Refereed papers (in English)

57. Sakuma, H., I. Katayama, K. Kawai, K. Tamura,
A small amount of water reduces the friction of the preferentially oriented montmorillonite gouge,
Applied Clay Science, 243, 107058, https://doi.org/10.1016/j.clay.2023.107058, 2023
56. Okuda, H.*, K. Kawai, H. Sakuma,
Atomic-scale interlayer friction of gibbsite is lower than brucite due to interactions of hydroxyls,
American Mineralogist, 108, 1476-1482, https://doi.org/10.2138/am-2022-8561, 2023
55. Ruj. T.**, G. Komatsu, G. Schmidt, S. Karunatillake, K. Kawai,
Tectonism of late Noachian Mars: Surface signatures from the southern highlands,
Remote Sensing, 14, 5664, 2022
54. Ruj. T.**, G. Komatsu, K. Kawai, H. Okuda, Z. Xiao, D. Dhingra,
Recent boulder falls within the Finsen crater on the lunar far side: An assessment of the possible triggering rationale,
Icarus, 377, 114904, 2022
53. De, K.**, T. Ruj, A. Kundu, N. Dasgupta, K. Kawai,
Evolution of Pyrrhae Fossae, Mars: An explication from the age estimation using the buffered crater counting technique,
Current Science, 121, 906-911, 2021
52. Ruj, T.**, K. Kawai,
A global investigation of wrinkle ridge formation events; Implications towards the thermal evolution of Mars,
Icarus, 369, 114625, doi:10.1016/j.icarus.2021.114625, 2021
[Press Release]
51. Suzuki, Y.*, K. Kawai, R.J. Geller,
Imaging paleoslabs and inferring the Clapeyron slope in D″ beneath the northern Pacific based on high-resolution inversion of seismic waveforms for 3-D transversely isotropic structure,
Physics of the Earth and Planetary Interiors , 321, 106751, doi:10.1016/j.pepi.2021.106751, 2021
[Press Release]
50. Konishi, K., A.F.E. Borgeaud, K. Kawai, R.J. Geller,
ANISOtime: Travel time computation software for laterally homogeneous, transversely isotropic, spherical media,
Seismological Research Letters, 92, 3811–3820, doi:10.1785/0220200306, 2021
[Visit Software Page]
49. Ohtaki, T., S. Tanaka, S. Kaneshima, W. Siripunvaraporn, S. Boonchaisuk, S. Noisagool, K. Kawai, T. Kim, Y. Suzuki, Y. Ishihara, K. Miyakawa, N. Takeuchi,
Seismic velocity structure of the upper inner core in the north polar region,
Physics of the Earth and Planetary Interiors, 311, 106636, doi:10.1016/j.pepi.2020.106636, 2021
48. Okuda, H.*, I. Katayama, H. Sakuma, K. Kawai,
Effect of normal stress on the frictional behavior of brucite: application to slow earthquakes at the subduction plate interface in the mantle wedge,
Solid Earth, 12, 171-186, doi:10.5194/se-12-171-2021, 2021
47. Sakuma, H., K. Kawai, T. Kogure,
Interlayer energy of pyrophyllite: Implications for macroscopic friction,
American Mineralogist, 105, 1204–1211, doi:10.2138/am-2020-7333, 2020
46. Suzuki, Y.*, K. Kawai, R. J. Geller, S. Tanaka, W. Siripunvaraporn, S. Boonchaisuk, S. Noisagool, Y. Ishihara, T. Kim,
High-resolution 3-D S-velocity structure in the D″ region at the western margin of the Pacific LLSVP: Evidence for small-scale plumes and paleoslabs,
Physics of the Earth and Planetary Interiors, 307, 106544, doi:10.1016/2020.106544, 2020
45. Tanaka, S., W. Siripunvaraporn, S. Boonchaisuk, S. Noisagool, T. Kim, K. Kawai, Y. Suzuki, Y. Ishihara, R. Iritani, K. Miyakawa, N. Takeuchi, H. Kawakatsu,
Thai Seismic Array (TSAR) Project,
Bulletin of the Earthquake Research Institute, 94, 1-11, 2019
44. Okuda, H.*, K. Kawai, H. Sakuma,
First‐principles investigation of frictional characteristics of brucite: An application to its macroscopic frictional characteristics,
Journal of Geophysical Research: Sollid Earth, 124, 10423-10443, doi:10.1029/2019JB017740, 2019
43. Borgeaud, A.F.E.*, K. Kawai, R.J. Geller,
Three‐dimensional S velocity structure of the mantle transition zone beneath Central America and the Gulf of Mexico inferred using waveform inversion,
Journal of Geophysical Research: Solid Earth, 124,  9664–9681, doi:10.1029/2018JB016924, 2019
[Press Release] [GeoSpace by AGU]
42. Komatsu, G., R. Ishimaru, N. Miyake, K. Kawai, M. Kobayashi, H. Sakuma, T. Matsui,
The Goshogake mud volcano field, Tohoku, northern Japan: An acidic, high-temperature system related to magmatic volcanism,
Geomorphology, 329, 32-45, doi:10.1016/j.geomorph.2018.12.035, 2019
41. Sakuma, H., K. Kawai, I. Katayama, S. Suehara,
What is the origin of macroscopic friction?,
Science Advances, 4, eaav2268, doi:10.1126/sciadv.aav2268, 2018
(OPEN ACCESS)
[Press Release @UT] [Press Release @NIMS] [Press Release @EurekAlert!]
40. Nishi, M., S. Gréaux, S. Tateno, Y. Kuwayama, K. Kawai, T. Irifune, S. Maruyama,
