Because rivers are a “snapshot” of the weathering process, my research analyzes river chemistry to understand current rates of basalt weathering, and how much atmospheric carbon is being sequestered by this process. I also am trying to understand what parameters influence weathering rates, such as the presence of glaciers, vegetative cover, or rock age and crystallinity by comparing river chemistry from many different types of watersheds throughout Iceland.
What exactly is fieldwork?
Most of what fieldwork actually is is logistics and on-the-go problem solving. Planning fieldwork includes figuring out where to sample, what gear you need, ordering and packing it, and figuring out how to get it to remote areas of Iceland and back in (mostly) one piece. Planning and logistics is 90% of the work.
Aqueous geochemistry gear consists of lots of bottles, of all shapes and sizes, plus equipment to set up an entire makeshift lab in the field. Acquiring and organizing the proper equipment must happen months in advance. Plus, you need back ups or everything in case something goes wrong.
Once you’re in the field and unpacked, preparing for sampling each day consists of calibrating equipment needed, and looking at maps to plan where you’e going to go, and driving a ton!
After several hours of hiking and fording streams, arriving at the site is where the fun begins. I take detailed notes and GPS data, measure pH and temperature, then collect my water samples.
I use a peristaltic drill pump and filter to sample river water. Different size and type bottles are needed depending on what the sample is for (isotopes, cations, anions, colloids, etc). To measure dissolved carbon (DIC) and carbon isotopes, I inject water with a syringe and needle into a glass vial.
Claire Nelson 