Article
Geochemistry & Geophysics
Ping He, Yangmao Wen, Shuiping Li, Kaihua Ding, Zhicai Li, Caijun Xu
Summary: The Tien Shan is the largest and most active intracontinental orogenic belt on Earth, providing a natural laboratory for understanding Cenozoic orogenic processes driven by the India-Asia collision. A Mw 6.1 earthquake that struck the Kalpin region on January 19, 2020 has highlighted the ongoing orogenic processes and potential seismic hazard in the area. Analysis of geodetic observations has revealed a nearly subhorizontal decollement plane in the region, indicating a risk of frequent moderate earthquakes in the future.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Sandra Slead, Meng (Matt) Wei
Summary: Interferometric Synthetic Aperture Radar (InSAR) is used to measure ground deformation caused by underground nuclear testing, and a finite-element model (FEM) is presented to analyze the nuclear test site in North Korea using InSAR data. The model incorporates topography, mechanical heterogeneity and simulates elastic deformation caused by underground explosions. Results show that mechanical layering has a significant impact on deformation modeling. A parameter search is performed to estimate the yield and depth of burial for the 4th nuclear test in North Korea. The study provides an independent and complementary method for estimating yield in data-limited regions.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Mahin Jafari, Mahtab Aflaki, Zahra Mousavi, Andrea Walpersdorf, Khalil Motaghi
Summary: The Ganaveh earthquake occurred on April 18, 2021 in the southwest of the Dezful embayment, Iran. It was a mainly compressive event with a magnitude of M-w 5.8. The InSAR coseismic displacement maps showed a maximum surface displacement of 17 cm in the satellite line of sight. The earthquake occurred within the competent layers of the Zagros sedimentary cover, beneath the Gachsaran formation.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
Zhikai Wang, Satish C. Singh, Cecile Prigent, Emma P. M. Gregory, Milena Marjanovic
Summary: Transform faults accommodate lateral motions between lithospheric plates, and this study presents new findings about the deep structure of the Romanche transform fault. The seismic data indicates the presence of a low-velocity anomaly, likely due to extensive serpentinization and a hydrated shear mylonite zone. Water sourced from seawater-derived fluids infiltrates the fault, leading to a low-temperature, water-induced melting zone and thinning of the lithosphere at the transform fault.
Article
Geochemistry & Geophysics
Wenyu Gong, Xiaogang Song, Yingfeng Zhang, Jun Hua, Haoyue Sun, Dezheng Zhao, Chuanhua Zhu, Xianjian Shan
Summary: This study used InSAR technology to conduct geological measurements in the Daliangshan area, and found the presence of three major faults involved in left-lateral strike-slip motion. By inverting the model, the movement parameters of these faults were determined. The study also confirmed the strong deformation in the middle section of the Daliangshan fault.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
Yinuo Zhang, Fan Zhang, Xubo Zhang, Tao Zhang, Jian Lin, Zhiyuan Zhou, Jiangyang Zhang
Summary: The mantle plumes modify geophysical and geochemical features along mid-ocean ridges. This study focuses on the interaction between the Jan Mayen Hotspot and the Mohns Ridge in the Arctic Ocean. By analyzing geophysical observations and using modeling results, the properties of the Jan Mayen plume were estimated, and the influence of the transform fault on plume dispersion was evaluated.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Nikos Svigkas, Simone Atzori, Andrey Kozhurin, Cristiano Tolomei, Andrea Antonioli, Giuseppe Pezzo
Summary: On January 9, 2020, a M6.4 strike-slip earthquake occurred in the Bering Sea, north of the Asian margin. The earthquake revealed a previously unknown active fault with left-lateral kinematics, crossing the Khatyrka-Vyvenka fault zone. This fault structure, along with another similar structure to the east, has created a segmented, step-like boundary of the plate/stream.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Multidisciplinary Sciences
Ingo Grevemeyer, Lars H. Ruepke, Jason P. Morgan, Karthik Iyer, Colin W. Devey
Summary: Oceanic transform faults, which were previously believed to be conservative two-dimensional strike-slip boundaries, are revealed to be more complex due to deeper seafloor along the faults than their associated fracture zones. Accretion at intersections between oceanic ridges and transform faults is asymmetric, with outside corners showing shallower relief and more extensive magmatism. This leads to a two-stage process of accretion at transform-fault systems, different from other regions along mid-ocean ridges.
