Article
Geosciences, Multidisciplinary
Yunguo Chen, Yan Hu, Liang Qian, Guojie Meng
Summary: This study used GPS data to analyze the postseismic displacements of the Yushu earthquake in April 2010. It focused on the afterslip of the fault, viscoelastic relaxation, and poroelastic rebound as postseismic deformation processes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Min Wang, Zheng-Kang Shen, Yan-Zhao Wang, Roland Burgmann, Fan Wang, Pei-Zhen Zhang, Hua Liao, Rui Zhang, Qi Wang, Zai-Sen Jiang, Wei-Tao Chen, Ming Hao, Yu Li, Tie Gu, Wei Tao, Kang Wang, Lian Xue
Summary: The study focuses on the tectonic deformation of the Tibetan Plateau, particularly on the rheological structure of eastern Tibet, by modeling GPS data. The results provide insights into the steady-state and transient viscosities of the lower-crustal and upper-mantle, showing nonlinear deformation mechanisms. Adjacent blocks exhibit higher rheological strength, consistent with changes in crustal material properties and interseismic deformation styles.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Haipeng Luo, Kelin Wang
Summary: This study investigates the complexities of vertical deformation following subduction earthquakes. The results show that most megathrust earthquakes exhibit a three-segment, long-wavelength pattern of uplift and subsidence, controlled by coseismic fault slip. Afterslip, on the other hand, leads to site-specific and heterogeneous vertical deformation, but can be adequately modeled using a simple elastic model. This research has important implications for understanding the mechanism of afterslip and interpreting coastal paleoseismic records.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Carlos Pena, Oliver Heidbach, Marcos Moreno, Daniel Melnick, Onno Oncken
Summary: This study evaluates the transfer of stresses from megathrust earthquakes to adjacent segments using a 3D forward model and GPS and seismic data. The results show CFS changes of about 0.06 bar induced by the 2010 Maule earthquake, with different impacts observed between linear and power-law rheology models on postseismic deformation and CFS changes.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Xiong Zhao, Caijun Xu, Yangmao Wen, Kefeng He, Jiuyuan Yang, Jianjun Wang
Summary: In this study, the 2D postseismic deformation field of the Mw 7.3 Darbandikhan earthquake in the border between Iran and Iraq was obtained using the multidimensional small baseline subset technique. The joint model analysis was then used to estimate the viscosity of the lower crust and the distribution of afterslip in the Zagros Mountains. The stability and reliability of the faults and the joint model were also verified.
Article
Mathematics, Interdisciplinary Applications
Eitan E. Asher, Shlomo Havlin, Shay Moshel, Yosef Ashkenazy
Summary: Studies have shown that the rate of earthquakes increases a few days before a mainshock, validating the inverse Omori law. However, the Omori-Utsu law does not hold for individual mainshocks but only when considering many mainshocks statistically.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Geochemistry & Geophysics
Zhen Tian, Jeffrey T. Freymueller, Zhiqiang Yang
Summary: Observations of approximately 7 years of postseismic deformation following the 2012 M-w 7.8 Haida Gwaii and 2013 M-w 7.5 Craig earthquakes in western British Columbia and southeastern Alaska provide insight into regional rheologic structure and seismic hazards. A stress-driven afterslip-only model is insufficient to explain the rates and spatial patterns of the far-field postseismic deformation, leading to the development of an integrated model combining afterslip and distributed viscous flow. The integrated model suggests a 60-km thick lithosphere overlying a Burgers body asthenosphere with a Maxwell viscosity of 2 x 10(19) Pa s, in good agreement with glacial isostatic adjustment data.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Grace A. Nield, Matt A. King, Achraf Koulali, Nahidul Samrat
Summary: Large earthquakes near Antarctica can cause postseismic deformation that needs to be considered when constraining geophysical models.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Junichi Fukuda, Kaj M. Johnson
Summary: A method for estimating the parameters of postseismic deformation models following great subduction earthquakes was developed, incorporating afterslip and viscoelastic relaxation mechanisms. Bayesian formulation and algorithm were used to estimate the posterior probability density function, allowing for quantification of uncertainties in the model parameters. Application to the 2011 Tohoku-Oki earthquake showed tight constraints on the model parameters, effectively reproducing spatial and temporal patterns of postseismic deformation.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Shunying Hong, Mian Liu
Summary: Using InSAR and GPS observations, this study constructed an afterslip model for the Gorkha region over three years after the 2015 earthquake, confirming that afterslip dominated the observed postseismic deformation, releasing energy equivalent to an Mw 7.32 earthquake. The afterslip occurred mostly in the downdip ductile shear zone and was controlled by rheological properties. The updip portion of the Main Frontal Thrust zone remains potentially seismically active, as it was not ruptured by coseismic slip or unlocked by afterslip.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Review
Geosciences, Multidisciplinary
Sambuddha Dhar, Jun Muto, Yusaku Ohta, Takeshi Iinuma
Summary: The 2011 Tohoku-oki earthquake provided valuable data for studying postseismic deformation and the rheological heterogeneities of the viscoelastic earth. Researchers used a dense network of GNSS stations to investigate the different mechanisms responsible for the observed crustal deformation. However, the contribution of rheological heterogeneities to postseismic deformation is still poorly understood.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Lijia He, Guangcai Feng, Xiongxiao Wu, Hao Lu, Wenbin Xu, Yuedong Wang, Jihong Liu, Jun Hu, Zhiwei Li
Summary: The Mw 7.4 Maduo earthquake on May 22nd, 2021 in Tibet Plateau activated at least five fault segments with curved geometry and peak coseismic slip of about 5 m. Postseismic slip mainly occurred toward the downdip direction of the main coseismic slip asperities, accounting for approximately 15.3% of the coseismic one. Stress analysis suggests that the nucleation of the Maduo earthquake is partially facilitated by the 1947 M7.7 Dari earthquake.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Review
Energy & Fuels
Aref Abbasi Moud
Summary: This review paper presents an overview of the challenges associated with asphaltene in crude oil production and transportation, including deposition, aggregation, and emulsification. Rheology is used to study the flow behavior of asphaltene in different mediums.
