• Event Date : 09-19-2022
  • Location: Michoacan, Mexico
  • Report Date : 10-17-2022
  • Event Category: Earthquake
  • EQ Magnitude: 7.7
  • Report Number: GEER-078
  • DOI: doi:10.18118/G6B95P
  • Event Latitude: 18.24
  • Event Longitude: -103.28
  • Team:
    Juan M.    Mayoral V (Team Lead)
    Kevin B.    Clahan
    Daniel    De La Rosa A
    Mauricio    Perez D
    Jonathan P.    Stewart
  • Summary: An interface subduction earthquake of moment magnitude 7.7 occurred on September 19, 2022, along the Middle America trench megathrust near the central Pacific coast of Mexico in the state of Michoacan. The earthquake occurred at a relatively shallow depth of 15 km where the Cocos plate is subducting beneath the North America plate. According to the Civil Protection Coordination – the federal agency in charge of leading all activities at the national level to mitigate the effects of natural hazards – there was structural and nonstructural damage in 5,972 houses and 116 schools. Two fatalities occurred due to building collapses in Manzanillo, Colima. An M6.9 aftershock occurred on September 22, 2022 and resulted in two additional fatalities. Following the September 19, 2022 event, a joint geotechnical engineering reconnaissance effort was organized between the Group of Advance Numerical Modeling and Instrumentation from the Institute of Engineering at National Autonomous University of México, GEOSIM-IIUNAM, Lettis Consultants International, Inc., and the Geotechnical Extreme Events Reconnaissance Association, GEER, to perform a field reconnaissance of the seismic, geological, and geotechnical issues caused by the September 19, 2022, earthquake. The reconnaissance involved geo-located observations over an 842 km path, with stops at key locations where earthquake effects were observed. These effects included structural damage, roadway and bridge damage, damage to a drainage culvert, and ground failure from liquefaction, lateral spreading, and landsliding. To the extent practical, incidents of ground failure have been mapped so that adjacent areas of non-ground failure can be identified.
  • File Upload :
    File Title File Version File Date File Type
    Full Report 1 10-17-2022
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  • Contact Info :
    Name Phone Email Address
    Jonathan Stewart jstewart@seas.ucla.edu
The work of the GEER Association, in general, is based upon work supported in part by the National Science Foundation through the Geotechnical Engineering Program under Grant No. CMMI-1826118. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF. The GEER Association is made possible by the vision and support of the NSF Geotechnical Engineering Program Directors: Dr. Richard Fragaszy and the late Dr. Cliff Astill. GEER members also donate their time, talent, and resources to collect time-sensitive field observations of the effects of extreme events.