High-pressure phase transitions of lunar highland anorthosite in the deep Earth’s mantle,
Geoscience Frontiers, 9, 1859-1870, doi:10.1016/ j.gsf.2017.10.002, 2018
(OPEN ACCESS)
39. Yamaya, L.*, A.F.E. Borgeaud, K. Kawai, R.J. Geller, K. Konishi,
Effects of redetermination of source time functions on the 3-D velocity structure inferred by waveform inversion,
Physics of the Earth and Planetary Interiors,  282, 117-143, doi:10.1016/j.pepi.2018.04.012, 2018
38. Gréaux, S., M. Nishi, S. Tateno, Y. Kuwayama, N. Hirao, K. Kawai, T. Irifune, S. Maruyama,
High-pressure phase relation of KREEP basalts: a clue for finding the lost Hadean crust?,
Physics of the Earth and Planetary Interiors, 274, 184-194, doi:10/1016/j. pepi.2017.12.004, 2018
37. Borgeaud, A.F.E.*, K. Kawai, K. Konishi, R.J. Geller,
Imaging paleoslabs in the D′′ layer beneath Central America and the Caribbean using seismic waveform inversion,
Science Advances, 3, e1602700, doi:10.1126/sciadv.1602700, 2017
(OPEN ACCESS)
[Press Release] [Embassy of Switzerland in Japan]
36. Ichikawa, H., S. Yamamoto, K. Kawai, M. Kameyama,
Estimate of subduction rate of island arcs to the deep mantle,
Journal of Geophysical Research: Solid Earth, 121, 5447–5460, doi:10.1002/2016JB013119, 2016
35. Borgeaud, A.F.E. *, K. Konishi, K. Kawai, R.J. Geller,
Finite frequency effects on apparent S-wave splitting in the D” layer: comparison between ray theory and full-wave synthetics,
Geophysical Journal International, 207, 12-28, doi:10.1093/gji/ggw254, 2016
34. Suzuki, Y.*, K. Kawai, K. Konishi, A.F.E. Borgeaud, R.J. Geller,
Waveform inversion for 3–D shear velocity structure of D” beneath the Northern Pacific: Possible evidence for a remnant slab and a ‘passive plume’,
Earth, Planets and Space, 68, 198 (8pp), doi:10.1186/s40623-016-0576-0, 2016
(OPEN ACCESS)
[BLOG]
33. Katayama, I., T. Kubo, H. Sakuma, K. Kawai,
Can clay minerals account for the non-asperity on the subducting plate interface,
Progress in Earth and Planetary Science, 2, 30 (8pp) doi:10.1186/s40645-015-0063-4, 2015
(OPEN ACCESS)
32. Kawai, K., H. Sakuma, I. Katayama, K. Tamura,
Frictional characteristics of single and polycrystalline muscovite and influence of fluid chemistry,
Journal of Geophysical Research: Solid Earth, 120, 6209-6218, doi:10.1002/2015JB012286, 2015
(NOW OPEN ACCESS)
31. Kawai, K., T. Tsuchiya,
Small shear modulus of cubic CaSiO3 perovskite,
Geophysical Research Letters, 42, 2718-2726, 2015
(NOW OPEN ACCESS)
30. Kawai, K., T. Tsuchiya,
Elasticity and phase stability of pyrope garnet from ab initio computation,
Physics of the Earth and Planetary Interiors, 240, 125-131, 2015
29. Ichikawa, H., M. Kameyama, H. Senshu, K. Kawai, S. Maruyama,
Influence of majorite on hot plumes,
Geophysical Research Letters, 41, 7501-7507, 2014
(NOW OPEN ACCESS)
28. Konishi, K., K. Kawai, R.J. Geller, N. Fuji,
Waveform inversion for localized 3-D seismic velocity structure in the lowermost mantle beneath the Western Pacific,
Geophysical Journal International, 199, 1245-1267, 2014
(NOW OPEN ACCESS)
27. Kawai, K., T. Tsuchiya,
P-V-T equation of state of cubic CaSiO3 perovskite from first principles computation,
Journal of Geophysical Research: Solid Earth, 119, 2801-2809, 2014
(NOW OPEN ACCESS)
26. Kawai, K., K. Konishi, R.J. Geller, N. Fuji,
Methods for inversion of body-wave waveforms for localized three-dimensional seismic structure and an application to D” beneath Central America,
Geophysical Journal International, 197, 495-524, 2014
(NOW OPEN ACCESS)
[Astronomy & Geophysics: Sharper eyes on the deep Earth]
25. Ichikawa, H., M. Kameyama, K. Kawai,
Mantle convection with continental drift and heat source around the mantle transition zone,
Gondwana Research, 24, 1080-1090, 2013
24. Ichikawa, H., K. Kawai, S. Yamamoto, M. Kameyama,
Supply rate of continental materials to the deep mantle through subduction channels,
Tectonophysics, 592, 46-52, 2013
23. Tsuchiya, T., K. Kawai, S. Maruyama,
Expanding-contracting Earth,
Geoscience Frontiers, 4, 341-347, 2013
(OPEN ACCESS)
22. Kawai, K., S. Yamamoto, T. Tsuchiya, S. Maruyama,
The second continent: Existence of granitic continental materials around the bottom of the mantle transition zone,
Geoscience Frontiers, 4, 1-6, 2013
(OPEN ACCESS)
21. Kawai, K., T. Tsuchiya,
First principles study on the high-pressure phase transition and elasticity of KAlSi3O8 K-hollandite,
American Mineralogist, 98, 207-218, 2013
(Selected as a Notable Paper by MSA)
20. Konishi, K., K. Kawai, R.J. Geller, N. Fuji,