Article
Geosciences, Multidisciplinary
Harsh K. Gupta, Rajesh Rekapalli
Summary: Strong to great earthquakes weaken the structural strength of subsurface strata and civil constructions. The occurrence of Mw ≥ 5 aftershocks contributes to loss of lives and property damage. This study analyzes the activity of Mw ≥ 5 aftershocks within a 300 km radius from the epicenter using the modified Omori Law and compares the results with the exponential scaling law. The analysis suggests that the temporal variation of the p-value and its slope are key elements in understanding the duration of aftershocks.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Lauren A. Ward, Katherine A. Guns, Bridget R. Smith-Konter, Xiaohua Xu, Yehuda Bock, David T. Sandwell
Summary: Using observations from the Ridgecrest sequence, this study investigates vertical postseismic deformation and reveals the contributions of different mechanisms to the displacement. The results show that viscoelastic relaxation explains the majority of the cumulative vertical deformation, while near-field horizontal deformation is mainly caused by afterslip. Additionally, the higher temporal and spatial resolution of the GNSS array will aid in studying the evolution of deformation in the entire network.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Tadashi Yamasaki, Hiroaki Takahashi, Mako Ohzono, Tim J. Wright, Tomokazu Kobayashi
Summary: The study investigates the impact of elastic thickness non-uniformity on viscoelastic crustal deformation caused by magma emplacement in active volcanoes. Findings suggest that the post-emplacement viscoelastic subsidence can be affected by the elastic thickness non-uniformity, depending on the relationship between the horizontal width of magma emplacement and the thinner elastic layer. The influence of the non-uniformity on estimating crustal viscosity is minimal unless the spatial variation of geothermal gradient is considered.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geology
Emma K. Bramham, Tim J. Wright, Douglas A. Paton, David M. Hodgson
Summary: This study investigates fault growth in a magmatically resurfaced region of the Krafla fissure swarm in Iceland, finding that shorter faults tend to retain fissure-like features with minimal vertical displacement, while longer faults typically exhibit vertical displacement along most of their length. The study proposes a hybrid growth mechanism involving fissure-like fractures initiating at the surface and subsequent vertical displacement accumulation, contributing to a wide distribution of displacement-length ratios.
Editorial Material
Geosciences, Multidisciplinary
Yosuke Aoki, Masato Furuya, Francesco De Zan, Marie-Pierre Doin, Michael Eineder, Masato Ohki, Tim J. Wright
EARTH PLANETS AND SPACE
(2021)
Article
Geochemistry & Geophysics
Ryo Okuwaki, Wenyuan Fan, Masumi Yamada, Hikaru Osawa, Tim J. Wright
Summary: Landslides triggered by heavy rainfall, such as during the transit of Typhoon Talas, can cause devastating damage and pose natural hazards. Research indicates that small and large landslides may share similar failure mechanisms, and a sparse seismic network can be used for early detection and location of landslides.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Nantheera Anantrasirichai, Juliet Biggs, Krisztina Kelevitz, Zahra Sadeghi, Tim Wright, James Thompson, Alin Marian Achim, David Bull
Summary: The article discusses the use of deep learning methods to detect deformation signals in the national-scale velocity field of the UK and proposes three methods to address the challenges. Through the analysis of velocity maps spanning from 2015 to 2019, several areas of ground motion causes were successfully detected.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2021)
Article
Environmental Sciences
Z. Sadeghi, T. J. Wright, A. J. Hooper, C. Jordan, A. Novellino, L. Bateson, J. Biggs
Summary: This study focuses on developing a method for assessing different InSAR processing results. Results show that different methods detect main areas of ground motion and provide comparable results, but with considerable differences in factors such as density and coverage.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Geosciences, Multidisciplinary
Ian J. Hamling, Tim J. Wright, Sigrun Hreinsdottir, Laura M. Wallace
Summary: Measuring the deformation at the Earth's surface is crucial for understanding seismic hazard and volcanic unrest, as well as the effects of land movements on sea level rise. In this study, we use a combination of InSAR observations, interseismic campaign data, and continuous GNSS velocities to create a high-resolution velocity field for New Zealand. Our findings reveal significant variability in vertical rates caused by volcanic, tectonic, and anthropogenic sources. We also observe interseismic subsidence in the Kaikoura region and localized uplift of the Southern Alps.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Yasser Maghsoudi, Andrew J. Hooper, Tim J. Wright, Milan Lazecky, Homa Ansari
