Article
Construction & Building Technology
Mohammad A. Alhassan, Rajai Z. Al Rousan, Moheldeen A. Hejazi, Layla K. Amaireh
Summary: This paper provides an approximate analysis of quadrilateral slabs with different aspect ratios and boundary conditions based on actual two-way action. The hydrostatic point phenomenon is established as a reference point for identifying slabs with actual two-way action, while also introducing material nonlinearity into the design by using extreme positive point moment. The study also normalizes the moment of the plate in both directions and isolates the hydrostatic phenomenon.
ADVANCES IN STRUCTURAL ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Prantik Mandal, Satish Saha, Sudesh Kumar, Sandeep Gupta, Rahul Biswas, Sanjay Kumar, K. Sivaram, B. N. Prasad, M. Saidixit, Raju Prathigadapa, Bhoopender Singh, S. Madhusudan
Summary: A seismic network was deployed in and around Hyderabad city, recording a rare lower-crustal cratonic earthquake. Source parameters and moment tensor solutions were modeled using broadband waveforms, indicating a possible sudden movement due to high fluid pore pressure in the viscous lower crust.
PURE AND APPLIED GEOPHYSICS
(2022)
Article
Multidisciplinary Sciences
Benjamin A. Brooks, Dara Goldberg, John DeSanto, Todd L. Ericksen, Spahr C. Webb, Scott L. Nooner, C. David Chadwell, James Foster, Sarah Minson, Robert Witter, Peter Haeussler, Jeffrey Freymueller, William Barnhart, Johanna Nevitt
Summary: The shallower portions of subduction zone megathrust faults are responsible for the most hazardous tsunamigenic earthquakes on Earth. However, due to the challenges of seafloor observations, it is still unclear how and when these faults slip. Through geodetic surveys before and after the July 29, 2021 Chignik, Alaska earthquake, it was determined that there was cumulative horizontal displacement of approximately 1.4 meters within 60 kilometers from the megathrust front. Similar displacements have only been observed for the 2011 Tohoku earthquake. It is estimated that there was 2 to 3 meters of afterslip on the shallower portion of the megathrust, indicating previous interseismic and coseismic slip. The analysis suggests that by 2.5 months, the shallower and deeper moments on the megathrust had effectively equilibrated, implying that the tsunami potential is not elevated post-earthquake.
Article
Geosciences, Multidisciplinary
Maryam Akbarzadeh Aghdam, Abdolreza Ghods, Farhad Sobouti, Khalil Motaghi, Keith Priestley, Mohammad Enayat
Summary: The Makran subduction zone is difficult to monitor due to limited seismic activity, but a temporary seismic network was installed to investigate the relationship between different regions and detect seismicity. The observed seismicity suggests the presence of structural boundaries and seismically inactive areas.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geochemistry & Geophysics
Keita Chiba
Summary: The study analyzed the spatiotemporal stress states in the aftershock region of the 2005 West Off Fukuoka Prefecture Earthquake through b values and focal mechanism solutions, revealing depth-dependent variations. The results suggest a change in stress state in the deep region and imply a relatively high likelihood of future large earthquakes along the southeastern part of the aftershock region.
PURE AND APPLIED GEOPHYSICS
(2021)
Article
Geochemistry & Geophysics
Wardah Fadil, Shengji Wei, Kyle Bradley, Yu Wang, Yumei He, Eric Sandvol, Bor-Shouh Huang, Judith Hubbard, Myo Thant, Yin Myo Min Htwe
Summary: We have derived a new earthquake focal mechanism catalog for earthquakes with Mw > 4.0 in the Myanmar region from 2016 to 2021. Our results show better correlation with mapped active faults and reveal seismic activity along previously unmapped blind faults. The catalog also provides insights into the activity and characteristics of different fault segments in the region, as well as the deformation processes within the slab.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2023)
Article
Geochemistry & Geophysics
A. K. Abd el-aal, A. Al-Enezi, H. Saadalla, F. Al-Jeri
Summary: A sequence of small/micro earthquakes struck near an oil production field in the northern part of Kuwait on November 15, 2019. The earthquakes ranged between magnitudes of 0.8 to 4.1 and lasted for two days. Modern geophysical analysis revealed that the earthquakes had both anthropogenic and tectonic components.
Article
Geosciences, Multidisciplinary
Stefano Mazzoli, Sergio Nardo, Alessandra Ascione, Valentino Di Donato, Carlo Terranova, Giuseppe Vilardo
Summary: The millimetre accuracy of Synthetic Aperture Radar (SAR) measurements and multi-temporal data analyses provide crucial information on surface displacements caused by strong earthquakes. The analysis of SAR interferometry data allows for a better understanding of the geometry, kinematics, and temporal behavior of earthquake-generating faults, making it a promising technique in the field of earthquake precursors. The study of ground displacements in the region struck by the M-w 6.3, 2009 L'Aquila earthquake using SAR data shows a reversal of motions on a yearly scale, indicating a potential earthquake precursor signal.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2021)
Article
Geosciences, Multidisciplinary
Stefano Mazzoli, Sergio Nardo, Alessandra Ascione, Valentino Di Donato, Carlo Terranova, Giuseppe Vilardo
Summary: The study utilized Synthetic Aperture Radar data to identify earthquake precursor signals, revealing the ground displacements caused by earthquakes. Different ground motion patterns were observed at various time scales, indicating the potential of SAR data in earthquake research.
