Timothy M Shanahan
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
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)
Peter E Carlson, Ph.D., expected 2018
Stalagmites that grow near the entrances of caves are often avoided for the purposes of paleoclimate reconstruction, due to worries about fluctuating atmospheric conditions and microbiological influences interfering with calcite growth dynamics. I study how these near-entrance stalagmites might serve as high-resolution records of surface temperature. I am investigating temperatures recorded in the oxygen-isotope, trace element, and clumped-isotope compositions of a near-entrance stalagmite from Westcave Preserve in central Texas. I have also been monitoring active drip sites in Westcave since 2013 in order to characterize modern responses in drip water and calcite chemistry to changing environmental conditions.
Veronica J Anderson, Ph.D., expected 2015
My research focuses on understanding the tectonic history of the Eastern Cordillera using a variety of methods, with an emphasis on using paleoclimatic proxies to understand the effects of surface uplift on Colombian climate. I have utilized organic geochemical proxies for paleotemperature (the MBT/CBT index) and for the isotopic composition of rainfall (hydrogen isotopes in leaf waxes) in order to quantify surface uplift in the Eastern Cordillera. I am also analyzing sedimentary provenance data and thermochronological data to determine the timing of uplift of a large area of exposed basement at the southern end of the Colombian Eastern Cordillera. tl;dr: Basin anaysis, organic geochemistry, low-temperature thermochronology
Travis Z Wicks, M.S., expected 2013 (Supervisor)
Kiara Gomez (Supervisor)
Erin M Keenan Early
My research focuses on using ZooMS (zooarchaeology by mass spectrometry) to improve species identification in North America, with an eye to increasing understanding of paleoenvironment during the Pleistocene and early Holocene. This research includes building a North American ZooMS database and exploring ways to improve collagen extraction.
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)
|2016||Fall||GEO 303||Introduction To Geology|
|2016||Fall||GEO 191||Paleoclimate Topics Seminar|
|2016||Fall||GEO 394||Rsch In Geological Sciences|
|2016||Spring||GEO 303||Introduction To Geology|
|2016||Spring||GEO 291||Current Topics Paleoclimate|
|2015||Fall||GEO 303||Introduction To Geology|
|2015||Spring||GEO 302C||Climate: Past, Present, Future|
|2014||Fall||GEO 303||Introduction To Geology|
|2014||Fall||GEO 394||Rsch In Environmental Change|
|2014||Spring||GEO 302C||Climate: Past, Present, Future|