Methane (CH4) is an important energy resource and significant long-lived greenhouse gas with a wide range of origins. Understanding the sources and sinks of methane is critical for studies of energy exploration, biogeochemical cycling of carbon and climate change. It is also the key to quantifying the Earth’s global carbon cycle and fluxes. However the diversity of methane sources have resulted in poorly constrained understanding of the processes of methane formation and migration. Recent pilot studies have shown that the precise measurement of four or more isotopologues of methane (12CH4, 13CH4, 12CH3D and 13CH3D) may allow estimation of the temperature at which a sample of methane was formed or thermally equilibrated. The major aim of this project is to further develop this technique by studying methane samples from various geological settings to test if the methane isotopologue thermometer could generate results that are consistent with previous understanding of methane formation temperatures. For example, biogenic gases are formed at the temperatures below ~80oC and thermogenic gases are formed at the temperatures above 60oC and reaching 160oC-200oC. In contrast, noble gases have long been proven as a versatile tool in the investigation of origin and physical processes of methane occurring in hydrocarbon systems. This project will also study noble gas isotope signatures in gas samples to support the interpretation of methane isotopologue results. The novel combination of an indirect inorganic noble gas tracer with a direct organic methane isotopologue tracer will open a new door in understanding natural gas resources. It will reveal information on methane formation pathways, controls on resource potential during basin evolution history, and gas release and transport mechanisms in gas reservoirs.
The student will study suites of gas samples from natural gas fields provided by industrial partners. Collaborations with major energy companies have been set up recently to facilitate this. Gas samples will be anaylsed for noble gas isotopes, abundance composition and stable isotopes (13CCH4, DCH4, 13CCO2 and methane clumped isotopes). These analyses utilize state-of-the-art noble gas instrument and Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS) instrument at Lancaster Environment Centre.
Further Information: http://www.lancaster.ac.uk/sci-tech/downloads/phd_264.pdf
Academic Requirements: First-class or 2.1 (Hons) degree, or Masters degree (or equivalent) in an appropriate subject.
Deadline for applications: 14 February 2016
Provisional Interview Date: [tbc] Week Beginning 29 February 2016
Start Date: October 2016
Application process: Please upload a completed application form (download from http://www.lancaster.ac.uk/media/lancaster-university/content-assets/documents/lec/pg/LEC_Funded_PhD_Application_Form.docx) outlining your background and suitability for this project and a CV at LEC Postgraduate Research Applications, http://www.lec.lancs.ac.uk/postgraduate/pgresearch/apply-online.
You also require two references, please send the reference form (download from http://www.lancaster.ac.uk/media/lancaster-university/content-assets/documents/lec/pg/LEC_Funded_PhD_Reference_Form.docx) to your two referees and ask them to email it to Andy Harrod ([Email Address Removed]), Postgraduate Research (PGR) Co-ordinator, Lancaster Environment Centre by the deadline.
Due to the limited time between the closing date and the interview date, it is essential that you ensure references are submitted by the closing date or as soon as possible.
1. Ono, S., Wang, D.T., Gruen, D.S., Sherwood Lollar, B., Zahniser, M.S., McManus, B.J. and Nelson, D.D. (2014) Measurement of a Doubly Substituted Methane Isotopologue, 13CH3D, by Tunable Infrared Laser Direct Absorption Spectroscopy. Analytical Chemistry 86, 6487-6494.
2. Stolper, D., Martini, A., Clog, M., Douglas, P., Shusta, S., Valentine, D., Sessions, A. and Eiler, J. (2015) Distinguishing and understanding thermogenic and biogenic sources of methane using multiply substituted isotopologues. Geochimica et Cosmochimica Acta 161, 219-247.
3. Stolper, D.A., Lawson, M., Davis, C.L., Ferreira, A.A., Neto, E.V.S., Ellis, G.S., Lewan, M.D., Martini, A.M., Tang, Y., Schoell, M., Sessions, A.L. and Eiler, J.M. (2014) Formation temperatures of thermogenic and biogenic methane. Science 344, 1500-1503.
4. Stolper, D.A., Sessions, A.L., Ferreira, A.A., Santos Neto, E.V., Schimmelmann, A., Shusta, S.S., Valentine, D.L. and Eiler, J.M. (2014) Combined 13C–D and D–D clumping in methane: Methods and preliminary results. Geochimica et Cosmochimica Acta 126, 169-191.
5. Wang, D.T., Gruen, D.S., Lollar, B.S., Hinrichs, K.-U., Stewart, L.C., Holden, J.F., Hristov, A.N., Pohlman, J.W., Morrill, P.L., Könneke, M., Delwiche, K.B., Reeves, E.P., Sutcliffe, C.N., Ritter, D.J., Seewald, J.S., McIntosh, J.C., Hemond, H.F., Kubo, M.D., Cardace, D., Hoehler, T.M. and Ono, S. (2015) Nonequilibrium clumped isotope signals in microbial methane. Science 348, 428-431.
6. Zhou, Z., Ballentine, C.J., Kipfer, R., Schoell, M. and Thibodeaux, S. (2005) Noble gas tracing of groundwater/coalbed methane interaction in the San Juan Basin, USA. Geochimica et Cosmochimica Acta 69, 5413-5428.
7. Zhou, Z., Ballentine, C.J., Schoell, M. and Stevens, S.H. (2012) Identifying and quantifying natural CO2 sequestration processes over geological timescales: The Jackson Dome CO2 Deposit, USA. Geochimica et Cosmochimica Acta 86, 257-275.