小原研究室

主要論文

[2016年]
K.Chao and K.Obara, Triggered Tectonic Tremor in Various Types of Fault Systems of Japan Following the 2012 Mw8.6 Sumatra Earthquake, J. Geophys. Res., 121, 170-187, doi:10.1002/2015JB012566, 2016.
R. Takagi, K.Obara and T.Maeda, Slow slip event within a gap between tremor and locked zones in the Nankai subduction zone, Geophys. Res. Lett., 43, 1066-1074. doi:10.1002/2015GL066987, 2016.
N. Poiata, C. Satriano,J.P.Vilotte, P.Berbard, and K.Obara, Multi-band array detection and location of seismic sources recorded by dense seismic networks, Geophys. J. Int., 205, 1548-1573, doi:10.1093/gji/ggw071, 2016.
Annoura, S., K. Obara, and T. Maeda, Total energy of deep low-frequency tremor in the Nankai subduction zone, southwest Japan, Geophys. Res. Lett., 43, 2562-2567, doi:10.1002/2016GL06778, 2016.
Takemura, S., T. Maeda, T. Furumura, and K. Obara, Constraining the source location of the 30 May 2015 (Mw 7.9) Bonin deep-focus earthquake using seismogram envelopes of high-frequency P waveforms: occurrence of deep-focus earthquake at the bottom of a subducting slab, Geophys. Res. Lett., 43, 9, 4297-4302, doi:10.1002/2016GL068437, 2016
K. Obara and A. Kato, Connecting slow earthquakes to huge earthquakes, Science, 353, (6296), 253-257. doi:10.1126/science.aaf1512, 2016.
Kato, A., J. Fukuda, S. Nakagawa and K. Obara, Foreshock migration preceding the 2016 Mw 7.0 Kumamoto earthquake, Japan, Geophys. Res. Lett., doi:10.1002/2016GL070079, 2016.
Maeda, T., K. Nishida, R. Takagi, and K. Obara, Reconstruction of a 2D seismic wavefield by seismic gradiometry, Prog. Earth Planet. Sci., 3, 31, doi:10.1186/s40645-016-0107-4, 2016.
J. Gomberg, A. Wech, K. Creager, K. Obara, and D. Agnew, Reconsidering earthquake scaling, Geophys. Res. Lett., 43, 6243-6251, doi:10.1002/2016GL069967, 2016.
[2015年]
Takagi, R., K. Nishida, Y. Aoki, T. Maeda, K. Masuda, M. Takeo, K. Obara, K. Shiomi, M. Sato, and K. Saito, A single bit matters: Coherent noise of seismic data loggers, Seism. Res. Lett., 86, 3, 901-907, doi:10.1785/0220150030, 2015.
Maeda, T., K. Obara, M. Shinohara, T. Kanazawa, K. Uehira, Successive estimation of a tsunami wavefield without earthquake source data: A data assimilation approach toward real-time tsunami forecasting, Geophys. Res. Lett., 42, 7923-7932, doi:10.1002/2015GL065588, 2015.
Sandanbata, O., K. Obara, T. Maeda, R. Takagi, and K. Satake, Sudden changes in the amplitude-frequency distribution of long-period tremors at Aso volcano, southwest Japan, Geophys. Res. Lett., 42, 23, 10256-10262, doi:10.1002/2015GL066443, 2015.
Y.Asano, K.Obara and T. Matsuzawa, H. Hirose, Y. Ito, Possible shallow slow slip events in Hyuga-nada, Nankai subduction zone, inferred from migration of very-low-frequency earthquakes, Geophys. Res. Lett., 42, 331-338, doi:10.1002/2014GL062165, 2015.
Y.Yamashita, H.Yakiwara, Y. Asano, H. Shimizu, K. Uchida, S. Hirano, K. Umakoshi, H. Miyamachi, M. Nakamoto, M. Fukui, M. Kamizono, H. Kanehara, T. Yamada, M. Shinohara, K. Obara, Migrating tremor off southern Kyushu as evidence for slow slip of a shallow subduction interface, Science, 348, 676-679, doi:10.1126/science.aaa4242, 2015.
T. Matsuzawa, Y.Asano and K.Obara, Very low frequency earthquakes off the Pacific coast of Tohoku, Japan, Geophys. Res. Lett., 42, 4318-4325, doi:10.1002/2015GL063959, 2015.
A. A. Delorey, K.Chao and K.Obara, P.A.Johnson, Cascading elastic perturbation in Japan due to the 2012 Mw 8.6 Indian Ocean earthquake, Science Advances, 1, e1500468, doi:10.1126/sciadv.1500468, 2015.
[2014年]
Maeda, T., T. Furumura, and K. Obara, Scattering of teleseismic P-waves by the Japan Trench: A significant effect of reverberation in the seawater column, Earth Planet. Sci. Lett., 397, 1, 101-110, doi:10.1016/j.epsl.2014.04.037, 2014.
Takashi Iidaka, Jun Muto, Kazushige Obara, Toshihiro Igarashi and Bunichiro Shibazaki, Trench-parallel crustal anisotropy along the trench in the fore-arc region of Japan, Geophys. Res. Lett., 41, 6, 1957-1963, doi:10.1002/2013GL058359, 2014.
