High‐Resolution Surface Velocities and Strain for Anatolia From Sentinel‐1 InSAR and GNSS Data

Jonathan R Weiss,Richard J Walters,Pablo J González,Hua Wang,Karsten Spaans,Andrew J Hooper,Zhenhong Li,Chris Rollins,Yu Morishita,John R Elliott,Tim J Wright,Barry Parsons,Chen Yu,Ekbal Hussain,Milan Lazecky

doi:10.1029/2020gl087376

Abstract

AbstractMeasurements of present‐day surface deformation are essential for the assessment of long‐term seismic hazard. The European Space Agency's Sentinel‐1 satellites enable global, high‐resolution observation of crustal motion from Interferometric Synthetic Aperture Radar (InSAR). We have developed automated InSAR processing systems that exploit the first ~5 years of Sentinel‐1 data to measure surface motions for the ~800,000‐km2 Anatolian region. Our new 3‐D velocity and strain rate fields illuminate deformation patterns dominated by westward motion of Anatolia relative to Eurasia, localized strain accumulation along the North and East Anatolian Faults, and rapid vertical signals associated with anthropogenic activities and to a lesser extent extension across the grabens of western Anatolia. We show that automatically processed Sentinel‐1 InSAR data can characterize details of the velocity and strain rate fields with high resolution and accuracy over large regions. These results are important for assessing the relationship between strain accumulation and release in earthquakes.

Highlights

Our new 3‐D velocity and strain rate fields illuminate deformation patterns dominated by westward motion of Anatolia relative to Eurasia, localized strain accumulation along the North and East Anatolian Faults, and rapid vertical signals associated with anthropogenic activities and to a lesser extent extension across the grabens of western Anatolia
We show that by combining Sentinel‐1 Interferometric Synthetic Aperture Radar (InSAR) data with Global Navigation Satellite System (GNSS) measurements we can enhance our view of surface deformation associated with active tectonics, the earthquake cycle, and anthropogenic processes
Another characteristic of our combined Sentinel‐1 InSAR and GNSS result is that the inferred strain rates along the North Anatolian Fault (NAF) (Figure 4) are typically half of those stemming from an analysis of Envisat InSAR data by Hussain et al (2018), who took a different approach to estimating strain rate by modeling fault‐parallel velocities using 1‐D elastic dislocation theory

Summary

Introduction

Geodetic measurements of crustal motion are crucial for understanding the earthquake cycle (e.g., Elliott et al, 2016; Hearn, 2003; Smith & Sandwell, 2006; Wright, 2016; Wright et al, 2001), characterizing spatial variations in lithospheric rheology and fault frictional properties (e.g., Jolivet et al, 2013; Lindsey et al, 2014; Weiss et al, 2019), and illuminating the mechanics of large‐scale continental deformation (e.g., England et al, 2016; Loveless & Meade, 2011; Walters et al, 2017). We combine InSAR observations from the first ~5 years of the Sentinel‐1 mission with published GNSS data to create high‐resolution surface velocity and strain rate fields for the region

Sentinel‐1 Data and LiCSAR Processing

Interseismic LOS Velocity Field Estimation and Uncertainties

East‐West and Vertical Surface Velocities for Anatolia

Velocity and Strain Rate Fields From Sentinel‐1 InSAR and GNSS Data

Conclusions

Data Availability Statement