Dr Michael Hermoso

NERC Research Fellow

Email: Michael.Hermoso@earth.ox.ac.uk
TEL: +44 (0)1865 27 2000
FAX: +44 (0)1865 27 2072

Research Profile

My research intererests center around palaeoceanography and biogeochemistry of the marine calcifiers. I am currently interested in developping a mechanistic understanding of stable isotopes in coccolithophores in order to unlock a part of the information contained in the geological record and derive actual (i.e., "vital effect-free") variations of the chemistry of seawater in the past. The coccolithophores are unicellular marine algae living in the surface of the oceans. These calcifying and photosynthetic organisms have an influential role on the exchange of carbon dioxide between the atmosphere and the ocean and are responsible for a large part of the carbon drawdown to the seafloor. In the laboratory, it is possible to reproduce a range of environmental conditions and investigate the effect of the changes in the chemical composition of the biominerals and measure the intensity of the biological-induced fractionation of stable isotopes in coccoliths. Identifying what causes this vital effect will help developing a quantitative approach. Once such a calibration between extracellular parameters and the geochemistry of the mineralisation is obtained, I will test the outcomes pertaining the biogeochemistry of these organisms against the climatic variability of natural environment both geographically and temporally. These new constrains will also be relevant for predicting the response of the oceanic carbonate system to future climate changes because the behaviour of the surface ocean is a key parameter used for most climatic models.  

Teaching Profile

  • Fundamentals of Geology I: Lectures/practicals "Sedimentary rocks & Sedimentary environments" (1st year).
  • Geochemistry: Lectures/practicals "Stable Isotopes" (2nd year) 
  • Dorset Fieldtrip (2nd year).
  • Master's and D.Phil Student Mentoring.

Selected Publications

Hermoso, M., Chan, I.Z.X., McClelland, H.L.O., Heureux, A.M.C. and Rickaby, R.E.M. (2016). Vanishing coccolith vital effects with alleviated carbon limitation. Biogeosciences, 13, 301-312, doi:10.5194/bg-13-301-2016.

Hermoso, M. and Hesselbo, S.P. (2016). Comment on “New insights in the pattern and timing of the Early Jurassic calcareous nannofossil crisis” by M. E. Clémence et al. [Palaeogeography Palaeoclimatology Palaeoecology 427 (2015) 100–108]. Palaeogeography, Palaeoclimatology, Palaeoecology, in press, doi: 10.1016/j.palaeo.2015.12.005.

Hermoso, M. (2015). Control of ambient pH on growth and stable isotopes in phytoplanktonic calcifying algae. Paleoceanography, 30, 1100-1112, doi:10.1002/2015PA002844.

Percival, L.M.E., Witt, M.L., Mather, T.A., Hermoso, M. et al. (2015). Globally enhanced mercury deposition during the end-Pliensbachian extinction and Toarcian OAE: A link to the Karoo-Ferrar Large Igneous Province. Earth and Planetary Science Letters, 428, 267-280, doi:10.1016/j.epsl.2015.06.064.

Hermoso, M., Candelier, Y., Browning, T.J. and Minoletti, F. (2015). Environmental control of the isotopic composition of subfossil coccolith calcite: Are laboratory culture data transferable to the natural environment? GeoResJ, 7, 35-42, doi:10.1016/j.grj.2015.05.002.

Hermoso, M. (2014). Coccolith-derived isotopic proxies in palaeoceanography: where geologists need biologists [Review article]. Cryptogamie, Algologie, 35, 323-352, doi:10.7872/crya.v35.iss4.2014.323.

Minoletti, F., Hermoso, M., Candelier, Y. and Probert I. (2014). Calibration of stable isotope composition of Thoracosphaera heimii (dinoflagellate) calcite for reconstructing paleotemperatures in the intermediate photic zone. Paleoceanography, 29, 1111-1126, doi:10.1002/2014PA002694.

Hermoso, M., Horner, T.J., Minoletti, F. and Rickaby, R.E.M. (2014). Constraints on the vital effect in coccolithophore and dinoflagellate calcite by oxygen isotopic modification of seawater. Geochimica et Cosmochimica Acta, 141, 612-627, doi.10.1016/gca.2014.05.002.

