Plate-scale measurement of interseismic strain from Sentinel-1
Abstract
The measurement of interseismic crustal deformation at high spatial resolution, with high accuracy and over large geographical areas is critical both for furthering our understanding of the mechanics of continental deformation and for improving forecasts of earthquake hazard, but to-date has been hampered by the limitations of current geodetic datasets. However, the launch of the European Space Agency's new pair of Sentinel-1 radar satellites, with a regular 24 day minimum revisit interval over global tectonic belts, is set to overcome these limitations, enabling global, high-resolution, high-accuracy measurements of crustal velocities from Interferometric Synthetic Aperture Radar (InSAR). Here we make the first demonstration of Sentinel-1's ability to measure interseismic deformation at the tectonic-plate scale. We use the first 2 years of data from the Sentinel-1 mission to measure crustal velocity for a 400,000 km2 area of Turkey, including the majority of the Anatolian microplate and most of the onshore North and East Anatolian Faults (NAF and EAF). We map the westwards motion of Anatolia relative to Eurasia, and the associated strain accumulation along the NAF and EAF, at high spatial resolution. We also use these results as an opportunity to assess the future capability of Sentinel-1 for measuring interseismic deformation. We analyse how the accuracy of our crustal velocity measurements have increased over the last 2 years, and show that this agrees well with theoretical estimates of the temporal evolution of our measurement uncertainties. We use this to predict that for the 100 km lengthscales important for measuring interseismic deformation, uncertainty on InSAR line-of-sight velocities will reach 2 mm/yr within the next year, which is equivalent accuracy to past InSAR studies for this region, and will then rapidly surpass the accuracy that has been possible with previous InSAR datasets. Finally, based on these results, we estimate global detection thresholds for interseismic deformation over the 20 year lifetime of the Sentinel-1 mission, and predict that by the end of the mission, it will be possible to measure interseismic deformation across 86-90% of the continental area that has a strain-rate greater than 10 nanostrains/yr.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.G22A..01W
- Keywords:
-
- 1240 Satellite geodesy: results;
- GEODESY AND GRAVITYDE: 1241 Satellite geodesy: technical issues;
- GEODESY AND GRAVITYDE: 7215 Earthquake source observations;
- SEISMOLOGYDE: 8419 Volcano monitoring;
- VOLCANOLOGY