Abstract
We study the rupture process of the Mw 8.3 Illapel, Chile earthquake that occurred on 16 September 2015 using the US seismic network as a large aperture array. We apply the back-projection technique using two frequency bands, 0.1–0.5 and 0.25–1 Hz. Both frequency bands reveal that this event is characterized by rupture of three patches. The higher frequency band shows an earlier burst of seismic radiation and illuminates a relatively down-dip patch of energy radiation. On the other hand, the lower frequency band shows a more up-dip rupture and matches well with the slip inversion model in other studies. The Illapel earthquake ruptures about 100-km along-strike, and shows 40-km up-dip and 40-km down-dip movement along the subduction megathrust fault. The earthquake first ruptures around the epicenter with a relatively low level of seismic radiation. Then, it propagates northeast along the Juan Femandez Ridge (JFR) to rupture a patch down-dip accompanied by strong higher frequency seismic radiation. Finally, it ruptures to the northwest of the epicenter and terminates south of the Challenger fracture zone (CFZ), releasing a burst of strong lower frequency seismic radiation. Most of the aftershocks are either within or at the edge of the rupture patch, a region characterized by high coupling in central Chile. The rupture is bounded along-strike by two fractures zones to the north and south. The JFR to the south of the rupture zone may have acted as a barrier along-strike, leaving the area south of the mainshock vulnerable for a large damaging earthquake in the near future.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Barazangi, M., and Isacks, B. L. (1976), Spatial distribution of earthquakes and subduction of the Nazca plate beneath South America, Geology, 4, 686–692.
Barrientos, S. (1995), Dual seismogenic behavior: the 1985 Central Chile earthquake, Geophys. Res. Lett., 22 (24), 3541–3544.
Beck, S., Barrientos, S., Kausel, E., and Reyes, M. (1998), Source characteristics of historic earthquakes along the central Chile subduction zone, J. South Am. Earth Sci., 11(2), 115–129.
Contreras-Reyes, E., Grevemeyer, I., Flueh, E. R., and Reichert, C. (2008), Upper lithospheric structure of the subduction zone offshore of southern Arauco peninsula, Chile, at 38° S, J. Geophys. Res., 113, B07303, doi:10.1029/2007JB005569.
Contreras-Reyes, E., and Carrizo, D. (2011), Control of high oceanic features and subduction channel on earthquake ruptures along the Chile–Peru subduction zone, Physics of the Earth and Planetary Interiors, 186, 49–58.
Delouis, B., Nocquet, J. M., and Vall’ee, M. (2010), Slip distribution of the February 27, 2010 Mw = 8.8 Maule earthquake, central Chile, from static and high-rate GPS, InSAR, and broadband teleseismic data, Geophys. Res. Lett., 37, L17305.
Demets, C., Gordon, R. G., Argus, D. F., and Stein, S. (1994), Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions, Geophys. Res. Lett., 21, 2191–2194.
Fan, W., and Shearer, P. M. (2015), Detailed rupture imaging of the 25 April 2015 Nepal earthquake using teleseismic P waves, Geophys. Res. Lett., 42, 5744–5752, doi:10.1002/2015GL064587.
Fromm, R., Zandt, G., and Beck, S. L. (2004), Crustal thickness beneath the Andes and Sierras Pampeanas at 30° S inferred from Pn apparent phase velocities, Geophys. Res. Lett., 31, L06625, doi:10.1029/2003GL019231.
Ghosh, A., Vidale, J. E., and Creager, K. C. (2012), Tremor asperities in the transition zone control evolution of slow earthquakes, J. Geophys. Res., 117, B10301, doi:10.1029/2012JB009249.
Heidarzadeh, M., Murotani, S., Satake, K., Ishibe, T., and Gusman, A. R. (2015), Source model of the 16 September 2015 Illapel, Chile Mw 8.4 earthquake based on teleseismic and tsunami data, Geophys. Res. Lett., 43 (2), 643–650, doi:10.1002/2015GL067297.
Ishii, M., Shearer, P. M., Houston, H., and Vidale, J. E. (2005). Extent, duration and speed of the 2004 Sumatra-Andaman earthquake imaged by the Hi-net array, Nature, 435, 933–936, doi:10.1038/nature03675.
Kelleher, J. A. (1972), Rupture zones of large South American earthquakes and some predictions, J. Geophys. Res., 77, 2087–2103, doi:10.1029/JB077i011p02087.
Kennett, B. L. N., and Engdahl, E. R. (1991), Traveltimes for global earthquake location and phase identification, Geophys. J. Int., 105(2), 429–465.
Kiser, E., and Ishii, M. (2011), The 2010 Mw 8.8 Chile earthquake: Triggering on multiple segments and frequency-dependent rupture behavior, Geophys. Res. Lett., 38, L07301, doi:10.1029/2011GL047140.
Kiser, E., and Ishii, M. (2013), Hidden aftershocks of the 2011 Mw ~ 9.0 Tohoku, Japan earthquake imaged with the backprojection method, J. Geophys. Res. Solid Earth, 118, 5564–5576, doi:10.1002/2013JB010158.
