Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner

Abstract

[1] Using 3D terrestrial laser scan (TLS) technology, we have recorded postseismic deformation on and adjacent to the surface rupture formed during the 6th April 2009 L'Aquila normal faulting earthquake (Mw 6.3). Using surface modeling techniques and repeated surveys 8-124 days after the earthquake, we have produced a 4D dataset of postseismic deformation across a 3 × 65 m area at high horizontal spatial resolution. We detected millimetrescale movements partitioned between discrete surface rupture slip and development of a hangingwall syncline over 10's of meters. We interpret the results as the signal of shallow afterslip in the fault zone. We find 52% of the total postseismic hangingwall vertical motion occurs as deformation within 30 m of the surface rupture. The total postseismic vertical motions are approximately 50% that of the coseismic. We highlight the importance of quantifying partitioned postseismic contributions when applying empirical slip-magnitude datasets to infer palaeoearthquake magnitudes.

Principal Slip Zones in Limestone: Microstructural Characterization and Implications for the Seismic Cycle (Tre Monti Fault, Central Apennines, Italy)

“…Second, laser-strainmeters located in boreholes approximately 20 km north-east of the epicentral area recorded the propagation of ''slow slip'' events in the few days after the mainshock, most likely representing afterslip on the Paganica fault plane (AMORUSO and CRESCENTINI, 2009). Third, WILKINSON et al (2010) used terrestrial laser-scan data collected 8-124 days after the main shock to record afterslip at one position along the surface rupture. They documented a total of approximately 30 mm of surface afterslip, equating to *40% of the observed coseismic surface displacement (BONCIO et al, 2010;WILKINSON et al, 2010).…”

The anatomy of the 2009 L'Aquila normal fault system (central Italy) imaged by high resolution foreshock and aftershock locations

“…These features have been interpreted as a direct expression of fault rupture. 3D laser scan technology (TLS) and GPS data located postseismic deformation around the main slip patches [Wilkinson et al, 2010;Cheloni et al, 2010]. [8] There are still open questions concerning the role played by the preexisting compressional structures on the evolution and geometry of Quaternary complex normal fault system and consequently on the deformation style of the central Apennine.…”

3-D visualisation of palaeoseismic trench stratigraphy and trench logging using terrestrial remote sensing and GPR – a multiparametric interpretation

“…So far, this modern technology has been used for fault mapping at regional-to microscale coverage with up to millimetre resolution (e.g. Arrowsmith and Zielke, 2009;Begg and Mouslopoulou, 2010;Wilkinson et al, 2010Wilkinson et al, , 2015Bubeck et al, 2015). Further, the visualisation of bare-earth topography at a regional scale (Cunningham et al, 2006) and the detection of roughness changes along fault scarps (Wiatr et al, 2015) are scopes of application.…”