The great 1787 Mexican tsunami

Abstract

Tsunamis have proven to represent a significant hazard around the globe and there is increased awareness about their occurrence. The Pacific coast in southern México is no exception, because there is firm evidence of the effects of past large tsunamis. Here we present results from computer-aided modeling of the March 28, 1787-''San Sixto'' earthquake and tsunami, and focus on the regions of Acapulco, Corralero, Jamiltepec, and Tehuantepec, located along the Guerrero-Oaxaca coast. The theoretical waveforms suggest wave heights in excess of 4 m and 18 m at specific locations in Acapulco and Corralero, respectively, and wave heights of at least 2 m at locations in Jamiltepec and Tehuantepec. From our modeling results and based on historical documents and the topography of the area, we conclude that these wave heights would have been sufficient to cause inundations that in the case of Acapulco were restricted to several meters inland, but in other areas like Corralero reached at least 6 km inland. Our results are consistent with published and unpublished damage reports that attest to the hazards associated with great earthquakes and tsunamis along the subduction zone in Mexico

Source Model of the October 9, 1995 Jalisco-Colima Tsunami as constrained by field survey reports, and on the numerical simulation of the tsunami

“…This paper follows the methodology used by Núñez-Cornú et al (2008) to model the mechanism of the 1787 Tsunami source from…”

“…While recent (Sumatra 2004; Chile 2010; Japan 2011) and historical (Chile 1960; Alaska 1964; Aleutians 1957) distant tsunamis have not generated damage on the west coast of Mexico, historical destructive tsunamis were originated by local earthquakes with interplate contact area located between the coast and the Middle America Trench, such as the one occurred off the coast of Oaxaca in 1787 (Núñez-Cornú et al, 2008).…”

Long‐Lived Tsunami Edge Waves and Shelf Resonance From the M8.2 Tehuantepec Earthquake

“…Further, the Tehauntepec coastline is low-lying with broad coastal plains reminiscent of the Sendai plain in Japan where inundation distances as long as 8 km were observed during the 2011 M9 Tohoku-oki earthquake (Mori et al, 2012). Megathrust events as large as M8.6 are interpreted in the paleoseismic record for the region going back 300 years (Núñez-Cornú et al, 2008;Suárez & Albini, 2009), and there is reason to believe that more tsunamigenic shallower normal faulting events, like the 2017 M8.2 Tehuantepec earthquake, are possible as well. Indeed, in this case it was fortunate that slip occurred landward of the trench, a more oceanward event, similar to the M8.6 1933 Sanriku Japan normal faulting earthquake (Okal et al, 2016) would produce far larger vertical deformation.…”

Rapid Geodetic Analysis of Subduction Zone Earthquakes Leveraging a 3‐D Elastic Green's Function Library

“…The slip distributions of these scenarios (e.g., Figures 5a and 5i) are generated by spatial random fields following a von Karman autocorrelation function (Mai & Beroza, 2002). These finite-fault models are equivalent to a moment magnitude of M w 8.6 that is comparable to the historical great 1787 event (Núñez-Cornú et al, 2008;Ramirez-Herrera et al, 2013;Suárez & Albini, 2009). The synthetic GPS data are calculated by an FEM-based forward model whose rock rigidity calculation inherits ±10% uniformly distributed randomized noise of P wave velocity (V p ) derived from CRUST2.0 (c.f.…”