Space Shuttle photo STS052-0073-0004.
Hierro, a shield volcano, has had a single historic eruption from the Volcan de Lomo Negro vent in 1793. The eruption lasted about one month and produced lava flows. Carracedo proposed the volcano has three rift zones and the El Golfo, El Julan, and Las Playas valleys are the result of giant landslides.
Sources of Information:
Carracedo, J.C., 1994, The Canary Islands: an example of structural control on the growth of large oceanic-island volcanoes. J. Volcanology and Geothermal Research, v. 60, p. 225-241.
Neumann van Padang, M., Richards, A.F., Machado, F., Bravo, T., Baker, E., Le Maitre, W., 1967, Part XXI, Atlantic Ocean: Catalogue of the active volcanoes of the world, International Association of Volcanology, Rome, Italy, 128 p.
Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.
Images of Volcanoes To VolcanoWorld