× Visitor Information People Laboratory facilities Lab Methods Publications Press Cosmocams - see the lab Cosmogenic Links Geocosmo list serve Fun Photos & Videos Operating Information Lab Safety Paul Bierman's webpage About the Lab Social Media Papers X (login required) Contact Us

Eric Portenga



Eric comes to UVM from the University of Michigan where he obtained his BS in Geological Sciences in 2008. He will be continuing the 10Be cosmogenic investigation in the Appalachian Mountains, measuring bedrock erosion rates.

PhD dissertation, Earth Sciences (University of Glasgow and Macquaire University)


MS Thesis, Geology (University of Vermont, 2011)

Using 10Be to constrain erosion rates of bedrock outcrops globally and in the central Appalachian Mountains
download pdf of MS thesis proposal
download MS thesis proposal slides (ppt) (pdf)
download pdf of MS thesis progress report
download MS thesis progress report slides (ppt) (pdf)
download MS thesis defense slides (ppt) (pdf)
download pdf of MS thesis

Undergraduate degree

University of Michigan, B.S. Geological Sciences, 2008

Related Links

Eric's Eastern Michigan web page

Current Position and Contact Information (7/2018)

Assistant Professor
Eastern Michigan University
Department of Geography & Geology
409 King Hall
Ypsilanti, MI 48197

Refereed Papers

Portenga, E. W., Ullman, D. J., Corbett, L. B., Bierman, P. R., and Caffee, M. (2023) Early Holocene ice retreat from Isle Royale in the Laurentian Great Lakes constrained with 10Be exposure-age dating, Geochronology. doi.org/10.5194

VanLandingham, L., Portenga, E. W., Lefroy, T., Bierman,P. R., and Hidy, A. J. (2022) Comparison of basin-scale in situ and meteoric 10Be erosion and denudation rates in felsic lithologies across an elevation gradient at the George River, northeast Tasmania, Australia, Geochronology, 4, 153–176 doi.org/10.5194/gchron-4-153-2022

Bierman, P. R, Bender, A. M., Christ, A., Corbett, L., Halsted, C., Portenga, E., and Schmidt, A., (2020) Dating by Cosmogenic Nuclides, Encyclopedia of Geology, Second Edition, p. 101-115. doi.org/10.1016/B978-0-08-102908-4.00124-7

Portenga, E., Bierman, P. R., Trodick, C., Dejong, B., Greene, S. and Pavich, M. (2019) Erosion rates and sediment flux within the Potomac River basin quantified over millennial timescales using beryllium isotopes. GSA Bulletin. doi.org/10.1130/B31840.1

Bierman, P. R., Shakun, J., Portenga, E., Rood, D, and Corbett, L. B. (2018). Directly dating post-glacial Greenlandic emergence at high resolution using in situ 10Be. Quaternary Research. Published online: 12 April 2018. doi:10.1017/qua.2018.6

Bierman, P. R. and Portenga, E. (2017) Beryllium Isotopes. In: Encyclopedia of Geochemistry (W.M. White, ed.) Springer. Published online: 13 September 2017. doi:10.1007/978-3-319-39193-9_81-1

Portenga, E. W., Bishop, P., Rood, D. H. and Bierman, P. R. (2017) Combining bulk sediment OSL and meteoric 10Be fingerprinting techniques to identify gully initiation sites and erosion depths. Journal of Geophysical Research - Earth Surface. v. 122(2), p. 513-517. doi:10.1002/2016JF004052

Linari (Sullivan), C. L., Bierman, P. R.R., Portenga, E., Pavich, M.J., Finkel, R.C. and Freeman, S. (2016) Rates of erosion and landscape change along the Blue Ridge escarpment, southern Appalachian Mountains, estimated from in situ cosmogenic 10Be. Earth Surface Processes and Landforms. v. 42, p. 928-940. doi:10.1002/esp.4051

Portenga, E. W., Rood, D. H., Bishop, P. and Bierman, P. R. (2016) Isotopic evidence for a mid-Holocene landscape response to Aboriginal burning in southeastern Australia. Geology. v. 44(2), p. 131-134. doi:10.1130/G37257.1
(see press release)
(ABC news story)

Portenga, E., Bierman, P. R., Duncan, C., Corbett, L. B., Kehrwald, N. M. and Rood, D. (2015) Erosion rates of the Bhutanese Himalaya determined using in situ-produced 10Be. Geomorphology. v. 233, p. 112-126. doi:10.1016/j.geomorph.2014.09.027

Bierman, P. R., Coppersmith, R., Hanson, K., Neveling, J., Portenga, E. and Rood, D. (2014) A cosmogenic view of erosion, relief generation, and the age of faulting in Southern Africa. GSA Today. v. 24(9), p. 4-11. doi:10.1130/GSATG206A.1

Portenga, E. W., Bierman, P. R., Rizzo, D. M. and Rood, D. H. (2013) Low rates of bedrock outcrop erosion in the central Appalachian Mountains inferred from in situ 10Be. Geological Society of America Bulletin. v. 125(1-2), p. 201-215. doi:10.1130/B30559.1

Portenga, E. and Bierman, P. R. (2011) Understanding Earth’s Eroding Surface with 10Be. GSA Today. v. 21(8), p. 4-10. doi:10.1130/G111A.1
(download .xls data repository)

Abstracts

Portenga, E.W., Bogoski, C., O’Neill, C., Skora, S., Townsend, K., Corbett, L.B., Bierman, P.R., and Caffee, M.W. 2023. 10Be reproducibility in the Santa Monica Mountains from 2016–2021: A longitudinal 10Be replicate study through fire, atmospheric rivers, and mass movements. Geological Society of America Abstracts with Programs 55(6): 394832. doi.org/10.1130/abs/2023AM-394832

