The second month of my grant was spent mapping, reading, and getting ready to go into the field. I’m scheduled to head into the mountains to do reconnaissance work at a potential field site with scientists I’ve met during my Fulbright.

My Fulbright advisor Esteban Sagredo is teaching an undergraduate Geomorphology class and he was kind enough to invite me to join their fieldtrip to the Cajón del Maipo, a drainage basin that supplies most of the water for Santiago. This was the first geology fieldtrip for many of the students. The focus of the trip was to observe the modern geomorphic processes, a skill whose complexity and value is not to be underestimated. There is always more to learn from the rocks. The first stop was at a river I skipped across without fear of the water reaching the laces-level on my hiking boots. Esteban encouraged us to look around. We noticed stream-cuts easily 20 meters overhead. Just a meter or so above that was a very lucky house that just escaped the last flood. As glaciers retreat and more precipitation falls in liquid form, the frequency of floods will increase, and city planning has not kept pace with global warming. Houses are still being built in places that won’t be around in a few decades. There has been an increase in the frequency of landslides in the area, which is attributed to the rising of the 0 degree isotherm. Terrain that was previously frozen, now has liquid water running through it, making gravity’s work easier. At our next stop, right below steep talus slopes we saw houses, some still being constructed right in the danger zone at the base of these liquefying terrains.

Represa at the Cajón del Maipo

Esteban and his PhD student Rodrigo Soteres are advising my work mapping Baño Nuevo, a glacial valley just north of Cohaique. To do this we use ArcGIS, digital elevation models, and stereo pair aerial images purchased from the Servicio Aerofotogrametrico in Santiago. They have an impressive collection of high resolution stereo pair images taken from airplane flights on film. We’ve already dated extensively the moraine limits, which gives us the exposure ages of individual landforms. The idea of the geomorphic mapping is to use our dated points and field observation to make interpretations about the character and origin of the surface deposits. This gives us a picture of the whole valley and helps us group the dates according to their glacial advance. For example, if we were to get a population of exposure ages of boulders deposited by glaciers ranging from 18-22 thousands of years, with high-resolution geomorphic mapping we might be able to say that there were two glacial advances, one from 18 to 20 and a second from 20 to 22 thousands of years before the present.

I started auditing a research class in the geography department. It is a class focused around helping PhD students prepare their research projects. We each presented a literature review of a piece of our doctoral research followed by feedback from the professors. They told me at the beginning that they can be harsh inside the classroom, but once the class time ends friendliness resumes. I got some helpful feedback, thoughtful questions, and we are all still friends outside the classroom.

I’m headed to NYC in three weeks to do lab work on samples we collected from Lago Vintter in September. We can do the first step of sample processing here at la Católica, separating a single mineral, quartz, from the whole rock. But the following step, separating only one element, beryllium, from the quartz requires a lab with special amendments to keep everything very clean. Beryllium is abundant in the soil, dust and metals all around us, but we’re interested in measuring only the beryllium in our rock sample. The lab at la Católica has just been built and is still developing the clean lab capabilities required for the second step in the method.