Isabela Island
Shaped singularly like a seahorse, Isabela is the largest of the Galapagos islands, formed from the amalgamation of six volcanoes that erupted half a million years ago.
The geology on these islands fascinated Darwin, for he was a true polymath, not just interested in natural history, and he devoted a proportion of his Voyage of the Beagle Galapagos chapter to a study of volcanoes. “From their regular form, they gave the country a workshop appearance, which strongly reminded me of those parts of Staffordshire where the great iron foundries are most numerous.” Referring to the lava beds he remarked, “Nothing could be imagined more rough and horrid than the surface of the more modern streams.”
Volcanoes on the Galapagos are everywhere, for in a sense volcanoes are the Galapagos. Darwin had a tough time acquainting himself with them. “The day on which I visited the little craters, was glowing hot, and the scrambling over the rough surface, and through the intricate thickets, was very fatiguing…”
For us, landing on Isabela to visit a volcano up close and personal was a good deal easier. You can’t miss the main caldera on Isabela: Sierra Negra. It’s vast - about ten kilometres wide - one of the largest in the world in fact, and a regular ‘erupter’. In contrast to Darwin’s experience, we took a smooth minibus ride to the start of our journey: a hike (for half of us) and a horse ride (for me and the others). Riding a horse through cooling breezes and light drizzle was a great way to take in the landscape and its inhabitants.
We were fortunate to get close-up views of a crimson-coloured Vermillion flycatcher and Smooth-billed Ani, along with several mockingbirds and associated finches. Looking over the edge of the caldera was to gaze on a vast moonscape of black waste unbroken by vegetation. Striking out on foot beyond the end of the horse trail we could reach the area that had erupted most recently - the ‘danger zone’ as our guide remarked. Below us were mini craters, whilst close to the path lay small holes leading down towards the active subterranean chamber. From its catalogue of previous episodes, we tried not to dwell on the fact that an eruption of Sierra Negra was overdue. We took hurried photos and literally cantered back along the track towards the minibus.