JOURNAL OF THE GEOLOGICAL SOCIETY
(2021)
Article
Geosciences, Multidisciplinary
Yoshihisa Iio, Satoshi Matsumoto, Yusuke Yamashita, Shin'ichi Sakai, Kazuhide Tomisaka, Masayo Sawada, Takashi Iidaka, Takaya Iwasaki, Megumi Kamizono, Hiroshi Katao, Aitaro Kato, Eiji Kurashimo, Yoshiko Teguri, Hiroo Tsuda, Takashi Ueno
EARTH PLANETS AND SPACE
(2020)
Article
Geosciences, Multidisciplinary
Satoshi Matsumoto, Yoshihisa Lio, Shinichi Sakai, Aitaro Kato
EARTH PLANETS AND SPACE
(2020)
Article
Geochemistry & Geophysics
A. Shito, S. Matsumoto, T. Ohkura, H. Shimizu, S. Sakai, Y. Iio, H. Takahashi, H. Yakiwara, T. Watanabe, M. Kosuga, T. Okada, M. Yoshimi, Y. Asano
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2020)
Article
Geochemistry & Geophysics
Kenny M. Graham, Martha K. Savage, Richard Arnold, Hubert J. Zal, Tomomi Okada, Yoshihisa Iio, Satoshi Matsumoto
GEOPHYSICAL JOURNAL INTERNATIONAL
(2020)
Correction
Geosciences, Multidisciplinary
Kodai Nakagomi, Toshiko Terakawa, Satoshi Matsumoto, Shinichiro Horikawa
EARTH PLANETS AND SPACE
(2021)
Article
Geosciences, Multidisciplinary
Kodai Nakagomi, Toshiko Terakawa, Satoshi Matsumoto, Shinichiro Horikawa
Summary: This study quantitatively examined the influence of pore fluid pressure and coseismic stress changes on seismicity rate changes following the 2016 Kumamoto earthquake. The results suggest that the increase in pore fluid pressure is an important physical mechanism triggering aftershock generation, especially in the southern part of the main rupture zone after the mainshock.
EARTH PLANETS AND SPACE
(2021)
Article
Geosciences, Multidisciplinary
Yuki Susukida, Kei Katsumata, Masayoshi Ichiyanagi, Mako Ohzono, Hiroshi Aoyama, Ryo Tanaka, Masamitsu Takada, Teruhiro Yamaguchi, Kazumi Okada, Hiroaki Takahashi, Shin'ichi Sakai, Satoshi Matsumoto, Tomomi Okada, Toru Matsuzawa, Hiroki Miyamachi, Shuichiro Hirano, Yoshiko Yamanaka, Shinichiro Horikawa, Masahiro Kosuga, Hiroshi Katao, Yoshihisa Iio, Airi Nagaoka, Noriko Tsumura, Tomotake Ueno, Koji Miyakawa, Shin'ichi Tanaka, Miwako Ando, Naoki Uchida, Ryosuke Azuma, Ryota Takagi, Keisuke Yoshida, Takashi Nakayama, Satoshi Hirahara, Toshiko Terakawa, Yuta Maeda, Hiroki Miyamachi, Hiroshi Yakiwara
Summary: The tectonic stress field in the aftershock area of the Hokkaido Eastern Iburi earthquake is predominantly characterized by reverse faulting and strike-slip faulting, with the P-axis being close to horizontal and the T-axis more vertical. The stress inversion method applied to focal mechanism solutions revealed that a reverse fault-type stress field is dominant in the aftershock area, with the maximum principal stress axis dipping eastward and the intermediate principal stress axis dipping southward, indicating a predominantly horizontal stress distribution.
EARTH PLANETS AND SPACE
(2021)
Article
Geosciences, Multidisciplinary
Koki Aizawa, Shinichi Takakura, Hisafumi Asaue, Katsuaki Koike, Ryokei Yoshimura, Ken'ichi Yamazaki, Shintaro Komatsu, Mitsuru Utsugi, Hiroyuki Inoue, Kaori Tsukamoto, Makoto Uyeshima, Takao Koyama, Wataru Kanda, Tohru Yoshinaga, Nobuo Matsushima, Kazunari Uchida, Yuko Tsukashima, Takeshi Matsushima, Hiroshi Ichihara, Dan Muramatsu, Yoshiko Teguri, Azusa Shito, Satoshi Matsumoto, Hiroshi Shimizu
Summary: Crustal earthquake ruptures tend to occur near fluid-rich zones, with ruptures initiated along the outer edge of low-resistivity fluid-rich zones leading to larger earthquakes. High-temperature fluid-rich zones arrest ruptures, while shallower low-temperature zones can either promote or arrest them. The distribution of mid-crustal fluids plays a role in the initiation, growth, and arrest of crustal earthquakes.
