LOS CABOS, Mexico – The underwater sand falls off the coast of the southern tip of the northwestern Mexican state of Baja California Sur continue to enthrall visitors more than 60 years after their discovery and decades after French oceanographer Jacques-Yves Cousteau first brought them to the world’s attention in the 1970s.
This phenomenon stems from friction between the North American and Pacific tectonic plates and the flow of strong marine currents characteristic of that region, which cause rivers of beautiful gold-colored sand to continually cascade over underwater cliffs at the point where Mexico’s Gulf of California meets the Pacific Ocean.
These sand falls are located within the Cabo San Lucas Flora and Fauna Protection area, a reserve that was established in November 1973 and covers an area of approximately 4,000 hectares (15 sq. miles), 95 percent of which is water.
They were first discovered in 1959 by Francis P. Shepard, a researcher for the Scripps Oceanographic Institute of San Diego, California, and were subsequently brought to the world’s attention by Cousteau, a famed French oceanographer, conservationist and filmmaker.
Geological evidence indicates the Gulf Of California was formed around 8 million years ago when tectonic forces rifted the Baja California Peninsula (now part of the Pacific Plate) off of the North American Plate.
These forces caused the formation of large submarine canyons at the edge of the continental shelf, among them the San Lucas Canyon off the resort city of Cabo San Lucas (at the southern tip of the peninsula) where the sand falls can be observed.
“The Cabo San Lucas region is a very short continental shelf that is just 30 meters (98 feet) deep,” Gerardo Gonzalez, a marine geologist and the head researcher at the Autonomous University of Baja California Sur, told EFE.
The experts said the limit of that shelf is reached at a distance of just 30 meters offshore and that a submarine canyon then begins that plummets to a depth of more than 3,000 meters at the mouth of the Gulf of California.
“This has made it very attractive and appealing to divers because it’s literally like a cascade of water, but instead of water it’s sand,” Gonzalez said.
One of these sand falls is located under the so-called arch of Cabo San Lucas, a distinctive rock formation at the southern tip of the Baja California Peninsula, where the waters of the Pacific Ocean commingle with those of the Gulf of California.
The currents at the entrance to the Gulf of California foment erosion, setting in motion tons of sand that flow down several kilometers to the ocean floor.
The director of Mexico’s National Commission of Natural Protected Areas in that region, Carlos Godinez, recalled that in 2005 the islands and other protected areas of the Gulf of California were designated as a World Heritage site.
The underwater sand falls attract hundreds of experienced divers, who not only are drawn to the unique beauty of that spectacle but also to the high level of marine biodiversity of the Gulf of California, which Cousteau termed “the world’s aquarium.”