Roca Partida


Roca Partida ranks as the smallest of the four Revillagigedo Islands, part of the Free and Sovereign State of Colima in Mexico. This uninhabited island encompasses an extremely small area, and many divers rank it among the most beautiful in Mexico. Divers must obtain permits from the Mexican Armed Forces to enter into this military zone.

Geography

The four Revillagigedo Islands originated as volcanoes. San Benedicto Island and Socorro Island erupted in 1953 and 1993, respectively. Clarion Island and Roca Partida lack recently known eruptions. Erosion over millennia reduced Roca Partida to a piece of bare rock, devoid of terrestrial vegetation.
Roca Partida, long and wide, rises into two peaks. A low-lying bare rock area divides these two peaks, hence the name "Split Rock." The two peaks measured and high in 1953, but the higher peak apparently lost several meters since then, as the photographs illustrate.

Fauna

Roca Partida lacks fresh water and supports no land animals. Nevertheless, the waters surrounding this islet teem with marine life. Several species of seabird breed on the rock, including Nazca booby, Sula granti, which probably ventures little farther northeast, Northeast Pacific brown booby, Sula leucogaster brewsteri, East Pacific sooty tern, Onychoprion fuscatus crissalisa doubtfully distinct subspecies, and East Pacific brown noddy, Anous stolidus ridgwayi

History

The island's first reported sighting was by the Spanish expedition of Ruy López de Villalobos, in November 1542, who charted it with its present-day name.