A Pioneering Aftershock Study of the Destructive 4 January 1920 Jalapa, Mexico, Earthquake

Research Article| July 25, 2018 A Pioneering Aftershock Study of the Destructive 4 January 1920 Jalapa, Mexico, Earthquake Gerardo Suárez; Gerardo Suárez aInstituto de Geofísica, Universidad Nacional Autónoma de México, Cd. Universitaria, Mexico City 04510, Mexico, gerardo@geofisica.unam.mxdnovelo@geofisica.unam.mx Search for other works by this author on: GSW Google Scholar D. A. Novelo‐Casanova D. A. Novelo‐Casanova aInstituto de Geofísica, Universidad Nacional Autónoma de México, Cd. Universitaria, Mexico City 04510, Mexico, gerardo@geofisica.unam.mxdnovelo@geofisica.unam.mx Search for other works by this author on: GSW Google Scholar Author and Article Information Gerardo Suárez aInstituto de Geofísica, Universidad Nacional Autónoma de México, Cd. Universitaria, Mexico City 04510, Mexico, gerardo@geofisica.unam.mxdnovelo@geofisica.unam.mx D. A. Novelo‐Casanova aInstituto de Geofísica, Universidad Nacional Autónoma de México, Cd. Universitaria, Mexico City 04510, Mexico, gerardo@geofisica.unam.mxdnovelo@geofisica.unam.mx Publisher: Seismological Society of America First Online: 25 Jul 2018 Online Issn: 1938-2057 Print Issn: 0895-0695 © Seismological Society of America Seismological Research Letters (2018) 89 (5): 1894–1899. https://doi.org/10.1785/0220180150 Article history First Online: 25 Jul 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Gerardo Suárez, D. A. Novelo‐Casanova; A Pioneering Aftershock Study of the Destructive 4 January 1920 Jalapa, Mexico, Earthquake. Seismological Research Letters 2018;; 89 (5): 1894–1899. doi: https://doi.org/10.1785/0220180150 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 On 4 January 1920, a magnitude Mw 6.4 earthquake occurred in the eastern Trans‐Mexican volcanic belt (TMVB) to the southwest of the city of Jalapa, Mexico. Structural damage was extensive in towns near the epicentral area. The more damaging phenomena, however, were mudflows in the high valleys that covered several villages. It was estimated that approximately 700 people died under the mud avalanches triggered by the earthquake on the steep slopes of the river valleys. The moderate‐sized 1920 Jalapa earthquake is the second deadliest earthquake in the history of Mexico and the only one in which extensive mudflows triggered by the earthquake were reported. Several active faults mapped in the central part of the Mexican volcanic belt have produced earthquakes as large as Mw 7.2. In the eastern portion of the belt, where the Jalapa earthquake took place, few faults have been mapped. Therefore, there is doubt about whether the 1920 earthquake was a shallow, crustal earthquake or whether it occurred within the subducted Cocos plate, as with other earthquakes located to the south of the TMVB. In what constitutes probably the first aftershock study after a destructive earthquake, the Mexican Seismological Service installed an 80‐kg, Wiechert vertical seismograph in the city of Jalapa after the earthquake. The S–P times of three aftershocks indicate that they occurred in the epicentral area, confirming it as a shallow crustal earthquake. This pioneering aftershock study helps confirm that crustal seismicity extends throughout the TMVB, where 40% of the population of Mexico lives. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Topic: earthquake and tectonic studies
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences