San Benedicto Island

The Island of San Benedicto, formerly called Anublada Island, is the third largest island of the Revillagigedo Islands, in Mexico. Its size is 4.8 km by 2.4 km, with an area of 10 km².

It is of volcanic origin. It has two prominent peaks, the highest, Bárcena, rises to a height of 310 meters near the southern part of the island. It has the typical shape of a volcanic crater. Bárcena has only one historical eruption recorded, it began on August 1, 1952 and continued until February 24, 1953. The eruption destroyed most of the terrestrial flora and fauna. Its climate is warm-subhumid with rain in summer. To the east of San Benedicto there is a beach where you can disembark. The Revillagigedo archipelago was declared a World Heritage Site in 2016 (ref. no. 1510).

History

The first recorded sighting of San Benedicto was made by the Spanish expedition of Hernando de Grijalva on December 28, 1533, which mapped it as Island of the Innocents because that day was the festival of the Holy Innocents (Massacre of the Innocents). In November 1542, it was sighted again by the expedition of Ruy López de Villalobos, who incorrectly identified it with Santo Tomás de Grijalva (current Socorro Island).

The eruption of the volcano in 1952-1953

The Bárcena volcano has an unverified record that it began around 8:30 a.m. m. of August 1, 1952 taken from the smoke outlet of "El Boquerón". It was recorded as a large volcanic eruption on scale 3 of the Volcanic Explosivity Index. The pyroclastic flow circled the island, soon the entire island was covered with ash and pumice until it reached a dense layer of approximately 3 meters. The valley between the Herrera crater and the Cineritic Cone was filled with ejecta and until approximately August 14, the cone that measures around 300 meters high was formed.

After a few months with little recorded activity, a second series of eruptions occurred that began on November 1, 1952. On December 8 of the same year, the magma broke the southeastern cone at its base and began to flow towards the sea. This continued until February 24, 1953.

On March 9, 1953, most volcanic activity had ceased, with the exception of the fumarole in the crater and the fissure at the base of the cone. Its lava has hardened, but it still retains a lot of heat. At the end of 1953, it became an inactive volcano again.

Ecology

The eruption wiped out—at least temporarily—all of the island's terrestrial flora and fauna, much as had happened on Krakatoa in 1883. The fauna, including the endemic species known as the San Benedicto Rock wren, became extinct around the 9:00 a.m. m. from August 1st. It is rare for an extinction to have been recorded with such precision, and in this case it was only possible because of how it was documented in the ejecta.

However, once the volcanic activity ceased and during the spring of 1953, the seabird returned to the island during the breeding season. It settled only north of the Herrera crater, where the ash it covers has already begun to erode. A few land crabs were present as well, having survived the eruption or, more likely, recolonizing the island and their ocean-dwelling larvae. Even so, it has very little or no plant species.

By late 1953, rain had washed away the ash and pumice deposits north of San Benedicto. At least half of the previously recorded plant taxa appeared again. Numerous seabirds arrive to breed, further north of Herrera, the blue-faced booby and the frigatebird stand out in the ditch between Herrera and Bárcena.

Flora

Only 10 plant taxa have been recorded at San Benedicto, which contains mainly herbs, occasionally with subshrubs and vines. It seems that not everything was extinct due to the 1952 eruption.

The flora of Revillagigedo contains several endemisms shared with Clarión Island: Bulbostylis nesiotica, Cyperus duripes and Perityle socorrosensis. The taxonomy of local Euphorbia anthonyi is not fully resolved. Other plants in San Benedicto are Aristolochia islandica, Cenchrus myosuroides, Eragrostis diversiflora, Erigeron crenatus, Ipomoea pes-caprae, ssp brasiliensis, Morning Glory Playa and Teucrium townsendii. There are eleven species of vascular plants here, six of them, as explained, endemic.

Fauna

The vertebrates in the fauna of San Benedicto today only consist entirely of seabirds. It appears that the Revillagigedo population of large crows were also bred on San Benedicto before the 1952 eruption, but this type of population was wiped out and the crows are no longer found—except perhaps rarely and as vagrants—on San Benedicto in the today.

On the northeastern edge of the Island is a place where several seabirds from the eastern tropical Pacific come to breed. The taxa that breed from San Benedicto are the following:

• Ardenna pacifies, Puffinus pacificus (o) Ardenna pacifies), more eastern breeding;
• ethereal rabijunco (Ethereal)Phaethon aethereus mesonautapossibly the northernmost farm;
• piquero camanay or piquero patiazul or alcatraz patiazul (Sula nebouxii nebouxiipossibly the northernmost farm;
• Nazca or alcatraz piquero (Sula granti), possibly the northernmost breeder;
• red-headed piquero (Philippines)Sula sula websteripossibly the northernmost breeder with different subspecies.
• brown piquero, brown alcatraz or bobaSula leucogaster brewsteri, northerner breeding;
• common frigate, pelagic frigate (Less ridiculous frigate, more northern breeding, different subspecies.

The nearly extinct Townsend's (or Revillagigedo's) shearwaters (Puffinus auricularis) do not resemble the St. Benedict's breed, but can occasionally be seen feeding offshore. Given that there are no invasive species on San Benedicto and also no predators, apart from frigatebirds of course, the island could be very suitable for establishing a new colony of them. In fact they could have been raised here before the 1952 eruption; As shearwaters are very conservative in choosing their breeding sites, this may explain why San Benedicto has not yet been recolonized by them.

Vanders of other species, such as brown pelican, buteo jamaicensiss, ospreys, barn swallows and chestnut warblers may occasionally visit the island, but ultimately, only passing through or to die, San Benedicto is still too barren to support a permanent resident population. Migrating waders, such as the curlew and the Alaskan sandpiper, now rest at San Benedicto for short stops more regularly.

Eco-friendly tourism

San Benedicto Island is a popular underwater diving destination known for encounters with dolphins, sharks, giant manta rays and other pelagic species. An area called "La Caldera" It is where divers commonly interact. Divers have also coexisted with tiger sharks, Galapagos sharks, silky sharks, and humpback whales. Since there are no public airports, divers come aboard yachts and/or boats from Cabo San Lucas, Baja California Sur or Manzanillo, Colima. The months of November and May are most popular to travel here, as this is when the weather and seas are calmer. To the east of San Benedicto there is a beach where you can disembark.