Department of Geography, Environment and Earth Sciences

Dr Mike Rogerson

Mike Rogerson

Senior Lecturer in Earth Science and Palaeoclimate

Department of Geography, Environment and Earth Sciences

  • Profile
  • Teaching
  • Research
  • Key Publications

Profile

Hi! I am a Lecturer in Earth Science and contribute to both our Geography and Geology teaching programmes. I am also Admissions tutor for all the Geography, Geology and Archaeology programmes run out of Geography, Environment and Earth Science, so please get into contact if you have any questions – no matter how small or silly!

I joined Hull as a Research Fellow, part funded by the UK Research Councils. Before then I spent two years as a postdoctoral researcher at the University of Utrecht (Netherlands). I did my PhD at the National Oceanography Centre in Southampton, subsequent to BSc and MSc degrees in Geology and Petroleum Geology at Imperial College, London.

My interests are rather broad, including past climate change, micropalaeontology, carbonate sedimentology and alkaline waste remediation. In all cases, I am interested in the processes causing change and forming products in these systems, and I like to approach them using theoretical and laboratory approaches to address problems identified in the field. Method development is therefore key to what I do, and I am particularly interested in developing physical modelling solutions to a range of geochemical problems from the fate of zinc contamination in upland streams in the UK to the growth and characteristics of carbonate deposits in the Mesozoic of the southern Atlantic.

Where I can, I bring my research into the classroom, enabling me to bring cutting-edge research into the lecture theatre. This is particularly true for my dissertation students, who can find themselves solving problems coming from anywhere from climate science, to metal pollution remediation to petroleum reservoir development. I’m also committed to teaching in the field – Geology and geography.

Teaching

Teaching

Teaching is key to what we do, and I like to bring in cutting-edge research themes wherever possible – from my work and from other peoples. Most of my teaching covers aspects of past climate and environmental change, and all aspects of “soft rock” geology. My interests all orbit the same key issue; how can we understand past environments from the signs they leave in the geological record?

  • 16119 : Global Environments
  • 16206 : Field Study Spain
  • 16236 : Climate Change 
  • 16272 : Dynamic Planet (leader)  
  • 16359 : Earth, Climate and Evolution (leader)

 

Research

Research Interests

I’m mostly interested in the environmental and climate records contained in the skeletons of marine plankton (foraminifera), in stalagmites and in freshwater limestones (“tufa”). All these things are mostly comprised of calcite, and so a single range of chemical techniques can be used throughout this work. It is wonderfully varied and stimulating work, and I can be doing ocean physics in the morning, solution chemistry at noon and microbial ecology by evening while chasing a single idea!

This kind of research can lead you in strange directions as well, and I also work on passive remediation of alkaline industrial waste, biomining of technological metals from waste materials and provide solutions to develop hydrocarbon reservoirs for the petroleum industry.

I enjoy fieldwork and am an active caver, but also like to work in laboratories and using mathematical models to understand how the Earth System works. Variety is after all the spice of life!

Current Funded Projects

Do humid phases in costal Libya reflect an intensified Atlantic storm Track?" (NE/J014133/1)

Past climate change did not simply occur as a sequence of alternating warm and cool periods. Some of the most important changes caused by naturally occurring climate cycles are related to alterations to the state of circulation in the ocean and atmosphere. A good example is the extreme cooling experienced by northwest Europe as a consequence of weakening in the Gulf Stream / North Atlantic Drift system that maintains Britains relatively mild climate. A crucial concern for understanding future, man-made climate change scenarios are the physical "rules" understanding these changes in circulation. This project aims to generate new understanding of the physical mechanism underlying changes in rainfall in the southern Mediterranean and North African regions.

There is convincing evidence that large magnitude and geographically widespread increases in rainfall occurred throughout North Africa during particular periods of the Earths past. These are periods when the northern hemisphere is receiving a relatively high share of the total incoming solar energy. The additional rainfall caused formation of new lakes and rivers in regions that are now desert and changed the distribution of a range of plants and animals, including early humans. It is thought that the additional rainfall is being routed to North Africa via a northward movement of the African monsoon, but this change is difficult to simulate in climate models and does not seem to fit with all of the data. Other mechanisms therefore also need to be investigated.

This project will test whether some of the rainfall involved in greening the Sahara was derived from storms coming in from the Atlantic, rather than the African monsoon. We will do this by measuring the properties of water trapped within a stalagmite during its formation. The stalagmite we will use came from the north coast of eastern Libya, and is perfectly positioned to receive and retain water from the Atlantic storm track. The water trapped in the stalagmite is made up of hydrogen and oxygen, both of which come in two common isotopes - 1-H or 2-H and 16-O or 18-O respectively. Mediterranean water is slightly more rich in 2-H and 18-O than Atlantic water. Combined with additional measurements of 18O made on the calcite of the stalagmite itself, we therefore expect to be able to differentiate between these two sources using a simple modelling approach.

The suggestion that Atlantic moisture was supplied to North Africa as rainfall in storm events raises a further possibility for this stalagmite, which is positioned within a few kilometers of the coast. Seawater has a characteristic ratio of the two common isotopes of strontium (87 and 86) which is different to that of most freshwaters. As seawater is transported into the atmosphere as aerosols during storm events, it is highly likely that the Sr-isotope ratio in our stalagmite will be shifted towards marine values during periods with higher occurrence of major storms. We can therefore exploit this measurement as a "storm index" in support of the oxygen and hydrogen isotope work.

Finally, we will build on our existing evidence that the time period we are investigating was more humid than today by measuring a suite of trace elements in the calcite of the stalagmite. Many elements respond to humidity in a variety of ways, with some only being available when a rich soil is in place (e.g. sulphur) and others being supplied in atmospheric dust during arid periods (e.g. iron).

If the tests our work provides show that our understanding of this system is correct we and other international research groups can carry on working within our existing paradigms. If our test proves that rainfall events are occurring at different places at different times, then researchers can adjust their efforts to investigate more appropriate representations of the system and develop new paradigms for glacial-interglacial changes in major rainfall systems.

This project is generously supported by the Natural Environment Research Council.

 

A New Network for Research into Past Shifts of the Mediterranean-Saharan Climate Boundary

This exciting new project will create an unprecedented improvement in our knowledge of the late Quaternary climate history of central North Africa. The projects webpage can be found here, with full lists of network participants. The project is generously supported by the Leverhulme Trust.

Project website

 

Current Research Projects

Mediterranean Palaeoclimate

The Mediterranean Sea represents a unique natural laboratory for palaeoclimate research, where changes in oceanic and atmospheric conditions result in significant alterations of circulation. In particular, I am interested in constraining changes in circulation on glacial / interglacial timescales. This behaviour depends upon the exchange with the Atlantic via the Strait of Gibraltar and the rate of loss of freshwater from the basin via evaporation.

The Strait of Gibraltar

Standing waves in the Strait of Gibraltar show the inflow of Atlantic water at the surface. This inflow is balanced by an outflow of salty Mediterranean water at the bottom.The Strait of Gibraltar represents the only natural connection between the Mediterranean Sea and the global ocean. Consequently, it plays a dominant role in determining the response of the Mediterranean to regional and global climate changes. By synthesising empirical and modelling evidence of past exchange conditions, it is possible to develop a robust understanding of the way the Atlantic-Mediterranean exchange responds to a variety of climatic forcings. This understanding allows us to relate regional events, such as the stagnation of the deep western Mediterranean at the end of the last glacial period, in the light of global processes occurring at the same time. Changes in the Gibraltar Exchange also has implications for regional circulation on the mid-latitude eastern North Atlantic margin and potentially has a role in governing the Atlantic "meridional overturning circulation". My recent work has been looking at the relationship between the settling depth of the Mediterranean Outflow Water and the density structure of the eastern North Atlantic. We have been able to show that it is likely that the Mediterranean acts as a negative feedback to changes in the Atlantic, add salt when overturning is slow and reducing salt addition when it is strong.

The Mediterranean freshwater flux

Collecting snails in the Libyan Sahara with Anne Osborne (Bristol) and our intrepid guide, Osama Ali Al-Mshersh (photo by Derek Vance).By combining the Mediterranean marine and terrestrial records, it is possible to identify past changes in regional ocean-atmosphere-land water exchange. While conventional archives of terrestrial conditions, most notably lakes, have given significant insight into the history of atmospheric circulation, as we enter the Age of the Speleothem (stalagmites / stalactites) it is clear that freshwater carbonates will play a pivotal role in the future: and as an enthusiastic caver, I'm not about to miss out on an opportunity like that!

