Did an underwater landslide trigger the June 22, 1932 tsunami off the Pacific coast of Mexico?

摘要

On June 22, 1932, a 10- to 12-m-high tsunami wave struck similar to 60 km off the Mexican Pacific coast. The associated earthquake that apparently produced this tsunami is questionable because of its relatively small magnitude (M (s) = 6.9) to produce such tsunami heights. Historical documents, survivor testimony, tsunami catalogs, a post-tsunami survey report, together with geomorphological interpretation of the continental shelf and slope, and numerical modeling were combined to characterize the tsunami parameters. Our results suggest that recorded maximum tsunami wave height, horizontal inundation, arrival time, directivity, effects, and damage are compatible with those characteristics related to an underwater landslide tsunami. The associated landslide (slump) is 4.2 km long, 3.9 km wide, 0.448 km thick, and is located in the upper continental shelf of the Armeria Canyon. Elucidating the cause and mechanisms of the near-field 1932 tsunami would aid in considering a wider spectrum of tsunami sources in hazard mitigation programs of the Mexican Pacific coast.