Sidebar Site Navigation
Riebe Lab Group
Surface Processes, Weathering, Cosmogenic Nuclides, Detrital Thermochronometry
office phone: +1 307 766-3965
1000 E. University Ave. Laramie, Wyoming 82071
Office: ESB 2008
Geology, PhD, University of California, Berkeley, 2000
Civil Engineering, BSE, University of Michigan, 1992, summa cum laude
My group focuses on understanding Earth’s surface and how it changes over time due to the uplift and erosion of mountains. Earth’s surface is the dynamic interface between air and rock. It’s also where we and lots of other familiar organisms live. There are lots of interesting connections between life and landscapes. We are studying some of them in ongoing work. Hence, some aspects of our research naturally reach across science and into management, addressing practical issues involving the sustainability of vital ecosystem resources.
Our research often involves transdisciplinary approaches. It's not enough to just study geology. For example, water and life are central to converting rock to soil and moving it across landscapes. Making progress on current challenges in surface processes research requires integration of geology, hydrology, ecosystem science, geochemistry, and an understanding of human impacts on landscapes.
We seek quantitative insight on surface processes. To obtain it, we employ a variety of geochemical, isotopic and geophysical methods. Together our measurements reveal patterns of erosion, weathering, regolith formation, watershed geochemistry and landscape evolution. Hence they are vital to making advances on many exciting problems in surface processes research.Some of our research methods include:
- cosmogenic nuclides, which reveal long-term erosion rates of rock, soil & entire catchments [PDF primer];
- detrital thermochronometry, which sheds light on the sources of eroded material in streams and deposits;
- geochemical mass balance, which helps constrain the relative importance of chemical and physical erosion; &
- near-surface geophysics, which reveals the architecture of weathering and water storage in the critical zone.
- 2013–18 NSF EAR 1331939 Southern Sierra Critical Zone Observatory (CoPI)
- 2013–15 NSF EAR 1325033 Spatial variability in eroded sediment size & geomorphic processes (Lead PI)
- 2013–14 NSF EAR 1242284 Drilling, sampling & imaging the depths of the critical zone (Workshop, PI)
- 2012–17 NSF OAI 1208909 The Wyoming Center for Environmental Hydrology & Geophysics (Investigator)
- 2012–14 NSF EAR 1148224 Be-10 in detrital magnetite as a new tool in erosion & weathering studies (PI)
Several facets of our field work are based in the National Science Foundation's Critical Zone Observatories. In particular, we are conducting ongoing research on erosion and weathering at the CZOs in the Southern Sierra Nevada and at Luquillo, Puerto Rico.
Cosmogenic Nuclide Labs: We oversee two spacious wet-chemical labs devoted to purification and dissolution of quartz and magnetite. Once minerals are dissolved, cosmogenic nuclides are extracted and prepared for analysis. We use these nuclides to measure rates of weathering, erosion, and sedimentation. Our cosmogenic nuclide lab facilities are open for use by collaborators on select projects. Contact me by e-mail for information.
Materials Characterization Labs: We have facilities for isolating other minerals, besides quartz; of particular interest to us at the moment is apatite, for detrital thermochronometry. We also boast a cottage industry in the geochemical analysis of soils and rock using XRF and XRD; this supports our quest for a quantitative understanding of weathering, erosion, and soil development in landscapes.
Student Research Opportunities
I am always on the lookout for sharp, motivated graduate students. In the wake of recent sucess in acquiring research funds, I will be seeking to admit at least one student in the next admissions cycle. If you are thinking about graduate studies in geomorphology or low-temperature geochemistry and are interested in my group's projects, you are welcome to contact me by e-mail.Any inquiries about graduate studies should include:
- a current CV or resume;
- a one-page statement of interest in graduate studies in my research group;
- a copy of your academic transcript(s) – unofficial copies are OK at this stage; &
- if available, your most recent GRE scores.
