Article
Geochemistry & Geophysics
Hari Ram Thapa, Surya Pachhai, Abdelkrim Aoudia, Daniel Manu-Marfo, Keith Priestley, Supriyo Mitra
Summary: A highly resolved 3-D structure of the crust is essential for better understanding the physics of earthquakes and assessing seismic hazard in Nepal. This study presents a new 3-D S-wave velocity structure using ambient noise tomography, which reveals the control of S-wave velocity on earthquake rupture propagation and arrest. The study also provides insights into the structure of the Main Himalayan Thrust beneath Nepal.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
W. Sun, M. D. Sacchi, Y. J. Gu
Summary: This study presents a multichannel sparse deconvolution method that utilizes the cross-trace coherency of RFs at individual stations for stable and accurate imaging outcomes. The method retrieves high-resolution and spatially continuous conversion energy and offers robustness against noise, increasing the volume of usable and high-quality data for receiver function analysis.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Yu Wei, Shuangxi Zhang, Mengkui Li, Tengfei Wu, Yujin Hua, Yu Zhang, Jianfeng Cai
Summary: In this study, a 3-D S-wave velocity model was constructed to reveal the characteristics of the Qinling-Dabie orogenic belt and its collision processes and tectonic evolution with the North China Block and Yangtze Block. The results support a two-stage exhumation model for the high-pressure/ultra-high-pressure rocks and provide evidence for the delamination of the lower crust in the orogenic belt.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Davide Tadiello, Carla Braitenberg
Summary: The southern Alpine regions have been affected by various magmatic and volcanic events from the Paleozoic to the Tertiary, which has significantly influenced the density distribution and structural setting at lithosphere scale. The gravity field has been used to create a 3D lithosphere density model, revealing a complex density distribution in alignment with different geological domains. The source of a positive gravity anomaly in the southern Alpine region is suggested to be related to magmatic intrusions and mafic and ultramafic magmatic underplating.
Article
Geochemistry & Geophysics
Yuqing Chen, Erdinc Saygin
Summary: Ambient noise seismic data are widely used for subsurface exploration, and the two-step dispersion inversion method is commonly used to analyze these data. However, this method assumes a 1-D layered model, which can lead to inaccurate results. To overcome this limitation, we propose a 2-D wave-equation dispersion inversion method, which reconstructs the subsurface S velocity model in one step and simulates wave propagation using an elastic wave-equation model. Our study focuses on the Gorgon OBN survey in Western Australia, where we utilize continuous ambient noise signals recorded by each ocean bottom node to retrieve Scholte waves and generate a 2-D S velocity structure. We then use a neural network-based method to interpolate the 2-D velocity slices into a continuous 3-D velocity model. The comparison between the predicted and observed data demonstrates the effectiveness of our methods.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Guiping Yu, Zhi Zhang, Tao Xu, Xuelai Li, Minling Wang, Xi Guo, Jiao Xu, Jue Hou, Guihong Guo, Jose Badal
Summary: Detection of faults and sedimentary layers in urban subsoil is crucial for underground space utilization and earthquake hazard mitigation. This study uses ambient seismic noise cross-correlation method and surface-wave tomography to extract dispersion curves and obtain a high-resolution S-wave velocity model of Guilin. The results reveal the sediment thickness, the occurrence and location of major faults, and the evolution of the basin. Urban seismic imaging is important for understanding tectonic and tectonic-subsidence earthquake hazards associated with buried faults.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Jianqiang Kang, Jiangtao Han, Rui Gao, Lijia Liu, Zhonghua Xin, Fanwen Meng, Zhenyu Guo, Tianqi Wang
Summary: This study reveals the presence of large-scale conductive anomalies and a rheological channel beneath the Jinsha River suture in the northern Tibetan Plateau. The convergence of the Indian and Asian plates may be the driving mechanism for the reactivation of this suture, resulting in enhanced convection in the mantle and subsequent melting of the crust. These findings provide valuable insights into the geodynamic evolution of the northern Tibetan Plateau and contribute to our understanding of continental convergence processes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Mingrui Li, Hongjian Fang, Rui Gao
