Imagine the wind carrying whispers of ancient volcanoes. Here at Cerro Mundo the Galápagos Islands reveal their fiery heart.
Cerro Mundo is not just a hill. It is a monument to the raw power that birthed this archipelago. Its story is etched in lava and sculpted by time.
These islands rose from the Pacific. Volcanism has been continuous here for at least 20 million years. Imagine the Earth’s mantle plume pushing up through the ocean floor. The Nazca plate moved eastward. It gave rise to a platform 3 kilometers thick. This platform underlies the islands.
The Galápagos are characterized by numerous volcanoes. Some have plume magma sources. Others come from the asthenosphere. This may be due to the young and thin oceanic crust.
The Galápagos Spreading Center caused structural weaknesses. This led to eruptions forming the Galápagos Platform. Fernandina and Isabela are aligned along these weaknesses. Lacking a well-defined rift zone the islands inflate prior to eruption.
Sierra Negra on Isabela Island experienced a 240 cm uplift between 1992 and 1998. Its most recent eruption was in 2005. Fernandina Island indicated a 90 cm uplift. Its most recent eruption was in 2009. Alcedo on Isabela Island had an uplift of greater than 90 cm. Its most recent eruption was in 1993.
The volcanoes here are closer together. They are smaller in size with larger calderas. Isabela Island includes six major volcanoes. They are Ecuador Wolf Darwin Alcedo Sierra Negra and Cerro Azul. Their most recent eruptions range from 1813 to 2008.
The shape of these volcanoes is tall and rounded. This differs from the wide smooth shapes in the Hawaiian Islands. The Galápagos shape is due to radial and circumferential fissures.
The volcanoes at the west end of the archipelago are taller and younger. They have well-developed calderas. They are mostly composed of tholeiitic basalt. Those on the east are shorter and older. They lack calderas. They have a more diverse composition.
The ages of the islands increase from west to east. Fernandina is 0.05 Ma. Isabela is 0.65 Ma. Santiago is 1.10 Ma. Santa Cruz is 1.7 Ma. Santa Fe is 2.90 Ma. San Cristobal is 3.2 Ma.
The calderas on Sierra Negra and Alcedo have active fault systems. The Sierra Negra fault is associated with a sill 2 km below the caldera. Fernandina experienced the largest basaltic volcano collapse in history. This occurred during the 1968 phreatomagmatic eruption. Fernandina has been the most active volcano since 1790.
Here at Cerro Mundo you witness nature’s ongoing experiment. These islands continue to evolve. New species arise. The land shifts. The volcanoes rumble. It is a privilege to stand on this dynamic ground. Feel the pulse of the planet beneath your feet.