2017 Mw 8.1 Tehuantepec Earthquake: Deep Slip and Rupture Directivity Enhance Ground Shaking but Weaken the Tsunami

Research Article| May 30, 2018 2017 Mw 8.1 Tehuantepec Earthquake: Deep Slip and Rupture Directivity Enhance Ground Shaking but Weaken the Tsunami Kejie Chen; Kejie Chen aJet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 U.S.A., Kejie.Chen@jpl.nasa.gov, Zhen.Liu@jpl.nasa.gov, yuhe.t.song@jpl.nasa.gov Search for other works by this author on: GSW Google Scholar Wanpeng Feng; Wanpeng Feng bCanada Center for Mapping and Earth Observation, Natural Resources Canada, Ottawa, Ontario, Canada K1A 0E4, wanpeng.feng@canada.ca Search for other works by this author on: GSW Google Scholar Zhen Liu; Zhen Liu aJet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 U.S.A., Kejie.Chen@jpl.nasa.gov, Zhen.Liu@jpl.nasa.gov, yuhe.t.song@jpl.nasa.gov Search for other works by this author on: GSW Google Scholar Y. Tony Song Y. Tony Song aJet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 U.S.A., Kejie.Chen@jpl.nasa.gov, Zhen.Liu@jpl.nasa.gov, yuhe.t.song@jpl.nasa.gov Search for other works by this author on: GSW Google Scholar Seismological Research Letters (2018) 89 (4): 1314–1322. https://doi.org/10.1785/0220170277 Article history first online: 30 May 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Kejie Chen, Wanpeng Feng, Zhen Liu, Y. Tony Song; 2017 Mw 8.1 Tehuantepec Earthquake: Deep Slip and Rupture Directivity Enhance Ground Shaking but Weaken the Tsunami. Seismological Research Letters 2018;; 89 (4): 1314–1322. doi: https://doi.org/10.1785/0220170277 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search ABSTRACT The 8 September 2017 Mw 8.1 Tehuantepec normal‐faulting earthquake caused unexpected widespread intensive shaking, strongly felt as far as Mexico City about 720 km northwest of the epicenter, and generated a 1.8 m tsunami at the coast. Just 11 days later, another devastating Mw 7.1 Puebla earthquake occurred near Mexico City. In this contribution, we characterized this event by a joint inversion using static Global Positioning System (GPS) offsets, Interferometric Synthetic Aperture Radar (InSAR) measurements, high‐rate GPS, and teleseismic displacement waveforms, then validated the preferred model by tsunami observations. We demonstrate that the Tehuantepec earthquake rupture propagates mainly unilaterally toward the northwest at a relatively high speed (⁠∼3.4 km/s⁠), with three asperities identified: the dominant one is centered between depths from ∼40 to 60 km while the other two are located at shallower (⁠∼20 km⁠) and deeper (⁠∼90 km⁠) depths, respectively. Moreover, we find the peak ground acceleration (PGA) recorded along the rupture propagation direction is much larger than that recorded at stations in the opposite direction with nearly identical epicentral distances (⁠∼700 km⁠). Dynamic displacements reaching 5 cm were also observed at a GPS station ∼1450 km from the epicenter. Based on these observations and our model results, we suggest that the deep slip in the low‐attenuation mantle and the rupture directivity likely enhance the nationwide ground shaking, whereas the shallow slip may contribute to the local tsunami heights. The derived slip distribution is valuable for future investigation on the explicit relationship between the Mw 8.1 Tehuantepec and Mw 7.1 Puebla events. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.