Galapagos volcanoes: Volcanic activity explains the origin of the Islands
In recent years, our planet has gone through incredible volcanic eruptions. Some major, some minor. They all reflect the basic instincts of our home. Planet Earth is a great dynamic planet, changing constantly, violently, quietly, while we hardly notice these changes. Perhaps Sir Charles Lyell (1797-1875), the father of Geology, had more courage to talk about changes in this apparently uniformitarian world. His masterpiece Principles of Geology is living proof that the concept of physical change is rather new to humankind. The Galapagos Islands are no exception in this ever-changing world. Past and present volcanic activity continues to change its shapes and forms.
Why are these volcanoes different from the Andes? Why are these volcanoes individually different?
What is true about the Galapagos volcanoes is that they’ve never had contact with the mainland. That means that these volcanoes emerged in the middle of the ocean. Now, there are two essential explanations for the differences seen between mainland volcanoes and island volcanoes: their magma chamber (area where molten rock resides) holds a different shape and therefore, oozing magma behaves differently. Also, the chemical composition of magma, dissolved gases, pressure content, etc, is different.
Galapagos volcanoes belong to a group called insular volcanoes, and their shape (when young) has the shape of an upside down saucer dish (like a dome). These volcanoes, once they interact with the volcanic hot spot, feed off that main source of molten rock until the chamber, as well as any crevice, huge crack, etc, gets filled up. Sometimes, those cracks find no escape, and they start to evacuate molten rock at different elevations and locations of the volcano. It is rather a gradual escape for the molten rock, unlike that of continental volcanoes where they get to be more explosive, gassier, and certainly more violent.
While exploring the islands, guests can witness different ages of the Galápagos volcanoes by choosing itineraries that will bring different geographic locations. For example, the older and more eroded volcanoes are seen in the East (Española, Santa Fé, Floreana, etc) of the archipelago, while the younger ones are seen in the West (Wolf, Alcedo, Darwin, La Cumbre, etc). A week in the Galápagos can give explorers a chance to see a good diversity of volcanoes.Volcanic Eruptions are King!
The latest eruption in the Galapagos occurred in May 2015, and it was on Isabela Island at Wolf Volcano. For weeks, the oozing lava came down the slopes after a fissure eruption started at around 01h00 on May 25th. Other importantly recorded eruptions have occurred on La Cumbre (Fernandina), Sierra Negra, Cerro Azul, Santiago, Marchena. An eruption is for sure an exciting moment in the islands, and hopefully soon, more unique experiences can be seen by our guests on board.By: Francisco Dousdebes