Directory

Field of study

• Sedimentary geology
• Stable isotope geochemistry
• Paleoenvironments of human evolution

Research interests

Dr. Bedaso's research focuses on establishing environmental and climatic framework of the past 5 Ma using isotopic tools from terrestrial records. He uses stable isotopes of carbon and oxygen from fossil tooth enamel and fossil soil (Paleosol) carbonates to reconstruct vegetation history (relative proportion of C3 and C4 plants), Paleodiet of ancient animals and climate history (aridity and temperature) from East Africa, which is relevant to human evolution. Most of his work is geographically located in the Afar Depression in Ethiopia, which is found within tectonically unique region of the Great East African Rift Valley. The area is considered as a cradle of mankind and known for yielding hominin and other mammalian fossils from sediments exposed by repeated faulting and erosion activities over the last 6 Ma. In addition to the paleo-studies, Dr. Bedaso also works in modern settings to be able to better understand the controls, distribution and natural variability of isotopes in modern environments through establishing networks of observational stations. In this regard, his current research is aimed at understanding water isotope variation in precipitation and identifying moisture sources in eastern Africa and ultimately to integrate these isotopic measurements into a coupled land-atmosphere modeling system.

Courses taught

• GEO 109: Earth, Environment, and Society
• GEO 115: Physical Geology
• SCI 210: Dynamic Earth
• GEO 208: Environmental Geology
• GEO 208L: Environmental Geology Lab
• GEO 308: Problems and Decisions in Environmental Geology
• GEO 303: Geology Field Camp (Colorado Rockies)
• GEO 412: Introductory Geochemistry
• GEO 412L: Introductory Geochemistry Lab
• GEO 404: Problems in Geology
• CAP 404: Virtual Geology Field Camp (2021)
• GEO 477: Honors Thesis
• GEO 478: Honors Thesis Project
• GEO 479L: Environmental Instrumentation Lab
• GEO 498: Research and Thesis Project
• GEO 495: Geology Seminar

Selected publications and presentations

Johnstone, C., Bedaso, Z., Ekberg, M. (2022). Characterizing surface water and groundwater interaction for sustainable water resources management in southwestern Ohio. Sustainable Water Resources Management, 8(1), 16. doi.org/10.1007/s40899-021-00598-6

Wu, S.-Y., Bedaso, Z. (2022). Quantifying moisture source for NW Ethiopian highlands and its implication for isotope variation. Journal of Hydrology, 605, 127322. doi.org/10.1016/j.jhydrol.2021.127322

Bedaso, Z., and Wu, S.Y., (2021). Linking precipitation and groundwater isotopes in Ethiopia-implications from local meteoric water lines and isoscapes. Journal of Hydrology. 126074. doi.org/10.1016/j.jhydrol.2021.126074.

Bedaso, Z.K., DeLuca, N.M., Levin, N.E., Zaitchik, B.F., Waugh, D.W., Wu, S.Y., Harman, C.J. and Shanko, D., (2020). Spatial and temporal variation in the isotopic composition of Ethiopian precipitation. Journal of Hydrology, 585, 124364. doi.org/10.1016/j.jhydrol.2019.124364.

Bedaso, Z., and Wu, S.Y., (2020). Daily precipitation isotope variation in Midwestern United States: Implication for hydroclimate and moisture source. Science of The Total Environment, 713, 136631. doi.org/10.1016/j.scitotenv.2020.136631.

Bedaso, Z.K., Wu, S.Y., *Johnson, A.N. and *McTighe, C., (2019). Assessing groundwater sustainability under changing climate using isotopic tracers and climate modelling, southwest Ohio, USA. Hydrological Sciences Journal, 64, 798-807. doi.org/10.1080/02626667.2019.1606429.

Wynn, J.G., Reed, K.E., Sponheimer, M., Kimbel, W.H., Alemseged, Z., Bedaso, Z.K., Campisano, C.J., 2016. "Dietary flexibility of Australopithecus afarensis in the face of paleoecological change during the middle Pliocene: Faunal evidence from Hadar, Ethiopia". Journal of Human Evolution. 99, 93–106.

Negash, E. W., Alemseged, Z., Wynn, J.G., Bedaso, Z. K. (2015) “Paleodietary reconstruction and abundance analysis of bovids from the Shungura Formation of South Omo.” Journal of Human Evolution 88, 127-136.

*Lestingi E., Bedaso, Z. K. (2016) “5.8 Ma Carbon isotope records of East African mammalian diet and their modern relatives.” Geological Society of America, Vol. 48, No. 5.

*Parks M., Bedaso Z. K. (2015) “Seasonal variations of stable isotope ratios of precipitation in Dayton area and sustainable water resources.” Geological Society of America, Vol. 47, No. 7, p.535.

*Negash E., Alemseged Z., Wynn J., Bedaso Z. K., Bobe R. (2015) "Stable isotope study of modern and fossil Tragelaphus: Interpreting the range of dietary signals with in a single genus." Geological Society of America Vol. 47, No. 7, p.284.

*Deluca N., Levin N., Bedaso Z.K., Zaitchik B., Waugh D., Harman C., Shanko D. (2015) “Spatial and temporal variation in the isotopic composition of Ethiopian Rainfall.” Geological Society of America Vol. 47, No. 7, p.92.

