Faculty & Staff
As the sole geographer at Denison, I teach several introductory and regional geography courses designed to spark student interest and broaden understanding of the diversity of environments and human/environment interactions around the world. These courses help to foster geographic (and environmental) literacy which I see as absolutely critical to our future. As human impacts on the planet continue to increase, we must have a citizenry that is knowledgeable and can make sound decisions about land and resource use. I also teach three intermediate to advanced courses concentrating on different groups of earth surface processes - Weather and Climate, Geomorphology, and Hydrogeology. We spend considerable time outside observing and measuring atmospheric, hydrologic and pedologic phenomena as well as computer times using spread sheets and gathering data from the web. All of my classes have a significant environmental focus and most are linked with Denison's Environmental Studies curriculum.
I have led some student trips to Cuba. We have studied both natural history and environmental issues in and around Havana and in the provinces of Pinar del Rio (west), Matanzas (central), and Santiago de Cuba (east). More information about the May Term 2000 trip can be obtained through the Cuba link.
In broad terms, my research focuses on the complex interactions among landforms, soils and climate. I study the dynamic environments along the margins of the former great Laurentide ice sheets, with particular emphasis on glacial deposits and the genesis of soils and paleosols. Lately much of my attention has been on the timing of drainage reversals associated with the advance of ice sheets into the Appalachian Plateau in East Central Ohio. In addition, I have conducted collaborative archaeological research at several sites in central Ohio and have worked on the biogeochemical modeling of soil nitrogen. Our discovery of gut contents (with living intestinal bacteria) with the recovery of the Burning Tree Mastodon has added important information about the late glacial environment and megafauna diets. Much of my research has involved students, both as field assistants and in independent senior projects that contribute to my research program. Other student research projects I have advised cover a wide range of topics. Examples of recent student research projects include a presettlement map of Licking County vegetation, the origin and mineralogy of beach sands on Kelley's Island, coastal zone management in southern Sri Lanka, an analysis of lacustrine sediments of Glacial Lake Licking, and an assessment of soil nutrient loading at the Buckeye Egg Farm.
- Frolking, T.A.. Holocene Hydrology, Soil Development and Landscape Evolution of the Bikeri Vésztö-Mágor Area in the Körös Basin of Eastern Hungary. Submitted for publication in monograph on the Körös Regional Archaeological Project in the Monumental Archaeologica Series, Costen Institute of Archaeology, UCLA.
- Gyucha, A., Duffy, P.R. and Frolking T.A. . The Körös Basin from the Neolithic to the Habsburgs: Linking settlement distributions with pre-regulation hydrology through multiple dataset overlay. In review. Geoarchaeology: An International Journal.
- Yerkes, R., Sarris, A., Frolking, T., Parkinson, W., Gyucha, A., Hardy, M. and Catanoso, L.. 2007. Geophysical and Geochemical Investigations at Two Early Copper Age Settlements in the Körös River Valley, Southeastern Hungary . Geoarchaeology: An International Journal. v. 22 no. 8 p. 845-871 View [pdf]
- Frolking, T.A. and M.A. Pachell*. 2006. Glacial Lake Licking: Late-Glacial Drainage Diversions and the Formation of Black Hand Gorge, Licking County, Ohio. Ohio Journal of Science. v. 106 no. 3 p. 103-111 View [pdf]
- Frolking, S., Frolking, T., Xiao, X., Boles, S. and Milliman, T. . 2005. A generalized methodology for mapping agricultural land use and management at sub-national scales, including a case study of combining census data and remote sensing data to map cropping intensity in Vietnam. Report prepared for Land and Water Division, Food and Agricultural Organization of the United Nations 75 p..
- Lepper, B.T. and Frolking, T.A.. 2003. Alligator Mound: Geoarchaeological and Iconographical Interpretations of a Late Prehistoric Effigy Mound in Central Ohio. Cambridge Archaological Journal. v. 13 no. 2 p. 147-167 View [pdf]
- Stam, A. and Frolking, T.A.. 2003. Environmental Status of Cuba: The Cuban View. A course book for Environmental issues of Cuba (Denison May Term) based largely on interviews with Cuban experts (1999-2001), being modified and added to on a continuous basis.