Summary: This study investigates the large-scale and intense magmatism in South China and its coeval metallogenic processes. By deploying high-resolution crustal models and utilizing dense nodal arrays, the study reveals shear wavespeed anomalies associated with crystallized igneous intrusions, suggesting their contribution to the mineral concentration in the Fankou ore deposit.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Lipeng He, Xinlei Sun, Pengfei Li, Sanxi Ai, Jianming Li
Summary: The study constructs a high-resolution 3D lithospheric S wave velocity model of the Jiuyishan region using joint inversion of receiver function and ambient noise data. The model reveals thick crust beneath the Yangtze block and thin crust beneath the Cathaysia block, with a complex boundary between the two blocks showing low-velocity anomalies in the middle crust and upper mantle, indicating asthenospheric upwellings.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Jyoti Sharma, M. Ravi Kumar, Ketan Singha Roy, S. K. Pal, P. N. S. Roy
Summary: The study revealed the presence of intracrustal layers, lid, and a low-velocity zone (LVZ) in the northwestern Deccan volcanic province, showing anisotropic and isotropic variations. The LVZ, which is a negative anomaly, may be related to partial melts, volatile materials, or a thermal anomaly.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Huan Kang, Dapeng Li, Guoliang Xue, Benyan Xu, Jianzhen Geng, Yang Yu
Summary: Strong post-collisional deformation and contemporaneous magmatic flare-ups have occurred in the southeastern Tibetan Plateau, indicating large-scale continental lithospheric modification. This study presents the discovery of 32-17 Ma mafic rocks in the Ailaoshan-Red River shear zone (ARSZ) and provides new insights into the correlation between regional deformation and magmatism. The study documents a three-stage magmatic evolution in the SE Tibetan Plateau and reveals a shift in mantle sources over time. The findings suggest an interdependent evolution between mantle source shift and synchronous deformation in and around the ARSZ.
Article
Geosciences, Multidisciplinary
Yesim Cubuk-Sabuncu, Kristin Jonsdottir, Corentin Caudron, Thomas Lecocq, Michelle Maree Parks, Halldor Geirsson, Aurelien Mordret
Summary: Repeated periods of inflation-deflation were detected near Mt. thorn orbjorn-Svartsengi in SW-Iceland from January to July 2020. Seismic ambient noise and interferometry were used to characterize the temporal variations of seismic velocities. The largest velocity drop was observed at the seismic station closest to the inflation source center, and the dv/v variations correlated with deformation measurements over the unrest period, indicating sensitivity to crustal processes.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Juqing Chen, Lei Pan, Zhengbo Li, Xiaofei Chen
Summary: This study used multimodal ambient noise tomography to investigate the shear-wave velocity structure of the crust and upper mantle in the eastern South China Block (SCB) and adjacent areas. The results reveal widespread mid-crustal low-velocity zones and upper mantle low-velocity zones, which are correlated with regional tectonics. The study provides insights into the effects of the Triassic continental collision and subsequent Pacific plate subduction on the eastern South China Block.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Juqing Chen, Lei Pan, Zhengbo Li, Xiaofei Chen
Summary: This study used shear-wave velocity imaging to reveal the distribution of low-velocity zones in the crust and upper mantle of the eastern South China Block and its adjacent areas, showing correlations with regional tectonics. The formation of these low-velocity zones is related to geological events and plate tectonics.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Engineering, Geological
Zhen Guo, Mi Zhou, Yu Huang, Jian Pu, Shu Zhou, Boyu Fu, Adnan Aydin
Summary: Long-term monitoring of slopes is significant for engineering geology research and geo-disaster prevention. In this study, a fast and low-cost computational framework based on ambient seismic noise recordings is proposed to detect gradual and cyclic changes inside slopes. A demonstration study was conducted on a road-cut slope in Southwest China, which showed the effectiveness of the framework in monitoring slope performance changes.