Summary: Interferometric Synthetic Aperture Radar (InSAR) is commonly used to measure deformation of the Earth's surface. However, using multiple multilooked shorter interferograms to overcome coherence loss can introduce a bias in the interferometric phase. To correct this bias, researchers propose a method based on constructing daisy chain sums of short-term interferograms and linearly relating the bias in an interferogram to the sum of biases in shorter interferograms.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Geochemistry & Geophysics
Q. Ou, S. Daout, J. R. Weiss, L. Shen, M. Lazecky, T. J. Wright, B. E. Parsons
Summary: The launches of Sentinel-1 satellites in 2014 and 2016 have ushered in a new era of high-resolution velocity and strain rate mapping for the continents. However, there are challenges in tying independently processed data sets to a common reference frame and generating high-resolution strain rate fields. This study analyzes Sentinel-1 data over the northeast Tibetan Plateau and develops new methods to derive east and vertical velocities with high resolution and accuracy. The resulting strain rate fields provide valuable insights into tectonic structures and have wide-ranging research applications.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Environmental Sciences
Krisztina Kelevitz, Alessandro Novellino, Arnaud Watlet, James Boyd, James Whiteley, Jonathan Chambers, Colm Jordan, Tim Wright, Andrew Hooper, Juliet Biggs
Summary: This paper presents a case study of using ESA's Sentinel-1 InSAR data to study the behavior and seasonal variations of the Hollin Hill landslide in the UK. The study shows that InSAR data provides valuable information about landslide movement and behavior. The installation of corner reflectors improves the accuracy of InSAR measurements and allows tracking of the most recent landslide movement.
Article
Geochemistry & Geophysics
E. W. Dualeh, S. K. Ebmeier, T. J. Wright, M. P. Poland, R. Grandin, A. J. Stinton, M. Camejo-Harry, B. Esse, M. Burton
Summary: Satellite radar backscatter provides unique information on the growth of lava domes during volcanic eruptions. In this study, an approach for estimating volcanic topography from backscatter images is presented. The study focuses on the dome growth during the 2021 eruption at La Soufriere and reveals an acceleration in extrusion rate prior to the explosive eruption.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Jin Fang, Qi Ou, Tim J. Wright, Ryo Okuwaki, Ruth M. J. Amey, Tim J. Craig, John R. Elliott, Andy Hooper, Milan Lazecky, Yasser Maghsoudi
Summary: This study analyzes an earthquake that occurred on a secondary fault and determines the distribution of coseismic slip and afterslip. It also discusses the implications for seismic hazard away from major tectonic block boundaries.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Proceedings Paper
Geosciences, Multidisciplinary
Milan Lazecky, Jin Fang, Andy Hooper, Tim Wright
Summary: This article describes an improved tool for phase unwrapping, developed and applied routinely in the COMET LiCSAR system to produce Sentinel-1 interferograms with a resolution of 0.001 degrees (WGS-84). The existing standard methods are used on regularly available data to improve the reliability of the phase unwrapping procedure and increase the coverage of unwrapped pixels. The main idea is to reduce high phase gradients by extracting and unwrapping long-wave spatial signal and signal related to the atmosphere.
2022 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS 2022)
(2022)
Article
Geochemistry & Geophysics
Krisztina Kelevitz, Tim J. Wright, Andrew J. Hooper, Sivasakthy Selvakumaran
Summary: High-precision monitoring of infrastructure can be achieved using artificial reflectors, but large reflectors are often not feasible in urban areas. A multiple corner-reflector array can be used to replace a single large reflector, as long as careful positioning is done to ensure constructive interference. The applications of multiple small corner reflectors in urban areas are wide-ranging, including essential infrastructure monitoring and structural health assessment.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Engineering, Electrical & Electronic
Gabriel Martin, Andrew Hooper, Tim J. Wright, Sivasakthy Selvakumaran
Summary: This study explores the application of blind source separation algorithms to MT-InSAR for automatic identification of deformation patterns in buildings and structures. The proposed methodology is validated using synthetic and real MT-InSAR data, showing its effectiveness in InSAR time-series analysis and robustness to noise. This has significant implications for monitoring large-scale infrastructure and understanding the performance changes of structures over time.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2022)