Article
Geochemistry & Geophysics
D. W. Vasco, Sergey Samsonov, Kang Wang, Roland Burgmann, Pierre Jeanne, William Foxall, Yingqi Zhang
Summary: This study uses InSAR observations to estimate the displacements at a natural gas storage site in Honor Rancho, California. By removing the reservoir signal, the residuals are used to characterize the background variations and identify anomalies. The results show temporal and spatial variations in the residuals, with larger displacements observed in a southern alluvial valley.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
D. W. Vasco, Sergey Samsonov, Kang Wang, Roland Burgmann, Pierre Jeanne, William Foxall, Yingqi Zhang
Summary: The study utilizes InSAR observations for estimating line-of-sight displacements, showing potential value in characterizing surface deformation background and detecting unusually large residuals.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Wei Xiong, Pengfei Yu, Wei Chen, Gang Liu, Bin Zhao, Zhaosheng Nie, Xuejun Qiao
Summary: The earthquake that struck the Kupa Valley region in northwestern Croatia on December 29, 2020, caused significant ground deformation and severe damage in the epicentral zone. The research results indicate that the earthquake was a dextral event with a peak slip of 3.50 meters at a depth of 3.47 km.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geology
Emma P. M. Gregory, Satish C. Singh, Milena Marjanovic, Zhikai Wang
Summary: Using seismic data, researchers have found the presence of a Moho and a low-velocity anomaly beneath the Romanche transform valley floor, suggesting the crust may consist of fractured mafic material. The complex and heterogeneous structure of the transform fault could have significant influence on earthquake rupture and alteration processes.
Article
Geochemistry & Geophysics
Jeremy Maurer, Kathryn Materna
Summary: Geodetic velocity data are used to estimate crustal surface strain rates, which are important for seismic hazard assessment. However, since geodetic data are spatially scattered, interpolation is needed to estimate strain rates everywhere. This study compares different interpolation methods for strain rate estimation using Global Navigation Satellite System (GNSS) data in southern California, and investigates the sources of variability in inferred strain rates. The results highlight the influence of parameter choices and suggest using the L-curve approach for quantifying the trade-off between data fit and reflective models. The study also introduces an open-source Python package, Strain_2D, for calculating strain rates.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Zhiyong Yan, Lin Chen, Xiong Xiong, Bo Wan, Houze Xu
Summary: Research shows that oceanic plateaus play a key role in subduction zone reorganization, with different sizes and compositions leading to different subduction styles, including steep subduction, breakoff of subducting slab followed by flat-slab subduction, and subduction zone jump. These geodynamic results reveal the tectonic force switch in the overriding lithosphere during subduction zone reorganization, helping identify past subduction zone changes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Environmental Sciences
Xiaoqi Yu, Xiao Lou, Yan Yan, Zhongwei Yan, Wencong Cheng, Zhibin Wang, Deming Zhao, Jiangjiang Xia
Summary: A conventional way to monitor severe convective weather is using radar, but it is not applicable to oceanic areas without radar deployment. This study built reconstruction models based on U-Net for different underlying surfaces and found that the comprehensive use of land, coast, and offshore datasets is more suitable for oceanic reconstruction. Satellite cloud-related features are most important for reconstruction, followed by satellite water-related features and satellite temperature-related features. The STR-UNet models accurately reconstructed the convective center in terms of shape, location, intensity, and range, achieving the goal of detecting severe convective weather where radar is not present.
