Fernandina

Fernandina is the most active volcano in the Galápagos Islands, with 33 recorded eruptions — more than any other island in the archipelago.

The 1968 caldera collapse dropped the caldera floor approximately 350 m in a single event, swallowing a pre-existing caldera lake — the most powerful explosive eruption ever documented in the Galápagos.

Fernandina Island has never been colonized by invasive species, making it one of the most pristine volcanic islands on Earth.

The 1988 eruption caused the collapse of nearly 1 km³ of the east caldera wall, generating a massive debris avalanche that covered the caldera floor.

Fernandina's summit caldera is 5 × 6.5 km and approximately 900 m deep — one of the deepest calderas relative to volcano height of any shield volcano on Earth.

The island is home to the flightless cormorant (Phalacrocorax harrisi), which exists nowhere else on the planet and has evolved in response to the island's unique volcanic ecology.

In 2019, a living Fernandina giant tortoise (Chelonoidis phantasticus) was rediscovered on the island after being considered potentially extinct for over a century.

Captain Benjamin Morrell, who witnessed the 1825 eruption, claimed the sea around Fernandina boiled so intensely that pitch melted on his ship — an account modern volcanologists consider greatly exaggerated.

Fernandina lies directly above the Galápagos mantle plume, the hotspot that has built the entire island chain over at least 20 million years.

The volcano erupts exclusively basaltic lava — highly fluid flows that can travel from the summit to the coast, a distance of over 10 km.

Fernandina's eruption frequency — roughly one event every 3–4 years in recent decades — rivals that of Kīlauea in Hawaii.

The Bolívar Channel between Fernandina and Isabela is one of the richest marine environments in the Galápagos due to cold-water upwelling.