In my courses I challenge students to identify, understand, and quantify the chemical and physical processes that shape landscapes, generate soils, and modify water quality. My teaching approach emphasizes a mechanistic understanding of Earth systems, including hands-on field components and readings from current research whenever appropriate. Central in my teaching philosophy is the development of problem-solving skills and critical thinking abilities. Whenever possible, I include exercises based on my experience as an industry consultant – the goal is to help prepare our geology and geophysics graduates as best I can for the real-world problems they will face throughout their careers.Recent courses:
- GEOL/ENR 1500 Water, Dirt & Earth's Environment Fall
- GEOL 2150 Geomorphology Spring
- GEOL 4/5760 Rates & Timescales of Surface Processes Spring
- GEOL/ENR 4/5200 Environmental Data Analysis in development for Spring
Citation statistics (updated 11/1/13):
876 total citations; 5 first-author papers with >80 citations
* denotes student under my direct supervision; ◊ denotes student collaborator
Riebe, C. S., Sklar, L. S., Overstreet, B. T.*, Wooster, J. K. Optimal reproductive potential in salmon spawning substrates linked to grain size and fish length. Water Resources Research (in revision)
Hahm W. J.*, Riebe, C. S., Lukens, C. E.*, Araki, S.* Bedrock composition regulates mountain ecosystems and landscape evolution. Proceedings of the National Academy of Sciences (in revision)
Dixon, J. L., Riebe, C. S., Making soil. Elements (invited contribution in review)
Holbrook, W. S., Riebe, C. S., Elwaseif, M., Hayes, J. L.◊, Harry, D., Reeder, K., Malazian, A., Dosseto, A., Hartsough, P. & Hopmans, J. (in press) Geophysical constraints on deep weathering and water storage potential in the Southern Sierra Critical Zone Observatory. Earth Surface Processes and Landforms
Granger, D. E. & Riebe, C. S. (in press) Cosmogenic Nuclides in Weathering and Erosion. for "Treatise on Geochemistry, Volume 5: Surface and Ground Water, Weathering, and Soils." (2nd edition).
Riebe, C. S. & Granger D. E. 2012. Quantifying effects of deep and near-surface chemical erosion on cosmogenic nuclide buildup in soils, saprolite and sediment. Earth Surface Processes and Landforms. DOI: 10.1002/esp.3339 [PDF reprint]
Jessup, B. S.*, Hahm, W. J.*, Miller, S. N., Kirchner, J. W. & Riebe, C. S. 2011. Landscape response to tipping points in granite weathering: The case of stepped topography in the Southern Sierra Critical Zone Observatory. Applied Geochemistry 26 (Supplement 1): S48-S50. [PDF reprint]
Brantley, S. L. & 28 others. 2011. Twelve Testable Hypotheses on the Geobiology of Weathering. Geobiology. DOI: 10.1111/j.1472-4669.2010.00264.x [PDF reprint]
Ferrier, K. L., Kirchner, J. W., Riebe, C. S. & Finkel, R. C. 2010. Mineral-specific chemical weathering rates over millennial timescales: Measurements at Rio Icacos, Puerto Rico. Chem. Geol. 277:101-114. [PDF reprint]
Granger, D. E. & Riebe, C. S. 2007. Cosmogenic Nuclides in Weathering and Erosion. In "Treatise on Geochemistry, Volume 5: Surface and Ground Water, Weathering, and Soils." J. I. Drever (editor). Elsevier, London. [PDF reprint]
Riebe, C. S., Kirchner, J. W. & Finkel. R. C., 2004. Erosional and climatic effects on long-term chemical weathering rates in granitic landscapes spanning diverse climate regimes. Earth Planet. Sci. Lett. 224:547–562. [PDF reprint]
Riebe, C. S., Kirchner, J. W. & Finkel, R. C. 2004. Sharp decrease in long-term chemical weathering rates along an altitudinal transect. Earth Planet. Sci. Lett. 218:421–434. [PDF reprint]
Riebe, C. S., Kirchner, J. W., Finkel, R. C. 2003. Long-term rates of chemical weathering and physical erosion from cosmogenic nuclides and geochemical mass balance. Geochim. Cosmochim. Acta 67:4411–4427. [PDF reprint]
Riebe, C. S., Kirchner, J. W. & Granger, D. E. 2001. Quantifying quartz enrichment and its consequences for cosmogenic measurements of erosion rates from alluvial sediment and regolith. Geomorphology 40:15–19. [PDF reprint]
Riebe, C. S., Kirchner, J. W., Granger, D. E., Finkel, R. C. 2001. Strong tectonic and weak climatic control of long-term chemical weathering rates. Geology 29:511–514. [PDF reprint]
Kirchner, J. W., Finkel, R. C., Riebe, C. S., Granger, D. E., Clayton, J. L. & Megahan, W. F. 2001. Mountain erosion over 10 yr, 10 k.y., and 10 m.y. time scales. Geology 29:591–594. [PDF reprint]
Riebe, C. S., Kirchner, J. W., Granger, D. E. & Finkel, R. C. 2001. Minimal climatic control of erosion rates in the Sierra Nevada, California. Geology 29:447–450. [PDF reprint]
Granger, D. E., Riebe, C. S., Kirchner, J. W., Finkel & R. C. 2001. Modulation of erosion on steep granitic slopes by boulder armoring, as revealed by cosmogenic 26Al and 10Be. Earth Planet. Sci. Lett. 186:269–281. [PDF reprint]
Riebe, C. S., Kirchner, J. W., Granger, D. E. & Finkel, R. C. 2000. Erosional equilibrium and disequilibrium in the Sierra Nevada, inferred from cosmogenic 26Al and 10Be in alluvial sediment. Geology 28:803–806. [PDF reprint]