Article
Geology
Shaozhuo Liu, Zheng-Kang Shen, Roland Burgmann, Sigurjon Jonsson
Summary: Research on postseismic deformation after the 1992 Landers and 1999 Hector Mine earthquakes in the Mojave Desert has shown that the near-field postseismic transients lasted longer than expected, leading to a revision of postseismic modeling. New models suggest that the lower crust in the Mojave region has a similar effective viscosity to the underlying mantle asthenosphere, and the transient viscosity of the upper mantle increases over time, supporting frequency-dependent rheology theories. These findings also align with rheological characteristics observed in the 2019 Ridgecrest earthquakes.
Article
Geochemistry & Geophysics
H. Vasyura-Bathke, J. Dettmer, R. Dutta, P. M. Mai, S. Jonsson
Summary: This study focuses on estimating centroid moment tensor (CMT) parameters from seismic waveforms, highlighting the importance of incorporating theory errors, especially related to velocity-model uncertainties, in parameter estimation to improve the realism of parameter uncertainty quantification. Various noise models and estimation approaches are compared, with the iterative non-stationary error covariance matrix estimation method showing the best performance and computational efficiency. The inclusion of velocity-model uncertainties is particularly crucial in cases where the velocity structure is poorly known.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Matthieu Ribot, Yann Klinger, Sigurjon Jonsson, Ulas Avsar, Edwige Pons-Branchu, Remi Matrau, Francis L. Mallon
Summary: Accurate knowledge of fault geometry is crucial for seismic hazard assessment. Recent multibeam bathymetric surveys in the Gulf of Aqaba have revealed a 50-km-long fault section showing evidence of recent activation, making it a significant candidate for future earthquake ruptures. Additionally, the linear geometry of the Arnona fault and its lack of large earthquakes despite a significant slip rate suggest the potential for a major earthquake in the near future.
Article
Geochemistry & Geophysics
Yunmeng Cao, Sigurjon Jonsson, Zhiwei Li
Summary: This study introduces a new tropospheric correction method based on global atmospheric models, which incorporates tropospheric stochastic models and horizontal heterogeneities into the weighting strategy for InSAR mapping. The method improves the corrections for interferograms and deformation analysis products, demonstrating the importance of considering these factors for accurate surface movement measurements using InSAR.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Nicolas Castro-Perdomo, Renier Viltres, Frederic Masson, Yann Klinger, Shaozhuo Liu, Maher Dhahry, Patrice Ulrich, Jean-Daniel Bernard, Remi Matrau, Abdulaziz Alothman, Hani Zahran, Robert Reilinger, P. Martin Mai, Sigurjon Jonsson
Summary: This study presents a new GPS velocity field to investigate the recent seismic dynamics of the southernmost part of the Gulf of Aqaba, revealing a decreasing locking depth from inland towards the southern junction with the Red Sea rift, along with a small systematic left-lateral residual motion. Additionally, estimates suggest elevated seismic hazard in the Gulf area, implying possible end of current interseismic period on main faults.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Xing Li, Sigurjon Jonsson, Yunmeng Cao
Summary: In this study, the researchers use a combination of advanced processing technique and time-series analysis to retrieve millimeter-level details of north-south deformation in areas where standard InSAR observations have limited sensitivity. The results show a decrease in earthquake hazard as the fault enters the Gulf of Aqaba basin. By applying this method, meaningful interseismic deformation rates of slow-moving and northerly striking faults can be obtained.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Engineering, Geological
Milad Kowsari, Benedikt Halldorsson, Jonas Thorn Snaebjornsson, Sigurjon Jonsson
Summary: This study re-evaluates seismic hazard in North Iceland with new ground motion models, highlighting the potential shortcomings of previous models in capturing the characteristics of Icelandic earthquake ground motion. The results indicate a significant increase in confidence of hazard estimates using the new models.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Rishabh Dutta, Sigurjon Jonsson, Hannes Vasyura-Bathke
