Research
A multidisciplinary team of scientists established CRB-CZO to integrate three major processes governing the critical zone: the water cycle, the mineral cycle, and the carbon cycle. Our holistic study of the entire 1440 km2 Christina River Basin watershed temporally integrates vertical and lateral carbon, mineral and water fluxes over a range of modern and historical land uses. 
Our overarching goal is to quantify the net carbon sink (or source) due to mineral production, weathering, erosion and deposition as materials are transported and transformed across geophysical boundaries that traditionally separate scientific disciplines (i.e. sapprolite → topsoils → aquifers → riparian floodplains → wetlands → river networks → salt marshes → estuaries → sea). Because a material flux that appears as a source at one location might result in sink in another location, a source-to-sink multidisciplinary study is required.
Science questions currently being addressed include:
• Are processes that mix minerals and carbon rate- limiting to watershed-scale carbon sequestration, chemical weathering and soil production?
• Do humans accelerate rates of carbon-mineral mixing and does this result in anthropogenic carbon sequestration significant to local, regional and global budgets?
Research highlights
• Intensive study sites for the impacts of three landuse end-members on hydrological, pedological and geomorphological processes:
° Mature forest
° Row crop agriculture
° Continuous excavation (landfill)• Long-term continuous datasets as a basis for hydrological and material transport models, including implementation of the Penn State Integrated Hydrological Model (PIHM).
• Intensive geochemical characterization of mineral weathering, carbon-mineral complex formation and carbon stabilization in soils and sediments of different origin and landuse.
• Source-to-sink sediment tracing study using radio-isotopes and other geochemical "fingerprints".
In-Situ Sensors and Instrumentation
The CRB-CZO is developing and deploying an advanced sensor network for real-time observations of hydrological and biogeochemical processes. These sensors range from basic meteorological and hydrological sensors that can be widely deployed at low cost, to advanced commercial field-instrumentation such as submersible UV-Vis spectrometry, to home-made geochemical sensors constructed from readily available electronic components. We are beginning to participate in the emerging open-source hardware movement to further the development of environmental sensors.
Objectives Summary
Our research is organized around four multi-disciplinary objectives:
