Faculty Profiles - ITO Takeo

Papers - ITO Takeo

Division display 1 - 20 of about 73 ／ All the affair displays >>

Probing asthenospheric density, temperature and elastic moduli below the Western United States Reviewed

T. Ito and M. Simons

Science Vol. 322 ( 6032 ) page： 947-951 2011.4

Physics-informed deep learning approach for modeling crustal deformation

Okazaki, T; Ito, T; Hirahara, K; Ueda, N

NATURE COMMUNICATIONS Vol. 13 ( 1 ) 2022.11

Language：English Publishing type：Research paper (scientific journal) Publisher：Nature Communications

The movement and deformation of the Earth’s crust and upper mantle provide critical insights into the evolution of earthquake processes and future earthquake potentials. Crustal deformation can be modeled by dislocation models that represent earthquake faults in the crust as defects in a continuum medium. In this study, we propose a physics-informed deep learning approach to model crustal deformation due to earthquakes. Neural networks can represent continuous displacement fields in arbitrary geometrical structures and mechanical properties of rocks by incorporating governing equations and boundary conditions into a loss function. The polar coordinate system is introduced to accurately model the displacement discontinuity on a fault as a boundary condition. We illustrate the validity and usefulness of this approach through example problems with strike-slip faults. This approach has a potential advantage over conventional approaches in that it could be straightforwardly extended to high dimensional, anelastic, nonlinear, and inverse problems.

DOI： 10.1038/s41467-022-34922-1

Web of Science

Scopus

PubMed

Asthenosphere rheology inferred from observations of the 2012 Indian Ocean earthquake Reviewed

Yan Hu, Roland Bürgmann, Paramesh Banerjee, Lujia Feng, Emma M. Hill, Takeo Ito, Takao Tabei, and Kelin Wang

Nature 2016.10

Complex rupture during the 12 January 2010 Haiti Earthquake Reviewed

R. Briggs, A. Sladen, E. Fielding, C. Prentice, K. Hudnut, P. Mann, F. Taylor, A. Crone, R. Gold, T. Ito and M. Simons

Nature Geoscience 2010.5

Temporary slip speed increases during short-term slow slip events with durations of one to three hours Reviewed

Earth, Planets and Space Vol. 76 ( 45 ) 2024.3

Evaluation of earthquake potential using a kinematic crustal block motion model in Java, Indonesia, based on GNSS observation Reviewed International coauthorship

R. Raharja, T. Ito, I. Meilano

Journal of Asian Earth Sciences: X Vol. 1 2024.1

Present-day land subsidence over Semarang revealed by time series InSAR new small baseline subset technique

Aditiya A., Ito T.

International Journal of Applied Earth Observation and Geoinformation Vol. 125 2023.12

Publisher：International Journal of Applied Earth Observation and Geoinformation

Over the last two decades, Semarang, located in the central region of Java island, Indonesia, has been undergoing significant land subsidence. Mainly attributed to reservoir compaction and fluid extraction, this subsidence has pronounced effects in coastal regions. However, the existing study on the details of subsidence and its application to accurately depict present circumstances has been insufficient. Utilizing the new small baseline subset technique and C-band SAR data from 2015 to 2022, this study delineates the spatial boundaries of land subsidence in Semarang and surrounding areas. Atmospheric effects were mitigated using the GACOS model during InSAR processing. The study reveals dominant vertical movements in Semarang's north coastal area, characterized by rapid and extensive changes. In contrast, horizontal movement shows relatively small changes in number to the east of the study area. Time series analysis indicates maximum subsidence rate of 100–120 mm/year in the northern and eastern part of Semarang and Demak. Available data from GNSS stations ensures the reliability of these findings. The correlation coefficient of 0.86 indicated substantial association between groundwater and deformation. Approximately 20 % of Semarang's land area is affected by land subsidence, which is notably more prevalent in alluvial soils and densely populated regions. In Demak, subsidence is primarily observed in agricultural regions, whereas in Kendal, the 50 mm/year subsidence rate represents a growing concern. This accelerating phenomenon poses substantial risks to the local environment and economic sectors. All authorities must harmonize regulations to force their roles, produce details spatial plan maps, and establish mitigation and adaptation infrastructure to handle the current crisis realistically.

