Joint estimates of co-seismic slip and early afterslip: neglecting early afterslip may bias co- and post-seismic slip models
Abstract
When analyzing the rupture of a large earthquake, geodetic data are generally characterized by either a good temporal (continuous GNSS) or a good spatial (InSAR and subpixel image correlation) resolution, but rarely both. As a consequence, many studies analyze the co-seismic rupture with data also including days of early post-seismic deformation. Here, we invert simultaneously for the co- and post-seismic slip with the condition that the sum of the two models remains compatible with data covering the two slip episodes.
We apply our approach to the 2009 Mw6.3 L'Aquila earthquake. We find that if the early afterslip signal (6 days after mainshock) is neglected, co-seismic slip is overestimated by 30% and post-seismic slip is underestimated by a factor of 3. We also show that early afterslip (6 days after mainshock) is preferentially located at the transition zone between the co-seismic rupture and the longer-term afterslip (9 months).- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T13D0298R
- Keywords:
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- 1209 Tectonic deformation;
- GEODESY AND GRAVITY;
- 1294 Instruments and techniques;
- GEODESY AND GRAVITY;
- 8118 Dynamics and mechanics of faulting;
- TECTONOPHYSICS;
- 8120 Dynamics of lithosphere and mantle: general;
- TECTONOPHYSICS