Waveform inversion of broad-band body-wave data for the S-velocity structure in the lowermost mantle beneath the Indian subcontinent and Tibetan Plateau,
Geophysical Journal International, 191, 305-316, 2012
(NOW OPEN ACCESS)
19. Fuji, N., S. Chevrot, L. Zhao, R.J. Geller, K. Kawai,
Partial derivatives of high-frequency compressional body waves for 3-D Earth structure,
Geophysical Journal International, 190, 522-540, 2012
(NOW OPEN ACCESS)
18. Kawai, K., T. Tsuchiya,
High-P,T phase relations in the NaAlSi2O6 system from first principles computation,
Physics and Chemistry of Minerals, 39, 305-310, 2012
17. Kawai, K., T. Tsuchiya,
First-principles investigations of elasticity and phase transition of grossular garnet,
Journal of Geophysical Research, 117, B02202, doi:10.1029/2011JB008529, 2012
(NOW OPEN ACCESS)
16. Kawai, K., T. Tsuchiya,
Phase stability and elastic properties of the NAL and CF phases in the NaMg2Al5SiO12 system from first principles,
American Mineralogist, 97, 305-314, 2012
15. Kawai, K., R.J. Geller,
Inversion of seismic waveforms for shear wave velocity structure in the lowermost mantle beneath the Hawaiian hotspot,
Physics of the Earth and Planetary Interiors, 183, 136-142, 2010
14. Kawai, K., T. Tsuchiya,
Ab initio investigation of high-pressure phase relation and elasticity in the NaAlSi2O6 system,
Geophysical Research Letters, 37, L17302, doi:10.1029/2010GL044310, 2010
(NOW OPEN ACCESS)
13. Kawai, K., R.J. Geller, N. Fuji,
Waveform inversion for S-wave structure in the lowermost mantle beneath the Arctic: Implications for mineralogy and chemical composition,
Geophysical Research Letters, 37, L16301, doi:10.1029/2010GL043654, 2010
(NOW OPEN ACCESS)
12. Kawai, K., R.J. Geller,
The vertical flow in the lowermost mantle beneath the Pacific from inversion of seismic waveforms for anisotropic structure,
Earth and Planetary Science Letters, 297, 190-198, 2010
[Press Release]
11. Fuji, N., K. Kawai, R.J. Geller,
A methodology for inversion of broadband seismic waveforms for elastic and anelastic structure and its application to the mantle transition zone beneath the northwestern Pacific,
Physics of the Earth and Planetary Interiors, 180, 118-137, 2010
10. Kawai, K., R.J. Geller,
Waveform inversion for localized seismic structure and an application to D” structure beneath the Pacific,
Journal of Geophysical Research, 115, B01305, doi:10.1029/2009JB006503, 2010
(NOW OPEN ACCESS)
9. Kawai, K., T. Tsuchiya,
Temperature profile in the lowermost mantle from seismological and mineral physics joint modeling,
Proceedings of the National Academy of Sciences of the United States of America, 106, 22,119-22,123, 2009
(NOW OPEN ACCESS)
[GRC][Ehime Univ.]
8. Kawai, K., S. Sekine, N. Fuji, R.J. Geller,
Waveform inversion for D” structure beneath northern Asia using Hi-net tiltmeter data,
Geophysical Research Letters, 36, L20314, doi:10.1029/2009GL039651, 2009
(NOW OPEN ACCESS)
7. Kawai, K., T. Tsuchiya, J. Tsuchiya, S. Maruyama,
Lost primordial continents,
Gondwana Research, 16, 581-586, 2009
6. Maruyama, S., A. Hasegawa, M. Santosh, T. Kogiso, S. Omori, H. Nakamura, K. Kawai, D. Zhao,
The dynamics of Big Mantle Wedge, Magma Factory, and Metamorphic -Metasomatic Factory in subduction zones,
Gondwana Research, 16, 414-430, 2009
5. Konishi, K., K. Kawai, R.J. Geller, N. Fuji,
MORB in the lowermost mantle beneath the western Pacific: Evidence from waveform inversion,
Earth and Planetary Science Letters, 278, 219-225, 2009
[Press Release]
4. Kawai, K., R.J. Geller, N. Fuji,
D” beneath the Arctic from inversion of shear waveforms,
Geophysical Research Letters, 34, L21305, doi:10.1029/2007GL031517, 2007
(NOW OPEN ACCESS)
3. Kawai, K., N. Takeuchi, R.J. Geller, N. Fuji,
Possible evidence for a double crossing phase transition in D” beneath Central America from inversion of seismic waveforms,
Geophysical Research Letters, 34, L09314, doi:10.1029/2007GL029642, 2007
(NOW OPEN ACCESS)
(Selected as Editor’s Highlights) [Press Release]
2. Kawai, K., N. Takeuchi, R.J. Geller,
Complete synthetic seismograms up to 2 Hz for transversely isotropic spherically symmetric media,
Geophysical Journal International, 164, 411-424, 2006
(NOW OPEN ACCESS)
1. Suetsugu, D., M. Shinohara, E. Araki, T. Kanazawa, K. Suyehiro, T. Yamada, K. Nakahigashi, H. Shiobara, H. Sugioka, K. Kawai, Y. Fukao,
Mantle discontinuity depths beneath the West Philippine Basin from receiver function analysis of deep-sea borehole and seafloor broadband waveforms,
Bulletin of the Seismological Society of America, 95, 1947-1956, 2005
* Collaboration with graduate student advisee

