Observing the Small Scale of Aseismic Slip along Continental Strike Slip Faults from Space
Abstract
Over the last 20 years, geodesy has enable the discovery of a wide range of unexpected modes of slip along active faults, thereby enriching our understanding of the earthquake cycle. Aseismic slip clearly affects the budget of strain along faults and is related to the nucleation, propagation and arrest of seismic ruptures. Earthquake cycle models explain the first order spatio-temporal evolution of slip over all phases of the earthquake cycle. Most of our current understanding is based on geodetic and seismological observations along subduction zones where strain rates are relatively high, resulting in large geodetic signals. However, because offshore geodesy still remains sparse, few observations at small spatial scales (i.e. smaller than a kilometer) of aseismic slip are available. We discuss our recent explorations of active fault slip - seismic and aseismic - along continental strike slip faults, illustrating what can be learned with long, high resolution time series of surface displacements derived from Synthetic Aperture Radar Interferometry. Using examples from Tibet, California, Turkey and Afghanistan, we show evidence of slow, aseismic slip over various spatial and temporal scales, focusing particularly on the small scale of aseismic slip. Using a Bayesian approach, we extract quantitative information from surface displacements and what can be learned from stochastic exploration of fault slip. Finally, we discuss some of the mechanical implications of these small scale, slow slip events. In particular, we conclude that aseismic slip might always be very transitory in nature.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.T42D..03J
- Keywords:
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- 5112 Microstructure;
- PHYSICAL PROPERTIES OF ROCKSDE: 7230 Seismicity and tectonics;
- SEISMOLOGYDE: 8118 Dynamics and mechanics of faulting;
- TECTONOPHYSICSDE: 8163 Rheology and friction of fault zones;
- TECTONOPHYSICS