DOI： 10.1016/j.jag.2023.103579

Scopus

Time Series InSAR Analysis over Jakarta Metropolitan Area Invited Reviewed International coauthorship

Agustan, Takeo Ito, Estu Kriswati, Hari Priyadi, Heri Sadmono, Rika Hernawati

2022 IEEE Asia-Pacific Conference on Geoscience, Electronics and Remote Sensing Technology 2023.4

Time Series InSAR for Ground Deformation Observation in Semarang Area, Central Java Reviewed

APSAR 2023 - 2023 8th Asia-Pacific Conference on Synthetic Aperture Radar 2023

Language：English Publishing type：Research paper (international conference proceedings) Publisher：APSAR 2023 - 2023 8th Asia-Pacific Conference on Synthetic Aperture Radar

The initiatives of open data and open platforms, combined with on-demand data processing in Synthetic Aperture Radar (SAR), enable more straightforward and accessible ground deformation research worldwide. The Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC) provides high-quality interferogram combination pairs based on the Small Baseline Subset (SBAS) technique and on-demand InSAR data analysis known as HyP3. HyP3 offers unwrapped phase data from Sentinel-1 satellites and other derived products that can be utilized with open-source deformation software such as Mintpy. This research aims to assess the quality of interferogram combination pairs by configuring networks of perpendicular and temporal baselines for observing ground deformation in Semarang, Central Java, Indonesia. The study demonstrates that HyP3 products enable time series analysis to determine deformation rates. Over 8.4 years, from November 15th, 2014, to April 14th, 2023, the Simpang Lima landmark in Semarang experienced an approximate subsidence rate of -0.87 cm/year. However, the maximum subsidence rate of approximately 11 cm/year was observed in the southeastern part of Semarang.

DOI： 10.1109/APSAR58496.2023.10388980

Scopus

Machine-learning-based detection of volcano seismicity using the spatial pattern of amplitudes Reviewed

Y. Maeda,Y. Yamanaka, T. Ito, S. Horikawa

Geophysical Journal International Vol. 225 ( 1 ) page： 416 - 444 2021.4

Land Subsidence Rate of Jakarta Metropolitan Area Observed By Stacking Sentinel-1 Data

Agustan, A; Kriswati, E; Ito, T; Abdullah, FM; Anantasena, Y; Nugroho, D

2021 IEEE ASIA-PACIFIC CONFERENCE ON GEOSCIENCE, ELECTRONICS AND REMOTE SENSING TECHNOLOGY (AGERS-2021) page： 69 - 72 2021

Publisher：2021 IEEE Asia-Pacific Conference on Geoscience, Electronics and Remote Sensing Technology, AGERS 2021 - Proceeding

The growth of Jakarta metropolitan area as capital city is increase from time to time. Even the rate of population growth tends to decline, but population still stresses Jakarta environment. The surface changes and ground deformation related to city growth can be observed continuously by satellite-based remote sensing. The launch of Sentinel-1 satellite with radar mission through Copernicus, which is a joint initiative of the European Commission and European Space Agency, enables continuous observation of earth's surface. This paper describes a study of ground deformation rate of Jakarta metropolitan area observed by processing Sentinel-1 data based on interferometric Synthetic Aperture Radar method. Only small perpendicular baselines of SAR data pairs are selected from 2015 to 2019 to avoid the use of external Digital Elevation Model data. The land subsidence rate is obtained by stacking the unwrapped phase and it is found that the rate is different across the region. In the western part, the rate is around -2cm/year whereas in the eastern part is around -3cm/year. The pattern and the rate of land subsidence are confirmed by ascending and descending orbit direction.

