![MX-Revillagigedo](https://upload.wikimedia.org/wikipedia/commons/b/b2/MX-Revillagigedo.PNG)
Roca Partida ( en, Split Rock) ranks as the smallest of the four
Revillagigedo Islands
The Revillagigedo Islands ( es, Islas Revillagigedo, ) or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem. They lie approximately from Socorro Island south and southwest of C ...
, part of the Free and Sovereign State of
Colima
Colima (), officially the Free and Sovereign State of Colima ( es, Estado Libre y Soberano de Colima), is one of the 31 states that make up the Political divisions of Mexico, 32 Federal Entities of Mexico. It shares its name with its capital and ...
in
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
. The uninhabited island (Latitude 19° 0'2.53"N, Longitude 112° 4'5.35"W) encompasses an extremely small area. Many
divers
Diver or divers may refer to:
*Diving (sport), the sport of performing acrobatics while jumping or falling into water
*Practitioner of underwater diving, including:
**scuba diving,
**freediving,
**surface-supplied diving,
**saturation diving, a ...
rank it among the most beautiful dive sites in Mexico. Divers must obtain permits from the
Mexican Armed Forces
The Mexican Armed Forces ( es, Fuerzas Armadas de México) are the military forces of the United Mexican States. The Spanish crown established a standing military in colonial Mexico in the eighteenth century. After Mexican independence in 1821, ...
to enter the military zone surrounding the island.
Geography
![Roca Partida](https://upload.wikimedia.org/wikipedia/commons/5/5c/Roca_Partida.jpg)
The four
Revillagigedo Islands
The Revillagigedo Islands ( es, Islas Revillagigedo, ) or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem. They lie approximately from Socorro Island south and southwest of C ...
originated as
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are ...
es.
San Benedicto Island
San Benedicto, formerly Isla de los Innocentes, is an uninhabited island, and third largest island of the Revillagigedo Islands, located in the Pacific Ocean.
It is 4.8 km by 2.4 km in size, with an area 10 km². It is of volcanic ...
and
Socorro Island
Socorro Island ( es, Isla Socorro) is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying off the country's western coast. The size is 16.5 by 11.5 km (10.25 by 7.15 miles), with an area of . It is the largest ...
erupted in 1953 and 1993, respectively.
Clarion Island
Isla Clarión, formerly called Santa Rosa, is the second largest, westernmost and most remote of Mexico's Revillagigedo Islands. The island is located west of Socorro Island and over from the Mexican mainland.
It has an area of and three pr ...
and Roca Partida lack recently known eruptions.
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
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 the two peaks, hence the name "Split Rock." The two peaks measured and high in 1953, but the higher peak apparently lost several meters (feet) since then, as the photographs illustrate.
Fauna
Roca Partida lacks
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
and supports no land animals. Nevertheless, the waters surrounding the islet teem with marine life. Several species of
seabird
Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...
breed on the rock, including the
Nazca booby
The Nazca booby (''Sula granti'') is a large seabird of the booby family, Sulidae, native to the eastern Pacific. First described by Walter Rothschild, 2nd Baron Rothschild, Walter Rothschild in 1902, it was long considered a subspecies of the ma ...
(), which probably ventures little farther to the northeast; the Northeast Pacific
brown booby (); the East Pacific
sooty tern
The sooty tern (''Onychoprion fuscatus'') is a seabird in the family Laridae. It is a bird of the tropical oceans, returning to land only to breed on islands throughout the equatorial zone.
Taxonomy
The sooty tern was described by Carl Linnaeu ...
(), a doubtfully distinct
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
; and the East Pacific
brown noddy
The brown noddy or common noddy (''Anous stolidus'') is a seabird in the family Laridae. The largest of the noddies, it can be told from the closely related black noddy by its larger size and plumage, which is dark brown rather than black. The b ...
().
History
The island's first reported sighting was in November 1542 by the Spanish expedition of
Ruy López de Villalobos
Ruy López de Villalobos (; ca. 1500 – April 4, 1546) was a Spanish explorer who sailed the Pacific from Mexico to establish a permanent foothold for Spain in the East Indies, which was near the Line of Demarcation between Spain and Portugal a ...
, who charted it with its present-day name.
References
External links
Marine Life of Roca PartidaScuba Diving in Roca Partida
Revillagigedo Islands
Islands of Colima
Pacific islands of Mexico
Stacks (geology)
Volcanoes of Colima
Uninhabited islands of Mexico
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