 2008 M _w 7.9 Wenchuan earthquake. The average co-seismic slip amount produced by this historical earthquake is estimated to be 2–3 m, comparable with that caused by the 2008 Wenchuan earthquake. Paleoseismic and archaeological evidence and radiocarbon dating results show that the penultimate great earthquake occurred in the Sichuan region during the late Tang-Song Dynasty, between AD 800 and 1000, suggesting a recurrence interval of ~1,000–1,200 years for Wenchuan-magnitude (M = ~8) earthquakes in the late Holocene within the Longmen Shan Thrust Belt. This finding is in contrast with previous estimates of 2,000–10,000 years for the recurrence interval of large earthquakes within the Longmen Shan Thrust Belt, as obtained from long-term slip rates based on the Global Positioning System and geological data, thereby necessitating substantial modifications to existing seismic-hazard models for the densely populated region at the eastern marginal zone of the Tibetan Plateau.  相似文献   

Collapse simulation of a four‐story steel moment frame by a distributed online hybrid test     

Tao Wang  Jason McCormick  Nobuya Yoshitake  Peng Pan  Yosuke Murata  Masayoshi Nakashima 《地震工程与结构动力学》2008,37(6):955-974

The collapse of a one‐bay, four‐story steel moment frame is simulated in this study by the proposed peer‐to‐peer (P2P) Internet online hybrid test system. The typical beam hinging mechanism, which is ensured by a strong‐column, weak‐beam design, is reproduced. The plastic hinges at the column bases are taken as the experimental portions, while the superstructure is analyzed numerically by a general‐purpose finite element program. The implicit plastic rotations of the two column bases are treated as boundary displacements. In order to account for the complex behavior of the column bases, the P2P system is modified to use the secant stiffness during iterations, and the physical specimens are designed such that the plastic hinge behavior can be obtained. For this study, the three substructures are distributed to different locations. A large ground motion is repeatedly imposed until the column bases lose their capacity to sustain the gravity load. As a result, significant deterioration is observed at both column bases. The proposed P2P system is thus demonstrated to be able to accommodate multiple‐tested substructures involving unstable behavior. The results suggest that the P2P Internet online hybrid test system provides a reliable means of studying structures up to collapse. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Thank you to 2022 Ocean Dynamics reviewers     

Ezer  Tal  Carniel  Sandro  Amin  Chabchoub  de Camargo  Ricardo  Estrada-Allis  Sheila N.  Gao  Guoping  Greatbatch  Richard J.  Lermusiaux  Pierre F. J.  Liu  Zhiyu  Miyazawa  Yasumasa  Forster  Alejandro Orfila  Panickal  Swapna  Phillips  Helen  Pinones  Andrea  Stanev  Emil  Volker  Christoph  Xu  Fanghua  Young  Emma 《Ocean Dynamics》2023,73(1):35-38

  相似文献   

Applying the adjoint-free 4dVar assimilation to modeling the Kuroshio south of Japan     

Miyazawa  Yasumasa  Yaremchuk  Max  Varlamov  Sergey M.  Miyama  Toru  Aoki  Kunihiro 《Ocean Dynamics》2020,70(8):1129-1149

Ocean Dynamics - Operational ocean nowcast/forecast systems require real-time sampling of oceanic data for representing realistic oceanic conditions. Satellite altimetry plays a key role in...  相似文献   

Longitudinal variability of the equatorial counter electrojet during the solar cycle 24     

Soares  Gabriel  Yamazaki  Yosuke  Matzka  Jürgen  Pinheiro  Katia  Stolle  Claudia  Alken  Patrick  Yoshikawa  Akimasa  Uozumi  Teiji  Fujimoto  Akiko  Kulkarni  Atul 《Studia Geophysica et Geodaetica》2019,63(2):304-319

Studia Geophysica et Geodaetica - Ground and space-based geomagnetic data were used in the investigation of the longitudinal, seasonal and lunar phase dependence of the equatorial counter...  相似文献