Review
Geochemistry & Geophysics
N. Uchida, R. Burgmann
Summary: Research has shown that there were indications of a potential great megathrust earthquake in NE Japan before the 2011 Tohoku earthquake, but a consensus assessment of the hazard was lacking. Since the earthquake, studies have made significant progress in revealing aspects such as coseismic rupture, aftershocks, and slow earthquakes.
REVIEWS OF GEOPHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Liming He, Lixin Wu, Kosuke Heki, Cong Guo
Summary: This study presents the anomalities of total electron content in the ionosphere before the 2011 M(w)9.0 Tohoku-oki earthquake, observed in northern Australia by the Global Navigation Satellite System (GNSS) stations. The onset time of the anomaly, determined by the Akaike's information criterion, is very close to the time observed in Japan. The positive TEC anomalies in Australia appear on the same longitude as the land area of NE Japan, supporting the model that electric fields within the ionosphere redistribute the electrons before large earthquakes.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Multidisciplinary Sciences
Piero Bellanova, Mike Frenken, Yuichi Nishimura, Jan Schwarzbauer, Klaus Reicherter
Summary: The 2011 Tohoku-oki tsunami caused massive damage along the northern Japanese Aomori coast, with the coastal control area being inundated up to 550 m inland. A previously undocumented woody-organic tsunami deposit was discovered, improving understanding of the documented part of the tsunami inundation and reducing underestimation.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Aerospace
Keke Xu, Rong He, Kezhao Li, Ankang Ren, Zhenhua Shao
Summary: By focusing on high-precision GNSS data processing and analysis, the study reveals the dynamic evolution of tectonics and crustal deformation along subduction zones. Common Mode Errors are removed, deformation signals are extracted, and regional spatiotemporal filtering is utilized to comprehensively display crustal motion characteristics.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Remote Sensing
Ankang Ren, Keke Xu, Zhenhua Shao, Xinqi Liu, Xiaoyi Wang
Summary: It is found that colored noise in GNSS time series has significant impact on parameter estimation of general linear trajectory models. To overcome this issue, maximum likelihood estimation is used to estimate the colored noise and a nonlinear least square algorithm with colored noise as the stochastic model is employed to calculate timescale parameters. The method is validated through simulation experiments and has shown significant improvements in reducing iteration times and decreasing parameter estimation deviations compared to traditional methods.
Correction
Multidisciplinary Sciences
Su-Yang Wang, Hai-Yang Zhuang, Hao Zhang, Hong-Jun He, Wei-Ping Jiang, Er-Lei Yao, Bin Ruan, Yong-Xin Wu, Yu Miao
Summary: A correction to the paper has been published.
NATURE COMMUNICATIONS
(2021)
Article
Geochemistry & Geophysics
Keisuke Yoshida
Summary: Fluid behavior in the crust plays a key role in earthquake occurrence by reducing fault strength and leading to localized high seismic wave attenuation in fault zones. This study examined near-source attenuation in a region of intense swarm activity triggered by fluid movement following the 2011 Tohoku-Oki earthquake in Japan. The method used in this study may be helpful in detecting high pore pressure anomalies at depth and understanding their relationship to earthquake occurrence.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Chemistry, Analytical
Dong-Hyo Sohn, Byung-Kyu Choi, Sungshil Kim, Sun-Cheon Park, Won-Jin Lee, Pil-Ho Park
Summary: The study on decaying post-seismic deformation on the Korean Peninsula indicates that crustal movement is gradually returning to its pre-earthquake motion, with the recovery pattern influenced by regional geologic structures and time.
Article
Geosciences, Multidisciplinary
Yuki Kodera, Naoki Hayashimoto, Koji Tamaribuchi, Keishi Noguchi, Ken Moriwaki, Ryo Takahashi, Masahiko Morimoto, Kuninori Okamoto, Mitsuyuki Hoshiba
Summary: After the 2011 Tohoku-Oki earthquake, the Japan Meteorological Agency made significant improvements to their earthquake early warning system by implementing new ground motion prediction methods and incorporating new observation facilities. These updates enhanced the accuracy and timeliness of earthquake predictions, showing substantial progress over the 10 years since the Tohoku-Oki earthquake.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Multidisciplinary Sciences
Kai Zhang, Yanru Wang, Yu Luo, Dineng Zhao, Mingwei Wang, Fanlin Yang, Ziyin Wu
Summary: The near-trench coseismic rupture behavior of the 2011 Tohoku-Oki earthquake is poorly understood due to lack of near-field observations. This study used differential bathymetry estimates with improved horizontal resolutions to investigate the near-trench coseismic slip behaviors. The results revealed a velocity-strengthening behavior in the shallow fault and significant off-fault deformation features near the backstop interface outcrop.