Wondimu, E., Alemseged, Z., Wynn, J. G., Bedaso, Z.  (2013) "Paleodietary reconstructions of Plio-Pleistocene Bovids using stable isotopes from the Shungura Formation, Omo, Ethiopia; Implication for Hominin environments." 4th East African Association for Palaeoanthropology and Palaeontology Conference, Mombasa, Kenya. 

Bedaso, Z.K., Wynn, J.G., Alemseged, Z., and Geraads, D. (2013). "Dietary and paleoenvironmental reconstruction using stable isotope analysis of herbivores tooth enamel from the Pliocene locality of Dikika, Ethiopia: implication for A. afarensis habitat and food resource." Journal of Human Evolution 64, 21-38.

Wynn, J.G., Sponheimer, M., Kimbel, W.H., Alemseged, Z., Reed, K., Bedaso, Z.K., and Norman, J.R. (2013). "Diet of Australopithecus afarensis from the Pliocene Hadar Formation, Ethiopia." Proceedings of the National Academy of Sciences, USA, 110: 10495-10500 doi: 10.1073/pnas.1222559110.

Bedaso, Z. K., Wynn, J.G., Alemseged, Z., and Geraads, D. (2010). "Paleoenvironmental reconstruction of the Asbole fauna (Busidima Formation, Afar, Ethiopia) using stable isotopes," Geobios, 43, 165-177.

Wynn, J.G., and Bedaso, Z.K. (2010). "Is the Ethiopian monsoon extinct? A comment on Aronson et al.," Journal of Human Evolution, 59, 133-138.

Bedaso Z. K., Norman R. J., Wynn G., Alemseged Z. (2011) "New Trace element (Sr, Ba) data for paleoecological reconstruction and evaluation of enamel diagenesis from Dikika, Ethiopia." GSA Abstract Vol. 43 No. 5

Bedaso Z. K., Wynn G. J., Alemseged Zeresenay.  (2010). "Pliocene Paleoenvironments of the Awash Valley, Ethiopia: The Isotope Record of Tooth Enamel and its Relevance to the Pliocene Paleoclimate of Northeastern Africa." AGU 13-17 December, San Francisco, USA

Marshall, M.H., Lamb, H.F., Davies, S.J., Leng, M.J., Bedaso Z. K., Umer, M., and Brayant C. (2009). "Climatic change in northern Ethiopia during the past 17,000 years: A diatom and stable isotope record from Lake Ashenge." Palaeogeogr. Palaeoclimatol. Palaeoecol. 279, 114–127.

Bedaso, Z.K. (2005) "Perspectives of climate change for human evolution and later impact on the environment, Paleoclimates and Human Evolution Workshop." (NSF Sponsored), Nov. 17-20, Virginia, USA.

Bedaso, Z.K. (2005). "Holocene environmental records of Lake Ashange," Natural and Cultural Heritages and Eco-tourism International Conference, June 24-27, Mekelle, Ethiopia.

SelectedWorks (www) >

Grants

Bedaso, Z., (PI), Wu, S-Y. (Co-PI), CAS-Climate: Understanding the link between regional climate patterns and water supply in the Horn of Africa ", NSF, $309K (May 2022 - April 2025).

Bedaso, Z., (PI), Collaborative Research: Quantifying East African hydroclimate seasonal variability for humid intervals during the 200kyrs, Omo-Turkana Basin", NSF, $157K. (Sept. 2021 - Aug. 2024).

Bedaso, Z., (PI), Tracing nitrate sources and processes with a combined isotope approach at Grand Lake St. Marys watershed, Ohio. Ohio Water Resource Center. 10K (June 2021 - May 2022).

Bedaso Z.K., (PI). Establishing modern oxygen isotope baseline in terrestrial records to understand the climate and environment of human evolution. STEM Catalyst Grant, $22,440 (June 2017- June 2018).

Bedaso Z. (PI), Proposal to Conduct Stable Isotopic Fingerprinting of Nitrate Contaminant Sources in the Great Miami River Watershed, Southwestern Ohio. Sponsored by Miami Conservancy District, $22, 848 (Jan. 2017-June 2018)

Wu, S. (Principal), Bedaso Z. (Co-Principal), Assessing the impact of climate change on the sustainability of groundwater resource in the Dayton region – an interdisciplinary approach. Sponsored by Hanley Sustainability Institute, $23,988 (May 2016-May 2017)

Major research participation

• Water isotope studies in precipitation and its implications for water resources and moisture sources in Ethiopia, East Africa (since 2012).
• Exploration of Neogene rift valley paleoenvironmental record from the red series sediments, northern Afar, Ethiopia, co-director (since 2006).
• Dikika Paleoantropology Research Project, Afar, Ethiopia (since 2006).
• Tana Project: Paleoenvironmental and paleoclimatic studies of Lake sediments from Northwestern Ethiopian Plateau (i.e., Lake Tana, Lake Ashange, Lake Hique and Lake Hrdibo), a collaborative research between University of Wales, Aberystwyth and Addis Ababa University (since 2002).
• Rift sedimentation and volcanism in Afar Depression in Ethiopia, a project funded by FWF Fond zur Förderung der wissenschaftlichen Forschung (since 2001).