Autonomous Extraction of Millimeter-scale Deformation in InSAR Time Series Using Deep Learning

TL;DR

This paper introduces a deep learning auto-encoder that autonomously detects millimeter-scale ground deformation in InSAR time series, enabling global fault slip analysis without prior fault knowledge.

Contribution

A novel deep auto-encoder architecture that isolates ground deformation signals from noise in InSAR data without needing prior fault information.

Findings

Achieved 2 mm detection accuracy over the North Anatolian Fault.

Revealed a previously unrecognized extent of slow earthquake activity.

Successfully generalized to inflation/deflation deformation in geothermal fields.

Abstract

Systematic characterization of slip behaviours on active faults is key to unraveling the physics of tectonic faulting and the interplay between slow and fast earthquakes. Interferometric Synthetic Aperture Radar (InSAR), by enabling measurement of ground deformation at a global scale every few days, may hold the key to those interactions. However, atmospheric propagation delays often exceed ground deformation of interest despite state-of-the art processing, and thus InSAR analysis requires expert interpretation and a priori knowledge of fault systems, precluding global investigations of deformation dynamics. Here we show that a deep auto-encoder architecture tailored to untangle ground deformation from noise in InSAR time series autonomously extracts deformation signals, without prior knowledge of a fault's location or slip behaviour. Applied to InSAR data over the North Anatolian Fault, our method reaches 2 mm detection, revealing a slow earthquake twice as extensive as previously recognized. We further explore the generalization of our approach to inflation/deflation-induced deformation, applying the same methodology to the geothermal field of Coso, California.