| Titre | Surface deformation associated with the 2015 Mw 8.3 Illapel earthquake revealed by satellite-based geodetic observations and its implications for the seismic cycle |
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| Auteur | Feng, W ;
Samsonov, S; Tian, Y; Qiu, Q; Li, P; Zhang, Y; Deng, Z; Omari,
K |
| Source | Earth and Planetary Science Letters vol. 460, 2017 p. 222-233, https://doi.org/10.1016/j.epsl.2016.11.018 |
| Image |  |
| Année | 2017 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20170195 |
| Éditeur | Elsevier BV |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.epsl.2016.11.018 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Région | Illapel |
| Lat/Long OENS | -76.0000 -67.0000 -28.0000 -38.0000 |
| Sujets | déplacement; télédétection; secousses séismiques; failles; zones de subduction; failles, effrondrement; établissement de modèles |
| Illustrations | cartes de localisation; images satellitaires; graphiques |
| Programme | Science de la télédétection spatiale |
| Diffusé | 2016 12 05 |
| Résumé | (disponible en anglais seulement)
In this study, we present inter-, co- and post-seismic displacements observed in the 2015 Illapel earthquake area by Global Positioning System (GPS) and
Synthetic Aperture Radar Interferometry (InSAR). RADARSAT-2, ALOS-2 and Sentinel-1A interferograms capture the co- and post-seismic displacements due to the Illapel earthquake. Based on a layered Earth structure, we modeled both co- and post-seismic
faulting behaviors on the subduction interface of central Chile. The best-fit model shows that the coseismic rupture broke a 200km×200km area with a maximum slip of 10 m at a depth of 20 km. Two distinct slip centers, likely controlled by local
ramp-flat structure, are revealed. The total coseismic geodetic moment is 2.76×1021Nm, equivalent to a moment magnitude 8.3. The accumulated afterslip in the first two months after the mainshock is observed on both sides of the coseismic rupture zone
with both ascending and descending Sentinel-1A interferograms. A limited overlap zone between co- and post-seismic slip models can be observed, suggesting partitioning of the frictional properties within the Illapel earthquake rupture zone. The total
afterslip releases ?5.0×1020Nm geodetic moment, which is equivalent to an earthquake of Mw 7.7. The 2010 Mw 8.8 Maule earthquake that occurred ?400 km away from the Illapel earthquake epicenter could have exerted certain effects on the seismic cycle
of the Illapel earthquake area. The seismic records from 2000 to 2015 imply that the rate of annual seismic moment release in the Illapel earthquake area dropped from 0.4 to 0.2×1019Nm/yr after the Maule earthquake. Based on the forward modeling with
the best-fit slip models determined in this study, we reproduce the local surface displacements before, during and after the Illapel earthquake. A rough deformation cycle, 105±29yr, calculated by using the coseismic displacements and interseismic
rate is basically identical with the revisit interval of M8 events in the adjacent areas of the Illapel earthquake, suggesting that elastic rebound theory is applicable for the long-term prediction in this region. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Wanpeng Feng, the first author of the paper, is working at CCMEO with a nserc visiting fellowship since October 2015. He has been working on
geophysics and geodetic applications for over 10 years. |
| GEOSCAN ID | 305954 |
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