Spring tides, storm surges, and the destruction of coastal middens: A case study from the upper Gulf of California, México.

This study used photogrammetry to analyze digital video taken before and after a new moon perigean spring tide that caused extensive damage to archaeological sites along the Upper Gulf of California coastline, south of San Felipe, Baja California, México. We created a 3D digital surface model (DSM) and orthophoto of the Conchero 4 site, a large multicomponent shell midden and sand dune. Results showed mass wasting (∼100 linear meters and ∼1500 m³) across the entire east-facing dune front and particularly heavy damage along the site's southern boundary, which faces the mouth of a large drainage. Our research adds a significant dimension to mounting global evidence that cultural heritage sites are eroding away in a wide variety of types of coastal environments, including low-energy tidally-dominated coastlines like the Upper Gulf of California. [ABSTRACT FROM AUTHOR]