NATURE COMMUNICATIONS
(2023)
Article
Geology
Ken Ikehara, Kazuko Usami, Tomohisa Irino, Akiko Omura, Robert G. Jenkins, Juichiro Ashi
Summary: Deep-sea turbidite deposits are valuable tools for submarine paleoseismology. By analyzing the event deposits from the 2011 Tohoku-oki earthquake and tsunami, researchers found that the deposits originated from multiple sources, indicating widespread seafloor disturbances. Different types of event deposits reflect varying sediment transport pathways, with limited long-distance transport observed despite the wide spatial distribution.
SEDIMENTARY GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Toshiya Fujiwara
Summary: Repeated multibeam bathymetric surveys were crucial in understanding the distribution of coseismic seafloor displacement caused by the 2011 Tohoku-oki earthquake. Large seafloor displacements were observed in the main rupture area, while smaller displacements were detected tens of kilometers away from the primary rupture zone.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Astronomy & Astrophysics
Ryoya Ikuta, Ryoto Oba, Daiki Kiguchi, Tomoya Hisada
Summary: The investigation revealed that the correlation between observed GNSS-based ionospheric total electron content (TEC) and large earthquakes as claimed by Iwata and Umeno (2016, ) and Iwata and Umeno (2017, ) is not significant during normal days. Furthermore, there are flaws in the criteria used for distinguishing preseismic ionospheric disturbances from other non-earthquake phenomena.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Tatsuya Kubota, Tatsuhiko Saito, Hiroaki Tsushima, Ryota Hino, Yusaku Ohta, Syuichi Suzuki, Daisuke Inazu
Summary: Recent studies have shown that ocean-bottom pressure gauges can record seismic waves in addition to tsunamis and seafloor permanent displacements. A method has been developed to extract dynamic ground motion waveforms from complex OBP data, successfully extracting low-frequency vertical seismograms. This will be vital for understanding earthquake ruptures, tsunami generation processes, and real-time tsunami forecasts.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Yulu Fan, Peng Zhang, Chengjun Feng, Jing Meng, Bangshen Qi, Jiming Wang, Chengxuan Tan
Summary: The impact of the Tohoku-Oki 3.11 M9.0 earthquake on the stability of faults in the Tangshan seismic region was investigated. The tectonic environment changed rapidly after the earthquake, but gradually returned to the pre-earthquake state. The stress accumulation level of major faults decreased after the earthquake and then began to gradually increase. The fault activity was strongest in the central and northern parts of the region, followed by the southern and western parts, and weakest in the eastern part.
FRONTIERS IN EARTH SCIENCE
(2022)
Editorial Material
Geosciences, Multidisciplinary
Hiroaki Takahashi, Nobuo Takai, Masahiro Chigira, Guojie Meng, Saeko Kita, Takuji Yamada
EARTH PLANETS AND SPACE
(2020)
Article
Environmental Sciences
Hiroshi L. Tanaka, Haruhisa Nakamichi, Masato Iguchi
Article
Environmental Sciences
Alexandros P. Poulidis, Atsushi Shimizu, Haruhisa Nakamichi, Masato Iguchi
Summary: The study introduces a high-resolution modelling-based approach for forecasting tephra hazards from volcanic eruptions. By analyzing data from the Sakurajima volcano eruption on July 16, 2018, key information is provided for potential early warning systems.
Article
Geosciences, Multidisciplinary
Takuji Yamada, Meitong Duan, Jun Kawahara
Summary: The study found that during the 2011 Tohoku earthquake, small earthquakes at the edges of large slip zones showed high stress drops, indicating high frictional strength and suppressed coseismic slip. Stress drops of small earthquakes in some areas likely decreased after the 2011 Tohoku earthquake, suggesting a reduction in frictional strength due to aftershock activity. This supports the idea that frictional properties on a subducting plate interface can be monitored by stress drops of small earthquakes.