Aitaro Kato, and Kazushige Obara, Step-like migration of early aftershocks following the 2007 Mw 6.7 Noto-Hanto earthquake, Japan, Geophys. Res. Lett., 41, 3864-3869, doi:10.1002/2014GL060427, 2014.
K.Obara, Contribution of Slow Earthquake Study for Assessing the Occurrence Potential of Megathrust Earthquakes, J. Disaster Research, 9, 317-329, 2014.
A. Kato, T.Igarashi and K. Obara, Detection of a hidden Boso slow slip event immediately after the 2011 Mw 9.0 Tohoku-Oki earthquake, Geophys. Res. Lett., doi:10.1002/2014GL061053, 2014.
J. Han, J. Vidale, H. Houston, K. Chao, K. Obara, Triggering of tremor and inferred slow slip by small earthquakes at the Nankai subduction zone in southwest Japan, Geophys. Res. Lett., 41, doi:10.1002/2014GL061898, 2014.
J. Fukuda, A. Kato, K. Obara, S. Miura, T. Kato, Imaging of the early acceleration phase of the 2013-2014 Boso slow slip event, Geophys. Res. Lett., 41, doi:10.1002/2014GL061550, 2014.
[2013年]
Kato, A., T. Igarashi, K. Obara, S. Sakai, T. Takeda, A. Saiga, T. Iidaka, T. Iwasaki, N. Hirata, K. Goto, H. Miyamachi, T. Matsushima, A. Kubo, H. Katao, Y. Yamanaka, T. Terakawa, H. Nakamichi, T. Okuda, S. Horikawa, N. Tsumura, N. Umino, T. Okada, M. Kosuga, H. Takahashi and T. Yamada, Imaging the source regions of normal faulting sequences induced by the 2011 M9.0 Tohoku-Oki earthquake, Geophys. Res. Lett., 40, doi:10.1002/grl.50104, 2013.
Kato, A., J. Fukuda, and K. Obara, Response of seismicity to static and dynamic stress changes induced by the 2011 M9.0 Tohoku-Oki earthquake, Geophys. Res. Lett., 40, doi:10.1002/grl.50699, 2013.
Takashi Iidaka and Kazushige Obara, Shear-wave splitting in a region with newly-activated seismicity after the 2011 Tohoku earthquake, Earth Planets Space, 65, 1059-1064, doi:10.5047/eps.2013.02.003, 2013.
T. Nishimura, T.Matsuzawa and K.Obara, Detection of short-term slow slip events along the Nankai Trough, southwest Japan, using GNSS data, J. Geophys. Res., 118, 3112-3125, doi:10.1002/jgrb.50222, 2013.
T.Matsuzawa, B.Shibazaki and K. Obara, H. Hirose, Comprehensive model of short- and long-term slow slip events in the Shikoku region of Japan, incorporating a realistic plate configuration, Geophys. Res. Lett., 40, 5125-5130, doi:10.1002/grl.51006, 2013.
R. Ishida, Y. Hiramatsu and T. Matsuzawa, K. Obara, Average slip rate at the transition zone on the plate interface beneath the Kii Peninsula, Japan, estimated from deep low-frequency tremors, Earth Planets Space, 65, 1047-1051, doi:10.5047/eps.2013.04.003, 2013.
K. Chao, Z.Peng, H. Gonzalez-Huizar, C. Aiken, B. Enescu, H. Kao, A. Wech, A. Velasco, K. Obara, and T. Matsuzawa, A Global Search for Triggered Tremor Following the 2011 Mw 9.0 Tohoku Earthquake, Bull. Seism. Soc. Am., 103, 1551-1571, doi:10.1785/0120120171, 2013.
[2013年]
T. Nishimura, T. Matsuzawa and K.Obara, 2013, Detection of short-term slow slip events along the Nankai Trough, southwest Japan, using GNSS data, Journal of Geophysical Research,DOI: 10.1002/jgrb.50222.
[2012年]
K.Obara, 2012, New detection of tremor triggered in Hokkaido, northern Japan by the 2004 Sumatra-Andaman earthquake, Geophysical Research Letters,doi:10.1029/2012GL053339.
K.Obara, T.Matsuzawa and S.Tanaka, T.Maeda, 2012, Depth-dependent mode of tremor migration beneath Kii Peninsula, Nankai subduction zone , GeophysicalResearch Letters, 39, L10308,doi:10.1029/2012GL051420.
A.Kato, K.Obara, T. Igarashi, H. Tsuruoka, S. Nakagawa and N. Hirata , 2012, Propagation of Slow Slip Leading Up to the 2011Mw 9.0 Tohoku-Oki Earthquake ,Science , 335, 705-708.
Shibazaki, B., K. Obara, T. Matsuzawa and H. Hirose, Modeling of slow slip events along the deep subduction zone in the Kii Peninsula and Tokai regions, southwest Japan, J. Geophys. Res., 117, B06311, doi:10.1029/2011JB009083, 2012.
