Aseismic Deformation Associated with an Earthquake Swarm in the Northern Apennines (Italy)
Abstract
Analyzing the displacement time series from continuous GPS (cGPS) with an Independent Component Analysis (ICA) we detect a transient deformation signal that correlates both in space and time with a seismic swarm activity (maximum Mw = 3.69 ± 0.09) occurred in the hanging wall of the Altotiberina normal fault (Northern Apennines, Italy) in 2013-2014. The geodetic transient lasted ∼6 months and produced a NW-SE trending extension of ∼ 5.3 mm, consistent with the regional tectonic regime. The seismicity and the geodetic signal are consistent with slip on two splay faults in the ATF hanging wall. Comparing the seismic moment associated with the geodetic transient and the seismic events, we observe that seismicity accounts for only a fraction of the measured geodetic deformation. The combined seismic and aseismic slip decreased the Coulomb stress on the locked shallow portion of the ATF, while the transition region to the creeping section has been loaded.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.T21A0546G
- Keywords:
-
- 1242 Seismic cycle related deformations;
- GEODESY AND GRAVITY;
- 8118 Dynamics and mechanics of faulting;
- TECTONOPHYSICS;
- 8163 Rheology and friction of fault zones;
- TECTONOPHYSICS