Galapagos Island Volcanoes
Considered to be young islands in geological terms, the Galapagos Islands are more or less four to five million years old. Formed by the eruption of underwater volcanoes, whose lava rose to the surface, the Galapagos today sits in a volcanically active region, which has had over 50 eruptions since it was first discovered in 1535 by Bishop Tomas de Berlanga, who was sailing from Panama to Peru.
Known as one of the top ten areas of volcanic activity on the planet, what makes the Galapagos Islands so geologically unique is the fact that this archipelago was never connected to the mainland, and was formed by hotspots on the Pacific Ocean floor. In geology, hotspots are superheated zones on the earth’s tectonic plates that sometimes heat up to such an extent that the magma causes the plates to melt and lava is released with such force that it forms islands above the surface of the water.
All the islands in the Galapagos are formed by a single volcano each, with the exception of Isla Isabela, which is made up of 6 volcanoes. Two distinct kinds of volcanoes can be found in the archipelago; and while both of them are shield volcanoes, the difference lies in their lithospheric thickness. Known as shield volcanoes because they resemble ‘inverted soup bowls,’ the volcanoes in the Galapagos are quite smooth and are made up of `basalt,’ which lets the lava flow easily to retain their shield-like shape.
The first recorded eruption in the Galapagos occurred in 1797 on Isla Isabela. The volcano in question here was Volcan Wolf, which sits some 1,707 m above sea level and is the highest point in the archipelago. The last recorded volcanic eruption in the Galapagos took place in October last year, when the Sierra Negra Volcano erupted. This volcano is also found on Isla Isabela as well.
Over the centuries eruptions have been also recorded in the volcanoes on the Islas Fernandina, Floreana, Marchena, Pinta, Santiago, Darwin, Santa Cruz, San Cristobal and Genovesa. On Isla Espanola and Isla Santa Fe the volcanoes have been extinct for millions of years now, but their volcanic structures have withstood the test of time. Isla Rabida’s and Isla Pinzon’s volcanoes have also been extinct, but only for a million years or so.