Lay, T., Ammon, C. J., Kanamori, H., Koper, K. D., Sufri, O., and Hutko, A. R. (2010), Teleseismic inversion for rupture process of the 27 February 2010 Chile (Mw 8.8) earthquake, Geophys. Res. Lett., 37, L13301, doi:10.1029/2010GL043379.
Lowrie, A., and Hey, R. (1981), Geological and geophysical variations along the western margin of Chile near lat 33° to 36° S and their relation to Nazca Plate subduction, in Nazca Plate: Crustal Formation and Andean Convergence, Mem. Geol. Soc. Am., 154, 741–754.
Marot, M., Monfret, T., Pardo, M., Ranalli, G., and Nolet, G. (2013), A double seismic zone in the subducting Juan Fernandez Ridge of the Nazca Plate (32° S), central Chile, J. Geophys. Res. Solid Earth, 118, 3462–3475, doi:10.1002/jgrb.50240.
Melgar, D., Fan, W., Riquelme, S., Geng, J., Liang, C., Fuentes, M., Vargas, G., Allen, R. M., Shearer, P. M., and Fielding, E. J. (2016), Slip segmentation and slow rupture to the trench during the 2015, Mw8.3 Illapel, Chile earthquake, Geophys. Res. Lett., 43, doi:10.1002/2015GL067369.
Meng, L., Ampuero, J. P., Sladen, A., and Rendon, H. (2012), High-resolution back-projection at regional distance: Application to the Haiti M7.0 earthquake and comparisons with finite source studies, J. Geophys. Res., 117, B04313, doi:10.1029/2011JB008702.
Metois, M., Socquet, A., and Vigny, C. (2012), Interseismic coupling, segmentation and mechanical behavior of the Central Chile subduction zone, J. Geophys. Res., 117, B03406, doi:10.1029/2011JB008736.
Pilger JR., R. H. (1981), Plate reconstructions, aseismic ridges and low-angle subduction beneath the Andes, Geol. Soc. Am. Bull., 92, 448–456.
Tapponier, P., and Molnar, P. (1976), Slip-line theory and largescale continental tectonics, Nature, 264, 319–324.
Tebbens, S. F., Cande, S. C., Kovacs, L., Parra, J. C., Labrecque, J. L., and Vergara, H. (1997), The Chile ridge: a tectonic framework, J. Geophys. Res., 102 (B6), 12035–12060, 726, doi:10.1029/96JB02581.
Von Huene, R., Corvalan, J., Flueh, E. R., Hinz, K., Korstgard, J., Ranero, C. R., and Weinrebe, W. (1997), Tectonic control of the subducting Juan Fernandez Ridge on the Andean margin near Valparaiso, Chile, Tectonics, 16, 474–488, doi:10.1029/96TC03703.
Walker, K., Ishii, M., Shearer, P. M. (2005). Rupture details of the 28 March 2005 Sumatra Mw 8.6 earthquake imaged with teleseismic P waves, Geophys. Res. Lett., 32, L24303, doi:10.1029/2005GL024395.
Xu, Y., Koper, K. D., Sufri, O., Zhu, L., and Hutko, A. (2009), Rupture imaging of the Mw 7.9 12 May 2008 Wenchuan earthquake from back-projection of teleseismic P waves, Geochem. Geophys. Geosyst., 10, Q04006, doi:10.1029/2008GC002335.
Ye, L., Lay, T., Kanamori, H., and Koper, K. D. (2015), Rapidly estimated seismic source parameters for the 16 September 2015 Illapel, Chile Mw 8.3 Earthquake, Pure Appl. Geophys. 173, 321–332, doi:10.1007/s00024-015-1202-y.
Yin, J., Yang, H., Yao, H., and Weng, H. (2016), Coseismic radiation and stress drop during the 2015 Mw 8.3 Illapel, Chile megathrust earthquake, Geophys. Res. Lett., 43, 1520–1528, doi:10.1002/2015GL067381.
Acknowledgments
The authors thank the Incorporated Research Institutions for Seismology (IRIS) for archiving and providing access to seismic data from all US seismic network stations used in this study. All the figures are made with generic mapping tools (GMT) (http://gmt.soest.hawaii.edu/). We thank Diego Melgar providing the slip inversion model for this earthquake. We also want to extend our thanks to two anonymous reviewers for their constructive comments that helped improve the content of this manuscript.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer International Publishing AG
About this chapter
Cite this chapter
Li, B., Ghosh, A. (2017). Imaging Rupture Process of the 2015 Mw 8.3 Illapel Earthquake Using the US Seismic Array. In: Braitenberg, C., Rabinovich, A. (eds) The Chile-2015 (Illapel) Earthquake and Tsunami. Pageoph Topical Volumes. Birkhäuser, Cham. https://doi.org/10.1007/978-3-319-57822-4_4
Download citation
DOI: https://doi.org/10.1007/978-3-319-57822-4_4
Published:
Publisher Name: Birkhäuser, Cham
Print ISBN: 978-3-319-57821-7
Online ISBN: 978-3-319-57822-4
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)