Timothy M Shanahan

Timothy M Shanahan
Associate Professor, Department of Geological Sciences, Jackson School of Geosciences

Email: tshanahan@jsg.utexas.edu
Work: +1 512 232 7051
Office: EPS 3.126
Mailcode: C1100

Dr. Shanahan's primary area of research is in paleoclimatology and environmental change, with a focus on using novel geochemical and isotopic approaches to reconstruct past global changes from the sedimentary geological record. The goal of this research is to understand the processes controlling past environmental and paleoclimate change. Current projects focus on understanding the linkages between climate change and ecosystem dynamics on timescales ranging from annual (i.e., varves) to orbital and at sites ranging from the tropics to the high latitudes.

Dr. Shanahan's laboratory methods include organic geochemical (biomarker) and compound-specific stable isotope analysis, scanning m-XRF analysis of trace elements in geological archives (sediments, carbonates, tree rings), development of high-resolution paleoenvironmental records from annually laminated sediments and cosmogenic nuclide surface exposure dating. He is interested in utilizing multi-proxy geochemical approaches to understanding environmental changes preserved in the geological record, and in integrating paleoclimate data and modeling approaches to understand the earth system.

Dr. Shanahan's laboratory is currently under construction, but will soon contain a new designated GC-IRMS system for compound-specific hydrogen and carbon isotope analysis, as well as GC-MS and HPLC-MS systems for the identification and quantification of organic compounds in natural samples. The laboratory will also contain various facilities for the preparation and purification of lipid extracts for analysis. Additional facilities will also be available for processing of samples for cosmogenic nuclide analysis and for the study of annually- laminated sediments.

Dr. Shanahan is happy to speak with motivated prospective graduate students.

Areas of Expertise

Paleoclimatology, paleoceanography, paleolimnology, sedimentary geology and geochemistry, organic geochemistry, isotope geochemistry, compound-specific stable isotope analysis

Research Locations

Kavli Fellow - National Academy of Sciences (2012)

NOAA Climate & Global Change Postdoctoral Fellowship - NOAA (2006)

Woods Hole Oceanographic Institution Postdoctoral Fellowship - Woods Hole Oceanographic Institution (2006)

NSF-IGERT research traineeship in Anthropology (2003)

McGinnies Fellowship for Arid Lands Studies, U. Arizona (2002)

NSF research traineeship in hydrology (1997)

Outstanding Graduating Senior, Dept. of Geosciences, Brown U. (1994)

National Association Of Geology Teachers Undergraduate Award (1994)

Sigma Xi (1994)

Graduate Students

Chijun (CJ) Sun , Ph.D., expected 2021 (Supervisor)
I am interested in understanding how the climate system responds to different forcings and under varying background climate states, with the goal of improving our predictions of future climate changes. My PhD research is focused on the use of organic geochemical (GDGTs, leaf wax) and stable isotope (C, H) proxies to reconstruct changes in climate in northeastern Mexico and the...

Junwen Peng , Ph.D., expected 2021 (Committee Member)
1. Shale sedimentology: transportation and deposition processes and mechanisms of the mudrock system. 2. Shale petrography: textural variation, mineral composition, grain assemblages composition, pore types, and diagenetic features. 3. Sedimentary geochemistry: trace metals used as proxies for paleoenvironmental and paleomarine system reconstructions (e.g., hydrographic circulation, seawater chemistry, productivity, and redox conditions). 4. Unconventional hydrocarbon resources: mechanisms of organic...

Erin M Keenan Early (Co-supervisor)
My research explores the use of geomolecular and biomolecular methodologies to address paleoenvironmental and paleoecological questions. Specifically I am researching the use of proteomics as applied to faunal material as a means of species identification and I am exploring the applications of brGDGTs recovered from various sources to aid in paleotemperature reconstruction. My work is largely restricted to the Quaternary,...

Natasha Piatrunia (Supervisor)
I am interested in using organic biological markers (biomarker) and stable isotope geochemistry to understand past changes in the climate on a variety of timescales. My Ph.D. research focuses on using branched glycerol dialkyl glycerol tetraethers (br-GDGTs) and hydrogen isotopes in leaf waxes of terrestrial plants in finely laminated lacustrine sediments from the North Island of New Zealand to generate...

