Article
Geochemistry & Geophysics
Apsara Sharma Dhakal, Irene Molinari, Lapo Boschi
Summary: Different methods of mapping seismic rupture in space and time often give inconsistent results for the same event. Building on previous work, we use a combination of time-reversal and backpropagation of seismic surface wave recordings to study the focusing of the time-reversed field at the seismic source. Our new method combines seismic time reversal with a surface wave ray-tracing algorithm based on a generalized spherical-harmonic parametrization of surface wave phase velocity, accounting for azimuthal anisotropy.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Ritsuya Shibata, Naofumi Aso, Genki Oikawa, Junichi Nakajima, Satoshi Ide
Summary: This study proposes radiation-corrected empirical Green's function (EGF) to accurately estimate Green's functions and reduce the dependence on specific seismic events. Synthetic tests and real applications demonstrate the superiority of radiation-corrected EGF over conventional EGF in specific but realistic cases.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Takashi Furumura, Takuto Maeda
Summary: This paper introduces an efficient approach to high-resolution time-reversal source imaging simulation, which assimilates observational data to determine clearer source images, even for deep and distant earthquakes. This data-assimilated-based simulation method is effective for early forecasting of strong ground motions caused by large earthquakes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Zoe Renat, Paul Cupillard, Yann Capdeville
Summary: This paper discusses the link between the focal spot and the original source using the concept of the homogenized point source. The study shows that the backpropagated wavefield is equivalent to the sum of two low-wavenumber fields resulting from the homogenization of the original point source.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Mehdi Raoofian-Naeeni, Ernian Pan, Morteza Eskandari-Ghadi, Shin-Chan Han
Summary: In this paper, a 3-D theoretical seismogram is synthesized for an elastic half-space with 'vertical transverse isotropy (VTI)' and 'elliptic anisotropy' using a semi-analytical formulation. The solution is obtained using the Hankel and Laplace integral transforms and the Cagniard contour integration scheme. The results show the detailed behavior of different seismic waves and mode conversions, as well as the effect of non-double-couple components of the moment tensor on wave amplitudes and polarities. The study also highlights the sensitivity of moment tensor decomposition to elastic coefficients in VTI media.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Xi Feng, Haiming Zhang
Summary: In this paper, an exact closed-form solution for the displacement in an elastic half-space due to a buried point force is derived, which is a natural generalization of the classical 3-D Lamb's problem. The closed-form expressions, obtained through similar procedures as presented by Johnson, involve elementary functions and elliptic integrals, and show perfect agreement with numerical results from Johnson, conclusively validating the explicit formulae.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Editorial Material
Geochemistry & Geophysics
Arjun Datta
Summary: The errors in the surface wave Green's tensor shown by Malkoti et al. have been acknowledged, as pointed out in the comment by Haney and Nakahara. The H/V amplitude ratio calculations were recomputed using expressions for Love and Rayleigh wave Green's tensors valid in the near-field provided by Haney and Nakahara. The differences due to the use of corrected Green's tensors only appear when the receivers are placed close to the edges of the modeling domain.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Shaoqian Hu, Huajian Yao, Hsin-Ying Yang
Summary: The study analyzed the backazimuth-dependent Rayleigh wave ellipticity in the contiguous United States, deriving a formulation relating period-dependent back-azimuthal Rayleigh wave ellipticity with depth-dependent azimuthal wave speed variation in a slightly anisotropic medium. The derived formulation provides complementary information on anisotropic parameters and can quantitatively explain the backazimuth-dependent Rayleigh wave ellipticity.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Chenglong Duan, David Lumley, Hejun Zhu
Summary: A new wave-equation imaging method has been developed to locate micro-earthquakes with increased resolution and reduced location errors. By separating and extrapolating P and S wavefields, as well as using three source imaging conditions, clean images without noisy artefacts have been obtained for microseismic source estimations. The method shows high resolution source location images and is relatively insensitive to ambient noise, providing accurate results for surface monitoring data.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Hisashi Nakahara, Kentaro Emoto, Takeshi Nishimura
