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- Wilkinson, M., et al.
(författare)
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Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner
- 2010
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 37, s. L10309-
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Tidskriftsartikel (refereegranskat)abstract
- 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 x 65 m area at high horizontal spatial resolution. We detected millimetre-scale 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. Citation: Wilkinson, M., et al. (2010), Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner.
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| 2. |
- Ferrario, Maria Francesca, et al.
(författare)
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Developing the First Intensity Prediction Equation Based on the Environmental Scale Intensity : A Case Study from Strong Normal-Faulting Earthquakes in the Italian Apennines
- 2020
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Ingår i: Seismological Research Letters. - : Seismological Society of America (SSA). - 0895-0695 .- 1938-2057. ; 91:5, s. 2611-2623
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Tidskriftsartikel (refereegranskat)abstract
- Earthquakes produce effects on the built and natural environment, the severity of which decays with distance from the epicenter. Empirical relations describing the intensity attenuation with distance are fundamental for seismic hazard assessment and for deriving parameters for preinstrumental events. Seismic intensity is usually assigned based on damage to buildings and infrastructures; this can be challenging for intensity degrees higher than X or when macroseismic fields of multiple events close in time are overlapping. A complementary approach is the study of earthquake environmental effects (EEEs), which are used to assign intensity on the environmental scale intensity (ESI) scale. However, a quantitative comparison between the ESI and traditional scales, and an equation describing the ESI attenuation with distance are still lacking. Here, we analyze 14 historical and instrumental events (time window 1688–2016) in the central and southern Apennines (Italy), comparing ESI and Mercalli–Cancani–Sieberg (MCS) intensities. Our results show that ESI consistently provides higher intensity near the epicenter and the attenuation is steeper than MCS. We derive the first intensity prediction equation for the ESI scale, which computes local intensity as a function of distance and epicentral intensity value. We document that, in the near field, the MCS attenuation for shallow crustal events occurred in the twenty-first century is steeper than previous events, whereas the ESI attenuation shows a consistent behavior through time. This result questions the reliability of current empirical relations for the investigation of future events. We recommend including EEEs in intensity assignments because they can guarantee consistency through time and help in evaluating the spatial and temporal evolution of damage progression during seismic sequences, thus ultimately improving seismic risk assessment.
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