DOI： 10.1109/AGERS53903.2021.9617239

Web of Science

Scopus

Urgent Joint Seismic Observation Data of the 2016 Kumamoto Earthquakes

SHITO Azusa, MITSUOKA Ayaho, MATSUMOTO Satoshi, MATSUSHIMA Takeshi, AIZAWA Koki, SHIMIZU Hiroshi, UCHIDA Kazunari, KAMIZONO Megumi, TEGURI Yoshiko, NAKAMOTO Manami, MIYAMACHI Rintaro, ICHIYANAGI Masayoshi, OHZONO Mako, OKADA Kazumi, KATSUMATA Kei, TAKADA Masamitsu, TAKAHASHI Hiroaki, TANIOKA Yuichiro, YAMAGUCHI Teruhiro, KOSUGA Masahiro, AZUMA Ryosuke, UCHIDA Naoki, EMOTO Kentaro, OHTA Yusaku, OKADA Tomomi, KAIDA Toshiki, KOZONO Tomofumi, SUZUKI Syuichi, TAKAGI Ryota, DEMACHI Tomotsugu, NAKAHARA Hisashi, NAKAYAMA Takashi, HIRAHARA Satoshi, MATSUZAWA Toru, MIURA Satoshi, YAMAMOTO Mare, IMANISHI Kazutoshi, UCHIDE Takahiko, YOSHIMI Masayuki, AOI Shin, ASANO Youichi, UENO Tomotake, FUJITA Eisuke, ABE Eiji, IIDAKA Takashi, IWASAKI Takaya, KATO Aitaro, KURASHIMO Eiji, SAKAI Shin’ichi, SHIINA Takahiro, SERIZAWA Masato, TANAKA Shinichi, NAKAGAWA Shigeki, HIRATA Naoshi, MASUDA Masataka, MIYAKAWA Koji, YAGI Takeo, WATANABE Atsushi, GOTO Kazuhiko, ITO Takeo, OKUDA Takashi, TERAKAWA Toshiko, HORIKAWA Shinichiro, MAEDA Yuta, MATSUHIRO Kenjiro, YAMANAKA Yoshiko, WATANABE Toshiki, IIO Yoshihisa, KATAO Hiroshi, KANO Yasuyuki, TSUDA Hiroo, MIURA Tsutomu, MURAMOTO Tomoya, YAMASHITA Yusuke, OKUBO Makoto, YAMASHINA Tadashi, OHKURA Takahiro, NAKAO Shigeru, HIRANO Shuichiro, MIYAMACHI Hiroki, YAKIWARA Hiroshi

Zisin (Journal of the Seismological Society of Japan. 2nd ser.) Vol. 73 ( 0 ) page： 149 - 157 2020.10

Earthquake potential in Costa Rica using three scenarios for the Central Costa Rica Deformed Belt as western boundary of the Panama Microplate Reviewed

Luis Alejandro Carvajal Soto, T. Ito, M. Protti, H. Kimura

Journal of South American Earth Sciences Vol. 97 page： 102375 2020.1

Ground Deformation Identification related to 2018 Lombok Earthquake Series based on Sentinel-1 Data Reviewed

Agustan, Rahma, N. Hanifa, Yudi Anantasena, M. Sadly, Takeo Ito

The 4th International Conference of Indonesian Society for Remote Sensing Vol. 280 ( 1 ) 2019.8

Interplate Coupling Distribution along the Nankai Trough in Southwest Japan estimated from the Block Motion Model based on Onshore GNSS and Seafloor GNSS/A Observations Reviewed

H. Kimura, K. Tadokoro and T.Ito

Journal of Geophysical Research Vol. 124 ( 6 ) page： 6140 - 6164 2019.6

Evaluation of the 2012 Indian Ocean coseismic fault model in 3-D heterogeneous structure based on vertical and horizontal GNSS observation, Reviewed

C. Pratama, T. Ito, T. Tabei, F. Kimata, E. Gunawan, Y. Ohta, T. Yamashina, I. Nurding, D. Sugiyanto, U. Muksin, N. Ismail, I. Meilano

AIP Conference Proceedings Vol. 1987 ( 1987 ) page： 020011 2018.7

Spatio-temporal afterslip distribution following the 2011 Tohoku-Oki earthquake using 3D viscoelastic Green's functions Reviewed

T. Ito, S. Suzuki, K. Kachishige, M. Hyodo

AIP Conference Proceedings Vol. 1987 ( 1987 ) page： 020056 2018.7

Coseismic Slip Distribution of the 2 July 2013 Mw 6.1 Aceh, Indonesia, Earthquake and Its Tectonic Implications Reviewed

Endra Gunawan, Sri Widiyantoro, Shindy Rosalia, Mudrik Rahmawan, Daryono, Irwan Meilano, Pepen Supendi, Takeo Ito, Takao Tabei, Fumiaki Kimata, Yusaku Ohta, Nazli Ismail

Bulletin of the Seismological Society of America Vol. 108 ( 4 ) page： 1918 - 1928 2018.6

Transient rheology of the oceanic asthenosphere following the 2012 Indian Ocean Earthquake inferred from geodetic data Reviewed

Cecep Pratama, Takeo Ito, Ryohei Sasajima, Takao Tabei, Fumiaki Kimata, Endra Gunawan, Yusaku Ohta, Tadashi Yamashina, Nazli Ismail, Irwandi Nurdin, Didik Sugiyanto, Umar Muksin, Irwan Meilano

