Lyman Persico

Assistant Professor of Geology

(814) 824-2076


Lyman Parker Persico, Ph.D.
Assistant Professor of Geology
Department of Geology
Phone: 814-824-2076

University of Vermont, B.S. in Environmental Science, 2002
University of New Mexico, M.S. in Geology, 2006
University of New Mexico, Ph.D. in Geology, 2012

Physical Geology
Geographic Information Systems (GIS)

Research Interests:
How do humans and climate shape the surface of the Earth? That is the overarching questions that drives Dr. Persico’s research. Dr. Persico has studied landscapes and surficial processes in the Northeast, Desert Southwest, and Rock Mountain West. His research methods include using both the Quaternary Record and modern geomorphic processes to quantify rates and types of landscape change. Dr. Persico’s research is heavily steeped in the geologic tradition of field-based research methods. Dr. Persico uses a wide array of laboratory analyses to augment field work including radiocarbon dating, optically stimulated luminescence, XRD, XRF, LiDAR, and GIS. Dr. Persico is currently exploring historical, prehistorical, and modern climate change through interdisciplinary approaches that combine aspects of ecology, hydrology, and fluvial geomorphology. Visit the Mercyhurst Geology Research Page and Dr. Persico’s personal page to learn more about his research.

Selected publications
Persico, L.P., Meyer, G., 2012, Stream Response to Holocene droughts and beaver activity in the Greater
Yellowstone Ecosystem, Earth Surface Processes and Landforms.

Persico, L.P., McFadden, L., Frechette, J., Meyer, G., 2011, Rock type and dust influx control
accretionary soil development on hillslopes in the Sandia Mountains, New Mexico, USA. Quaternary Research, 76 (3), p. 411-416.

Persico, L.P. and Meyer, G., 2009, Holocene beaver damming, fluvial geomorphology, and climate in
Yellowstone National Park, Wyoming. Quaternary Research 71 (3), p. 340-353.

Persico, L.P., Nichols, K.K., and Bierman P.R., 2005, Tracking painted pebbles: rates of sediment
movement on four Mojave Desert piedmont surfaces. Water Resources Research, 41(7), p. W07004.
(for Geology Resarch Page)
Ecosystem dynamics in changing climates
Recent drought severe drought throughout the United States highlights the pressing need to understand ecosystem dynamics in a changing climate. In the greater Yellowstone ecoystems Dr. Persico studies how river systems respond to climate change. Using Holocene river deposits, Dr. Persico has documented beaver damming activity and extreme flooding in the past four thousand years. Beaver damming has historically  been an component of stream dynamics in many watershed in Greater Yellowstone, however large droughts during the Medieval Climatic Anamololy (roughly 900 years ago) decreased stream flow making many smaller streams uninhabitable to beaver. During these periods of reduced beaver activity, streams experienced large erosive flooding events that were perhaps enhanced by increased forest fire activity. Dr. Persico has also conducted hydrologic modeling to document how drought reduces streamflow and creating ephemeral flow in the late summer. This research provides critical information for stream management in the Rocky Mountain West in the light of global warming, which will cause more severe and extended droughts in the coming decades.

Soil Formation and Geomorphology
Dr. Persico is also interested in the impact that soil formation has on slope geomrophology and hydrology. In the Sandia Mountains in central New Mexico, Dr. Persico has documented that outcrops of resistant rocktypes facilitate the accumulation of dust producing thick nonsteady state hill slope systems. Accumulation of dust has created soil horizons of pedogenic clay and carbonate that drastically alter soil hydrology and slow the downslope transport of colluvial materials.
Dr. Persico is also interested in the historic landscape and land uses changes in the northeast. Early in his career he documented changes to Vermont landscapes using recent and historical phototographys.