Critical Zone Observatories

The Flandrau Science Center and Planetarium of Tucson, AZ commissioned five 6-foot wide illustrations for The Critical Zone, an exhibit showcasing the cross-disciplinary research conducted at the Critical Zone Observatories throughout the United States. Each illustration helps carry the viewer down through the layers of the Critical Zone– Earth's outer skin, where water, atmosphere, ecosystems, soil, and rock interact. This exhibit and the observatories are both supported by the National Science Foundation. This exhibit was on display from 2016–2021.

Graphite and digital media. 70"x48". 2016.

1. Overview of the Earth's skin.

2. The uppermost layer, the Canopy, where water and gas exchanges take place between soil, plants, and the atmosphere.

3. The surface layer, where roots and their fungal associations form soil, facilitate decomposition, affect erosion, and provide rich habitats.

4. The Rhizosphere, where organic matter supports an immense biodiversity of macro- and microfauna.

Detail of a burrowing bee.

5. Where rock meets life. At these depths, life consists of microbes that get their energy from breaking-down rock.

• Acidithiobacillus ferrooxidans bacteria on pyrite, covered in mineral precipitates.

• Tubular mineral sheaths secreted by bacteria.

• Shewanella oneidensis bacteria on iron oxide clay, using iron as an energy source.