Hermoso, M., Delsate, D., Baudin, F., Le Callonnec, L., Minoletti, F., Renard, M. and Faber, A. (2014). Record of Early Toarcian carbon cycle perturbations in a nearshore environment: the Bascharage section (eastermost Paris Basin). Solid Earth, 5, 793-804, doi.10.5194/se-5-793-2014.

Hermoso, M. and Pellenard, P. (2014). Continental weathering and climatic changes inferred from clay mineralogy and paired carbon isotopes across the early to middle Toarcian in the Paris Basin. Palaeogeography, Palaeoclimatology, Palaeoecology, 399, 385-393, doi.10.1016/j.palaeo.2014.02.007.

Stevenson, E.I., Hermoso, M., Rickaby, R.E.M., Tyler, J.J., Minoletti, F., Parkinson, I.J., Mokadem, F. and Burton, K.W. (2014). Controls on Stable strontium isotope fractionation in coccolithophores with implications for the marine Sr cycle. Geochimica et Cosmochimica Acta, 128, 225-235, doi.10.1016/gca.2013.11.043.

Hermoso, M., Minoletti, F. and Pellenard, P. (2013). Black shale deposition during Toarcian super-greenhouse driven by sea level. Climate of the Past, 9, pp. 2703-2712,  doi.10.5194/cp-9-2703-2013.

Candelier, Y., Minoletti, F., Probert, I. and Hermoso, M. (2013). Temperature dependence of oxygen isotope fractionation in coccolith calcite: A culture and core top calibration of the genus Calcidiscus. Geochimica et Cosmochimica Acta, 100, pp. 264-281, doi.org/10.1016/j.gca.2012.09.040.

Egan, K.E., Rickaby, R.E.M.,  Leng, M.J., Hendry, K.R., Hermoso, M., Sloane, H.J., Bostock, H. and Halliday A.N. (2012). Diatom silicon isotopes as a proxy for silicic acid utilisation: A Southern Ocean core top calibration. Geochimica et Cosmochimica Acta, 96, pp. 174-192, doi.org/10.1016/j.gca.2012.08.002.

Hermoso, M., Minoletti, F., Rickaby, R.E.M., Hesselbo, S.P., Baudin, F. and Jenkyns, H.C., 2012. Dynamics of a stepped carbon-isotope excursion: ultra high-resolution study of Early Toarcian environmental change. Earth and Planetary Science Letters, 319, pp. 45-54, doi:10.1016/j.epsl.2011.12.021.

Scroxton, N., Bonham, S., Rickaby, R., Lawrence S., Hermoso, M. and Haywood, A., 2011. Persistent El Niño-Southern Oscillation variation during the Pliocene Epoch. Paleoceanography, 26, PA2214, doi:10.1029/2010PA002097.

Hermoso, M., Minoletti, F., Le Callonnec, L., Jenkyns, H.C., Hesselbo, S.P., Rickaby, R.E.M., Renard, M., de Rafélis, M. and Emmanuel, L., 2009. Global and local forcing of Early Toarcian seawater chemistry: a comparative study of different paleoceanographic settings (Paris and Lusitanian basins). Paleoceanography, 24, PA4208, doi:10.1029/2009PA001764.

Hermoso, M., Le Callonnec, L., Minoletti, F., Renard, M. and Hesselbo, S.P., 2009. Expression of the Early Toarcian carbon-isotope negative excursion in separated microfractions (Jurassic, Paris Basin). Earth and Planetary Science Letters, 277, pp. 194-203, doi.org/10.1016/j.epsl.2008.10.013.

Minoletti, F., Hermoso, M.* and Gressier, V., 2008. Separation of micron-sized sedimentary particles for palaeoceanography and calcareous nannofossil biogeochemistry. Nature protocols, 4 (1), pp. 14-24, doi.org/10.1038/nprot.2008.200. (* Co-lead author)

Emmanuel, L., Renard, M., Cubaynes, R., Rafélis, M. de, Hermoso, M., Le Callonnec, L. and Rey J., 2006. The "Schistes carton" of Quercy (Tarn, France): A lithological signature of a methane hydrate dissociation event in the Early Toarcian. Implications for correlations between Boreal and Tethyan realms. Bulletin de la Société géologique de France, 177 (5), pp. 237-247.

Other Information

I am part of the Ocean Biogeochemistry Research Group at Oxford.

I am part of the Stratigraphy and Sedimentology Research Group at Oxford.

I am also a honorary Research Associate of the National History Museum, Luxembourg [LINK].