EGU24-179, updated on 08 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The 1928 – 1937 Oaxaca Earthquake Sequence (Mexico)

Francisco J Nunez-Cornu1 and Diana Nunez2
Francisco J Nunez-Cornu and Diana Nunez
  • 1Universidad de Guadalajara, C. A. Sismologia y Volcanologia de Occidente, Puerto Vallarta, Mexico (
  • 2Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Spain. (

Oaxaca is the most seismically active region in Mexico and one of the most studied using different methodologies. This seismic activity is due to the subduction of the Cocos Plate beneath the North American Plate, which is considered an anomalous subduction zone since it is a truncated continental margin. Seventy-four earthquakes (M> 7.0) have been identified in the last 510 years, which is an average of one earthquake every 6.8 years. The seismic sequence occurred between 1928 and 1937 is the key to understand the regional seismotectonics. The locations of these nine events (M>7.0) reported by different authors differ by more than 100 km for the same earthquake. We relocated the aftershocks of these earthquakes using the seismograms from TAC (Tacubaya) and VCM (Veracruz) stations available at the Seismological Seismic Network (Mexico) archive reading pre-phases S-P.  To calibrate these readings, we relocate the seismicity in the region between 1950 and 1982 with the JHD Method using 1978, 1982, 1965 and 1968 earthquakes as Master Events. We look from this catalog the earthquakes registered in TAC and VCM in the period 1950 - 1982 and whose seismograms were in the archive were selected. The S-P prephases in TAC and VCM were read with the same criteria used previously. With these data we fitting a time-distance curve for each station. These curves were used to obtain more reliable aftershock area for each of the coastal earthquakes occurred during the 1928 – 1937 sequence.

How to cite: Nunez-Cornu, F. J. and Nunez, D.: The 1928 – 1937 Oaxaca Earthquake Sequence (Mexico), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-179,, 2024.