Field Trip: The Galápagos
J-term, January 2009
2009 was the Year of Darwin, in celebration of Charles Darwin's 200th birthday. Taking this opportunity, St. Norbert College geology and biology decided to pay a visit to those rough islands in the Pacific which have become so immortalized in scientific history: the Galápagos. Darwin may be remembered mainly for his contributions to biology, but he was a geologist by training. On his journey he made many important observations and postulations concerning geological processes. Beyond the historical interest, the Galápagos are a geologically fascinating group of young volcanic islands. We spent a month on a boat, island hopping and learning geology first-hand.
Before any large trip, it is a good idea to research where you are going. This is a schematic diagram depicting the formation of the Galápagos islands. Like the Hawai'ian islands, the Galápagos formed over a hotspot. A hotspot is a place just beneath the crust of the Earth where mantle is abnormally warm. This generates magma (molten rock) makes its way to the surface, building a series of volcanic islands up from the sea floor.
Being a series of volcanic islands, evidence of volcanic activity is omnipresent on the Galápagos. During an eruption, tons upon tons of volcanic ash and dust is thrown into the air. This later settles out as an ash layer. They layers can be an important took for geologic age dating. Here are layers of volcanic ash which have built up over time from eruption after eruption.
These are tuff-cone volcanoes. Tuff-cone volcanoes are similar to cindercone volcanoes. Instead of ejecting lava, cindercones eject fragments of bubbly rock called “scoria.” Scoria is similar to pumice, except that scoria is heavier.
Here the expedition explores an old lava tube. Lava tubes are one of the most exciting remnants of volcanism. As lava flows from a vent, the top and sides of the flow may cool and harden while the interior remains warm enough to flow. The hardened top and sides actually insulates the lava flow. This allows it to stay warmer and travel further than it otherwise could. If the tunnel empties as the flow recedes, it may leaving a long tunnel called a lava tube. Later on we snorkeled in a submerged lava tube.
The Galápagos islands are owned by the Republic of Ecuador. While in the Galápagos we took a short side-trip to the mainland, visiting Ecuador's Andes mountains. Here is the expedition posing at the equator in the Andes. Snow-capped Mt. Cotopaxi is visible in the background. Yes, you read that correctly -- snow-capped mountains at the equator.
This is another shot of the Mt. Cotopaxi in the Ecuadorian Andes Mountains. Mt. Cotopaxi is tall enough that it remains snow-capped, even at the equator.
Neither geology nor biology ends at the water’s edge. Snorkeling gives one a whole new view of geology and ecosystems. Even if the aquatic world is generally off-limits to us, it’s important to always keep the fish’s-eye and bird’s-eye perspectives in the back of one’s mind.
A Galápagos iguana relaxes on a basaltic rock.
An St. Norbert student stares down a Galápagos tortoise. Who will win this epic battle of woman versus beast?
Here is 6:03 minutes of video from the Galapagos. It looks like footage from a Discovery Channel nature show, but we were actually here, taking this video.
After two weeks it was time to bid farewell to the Galápagos islands. But our work didn’t end there. We presented on our trip to the college and local community. We also wrote research proposals for future expeditions. The trip was a rich, rewarding experience we will carry with us forever.