EARTH PLANETS AND SPACE
(2021)
Article
Geochemistry & Geophysics
Megan Madley, Alexander Yates, Martha Savage, Weiwei Wang, Tomomi Okada, Satoshi Matsumoto, Yoshihisa Iio, Katrina Jacobs
Summary: This study examines the seismic velocity changes before and after the Kaikoura earthquake in New Zealand. The results indicate a decrease in velocity immediately after the earthquake and an increase over a 1.5-year period. The changes are mainly observed within the uppermost 5 km of the subsurface.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Benjamin A. Heath, Donna Eberhart-Phillips, Federica Lanza, Clifford Thurber, Martha K. Savage, Tomomi Okada, Satoshi Matsumoto, Yoshihisa Iio, Stephen Bannister
Summary: In this study, the researchers investigated the relationship between the maturity of fault zones and the distribution of fractures in the upper crust. They found that immature fault zones, characterized by less efficient strain localization, have a broader distribution and higher concentration of fractures compared to more mature fault zones. The study suggests that the relative maturity of fault zones plays a role in the lateral variability of regional upper-crustal properties.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Yoshihisa Iio, Satoshi Matsumoto, Yusuke Yamashita, Shin'ichi Sakai, Kazuhide Tomisaka, Masayo Sawada, Takashi Iidaka, Takaya Iwasaki, Megumi Kamizono, Hiroshi Katao, Aitaro Kato, Eiji Kurashimo, Yoshiko Teguri, Hiroo Tsuda, Takashi Ueno
Summary: To determine the sizes of earthquakes, we analyzed data from a temporary seismic observation network in the aftershock area of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We compared the stress field estimated from focal mechanisms of aftershocks with the post-earthquake stress field and found that the differential stress before the earthquake was small near the horizontal edges. Similar results were obtained for the 2000 Mw 6.7 Western Tottori earthquake. This suggests that the fault size of large intraplate earthquakes can be determined by the region of small differential stress surrounding future earthquake faults.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Yuhei Yuasa, Satoshi Matsumoto
Summary: This study estimated the anelastic strain rate and interplate coupling rate in inland Kyushu, southwest Japan using Global Navigation Satellite System data. The results suggest that the island arc, such as Kyushu, has a complex deformation process, and the seismicity in the Beppu-Shimabara Graben (BSG) and left-lateral shear zone (LSZ) is strongly influenced by anelastic deformation in the lower crust. The development of BSG and LSZ is influenced by slab rollback and a subducting ridge, and there is a shear zone consisting of weak faults south of BSG.
Article
Multidisciplinary Sciences
Rezkia Dewi Andajani, Takeshi Tsuji, Tatsunori Ikeda, Satoshi Matsumoto, Keigo Kitamura, Jun Nishijima
Summary: Continuous seismic monitoring is crucial for deep geothermal energy exploration. By using a dense seismic network and automated event detection, we studied seismic activity near geothermal production areas of the Kuju volcanic complex. Most shallow events occurred along a lithological boundary or fracture zone, while deeper events may indicate fracturing associated with magmatic fluid intrusion. Our findings also suggest a correlation between seismicity and heavy rainfall leading to increased pore pressure in pre-existing fractures. These results demonstrate the importance of continuous seismic monitoring in supercritical geothermal energy exploration.
SCIENTIFIC REPORTS
(2023)
Article
Environmental Sciences
Yoshihisa Iio, Satoshi Matsumoto, Yusuke Yamashita, Shin'ichi Sakai, Kazuhide Tomisaka, Masayo Sawada, Takashi Iidaka, Takaya Iwasaki, Megumi Kamizono, Hiroshi Katao, Aitaro Kato, Eiji Kurashimo, Yoshiko Teguri, Hiroo Tsuda, Takashi Ueno
Summary: Aftershocks rarely occur near the horizontal edges and extensions of the fault, possibly because the mainshock rupture was arrested within areas characterized by substantial stress relaxation prior to the main earthquake.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)
Article
Environmental Sciences
Aitaro Kato, Shin'ichi Sakai, Satoshi Matsumoto, Yoshihisa Iio
Summary: Research indicates that young faults exhibit complex evolutionary characteristics, and fine structural complexities may impact seismic activity within fault zones. High-spatial-resolution images and a micro-earthquake catalog reveal the development of conjugate faults and earthquake cluster migration.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)