Year: 2025
Type: article
Abstract: In geodetic slip inversions, resolution rapidly decreases with distance from the observation, particularly for slip at depth as the deformation data are measured on ground surface.Traditionally, this resolution reduction was attributed to the weak deformation caused by distant fault slips.However, this study demonstrated that the primary cause is the variation in amplitudes of Green's functions, combined with the uniform amplitudes of spatial smoothing.In fault areas near the observations, the large-amplitude Green's functions result in weak smoothing and thus high resolution.Conversely, in areas distant from observations, weak Green's functions lead to strong smoothing and poor resolution.I proposed a method to enhance the resolution in distant fault areas from the observations by scaling the Green's functions.The method's effectiveness was validated through both synthetic tests and real earthquake applications.In synthetic tests, the method improved the recovery of deep slips in both location and amplitude.When applied to the 2008 Wenchuan earthquake, it resulted in smaller slips near the ground surface and larger slips at depth.For land-based deformation inversion of the 2011 Tohoku earthquakes, the method produced larger shallow slips near the trench and greater sea-floor uplift compared to the conventional method, which is valuable for accurate prediction of tsunami wave height.Additionally, this method may also be applicable to other inversions involving smoothing where amplitudes of columns in the coefficient matrix vary significantly.
DOI: 10.1093/gji/ggaf138
Author: Yong Zhang
Institution: Peking University
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,416
Awards: G3763873878, 滑坡物理过程的地震波反演研究
OpenAlex ID: W4409383279