Refereed papers (in Japanese)

5. 庄司真史, 小林佑介, 河合研志, 佐藤友彦,
視点の水平移動可能なBYOD型地学VR巡検教材の開発,
Development of BYOD-style horizontally movable virtual reality field trip tool for Earth science education,
地学教育, 74, 13-30, https://doi.org/10.18904/chigakukyoiku.74.1_13, 2022
4. 河合研志, 内出崇彦,
P波初動の水平面内振動方向を用いた震央決定の教材:
2011年東北地方太平洋沖地震の発生前後の飛騨地方の微小地震を例にとって
Teaching materials for determination of epicenters using P wave lateral polarity data for small earthquakes in the Hida, Japan, region before and after the 2011 off the Pacific coast of Tohoku Earthquake,
Journal of Geography (Chigaku Zasshi), 128, 465-475, 2019
(OPEN ACCESS)
3. 石川晃, 河合研志 (Ishikawa, A., K. Kawai),
アメリカ,ワイオミング州のリューサイトヒルズ・ランプロアイト
―深部マントルに由来する異常マグマ―
Ultrapotassic magma from the deep mantle, Leucite Hills Lamproite, Wyoming USA
Journal of Geography (Chigaku Zasshi), 124, 515-523, 2015
(OPEN ACCESS)
2. 丸山茂徳, 大森聡一, 千秋博紀, 河合研志, B.F. Windley,
太平洋型造山帯
-新しい概念の提唱と地球史における時空分布-
Pacific-type orogens: New concepts and variations in space and time from present to past,
地学雑誌、120, 115-223
, 2011
1. 河合研志, 土屋卓久, 丸山茂徳
第二大陸
The second continent,
地学雑誌、
119, 1197-1214, 2010