JOURNAL OF ASIAN EARTH SCIENCES Vol. 147 page： 50 - 59 2017.10

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Postseismic motion in the middle-field (100-500 km from the epicenter) geodetic data resulting from the 2012 Indian Ocean earthquake exhibited rapid change during the two months following the rupture. This pattern probably indicates multiple postseismic deformation mechanisms and might have been controlled by transient rheology. Therefore, the relative contribution of transient rheology in the oceanic asthenosphere and afterslip in the oceanic lithosphere should be incorporated to explain short- and long-term transitional features of post seismic signals. In this study, using two years of post-earthquake geodetic data from northern Sumatra, a three-dimensional spherical-earth finite-element model was constructed based on a heterogeneous structure and incorporating transient rheology. A rheology model combined with stress-driven afterslip was estimated. Our best fit model suggests an oceanic lithosphere thickness of 75 km with oceanic asthenosphere viscosity values of 1 x 10(17) Pas and 2 x 10(18) Pa s for the Kelvin and Maxwell viscosity models, respectively. The model results indicate that horizontal landward motion and vertical uplift in northern Sumatra require viscoelastic relaxation of the oceanic asthenosphere coupled with afterslip in the lithosphere. The present study demonstrates that transient rheology is essential for reproducing the rapidly changing motion of postseismic deformation in the middle-field area.

DOI： 10.1016/j.jseaes.2017.07.049

Web of Science

Scopus

Anisotropic Horizontal Thermal Contraction of Young Oceanic Lithosphere Inferred From Stress Release Due To Oceanic Intraplate Earthquakes Reviewed

Ryohei Sasajima, Takeo Ito

TECTONICS Vol. 36 ( 10 ) page： 1988 - 2021 2017.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER GEOPHYSICAL UNION

How freely the oceanic lithosphere contracts horizontally due to thermal contraction is important information, because it reflects the boundary condition of the oceanic lithosphere, which includes information regarding the magnitude of driving/resisting forces of plate tectonics. We investigated the horizontal thermal contraction of young oceanic lithosphere using an analysis of the intraplate stress release due to oceanic intraplate earthquakes (OCEQs) and numerical simulations. The stress release due to OCEQs in young oceanic lithosphere (5-15 Ma) shows significant differences between the spreading directional component and the ridge-parallel component. The extensional stress release of the ridge-parallel component is 6 times as large as that of the spreading directional component, while the compressional stress release of the ridge-parallel component is one seventh that of the spreading directional component. We conducted a numerical simulation of the thermal stress evolution of the oceanic lithosphere to investigate how the difference in the horizontal contraction rates between the spreading direction and the ridge-parallel direction can explain the observed anisotropic stress release. The result indicates that young oceanic lithosphere (5-15 Ma) barely contracts in the ridge-parallel direction (only 0-30% of the spreading directional contraction rate), while it contracts freely in the spreading direction due to the weakness of the oceanic ridge strength and the low-viscosity asthenosphere. From the results, we constrained the magnitude of the basal traction working on the bottom of the oceanic lithosphere to be smaller than 0.44 MPa.
Plain Language Summary How freely the oceanic lithosphere contracts horizontally due to thermal contraction is important information, because it reflects the boundary condition of the oceanic lithosphere, which includes information regarding the magnitude of driving/resisting forces of plate tectonics. We investigated the horizontal thermal contraction of the oceanic lithosphere using an analysis of the intraplate stress release due to oceanic intraplate earthquakes and found a significant anisotropy in the stress release in young oceanic lithosphere, that is, extensional stress release dominates in the ridge-parallel component while compressional stress release dominates in the spreading direction. Using a numerical simulation with the comparison to this observed result, we revealed that young oceanic lithosphere barely contracts in the ridge-parallel direction (only 0-25% of the spreading directional contraction rate), while it contracts freely in the spreading direction. The nearly free spreading directional contraction requires the smallness of the basal resistance traction on the bottom of the oceanic lithosphere, which implies the low-viscosity (weakness) of the oceanic asthenosphere. The ridge-parallel extensional thermal stress due to the estimated small ridge-parallel contraction may play a role in the weakening of the strength of the long oceanic transform faults; therefore, it may contribute to reduce the resistance to the seafloor spreading.

DOI： 10.1002/2017TC004680

Web of Science

Scopus

　 PREV - NEXT 　

<ITO Takeo>

Papers - ITO Takeo