EARTH PLANETS AND SPACE
(2021)
Article
Environmental Sciences
Atsushi Shimizu, Masato Iguchi, Haruhisa Nakamichi
Summary: The study on volcanic ash monitoring around Sakurajima volcano in Kagoshima, Japan showed a correlation between extinction coefficients and volcanic activity, but not an absolute correspondence. Changes in wind direction may lead to peaks in extinction coefficients, which do not necessarily coincide with peaks in ash fall density, possibly due to differences in particle size.
Article
Geosciences, Multidisciplinary
Midori Koike, Haruhisa Nakamichi
Summary: This study reveals that rapid dike intrusion can trigger seismic activity and geological deformation, with hypocenters and mechanism azimuths changing over time and space. The T-axes of the shallow cluster are parallel to the opening direction of the dike, while the P-axes and T-axes of the deep cluster have different distribution directions.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Hiroshi L. Tanaka, Haruhisa Nakamichi, Keiichi Kondo, Shoichi Akami, Masato Iguchi
Summary: This study applies a new data assimilation method called particle filter to a volcanic plume tracking model, and demonstrates its reliability and usefulness in preventing volcanic hazards by assimilating Multi-parameter (MP) radar observations. The particle filter algorithm computes statistical likelihood for each ash particle in the model based on the observed MP radar data, with high likelihood particles being retained and low likelihood particles being removed. The study determines a proper threshold value for resampling model particles, and shows a reasonable mix of observed, predicted, and resampled data, filling the open space between the prediction and observation.
JOURNAL OF DISASTER RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Haruhisa Nakamichi, Yoshiharu Hirayama, Toshiharu Ikeda, Hiroshi Ando, Keiji Takeuchi
Summary: The performance of a multi-channel seismometer system with phase-shifted optical interferometry was improved by introducing new sensors and a processing unit. The system was successfully deployed at Sakurajima Volcano and observed eruption events and lightning strikes. The study evaluated the system's performance in observing volcanic earthquakes and noise caused by lightning, showing that the new sensor can accurately observe earthquake events and is not affected by lightning. Additionally, the system was found to be effective in array analysis of volcanic earthquakes.
JOURNAL OF DISASTER RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Masato Iguchi, Haruhisa Nakamichi, Kosei Takishita, Alexandros P. Poulidis
Summary: This study focuses on the simulation of eruption activities in Sakurajima volcano, including volcanic ash eruption rate and plume height. The simulation is conducted using discrete values and validated with meteorological predictions and measurements. The results show a good agreement between the simulated values and actual observations.
JOURNAL OF DISASTER RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Eisuke Fujita, Hiroyuki A. Shimizu, Haruhisa Nakamichi
Summary: This study used numerical simulations to evaluate the damage caused by volcanic hazards, particularly lava flows. The study found that using high-precision terrain data can accurately simulate the distribution of lava flows and determine their arrival time. These findings are valuable for risk and crisis management.
JOURNAL OF DISASTER RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Magfira Syarifuddin, Satoru Oishi, Haruhisa Nakamichi, Masayuki Maki, Ratih Indri Hapsari, Hanggar Ganara Mawandha, Nurnaning Aisyah, Ahmad Basuki, Agoes Loeqman, Makoto Shimomura, Masato Iguchi
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2020)
Review
Geosciences, Multidisciplinary
Masato Iguchi, Haruhisa Nakamichi, Takeshi Tameguri
JOURNAL OF DISASTER RESEARCH
(2020)
Article
Geosciences, Multidisciplinary
Masato Iguchi, Haruhisa Nakamichi, Hiroshi Tanaka, Yusaku Ohta, Atsushi Shimizu, Daisuke Miki
JOURNAL OF DISASTER RESEARCH
(2019)
Article
Geosciences, Multidisciplinary
Haruhisa Nakamichi, Masato Iguchi, Hetty Triastuty, Hery Kuswandarto, Iyan Mulyana, Umar Rosadi, Hendra Gunawan, Gude Suantika, Nurnaning Aisyah, Agus Budi-Santoso, I. Gusti Made Agung Nandaka
JOURNAL OF DISASTER RESEARCH
(2019)
Article
Geosciences, Multidisciplinary
Masato Iguchi, Haruhisa Nakamichi, Kuniaki Miyamoto, Makoto Shimomura, I. Gusti Made Agung Nandaka, Agus Budi-Santoso, Sulistiyani, Nurnaning Aisyah
JOURNAL OF DISASTER RESEARCH
(2019)