Peter Carlson, Ph.D., 2018 (Committee Member)

Veronica Anderson, Ph.D., 2015 (Supervisor)

Travis Wicks, M.S., 2013 (Supervisor)

Megadroughts in the tropics: insights from the geological record, National Academy of Sciences Kavli Symposium: Indonesia, Solo, Indonesia (2012)

New constraints on the use of IP25 as a paleo-sea ice proxy, First workshop of the PAGES Sea Ice Proxy (SIP) working group on the basis of sea ice proxies, Montreal (2012)

Megadroughts, abrupt climate changes and ecosystem feedbacks in the West African monsoon, Lamont-Doherty Earth Observatory, New York (2011)

Ecosystem feedbacks and changes in the West African monsoon, University of Rochester, Rochester, NY (2011)

Abrupt climate change and ecosystem feedbacks in the West African monsoon, Syracuse University, Syracuse, NY (2011)

Abrupt climate change and ecosystem feedbacks in the West African monsoon, Texas Marine Science Institute, Port Aransas, TX (2011)

Megadroughts, abrupt climate changes and ecosystem feedbacks in the West African monsoon, The Open University, Milton Keynes, UK (2011)

ICDP Drilling at Lake Bosumtwi: Progress and challenges, Workshop on drilling of East African Lakes, Brown University, RI (2011)

Late Holocene megadroughts and temperature changes in the tropics: coherent century-scale climate variability across the tropics, American Geophysical Union annual meeting, San Francisco, CA (2011)

Lakes as archives of environmental change in Southeast Asia, Greater Mekong Delta meeting, Cambodia (2010)

Two millennia of climate change in tropical West Africa: a review., First workshop of the PAGES Africa 2k working group, Ghent, Belgium (2010)

2020Fall GEO 391 Paleoclimatology-Wb
2020Fall GEO 303 Introduction To Geology-Wb
2020Fall GEO 303 Introduction To Geology
2019Fall GEO 303 Introduction To Geology
2019Spring GEO 303 Introduction To Geology
2018Fall GEO 391 Paleoclimatology
2018Fall GEO 371T Paleoclimatology
2018Fall GEO 303 Introduction To Geology
2018Spring GEO 394 Rsch In Geological Sciences
2018Spring GEO 291 Paleoclimate Seminar
2018Spring GEO 303 Introduction To Geology
2017Fall GEO 394 Rsch In Geological Sciences
2017Fall GEO 291 Paleoclimate Seminar
2017Fall GEO 303 Introduction To Geology
2017Spring GEO 291 Paleoclimate Seminar
2017Spring GEO 394 Rsch In Geological Sciences
2017Spring GEO 303 Introduction To Geology
2016Fall GEO 394 Rsch In Geological Sciences
2016Fall GEO 391 Paleoclimatology
2016Fall GEO 191 Paleoclimate Topics Seminar
2016Fall GEO 371T Paleoclimatology
2016Fall GEO 303 Introduction To Geology
2016Spring GEO 391 Paleoclimatology
2016Spring GEO 291 Current Topics Paleoclimate
2016Spring GEO 303 Introduction To Geology
2015Fall GEO 303 Introduction To Geology
2015Spring GEO 302C Climate: Past, Present, Future
2014Fall GEO 394 Rsch In Environmental Change
2014Fall GEO 391 Paleoclimatology
2014Fall GEO 303 Introduction To Geology
2014Spring GEO 302C Climate: Past, Present, Future

Stable isotopes as hydroclimatic indicators (Undergraduate - Summer/fall/spring flexible)
I am looking for an undergraduate student researcher to work on the analysis of stable isotopes in natural waters and plant materials. No experience necessary. The student researcher will be trained in extracting water samples on a vacuum system and analysis of stable isotopes using a laser spectrometer. Depending on progress, there may be opportunities to publish this research


Paleoclimate reconstructions in the southern Rocky Mountains (Undergraduate - summer/fall/spring flexible)
I am looking for one or more undergraduate student researchers to work on paleoclimate reconstructions in the southern Rockies using geochemical indicators in lake sediments. No experience necessary. Depending on progress, there will be opportunities to publish.