Summary: In this study, analytical expressions of spatial gradients such as strain, rotation, and tilt components were presented to differentiate between Rayleigh and Love waves. The results show that different kinds of wave spatial gradients help correctly separate Rayleigh and Love waves.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Chloe Gradon, Philippe Roux, Ludovic Moreau, Albanne Lecointre, Yehuda Ben Zion
Summary: The study analyzed the localizations near the San Jacinto fault in California using array processing techniques, finding that most localizations outside the fault could be attributed to surface structures excited by wind, while some under the fault may be caused by earthquakes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Yutong Zhang, Haiming Zhang
Summary: This paper reports on the synthesis of Rayleigh and Love waves in horizontally double-layered elastic half-space and analyzes their behaviors. The results show that the higher-order modes of Rayleigh waves behave differently from the fundamental mode, while different modes of Love waves exhibit similar patterns.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Matthew M. Haney, Victor C. Tsai
Summary: We derive approximate expressions for the ellipticity of Rayleigh waves in a layered medium and propose an approximation method based on the energy equation. The results show that, by assuming the background medium to be homogeneous, we can obtain approximate results for weakly heterogeneous layers. Furthermore, we find that the product of ellipticity and squared phase velocity is linearly related to squared shear wave velocity in the subsurface.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Chengyu Sun, Zhinong Wang, Dunshi Wu, Ruiqian Cai, Han Wu
Summary: This study derived dispersion curves of surface waves and guided waves using the transmission matrix method, and unified their characteristics through the relative amplitude dispersion map (RADM). Tests showed that RADM accurately reflects the dispersion energy of surface and guided waves, which is of great significance for inverting near-surface P and S wave velocities.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Matthew M. Haney, Victor C. Tsai
Summary: The study derives approximate expressions for the ellipticity of Rayleigh waves in a layered medium based on a generalized energy equation. The accuracy of the approximation is demonstrated with a simple model, showing a linear relationship between ellipticity multiplied by squared phase velocity and squared shear wave velocity. The utility of the approximation is then demonstrated in a linear inversion scheme for shear wave velocity.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Wenyuan Fan, Ryo Okuwaki, Andrew J. Barbour, Yihe Huang, Guoqing Lin, Elizabeth S. Cochran
Summary: This study examines the seismic activity in the Gulf of California, Mexico, particularly focusing on a 6.9 magnitude earthquake near Canal de Ballenas. The researchers investigate the rupture properties of the earthquake and find evidence of a unilateral rupture propagation, possibly indicating a supershear rupture. They also observe that the earthquake triggered seismic activity at various sites in California, with different response characteristics.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Jianhua Gong, Wenyuan Fan, Ross Parnell-Turner
Summary: This study investigates the unique Quebrada system, a multi-strand RTF system on the East Pacific Rise. Through seismic observations and analysis, it reveals the complex seismic activity and possible heterogeneous rotations within the Quebrada system. The evolution of multi-strand RTFs is possibly influenced by strong local thermal and fluid effects, while the RTFs may regulate regional tectonics and form an intricate feedback system.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Ryo Okuwaki, Wenyuan Fan
Summary: On August 14, 2021, a devastating magnitude 7.2 earthquake struck Southern Haiti, causing severe damage and over 2000 casualties. Integrated seismological analyses revealed that the earthquake first ruptured a blind thrust fault and then propagated to a disconnected strike-slip fault. The complex rupture process suggests that the regional deformation is accommodated by a network of segmented faults with diverse faulting conditions.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Review
Oncology
Meng Lin, Jinmeng Liu, Fengping Zhang, Gaoxiu Qi, Shuqi Tao, Wenyuan Fan, Min Chen, Kang Ding, Fenghua Zhou
Summary: LRG1 plays a critical role in the proliferation, migration, and invasion of tumor cells and can serve as an early tumor and prognostic biomarker. Through the TGF-beta signaling pathway and other independent pathways, LRG1 regulates processes such as angiogenesis, epithelial-mesenchymal transition, and apoptosis, impacting the occurrence and development of tumors.
JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY
(2022)
Article
Geochemistry & Geophysics
Peter M. M. Shearer, Haoran Meng, Wenyuan Fan
Summary: We have successfully detected thousands of small earthquakes near an active strand of the San Jacinto fault zone in southern California using a dense seismic array. By correcting site effects and performing beamforming analysis, we have identified 13,408 events, including a significant number that were not cataloged before. These detections exhibit distinct characteristics and patterns, such as clusters associated with known earthquake locations and a Gutenberg-Richter distribution of amplitudes. The presence of foreshocks and their rate increase before mainshocks also follows an inverse Omori's law.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Engineering, Environmental
Wen-Yuan Fan, Xin Zhang, Pu-Can Guo, Guo-Ping Sheng
Summary: Phosphonates, an important organic phosphorus in wastewater, are difficult to remove using traditional biological treatments. This study found that ferrate can effectively remove phosphonates through oxidation and in-situ coagulation under near-neutral conditions. The ferrate-induced release of phosphate facilitated the removal of total phosphorus, with coagulation removal reaching up to 90% within 10 minutes. This work provides an efficient method for treating phosphonate-containing wastewaters.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Geosciences, Multidisciplinary
Xinyu Luo, Wenyuan Fan, Yuri Fialko
Summary: Landslides are a significant hazard in areas with steep topography and abundant precipitation, and their detection and characterization in remote areas can be challenging. In this study, a semiautomated workflow using seismic and geodetic observations is developed to improve the detection and characterization of landslides in Alaska. The combination of seismic and geodetic observations provides new insights into the dynamics of landslides.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geochemistry & Geophysics
Nicolas D. D. DeSalvio, Wenyuan Fan
Summary: Earthquakes can be triggered by passing waves of other distant events, providing hope for revealing earthquake nucleation processes. The physical mechanisms behind earthquake dynamic triggering are unclear, and individual case studies struggle to isolate competing hypotheses. To understand spatiotemporal patterns of dynamic triggering, researchers investigate southern California from 2008 to 2017. Results show that up to 70% of global M=6 events may have triggered earthquakes in southern California, with triggered seismicity often occurring hours after passing seismic waves. The phenomenon is primarily governed by local conditions and nonlinear processes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Tianze Liu, Jianhua Gong, Wenyuan Fan, Guoqing Lin
Summary: Ocean transform faults can generate characteristic earthquakes on a regular basis, and the Gofar transform fault in the Western Ocean experiences similar M6 earthquakes every 5 years. Microseismicity suggests that the fault is divided into five distinct zones, including a rupture barrier zone that may affect adjacent earthquakes. The role of pore fluids in regulating the slip behavior of the fault is still unknown.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Engineering, Environmental
Yanpeng Dong, Hongwei Zhu, Xingyu Xiang, Zhongdong Wang, Asad Ullah, Sajawal Raza, Chunying Zhu, Wenyuan Fan, Bing Sun, Youguang Ma, Taotao Fu
Summary: The dynamics of viscoelastic droplet formation in T-shaped asymmetric parallel microchannels were investigated using a high-speed camera. The effects of fluid viscoelasticity and flow rates on droplet stability, uniformity, and flow distribution were explored. The results showed that the viscoelasticity influenced the different stages of droplet formation, and increasing the continuous phase flow rate improved stability and affected droplet uniformity. Prediction models for fluid flow distribution, droplet size, and formation period were established, and the breakup mode and satellite droplet size were also studied. The findings demonstrated the importance of fluid viscoelasticity and flow rates in droplet formation.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Multidisciplinary Sciences
Zhe Jia, Zeyu Jin, Mathilde Marchandon, Thomas Ulrich, Alice-Agnes Gabriel, Wenyuan Fan, Peter Shearer, Xiaoyu Zou, John Rekoske, Fatih Bulut, Asli Garagon, Yuri Fialko
Summary: This study integrates multiscale seismic and space-geodetic observations with multifault kinematic inversions and dynamic rupture modeling to unravel the complex rupture history and stress-mediated fault interactions of the doublet earthquake event in Turkey in 2023. The results highlight the importance of combining near- and far-field observations with data-driven and physics-based models for seismic hazard assessment.
Article
Multidisciplinary Sciences
Gaoxiu Qi, Jinmeng Liu, Shuqi Tao, Wenyuan Fan, Haoning Zheng, Meihong Wang, Hanchao Yang, Yongting Liu, Huancai Liu, Fenghua Zhou
Summary: PHH3 expression was examined in different exophytic papillary urothelial neoplasms (EPUN) along with the expression of cell-cycle related proteins Ki67 and P53. The study found that PHH3 exhibited high specificity and sensitivity in diagnosing EPUN, and when combined with HEMC, Ki67 and P53, it could assist in the differential diagnosis and estimate the clinical progression of EPUN.
Article
Geosciences, Multidisciplinary
Wenyuan Fan, Andrew J. Barbour, Jeffrey J. McGuire, Yihe Huang, Guoqing Lin, Elizabeth S. Cochran, Ryo Okuwaki
Summary: Megathrust earthquakes and associated tsunamis are among the most severe natural disasters. Different slip behaviors, including slow earthquakes, can occur at subduction zones. Very low frequency earthquakes (VLFEs) are particularly enigmatic and difficult to detect reliably. This study reveals the existence of VLFEs in the Cascadia region, which may have implications for seismic hazard assessment in coastal communities.