[2011年]
K.Obara, T.Matsuzawa, S.Tanaka, T.Kimura, and T.Maeda, Migration properties of non‐volcanic tremor in Shikoku, southwest Japan, Geophys. Res. Lett., 38, L09311, doi:10.1029/2011GL047110, , 2011
K.Obara, Characteristics and interactions between non-volcanic tremor and related slow earthquakes in the Nankai subduction zone, southwest Japan, J. Geodynamics, 52, 229--248, 2011.
T. Maeda, K. Obara, T. Furumura, and T. Saito, Interference of long‐period seismic wavefield observed by the dense Hi‐net array in Japan, J. Geophys. Res., 116, B10303, doi:10.1029/2011JB008464, 2011.
[2010年]
Obara, K., Phenomenology of deep slow earthquake family in southwest Japan: Spatiotemporal characteristics and segmentation, J. Geophys. Res., 115, B00A25, doi:10.1029/2008JB006048, , 2010.
Obara, K. and M. Matsumura, Reverse Propagation of Surface Waves Reflected from a Sea Mountain range in the northwestern Pacific, Bull. Seism. Soc. Am., 100, 1342--1349, 2010.
Obara, K., T. Maeda, S. Tanaka and T. Matsuzawa, Depth-dependent activity of non-volcanic tremor in southwest Japan, Geophys. Res. Lett., 37, L13306, doi:10.1029/2010GL043679, , 2010.
Aoi, S., B. Enescu, W.Suzuki, Y. Asano, K. Obara, T. Kunugi and K. Shiomi, Stress transfer in the Tokai subduction zone from the 2009 Suruga Bay earthquake in Japan, Nature Geoscience, 3, 496--500, 2010.
Hirose, H. and K. Obara, Recurrence behavior of short-term slow slip and correlated non-volcanic tremor episodes in western Shikoku, southwest Japan, J. Geophys. Res., 115, B00A21, doi:10.1029/2008JB006050, , 2010.
Sekine, S., H. Hirose and K. Obara, Along-strike variations in short-term slow slip events in the southwest Japan subduction zone, J. Geophys. Res., 115, B00A27, doi:10.1029/2008JB006059, , 2010.
Ueno, T., T. Maeda, K. Obara, Y. Asano and T. Takeda, Migration of low frequency tremor revealed from multiple array analyses in western Shikoku, Japan, J. Geophys. Res., 115, B00A26, doi:10.1029/2008JB006051, , 2010.
Kimura, H., T. Takeda, K. Obara and K. Kasahara, Seismic Evidence for Active Underplating Below the Megathrust Earthquake Zone in Japan, Science, 329, 210--212, 2010.
Hirose, H., Y. Asano, K. Obara, T. Kimura, T. Matsuzawa, S. Tanaka and T. Maeda , Slow Earthquakes Linked Along Dip in the Nankai Subduction Zone, Science, 330, 1502, , 2010.
Hirose, T., Y. Hiramatsu and K. Obara, Characteristics of short-term slow slip events estimated from deep low-frequency tremors in Shikoku, Japan, J. Geophys. Res., 115, B10304, doi:10.1029/2010JB007608, 2010.
Matsuzawa, T., H. Hirose, B. Shibazaki and K. Obara, Modeling short- and long-term slow slip events in the seismic cycles of large subduction earthquakes, J. Geophys. Res., 115, B12301, doi:10.1029/2010JB007566, 2010.
[2009年]
Obara, K. and T. Maeda, Reverse propagation of T waves from the Emperor seamount chain, Geophys. Res. Lett., 36, L08304, doi:10.1029/2009GL037454, , 2009.
Obara, K., Inhomogeneous distribution of deep slow earthquake activity along the strike of the subducting Philippine Sea Plate, Gondwana Research, 16, 512--526, 2009.
Obara, K. and S. Sekine, Characteristic activity and migration of episodic tremor and slow-slip events in central Japan, Earth Planets Space, 61, 853--862, 2009.
Maeda, T. and K. Obara, Spatiotemporal distribution of seismic energy radiation from low-frequency tremor in western Shikoku, Japan, J. Geophys. Res., 114, B00A09, doi:10.1029/2008JB006043, , 2009.
Ito, Y., K. Obara, T. Matsuzawa and T. Maeda, Very low frequency earthquakes related to small asperities on the plate boundary interface at the locked to aseismic transition, J. Geophys. Res., 114, B00A13, doi:10.1029/2008JB006036, , 2009.
Matsuzawa, T., K. Obara and T. Maeda, Source duration of deep very low frequency earthquakes in western Shikoku, Japan, J. Geophys. Res., 114, B00A11, doi:10.1029/2008JB006044, , 2009.
小原一成, フィリピン海プレート沈み込みに伴う西南日本のスロー地震群の発見, 地震2, 61, S315--S327, 2009.
小原一成, 短期的スロースリップ・深部低周波微動、地震予知連絡会編「地震予知連絡会40年のあゆみ」, 国土地理院, 2009.
小原一成, 独立行政法人防災科学技術研究所、地震予知連絡会編「地震予知連絡会40年のあゆみ」, 国土地理院, 2009.