What question did this study set out to answer?

To develop integrated models for improved accuracy of 3D coseismic deformation fields using GNSS and InSAR data.

February 26, 2026Open Access

Integrated Dislocation and Strain Models for 3D Coseismic Deformation field from GNSS and InSAR

Key Points

To develop integrated models for improved accuracy of 3D coseismic deformation fields using GNSS and InSAR data.
Proposed Integrated Dislocation and Strain Models (IDSM) combining surface-constrained strain and subsurface-constrained dislocation models.
Utilized Variance Component Estimation (VCE) to optimize data weights from multiple sources.
Conducted simulation experiments to test method accuracy under various GNSS coverage conditions.
Achieved a 10% to 70% improvement in deformation recovery accuracy over ESISTEM-VCE, particularly notable in the north component.
Yangbi earthquake showed right-lateral strike-slip with a maximum east-west displacement of 87 mm and vertical subsidence of 59.8 mm.
Maduo earthquake displayed left-lateral strike-slip motion with an east-west displacement of 1.4 m and patchy fault distributions.

Abstract

Summary Accurate three-dimensional coseismic deformation fields are critical for fault mechanics analysis and hazard assessment, but the sparse distribution of Global Navigation Satellite System (GNSS) stations often limits reconstruction accuracy. This study proposes Integrated Dislocation and Strain Models (IDSM) that seamlessly integrate GNSS and Interferometric Synthetic Aperture Radar (InSAR) data. This is achieved by combining a surface-constrained strain model and a subsurface-constrained dislocation model, which adaptively optimizes multi-source data weights through Variance Component Estimation (VCE), challenging the traditional reliance on uniformly distributed observations. Simulation experiments demonstrate that under insufficient GNSS coverage, this method improves deformation recovery accuracy by 10 per cent to 70 per cent in the vertical, north, and east components compared to the ESISTEM-VCE (Extended Simultaneous and Integrated Strain Tensor Estimation from Geodetic and Satellite Deformation Measurements-VCE) method, with particularly significant enhancement in the north component. Applied to the 2021 Yangbi MW6.4 and Maduo MW7.4 earthquakes, the study reveals distinct deformation patterns: the Yangbi event exhibits right-lateral strike-slip rupture with a maximum east-west extensional displacement of 87 mm and vertical subsidence of 59.8 mm, showing antisymmetric horizontal deformation around the epicenter. In contrast, the Maduo earthquake is dominated by left-lateral strike-slip motion, with east-west displacement reaching 1.4 m, while north-south and vertical deformations display patchy distributions along the fault. Error analysis confirms accuracy improvements over the ESISTEM‑VCE method. For the Yangbi earthquake, the Root Mean Square Error (RMSE) decreased by 50 per cent (east), 64 per cent (north), and 44 per cent (vertical) at GNSS validation points. Corresponding improvements of 6.1 per cent (east) and 53.5 per cent (north) were achieved for the Maduo earthquake.

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Cite This Study

Zhu et al. (Mon,) studied this question.

synapsesocial.com/papers/699fe38b95ddcd3a253e77fd https://doi.org/https://doi.org/10.1093/gji/ggag073

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