- Lepper, B.T., and Frolking, T.A.. 2003. Alligator Mound: Geoarchaeological and Iconographical Interpretations of a Late Prehistoric Effigy Mound in Central Ohio. Cambridge Archaelogical Journal. v. 13 no. 2 p. 147-167
- Frolking, T.A. and Lepper, B.T.. 2001. Geomorphic and pedogenic evidence for bioturbation of artifacts at a multi-component site in Licking County, Ohio, USA. Geoarchaeology: An International Journal. v. 16 no. 3 p. 243-262
Answering a question incorrectly sparked my love for geology and geoscience education. In the freshman year of my undergraduate career, I enrolled in my first geology class. Early in the semester, the professor, who later became my mentor and eventually a good friend, asked the class to explain why the Hawaiian Islands form a straight line. I raised my hand and confidently answered that the hot-spot moved under the crust thus creating the linear chain of islands. "Actually, Dave, that's not quite right," my professor corrected, "but I like the way you're thinking," and then he began my first introduction to plate tectonics. I was disappointed to be wrong but proud that the professor appreciated my creative thinking. This one remark encouraged me to learn more and has inspired and motivated me ever since. One of my many goals as a educator is provide this same kind of enthusiasm and encouragement for my own students, even if they don't get the answer right the first time.
My current research involves documenting and interpreting records of environmental variation archived in the hard parts of modern and fossil organisms. This is accomplished primarily through calibration of environmental conditions with skeletal archives: specifically, geochemical variations and patterns of shell growth. The geochemical component of my work revolves around light stable-isotopes, while the analysis of growth patterns focuses on periodic increments deposited in response to environmental and astronomical pacemakers. Together, these analytical techniques, commonly referred to as sclerochronology, have enabled me to work in several different research areas. While each has a different focus, they are connected by a common theme: how are environmental conditions recorded in the geologic record in general, and in the skeletons of organisms in particular? And, how can these archives be used to address a variety of biological and geological questions?
My research explores past, present, and future atmospheric carbon dioxide levels. I am working on explaining why atmospheric carbon dioxide levels were lower during glacial times. My research on contemporary and future carbon dioxide levels attempts to explain why atmospheric carbon dioxide levels are increasing more slowly than expected.
I'm a volcanologist/petrologist and I teach classes on the rocks and minerals that make up the planet, along with the magmatic processes that lead to volcanic eruptions. I’ve been fascinated by geology since I was young, either with the vast mineral collection my grandmother in Massachusetts had collected or with the vistas of Nevado del Ruiz from my grandparents home in Colombia. Every rock (or crystal) does tell its own story, and that is what geologist do: unlock the history recorded in the rocks. That is how I like to teach geology – by looking at the process the created the rock and then how we see the record of that process imparted on the physical and chemical characteristics of the rocks and crystals. In that way, geology tells us about the dynamic events that have created the Earth and will change the planet far into the future. I am also interested in how humans interact with geology, specifically how we alter the su rface environment when exploiting the multitude of resources within the Earth. If you’re interested in any of these topics, contact me via email or on Twitter (@eruptionsblog).
My research focuses on volcanism and magmatism, both modern and ancient. I examine these processes by looking at the information recorded in crystals erupted in lavas and ash. By measuring the ratios of radioactive isotopes in these minerals, you can answer questions about the timescales of magmatic processes at volcanoes, such as how long does it take to generate a body of magma, how long can you store magma in the crust and what are the rates of eruptions during the lifetime of a volcano. All of these question lead us to a greater understanding of what happens under a volcano before an eruption.
Currently, I have active research projects at Lassen Peak in northern California, Mineral King in the central Sierra Nevada, and the Okataina Caldera in New Zealand. I have had students work with me on these research projects, leading to presentations at major geology meetings and co-authorships on research papers. If you’re interested in working with me, send me an email.
I also strong believe in making science accessible to the general public. To that end, I write a blog on volcanism called Eruptions. I distill the sometimes-disparate information out there about current eruptions, discuss volcanic process and features and break down current volcano research so that anyone can understand why its so exciting. The blog is visited by thousands of readers a day that vary from casual readers to seasoned volcano researchers.
Here are a selection of recent research publications if you’re interested in my research:
Klemetti EW, Lackey JS, Starnes JK*, accepted, Magmatic lulls in the Sierra Nevada captured in zircon from rhyolite of the Mineral King pendant, California: Geosphere.
Walker BJ, Klemetti EW, Grunder AL, Dilles JH, Tepley III F, Giles D, 2013, Crystal reaming during the assembly, maturation, and waning of an eleven-million-year crustal magma cycle: thermobarometry of the Aucanquilcha Volcanic Cluster: Contributions to Mineralogy and Petrology, doi 10.1007/s00410-012-0829-2.
Klemetti EW, Deering CD, Cooper KM and Roeske SM, 2011, Magmatic perturbations in the Okataina Caldera Complex at thousand-year timescales recorded in single zircon crystals from the Mt. Tarawera region, New Zealand: Earth and Planetary Science Letters, v.305, p. 184-194.
Klemetti EW and Grunder AL, 2008. Volcanic evolution of Volcán Aucanquilcha: a long lived dacite volcano in the Central Andes of northern Chile: Bulletin of Volcanology, v. 70, no. 5, p. 633-650.