The birth of Volcán Bárcena, Mexico 1952-53
Barcena volcano was born during 's only historic eruption which began on 1 August 1952, from the El Boquerón vent. The eruption began with powerful vulcanian explosions creating base surges, which were witnessed from a nearby fishing boat. Large amounts of ash and pumice quickly built a new cinder cone built at the southern end of the island. In the later stage of the eruption, a viscous lava dome and lava flow emerged from the crater in December and flew to the east and created a spectacular, perfectly half-circular lava delta, known as the "Delta Lavico".---
The birth of Barcena is described in detail by A.F. Richards (1959) who collected various eyewitness accounts. The birth of the volcano was witnessed by the crew of the clipper M/V Challenger. It began suddenly at 07:45 on 1 August 1952, when the crew aboard the fishing boat, at that time about 2 miles west of Punta Norte, saw a sudden pencil-like emission of white steam.
A few minutes later, a dark gray-black column of ash was observed, and violent explosions started, and the crew witnessed a base surge:
"A few minutes later, the steam column had largely dissipated and dark gray-black or cement-colored column of ash and steam shot skyward. It did not appear incandescent. Almost immediately, the eruption cloud began to spread laterally at the base." The surge was seen climbing over small hills and reached about 2 km lateral distance.
In the meanwhile, a dense cauliflower eruption column had reached about 4300-4500 ft altitude and further rose to 6700 ft, and spread laterally about 11,000 ft.
The vessel retreated at full speed from the eruption to avoid being hit by bombs, which could be seen falling into the sea southwest of Monticulo Cineritico: "The ocean, previously clear and blue, became turbid, due to suspended ejecta, and remained murky." Although not hit by the main part of the surge (it would have been destroyed), "several inches of powdery dust, ash and cinders (up to about 12 mm in diameter) fell upon the deck of the Challenger."
Ejecta quickly filled the valley between Herrera crater and Montículo Cinerítico, and by 14 August, the eruption had formed a new cone, Bárcena, some 300 m (over 1000 ft) high.
After some months with little activity, a second series of eruptions, more effusive, began on 1 November and a viscous lava dome started to form in the crater of Barcena. On 8 December, the magma broke through a notch in the cone's southeastern side and started to flow into the sea, where it formed a semi-circular cake-like flat lava delta, the "Delta Lavico". The activity continued to about 24 February 1953 and by 9 March, all activity apart from fumaroles in the crater and near its base had stopped.
Source and further reading:
- Bárcena photos (GVP collection of spectacular photos from the eruption)
- Richards A F (1959) "Geology of the Islas Revillagigedo, Mexico 1. Birth and development of Volcan Barcena, Isla San Benedicto" Bull Volc, v. 22, pp 73-124