Portenga, E.W., Ullman, D.J., Corbett, L.B., Bierman, P.R., and Caffee, M.W. 2023. The timing of Laurentide Ice Sheet retreat from Isle Royale in Lake Superior based on 10Be exposure ages. Geological Society of America Abstracts with Programs 55(6): 394799. doi.org/10.1130/abs/2023AM-394799

Portenga, E., Bogoski, C., Townsend, K.F., Bierman, P.R., Corbett, L.B., Clark, M.K., and Caffee, M.W. 2022. The impact of the 2018 Woolsey fire on 10Be concentrations measured in stream sand in the Santa Monica Mountains. Geological Society of American Annual Meeting, Denver, CO. Geological Society of America Abstracts with Programs 54(5): 383224. doi.org/10.1130/abs/2022AM-383224

Bogoski, C.J., Portenga, E.W., Corbett, L.B., Bierman, P.R., and Caffee, M.W. 2021. Reproducibility of 10Be concentrations in stream sand following the 2018 Woolsey Fire in Solstice Canyon, Santa Monica Mountains, California. Geological Society of America National Meeting, Portland, OR. Geological Society of America Abstracts with Programs 53(6): 369071. doi.org/10.1130/abs/2021AM-369071

Vanlandingham, L. A., Portenga, E. W., Bierman, P. R., and Lefroy, T. (2019) Analysis of 10Be-based erosion and denudation rates in the George River Basin, Tasmania, Australia. GSA Abstracts with Programs, Annual Meeting, Phoenix, AZ. v. 51(5), Abstract 263-6. doi:10.1130/abs/2019AM-338851

Portenga, E. W., Bierman, P. R., Trodick, C. D., DeJong, B., Rood, D. H., and Pavich, M. J. (2019) The current state of post-colonial landscape disturbance to the Potomac River and Chesapeake Bay. GSA Abstracts with Programs, Annual Meeting, Phoenix, AZ. v. 51(5), Abstract 213-8. doi:10.1130/abs/2019AM-332323

Portenga, E. W., Murray, K. E., Bhattarai, S., Bird, M. I., Corbett, L. B., Bierman, P. R., Caffee, M. W., Thomson, S. N., Fu, X., and Li, B. (2018) Investigating landscape response to human arrival to Australia and Anthropogenic fire using cosmogenic isotopes and low-temperature thermochronometers. GSA Abstracts with Programs, Annual Meeting, Indianapolis, IN. v. 50(6), Abstract 21-2. doi:10.1130/abs/2018AM-318514

Bierman, P. R., Coppersmith, R. Hanson, K. Rood, D. H., Portenga, E. and Neveling, J. (2016) Cosmogenic 10Be and 26Al dating of ancient surfaces and recent fault scarps in south central South Africa – indications of both fault motion and stability in a stable continental region. Abstract 35th International Geological Congress, Cape Town, South Africa. p. 4195. (download pdf)

Bierman, P. R., Portenga, E. W. and Kirby, E. (2015) Mapping erosion of the Appalachian Mountains using cosmogenic 10Be. GSA Abstracts with Programs, Annual Meeting, Baltimore, MD. v. 47(7), p. 677, Abstract 268-7. (download pdf)

Portenga, E. W., Bishop, P., Gore, D. B., Westaway, K. E., Rood, D. H. and Bierman, P. R. (2014) The when, what, and how of gully erosion and sediment deposition on the tablelands of New South Wales, Australia. GSA Abstracts with Programs, Annual meeting, Vancouver, British Columbia. v. 46(6), p.799, Abstract 332-3. (download pdf)

Portenga, E., Bierman, P. R. and Duncan, C. (2013) Rain, water, and ice: driving forces behind rapid erosion in western Bhutan. International Association of Geomorphologists Meeting, Paris. p. 280. (download pdf)

Bierman, P. R., Reusser, L. and Portenga, E. (2011) Using 10Be to quantify rates of landscape change in 'dead' Orogens – millennial scale rates of bedrock and basin-scale erosion in the southern and central Appalachian Mountains. EOS, AGU Fall meeting, San Francisco, CA. Abstract EP53C-08. (download pdf)

Bierman, P. R., Portenga, E., Reusser L., Graly J., Corbett, A. B. and Borg, J. (2010) Three decades tracing erosion and sediment with cosmogenic nuclides - where do we go next? Landscapes to Rock, Geological Society of London. (download pdf)

Portenga, E., Bierman, P. R., Trodick, C. and Rood, D. (2010) Low rates of bedrock outcrop erosion in the central Appalachian Mountains, inferred from in situ 10Be concentrations. GSA Abstracts with Programs, Annual meeting, Denver, CO. v. 42(5), p. 33, Abstract 4-12. (download pdf)

Trodick, C., Bierman, P. R., Pavich, M., Reusser, L., Portenga, E. and Rood, D. (2010) Basin Scale Erosion Rates from the Potomac River Basin using In Situ and Meteoric 10Be. GSA Abstracts with Programs, Annual meeting, Denver, CO. v. 42(5), p. 33, Abstract 4-13. (download pdf)

Nichols, K. K., Bierman, P. R., Reusser, L., Portenga, E., Matmon, A. and Rood, D. (2010) Dual 10Be isotope systems constrain the source of sediment and rate of erosion for the tropical Barron River catchment, Queensland, Australia. EOS, AGU Fall meeting, San Francisco, CA. Abstract EP33D-05. (download pdf)

Portenga, E. W., Bierman, P. R. and Rizzo, D. M. (2009) A global summary and analysis of exposed bedrock erosion rates estimated using in situ 10Be. GSA Abstracts with Programs, Annual meeting, Portland, OR. v. 41(7), p. 619, Abstract 244-1. (download pdf)