Lake research in Tanzania
This summer I will be doing tropical lake research on Lake Tanganyika, Tanzania. I'll be working with other students and faculty from the US and from the University of Dar es Salaam, which is located in the capital of Tanzania. The Kigoma field station will be used by people in our research group to study things like climate change, human impact on nutrients and erosion, evolution of lacustrine organisms, and several other topics.
My research project will use lake sediments to get a high-resolution record of recent climate change and environmental impacts. Specifically, I'll be studying controls on organic matter distribution and accumulation in different areas over time, and will also evaluate organic matter's relationship to grainsize and lake-bottom morphology.
To do this, I'll be measuring organic and inorganic matter abundances in cores taken in a transect roughly parallel to shore, in water about 100 m deep. I'll analyze total organic carbon (TOC) and total inorganic carbon (TIC), do smear slide descriptions, and perform laser particle size analysis, probably using a Spectrex Laser Particle counter. TOC will probably be determined using the loss-on-ignition (LOI) method, which can be useful, but can also give inflated organic matter concentrations if there is a lot of volatile non-carbon matter in the sediment.
We'll use a multicorer (which grabs sediment samples down to about 60 cm depth) and a gravity corer, which recovers sediment to about 2 m depth. I haven't used a multicorer or a gravity corer before, but the principles are simple: drop a heavy tube over the side of a boat, let it hit the bottom and sink into the mud, then pull it back up. Will have to do some more reading on specifics.