My research interests lie in the application of natural stable isotope chemistry to environmental and palaeoclimate studies. I am also very active in instrument design, developing new, high sensitivity isotope ratio mass spectrometers (IRMS)in order to analyse small samples with a high degree of precision, measure 'isotopic clusters', noble gas isotope ratios and the natural variation of oxygen in the atmosphere.
In my laboratory we use stable isotope geochemistry to help us understand aspects of past and present climate and environment change. The isotopic composition of fossil rainwater trapped in stalactites and stalagmites collected from caves helps us to unravel details of the climate in western Europe over the past 11,000 years. An analysis of magnetic dust and the isotopic composition of tiny marine creatures known as foraminifera in deep sea marine cores gives us clues to the processes that occur at the end of an ice age 130 thousand years ago when the climate changed rapidly from a cold glacial to a warm interglacial world. Even further back in geological time, some 65 million years ago, the dinosaurs became extinct at the end of the Cretaceous period. There is speculation as to the cause of the extinction: meteorite impact or volcanic activity with the huge eruption of the Deccan Traps in India. An analysis of dinosaur egg shells, collected from sediments that intermingle with the Deccan Trap volcanic lavas has helped us to understand the climate and atmospheric carbon dioxide levels at the time the dinosaurs became extinct.
Currently I am working on new isotope techniques for measuring palaeotemperatures using isotopic clusters or isotopologues and developing a high sensitivity noble gas mass spectrometer for in-situ cosmogenic isotope studies (tritium and neon)as a dating tool for groundwaters and landscape evolution studies.
Key Research Interests
Stable Isotope Geochemistry; in-situ cosmogenic isotope chemistry; noble gas chemistry; terrestrial and marine palaeoclimate analysis, Landscape evolution; hydrology and hydrogeology; isotopic oceanography; atmospheric chemistry; stable isotope instrumentation and techniques.
- Pentecost, A., J.E. Andrews, P.F. Dennis, A.Marca-Bell, S. Dennis (2006) Charophyte growth in small temperate water bodies: extreme isotopic disequilibrium and implications for the palaeoecology of shallow marl lakes. Palaeogeography, Palaeoclimatology, Palaeoecology, 240, 389-404 DOI: 10.1016/j.palaeo.2006.02.008
- Fukada, T., K.M. Hiscock, P.F. Dennis (2004) A dual-isotope approach to the nitrogen hydrochemistry of an urban aquifer. Applied Geochemistry, 19,709-719
- Dennis, P.F., P.J. Rowe, T.C. Atkinson (2001) The recovery and measurement of water from fluid inclusions in speleothem. Geochimica et Cosmochimica Acta, 65, 4081-4098 DOI: 10.1016/S0016-7037(00)00576-7
- Maher, B.M. and P.F. Dennis (2001) Evidence against dust mediated control of glacial-interglacial changes in atmospheric CO2. Nature, 411, 176-180 DOI: 10.1038/35075543
- Meredith, M., K. Heywood, P.F. Dennis, L. Goldson, R. White, E. Fahrbach, U. Schauer, S. Osterhus (2001) Freshwater fluxes through the western Fram Strait. Geophysical Research Letters, 28, 1615-1618
- Yeatman, S.G., L.J. Spokes, P.F. Dennis, T.D. Jickells (2001) Comparison of aerosol nitrogen isotopic composition at two coastal sites. Atmospheric Environment, 35, 1321-1335 DOI: 10.1016/S1352-2310(00)00408-8
Publications: EPrints Digital Repository