Postcards from Ecuador: Lively lagoons and volcanic geology brought to life on Isabela Island

Isabela Island, the last destination for the Honors College study abroad group, is the largest island in Galápagos, and in fact is bigger than all the other islands combined.

Formed by the merger of five huge shield volcanoes, the island is still very volcanically active, with one of its volcanoes, Sierra Negro, listed among the most active in the world.

Although it is by far the largest island, Isabela's main community, Puerto Villamil, is just the third largest settlement in the archipelago. A quiet, friendly town with soft sand streets and an incredibly laid back sensibility, Puerto Villamil was another in a long list of amazing locales for the program on this trip.

The group spent their first day on Isabela touring a tortoise breeding center, going for a walk through the mangroves to see wildlife including pink flamingos, taking a swim on the beach in the azure waters of the Pacific, and embarking on a snorkel session in a nearby lagoon that yielded up-close views of sea lions, whitetip reef sharks, green sea turtles, and more.

“It’s like being able to swim inside an aquarium,” said student Samantha Herlich, just before diving down to watch a school of passing fish.

The next day would hold another eye opening moment, but in a much different space. Shortly after breakfast, the group drove to the end of Isabela's only road and began a 10-mile hike up the slopes of Sierra Negro, which last had a major eruption in 2018. Seeing this “new rock” would be the goal of the group.

Upon arriving at the first “refugio” on the trail, the group was greeted by the incredible view inside Sierra Negro’s caldera – a massive cone about 7 miles across.

Below, at the bottom of the caldera, lay a massive expanse of new, pitch black rock, almost as far as the eye could see.

Cracks, fissures, and expansion joints ran across the surface of the now-cooled lava field. And while Sierra Negro was quiet today, based on the number of seismic monitoring stations and its past history, it won’t stay that way for long.

“I’m pretty sure this is the widest basaltic Caldera in the world, so you are really seeing something special,” said Honors College Director and Professor of Geology Scott Linneman. “And look at this day - are we lucky or what?”

The guides described the odds of a calm day with blue skies in the rainy season to be about a 1 in 20, so the class was even more appreciative a few miles farther up, where they could easily see where the magma leaked out of fissures atop Sierra Negro to roll in an inexorable black tide toward the sea.

A foot-weary but happy group made its way back to the bus in one piece, and after a hearty dinner, hit the hay to prepare for the last activity of the trip before beginning the long road back to Seattle: a last group hike and snorkel in the morning.

The pending end of the program was on the minds of a couple of the participants at dinner after the hike to Sierra Negro.

“In some ways it seems like we just started the trip – but when I think back to the things we did in Quito or in Otavalo, it also seems like that was months ago," said student Anna Byquist. “And we have seen and done so much.”

Fellow student Colette Webb agreed.

“It’s just hard to believe it’s almost over,” she said.


TOMORROW: Snorkeling Los Tuneles

WWU Geology student Annabelle Carozza surveys the inside of Sierra Negro's massive Caldera.
Cracks, fissures, and expansion joints run across the surface of the now-cooled lava field of Sierra Negro's massive caldera on a rare sunny day in the rainy season.