Vol. 43 No. 1 (2026)

Cover image:

Historical photograph by Camillus Sidney Fly of the 1887 Sonora earthquake rupture scarp, preserved in the Karl V. Steinbrugge Collection, National Information Service for Earthquake Engineering, University of California, Berkeley. See the review article by Castro et al. in this issue about this major Basin and Range Province earthquake.
The picture, taken some few months after the earthquake, shows the rupture scarp in a stand of ocotillo (Fouquieria splendens) between Arroyo Pitáycachi and Cañón de los Embudos. The view is from the northwest. The scarp is subvertical, composed of alluvial gravel cemented by caliche, and its height is estimated here as 4.7 m. The two persons are standing in a fissure that developed along the scarp. The ground surface is not rotated towards the scarp, which suggests a simple planar near-surface geometry of the rupture.
The pictures by Camillus S. Fly of the 1887 Sonora earthquake are to our knowledge the earliest contemporary photographs of an earthquake surface rupture worldwide and among the earliest landscape photographs of northeastern Sonora.