Summary: The study introduces how to use polynomial parameters to describe non-planar fault geometries and estimates non-planar fault parameters from geodetic data through Bayesian inference. The research shows that assumptions of simple planar fault geometries could bias fault-slip estimations in the presence of significant non-planar geometrical variations.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Renier Viltres, Adriano Nobile, Hannes Vasyura-Bathke, Daniele Trippanera, Wenbin Xu, Sigurjon Jonsson
Summary: On January 7, 2020, a M-w 6.4 earthquake occurred in the northeastern Caribbean near the island of Puerto Rico. The earthquake triggered a series of seismic activities, mainly located along an east-west elongated area along the southwestern coast of Puerto Rico, with some areas experiencing post-seismic movements. By analyzing ground measurement data and seismic waveforms, the fault parameters of the earthquake were determined, and an previously unmapped fault was discovered.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Carlos Pena, Sabrina Metzger, Oliver Heidbach, Jonathan Bedford, Bodo Bookhagen, Marcos Moreno, Onno Oncken, Fabrice Cotton
Summary: Megathrust earthquakes can induce changes in stress and pore pressure in the lithosphere-asthenosphere system, which are transiently relaxed during the postseismic period. The relative contributions of afterslip, viscoelasticity, and poroelasticity to observed surface deformation in the early postseismic phase are unclear. By analyzing geodetic data and using a poro-viscoelastic forward model combined with an afterslip inversion, it was found that poroelastic effects better explain the observed surface uplift pattern near the region of maximum coseismic slip. Neglecting poroelasticity can cause significant alterations in the spatial distribution of afterslip. Additionally, shallow crustal aftershocks tend to occur in regions with increased postseismic pore-pressure changes, suggesting a possible mechanical coupling between these processes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Renier Viltres, Sigurjon Jonsson, Abdulaziz O. Alothman, Shaozhuo Liu, Sylvie Leroy, Frederic Masson, Cecile Doubre, Robert Reilinger
Summary: The study of the present-day motion and internal deformation of the Arabian plate reveals its overall rigidity and minimal internal deformation, with localized strain likely due to anthropogenic activities and possible subsurface magmatic processes near its western margin.
Article
Geosciences, Multidisciplinary
Luigi Passarelli, Simone Cesca, Nima Nooshiri, Sigurjon Jonsson
Summary: The resistance of bathymetric highs to subduction results in large-scale morphological distortions of the outer-rise, trench, and fore-arc regions. Complex earthquake activity and segmentation of the interface are observed in the collision and subduction of the Loyalty Ridge, indicating a frictionally segmented interface where Mw >= 8 megathrust earthquakes are unlikely to occur.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
A. Zubovich, S. Metzger, T. Schone, J. Kley, O. Mosienko, C. Zech, B. Moldobekov, A. Shsarshebaev
Summary: The constant increase of geodetic instrumentation over the past decades enables us to not only detect ever smaller tectonic signals but also to monitor their evolution in time and space. We present spatial and temporal slip variations observed on a fault affected by a large, intermediate-field earthquake: the 2015 M(w)7.2 Sarez, Central Pamir, earthquake ruptured the sinistral, NE-trending Sarez-Karakul fault system.
Article
Geochemistry & Geophysics
Wasja Bloch, Sabrina Metzger, Bernd Schurr, Xiaohui Yuan, Lothar Ratschbacher, Sanaa Reuter, Qiang Xu, Junmeng Zhao, Shokhruhk Murodkulov, Ilhomjon Oimuhammadzoda
Summary: A sequence of strong earthquakes (M(W) 7.2, 6.4, 6.6) occurred in the Pamir of Central Asia from 2015 to 2017. These earthquakes provided unprecedented detail about the tectonic structures in the Pamir region, including thrusts, strike-slip faults, and normal faults. The aftershock triggering occurred on favorably oriented faults within a distance of <= 90 km.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Yunmeng Cao, Sigurjon Jonsson, Sigrun Hreinsdottir
Summary: Large-scale ground deformation in Iceland is mainly influenced by extensional plate-boundary deformation and uplift from glacial isostatic adjustment. By combining Sentinel-1 interferometric synthetic aperture radar data with Global Navigation Satellite System observations, we obtained time series of ground displacements. Our results significantly improved upon previous InSAR results by mitigating atmospheric errors and producing time series of deformation instead of just velocities.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)