The Galápagos Islands are an archipelago situated nearly 600 miles off the coast of Ecuador, where life and geology are inextricably linked. These islands are famous for their diverse, endemic species that inspired Charles Darwin’s theories of evolution. The existence of this region is a direct consequence of relentless volcanic activity, making it one of the most volcanically active regions on Earth. The continuous cycle of eruption and erosion shapes the landscape and its distinct flora and fauna.
Pinpointing the Most Recent Eruption
The most recent confirmed volcanic activity in the Galápagos Islands occurred in 2024 at La Cumbre volcano, located on Fernandina Island. This effusive eruption began on March 2, 2024, following seismic unrest and ground inflation detected by satellite monitoring. The event was characterized by low-viscosity basaltic lava that poured from a circular fissure on the volcano’s southeastern flank.
The eruption produced a sulfur dioxide plume and incandescent lava flows, which were visible from passing ships but generated very little ash. This type of low-explosivity eruption is common for Galápagos volcanoes, where gases separate easily from the fluid magma. Satellite data confirmed that the volcano had been gradually swelling since its previous eruption in 2020, indicating that magma was refilling the underground chamber.
The Active Volcanic Zone
The archipelago’s volcanic activity is primarily concentrated on the westernmost islands of Fernandina and Isabela. These islands host the most active volcanoes, including La Cumbre, Wolf, Sierra Negra, and Cerro Azul. The volcanoes here are classified as shield volcanoes, characterized by their gentle, concave slopes and broad, dome-like summits.
Their characteristic form results from the fluid, basaltic lava that flows easily and covers large distances before cooling. This low-viscosity magma creates two common types of lava flow: the smooth, ropy-textured Pahoehoe and the rough, fragmented A’a. Isabela, the largest island, is a formation of six shield volcanoes that have coalesced over time.
The Hotspot Mechanism
The geological engine driving this volcanism is the Galápagos Hotspot, a fixed thermal plume of material rising from deep within the Earth’s mantle. This plume remains stationary, while the overlying Nazca tectonic plate moves eastward at approximately 60 millimeters per year. The interaction between the fixed magma source and the moving plate creates the island chain.
As the Nazca plate drifts, it carries the newly formed volcanoes away from the heat source. This mechanism explains the distinct age progression across the archipelago. The western islands, such as Fernandina, are the youngest and most active because they sit directly over or near the hotspot. Conversely, the eastern islands, like Española, are older, smaller, and dormant. These older islands are slowly eroded by wind and sea, gradually sinking as the plate cools and subsides.
Ecological Consequences of Eruptions
Volcanic eruptions are a fundamental, recurring process that shapes the islands’ ecosystems and influences the evolution of their species. The immediate effect of an eruption is destructive, as lava flows incinerate vegetation and destroy existing habitats. Lava flows can isolate animal populations, which has contributed to the distinct evolutionary paths of species like the giant tortoises found on Isabela’s different volcanoes.
Volcanic activity provides long-term ecological benefits by creating new land and enabling ecological succession. The sterile, newly cooled lava fields are slowly colonized by pioneer species, restarting the cycle of life. Endemic species like the marine iguanas on Fernandina, who graze on marine algae, are accustomed to this cycle of destruction and renewal. Some populations have evolved to thrive on the barren, rocky coasts formed by past flows.