Chapter in book (Refereed)

5. Tsuchiya, T., T. Nakagawa, K. Kawai,
Numerical examination on the dynamics of subducted crustal materials with different densities.
In Core-Mantle Coevolution: A Multidisciplinary approach
Edited by T. Nakagawa, T. Tsuchiya, M. Satish-Kumar, and G. Helffrich), Chapter 6, https://doi.org/10.1002/9781119526919.ch6, 2023
4. Tsuchiya, T., K. Kawai, X. Wang, H. Ichikawa, H. Dekura,
Temperature of the lower mantle and core based on ab initio mineral physics data.
In Deep Earth: Physics and Chemistry of the Lower Mantle and Core
Edited by. H. Terasaki and R. A. Fischer, Wiley, doi:10.1002/9781118992487. Chap.2, pp.13-30, 2016
3. Kawai, K., T. Tsuchiya,
Elasticity of continental crust around the mantle transition zone.
In The Earth’s heterogeneous mantle, Edited by Khan, A., and F. Deschamps, Springer, Chap. 8, pp. 259-274, 2015
2. Ichikawa, H., K. Kawai, S. Yamamoto, M. Kameyama,
The effect of water on supply rate of continental materials to the deep mantle through subduction channels.
In The Earth’s heterogeneous mantle, Edited by Khan, A., and F. Deschamps, Springer, Chap. 9, pp. 275-299, 2015
1. Tsuchiya, T., K. Kawai,
Ab initio mineralogical model of the Earth’s lower mantle,
Edited by. S. Karato, Wiley-Blackwell, doi:10.1016/j.pepi.2018.04.012, pp. 213-243, 2013

Proceedings refereed

1. Funahashi, I., R. Kobayashi, S. Ohmura, K. Kawai,
Molecular dynamic simulations of elastic wave pulses in a copper crystal and a harmonic spring-beads system
Springer Proceedings in Physics, in press.

Patent

1. 河合研志, 庄司真史, 小林佑介,
震源情報可視化システム及び震源情報可視化方法, 特願2016-187518, 9/26/2016

Others

6. 鈴木裕輝, 河合研志,
タイ王国における広帯域地震観測計画 ~観測網の展開~,
新学術 核ーマントル共進化ニュースレターNo.4,
2018
5. 田中聡, 河合研志,
タイ王国における広帯域地震観測計画 ~日本人による地震観測事始〜,
新学術 核ーマントル共進化ニュースレターNo.2,
2018
4. 河合研志,
核マントル境界の温度構造および地球の熱進化, なゐふる, 2013
3. 河合研志, ゲラー・ロバート,
マントル最深部(D”層)の詳細構造 –新しい計算手法による推定-, 東京大学理学系研究科・理学部ニュース, 9月号, 2007
2. 河合研志, 大淵智勝, 五十嵐丈二,
鳥取県西部地震前の水平地殻変動; GPSデータの解析、京都大学防災研究所研究集会13K-4 報告書、地震発生準備過程の物理と観測, 2002
1. 五十嵐丈二, 角森史昭, 河合研志,
地殻応力臨界現象としての東海地震とその発生予測、京都大学防災研究所研究集会13K-4 報告書、地震発生準備過程の物理と観測, 2002