ENGINEERING GEOLOGY
(2023)
Article
Geochemistry & Geophysics
Laura Hughes, Calum J. Chamberlain, John Townend, Amanda M. Thomas
Summary: This study identified and analyzed repeating earthquakes in New Zealand, revealing 61 repeating earthquake families occurring between 2003 and 2020. These families have a range in magnitude and recurrence intervals, showing spatiotemporal correlation with known slow-slip events and tremor, but inconsistency in responses.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
T. McIntyre, K. Kublik, C. Currie, D. G. Pearson
Summary: This study utilized in situ methods to determine heat generation within cratonic lithospheric mantle peridotites. Results showed that unmetasomatized mantle has negligible heat production, while refertilized peridotites have slightly elevated heat generation. Typical cratonic mantle peridotites fall between these two bounds, ranging from 0.00004 to 0.006 mu W/m(3), producing lower estimates of lithospheric thickness compared to previous studies.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geosciences, Multidisciplinary
Huilin Wang, Claire A. Currie, Peter G. DeCelles
Summary: The central Andes is part of a Cordilleran orogen formed through continent-ocean convergence. In contrast to the thickened crust, the mantle lithosphere below much of the orogen is anomalously thin. Numerical models suggest that mantle flow can amplify a local lithosphere instability to orogen-wide lithosphere removal, rapidly eliminating accumulated mass in the orogen.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
C. J. Chamberlain, W. B. Frank, F. Lanza, J. Townend, E. Warren-Smith
Summary: The 2016 M7.8 Kaikoura earthquake is considered one of the most complex earthquakes in recorded history, involving significant rupture of at least 21 crustal faults. Through the use of various techniques, researchers constructed a catalog of seismic activities and fault ruptures, leading to key findings such as the earthquake nucleating on the Humps Fault and the reactivation of faults from previous sequences.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Bryant Chow, Yoshihiro Kaneko, Carl Tape, Ryan Modrak, Nick Mortimer, Stephen Bannister, John Townend
Summary: This study uses earthquake-based adjoint tomography to analyze the three-dimensional structure of the North Island and the adjacent Hikurangi subduction zone in New Zealand. The research reveals the material properties and velocity changes associated with the active subduction zone. The results also provide valuable insights into the geology and tectonic structures of the study area, especially in relation to the Hikurangi subduction zone.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Bryant Chow, Yoshihiro Kaneko, John Townend
Summary: Seamounts as seafloor heterogeneities affect slip behavior on megathrusts. In the Hikurangi subduction zone, previously unidentified deeply subducted seamounts are inferred from high-resolution velocity models, influencing seismicity and slow slip events. This study suggests that repeated seamount subduction may permanently damage the upper plate and impact plate coupling along the subduction interface.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Sarah Jaye Oliva, Cynthia J. Ebinger, Eleonora Rivalta, Charles A. Williams, Christelle Wauthier, Claire A. Currie
Summary: In continental rift systems, the role of rift magmatism in topography formation, plate state-of-stress, and volcanic and tectonic processes is crucial. However, the influence of magma intrusions, crustal thinning, and rift basin and flank topography on stress field rotations in rift zones is poorly understood.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Annemarie Christophersen, Yannik Behr, Craig Miller
Summary: Probabilistic methods, such as Bayesian networks (BNs), are recommended for eruption forecasting in volcano observatories. BNs provide a flexible framework to model complex volcano systems, incorporating expert elicitation and data learning. In collaboration with the New Zealand volcano monitoring group, a BN model was developed to forecast the probability of eruption for Mt Ruapehu, which showed good agreement with retrospective forecasts.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
R. F. D. McGregor, F. Illsley-Kemp, J. Townend
Summary: The Taupo Volcanic Zone is part of the Tonga-Kermadec volcanic arc in New Zealand and is characterized by extensional tectonic processes and magmatic activities. The seismicity in the Taupo Fault Belt, which is adjacent to the Taupo volcano, is influenced by regional tectonic and deep mafic magmatic systems. An increase in seismic activity in 2001 outside the caldera suggests that a magmatic intrusion beneath Lake Taupo's Western Bay initiated the unrest in the fault belt.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Tai-Chieh Yu, Claire A. Currie, Martyn J. Unsworth, Brandon F. W. Chase
