GOOD GEOLOGISTS ALWAYS CARRY NOTEBOOKS
by Devra Wexler, AB '98
I am not a good geologist.
I am in the Galapagos Islands with my family--my parents, sister, and husband. It is sure to be the trip of a lifetime, so we have packed multiple cameras, including one for underwater pictures, and several sets of binoculars, along with snorkeling gear, hiking shoes, and hats--and yes, even a little spiral-bound notebook as my travel journal.
Yet when we head out for a two-hour hike that will take us over amazing lava fields, I don't take my notebook with me. To be honest, I'm more excited to see the animals. So as our naturalist points out the layers of tuff along the path, and the gorgeous ropey masses of pahoehoe, all I can do is take pictures and try to remember everything she is saying. Afterwards, however, we go snorkeling, and the enormous sea turtles, funky starfish, and pelicans crash-landing among the incredible schools of colorful fish--parrotfish, king angel, wrass, barracuda, halfbeaks--drive the geology straight out of my head.
This happens day after day--a morning hike reminds me of all the reasons I loved studying geology, and my old passion for volcanoes awakens. And then I jump from the panga into the cold clear waters and a sea lion approaches, inviting me to swim with her. Pele's Ecuadorian counterpart can't really compete with these sleek whiskered playmates.
So I repeat: I am not a good geologist. But I am a good Brown Geo alum, and I'm happy to send in even just a short trip report. So here's what I learned from the naturalists' talks:
The Galapagos Islands, like Hawaii, reside on a hot spot. They are close to the margin of the Nazca and Cocos plates, which are moving apart fairly rapidly, so, unlike Hawaii with its nice even swoop to the northwest, these islands bunch up and spread out and tangle up towards the southeast. The volcanoes are rather lovely shield volcanoes, with multiple fissures and small calderas, making some areas look like moonscapes. The lava itself is a mix of pahoehoe and aa, with lava tubes in various locations. Along the paths, light brown layers of tuff provide a distinct contrast to the darker pahoehoe nearby. (I hope my pictures have captured that sufficiently.) The older islands have more vegetation, and the geologic and volcanic history of each island is closely tied to the evolutionary changes of the wildlife. The suspected evolution of the marine iguanas is particularly fascinating, but that's another story.
Our trip in early June came just weeks after eruptive activity in Galapagos--I'm so disappointed that we missed it! But what I did see was still incredibly cool. If only I'd taken notes...
Devra Wexler, '97 is a project director for traveling exhibitions at the Smithsonian Institute in Washington, DC