Volcanic eruption, Fernandina island, Galapagos, September 2017

Volcanic Eruptions: Galapagos Islands’ Natural Fireworks

Occasionally the Galapagos Islands remind us that it is a young volcanic archipelago. The mounts on Isabela and Fernandina erupt into short-term activity, giving visitors to the Galapagos a natural fireworks show.

Why the Galapagos Islands Have So Many Volcanoes

The Earth’s crust is made up of several dozen, slowly drifting plates. When one plate is forced beneath another – such as the Nazca Plate beneath the South American Plate – volcanoes like those in the Andes are formed.

Another way volcanoes are created is when a plate drifts over a hot spot, a place where the Earth’s molten innards burns through the crust above. As the plate moves over this stationary hot plume, it forms a string of volcanoes which grow into islands and become archipelagos, like the Hawai’ian Islands. Volcanoes on the older isles become extinct.

This is precisely how the Galapagos Islands are formed. They sit atop the Nazca Plate, which is drifting at a giant tortoise pace to the southeast. San Cristobal, the easternmost island, is approximately four million years old. Fernandina and Isabela, the westernmost main islands, are merely some 700,000 years old and thus still active.

Fernandina Island

On September 4th, Cumbre Volcano on Fernandina Island erupted for the first time in almost a decade. Two days earlier, a 4.6 earthquake between Fernandina and Isabela islands hinted that something was afoot. The quakes continued, growing more frequent, until on the afternoon of September 4th, the volcano erupted. The tour ship National Geographic Endeavour II happened to record that moment when Cumbre began emitting gas and steam. Lava is flowing from a fissure on Cumbre Volcano’s south-southwest side. Ecuador’s Geophysical Institute reports the volcanic activity is lessening. There are no human residents on Fernandina; however, wildlife is possibly threatened.

In modern times, Fernandina’s volcano has often been observed erupting. The activity occurs every few years, with notable flare-ups in 1988, 1991, and 1995. An eruption in 1968 caused the caldera to collapse, sending an ash cloud drifting to Isla Santa Cruz and beyond.

A gripping event was recorded in 1825 by Captain Benjamin Morrell. Right at the moment the island began spewing forth lava, his ship was becalmed in the Bolívar Channel between Fernandina and Isabela. Luckily, just in the nick of time, a slight breeze enabled him to sail to safety.

Isabela Island

Isabela is the Galapagos’ largest island and one of the most active geologically. It is composed of six volcanoes connected by lava flows. At the southwestern corner of the island is Cerro Azul, which last erupted in 2008. To the northeast is Sierra Negra (last eruption, 2005). Going northward is Alcedo (1993), Darwin (1813) and Wolf (2015). The “mouth” of this seahorse-shaped island is where the partially collapsed Volcán Ecuador is located (last eruption, 1150 CE).

Isabela’s activity has frequently been documented by pirates, whalers and scientific expeditions cruising through the Galapagos Islands. A fascinating account is told by scientist William Beebe in his 1926 book, The Arcturus Adventure.

You can check out Sierra Negra on a day tour from Puerto Villamil. At the volcano, which has one of the largest active craters in the world, old lava flows streak the lunar-like landscape.

Where Else You Might See Erupting Galapagos Islands

It is unlikely you’ll see islands in other parts of the Galapagos archipelago providing a fireworks show, though there is a remote possibility. Many of the eastern and central islands are millions of years older than the western ones, and their volcanoes long extinct.

According to the Smithsonian Institution’s Global Volcanism Program, it has been thousands of years since San Cristobal, Santa Cruz and Genovesa islands last saw volcanic activity. The islands further west tell a different story.

In recorded history, the last eruption on Floreana Island occurred in 1813, an event recorded by Captain David Porter of the USS Essex. Volcanic eruptions have occurred more recently on Santiago (1906), Pinta (1928) and Marchena (1991).

Effects of Volcanic Eruptions on Galapagos Wildlife

Although most of Galapagos’ volcanic eruptions in the last century have occurred on islands with no human population or far from towns and settlements, they still pose a danger to the archipelago’s unique wildlife. In the past, Galapagos fauna has faced a mixed bag of fortune.

With the May 2015 eruption of Volcán Wolf on Isabela Island, scientists were concerned the populations of giant tortoises and pink iguanas that inhabit the north and west slopes of the volcano might be endangered. Luckily, the ash and lava flowed to the east and southeast.

The local species of Fernandina giant tortoise was most likely decimated by volcanic eruption within the last 100 years. The effects of Cumbre Volcano’s 2017 activity on Fernandina wildlife will not be known until scientists can arrive there to survey the damage.

Effects of Volcanic Eruptions on Your Galapagos Cruise

The Galapagos Islands’ volcanoes are closely monitored by the national park, Ecuador’s Geophysical Institute and international agencies. Before an eruption, seismic (earthquake) activity increases, indicating that magma within the mount is moving.

Your itinerary may be affected by these periodic volcanic eruptions. If it includes a landing near the presently active volcano, that excursion may be cancelled due to safety concerns but your cruise will continue as normal. Punta Espinosa, on the northeast coast of Fernandina, is the only visitor site on that island. Some sites along Isabela’s coasts, like Black Turtle Point and Caleta Tagus at the foot of Volcán Darwin, are shadowed by volcanoes.


You can expect the unexpected while in the enchanting Galapagos Islands – and one of those things just may be a volcanic eruption, a mesmerizing natural fireworks display.


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Photo credit: via Twitter

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