Summary: Geophysical imaging reveals significant changes in mantle properties from the Southern Canadian Cordillera to the Laurentian Craton in southwestern Canada. A joint analysis of shear wave velocity and resistivity helps to quantify temperature and olivine water content at different depths, indicating a trade-off between temperature and water content in the cordillera region and cooler, drier conditions in the craton mantle lithosphere. The viscosity of the cordillera asthenosphere is lower, making it susceptible to small-scale convection, while the craton mantle lithosphere shows increased thickness towards the east.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
E. Warren-Smith, J. Townend, C. J. Chamberlain, C. Boulton, K. Michailos
Summary: Paleoseismic evidence suggests that key section boundaries conditionally inhibit rupture. Utilizing data from a seismometer network, this study examines the effects of material and structural heterogeneities on rupture behavior. The results highlight the importance of considering a range of factors when evaluating controls on rupture segmentation.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Shao-Jinn Chin, Rupert Sutherland, Martha K. Savage, John Townend, Julien Collot, Bernard Pelletier, Olivier Monge, Finnigan Illsley-Kemp
Summary: We used a network of seismometers near Noumea, the capital city of New Caledonia, to record and analyze earthquakes for 14 months. The earthquakes in southern New Caledonia are smaller but more hazardous due to their shallow depths and proximity to local communities. Our study highlights the need for long-term monitoring of local earthquakes in this region and suggests that current models overestimate the hazard from large earthquakes in nearby subduction zones. Further research is needed to improve ground motion prediction in subduction zone footwall settings.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Huilin Wang, Claire A. Currie
Summary: The outward growth of many mountain ranges is driven by the pulsed migration of the strain front. In the Central Andes, during the Cenozoic shortening, the strain front migrated abruptly eastward, isolating the plateau interior from deformation. Contrary to the traditional model, our numerical models show that the ductile lower crust plays a key role in orogen dynamics. As the orogen grows upward, the lower crust flows outward, causing stepwise expansion through landward-migrating deformation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geology
Hannu Seebeck, Russ Van Dissen, Nicola Litchfield, Philip M. Barnes, Andrew Nicol, Robert Langridge, David J. A. Barrell, Pilar Villamor, Susan Ellis, Mark Rattenbury, Stephen Bannister, Matthew Gerstenberger, Francesca Ghisetti, Rupert Sutherland, Hamish Hirschberg, Jeff Fraser, Scott D. Nodder, Mark Stirling, Jade Humphrey, Kyle J. Bland, Andrew Howell, Joshu Mountjoy, Vicki Moon, Timothy Stahl, Francesca Spinardi, Dougal Townsend, Kate Clark, Ian Hamling, Simon Cox, Willem de Lange, Paul Wopereis, Mike Johnston, Regine Morgenstern, Genevieve Coffey, Jennifer D. Eccles, Timothy Little, Bill Fry, Jonathan Griffin, John Townend, Nick Mortimer, Samantha Alcaraz, Cecile Massiot, Julie V. Rowland, James Muirhead, Phaedra Upton, Julie Lee
Summary: The New Zealand Community Fault Model (NZ CFM) is a publicly available model representing fault zones in New Zealand that have the potential to cause damaging earthquakes. It is compiled through collaborative engagement between earthquake-science experts and incorporates new and modified information. The NZ CFM consists of a two-dimensional map representation of fault zones and a three-dimensional representation projected down-dip from the mapped traces. This article summarizes the compilation and parameterization of the NZ CFM, its relation to previous datasets, and its applications in seismic hazard assessment and earthquake modeling for New Zealand.
NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS
(2023)
Review
Geosciences, Multidisciplinary
Claire A. Currie, Tai-Chieh Yu
Summary: Geodynamic models provide insights into lithosphere structure and evolution. This review focuses on geodynamic studies along a profile in southwestern Canada. Observations show changes in thermal structure along the profile, particularly in the transition from the cool forearc to the hot volcanic arc. The timing and mechanisms of lithosphere thinning in the Cordillera region are debated, and the presence of the enigmatic Cordillera-craton lithosphere step suggests long-term preservation of a strong and chemically depleted craton mantle lithosphere.
CANADIAN JOURNAL OF EARTH SCIENCES
(2023)