Sampling speleothems in Slovenia. (Photo by Andrej Mihevc).I am part of ongoing projects investigating speleothems, tufas (and freshwater snails; see above) from Libya (in collaboration with colleagues at Bristol and Tripoli) and Slovenia (in collaboration with colleagues from Southampton, Oxford, Postojna and Ljubljana). These projects aim to fully integrate these important archives with the already well developed marine record. This integration will mainly be via looking at changes in the oxygen stable isotope characteristics of the carbonates that make up the tufa and speleothems and which comprises the shells of a group of marine microorganisms known as Foraminifera. The semi-closed system of the Mediterranean gives the possibility of extracting detailed and specific knowledge about the past from comparing these datasets.

In vitro experimentation on freshwater carbonates (Tufas)

An early attempt at experimental tufa development.Tufas have unique potential for constraining past precipitation conditions, both in support of speleothem work and in isolation of it. They are also becoming recognised as important reservoirs for hydrocarbons, and microbial calcite precipitation is key to understanding how toxic metals can be removed from polluted water courses. However, these systems are difficult to understand. Here at Hull, we have built a unique facility for growing tufas (and anything else!) under controlled conditions. For the first time, this will allow physical and geochemical properties of tufa to be directly linked to conditions at the time of precipitation. Already we have demonstrated that the morphology and physical distribution of calcite precipitates are different in sterile systems and in systems colonised by the complex microbial consortia found in naturally occurring tufa systems. We have also shown that the organic mats (biofilms) produced by these consortia are capable of storing large inventories of divalent metal ions (Ca, Mg, Sr, Ba). This storage is sufficient to affect ambient water chemistry and may significantly alter the chemistry of the calcite deposited within the biofilm. This work gives strong support to the suggestion that naturally occurring precipitation is strongly influenced by microbial consortia.

Transportation and disturbance of benthic foraminifera

Working on a Miocene submarine canyon in Tabernas (Spain) with colleagues from Utrecht and Shell. (Photo by Kick Kleverlaan).The properties of bottom dwelling shell-forming protists (benthic foraminifera) during transportation in addition to the manner, timescale and successional order of foraminiferal recolonisation is currently poorly known. However, these organisms are important to palaeoenvironmental reconstruction and may be able to provide vital information about the functioning and recovery of benthic marine ecosystems in physically disturbed environments, both modern and fossil. Improved understanding of the response of assemblages to disturbance and the life-histories of individual taxa will benefit marine stewardship and improve the quality of environmental reconstructions from marine deposits. My previous work has shown that signatures of disturbance are preserved in benthic work seek to investigate the timescales and patterns of recolonisation in shallow water systems and post-mortem transportation in deepwater systems. My recent research student, Angela Kelham, as able to take this further and develop a completely novel method to identifying transport in these assemblages, and even un-mixing the transported and indigenous populations.

Research Students

Tim Horsfield is investigating two Slovenian stalagmites which grew very rapidly (up to 0.5mm per year) during the Holocene. These stalagmites potentially contain records of humidity and moisture source for the Northwest Balkans, and will add considerably to our knowledge of the sub-millennial climate changes and archaeological history of this region.  

Ashley Jones is working on zinc pollution in mine-water affected streams in northern England. The legacy of centuries of mining means many apparently pristine upland waterways are in fact seriously affected by metal pollutants, but we still have little understanding of their dynamics and ultimate fate. Using a mixing of field and experimental work, Ash is aiming at solving that problem.

Victor Oty is working on biomining of steel slags for e-tech metals, and remediation of the leachate solutions that arise from this activity. This work combines a complex suite of biological, chemical and environmental work, and is a unique effort at simultaneously solving major resource and environmental issues. This work comprises part of NERC project NE/K015648/1 led by Will Mayes in our Centre for Ecology and Marine Science.

I am interested in supporting future research studentships in any topic relevant to the above topics, or allied topics in palaeo-climate / -oceanography, biogeochemistry or benthic foraminiferal ecology.

 

Key Publications

Recent Publications

View my google scholar profile for full details of my publications.

Below is a list of my recent papers, and you can find hyperlinks to them all on my Google Scholar profile. If you can’t access any of these through your institution / subscription, please email me at m.rogerson@hull.ac.uk and I will send you a PDF.

Foster, W.J., Armynot du Châtelet, E. and Rogerson, M., 2012. Testing benthic foraminiferal distributions as a contemporary quantitative approach to biomonitoring estuarine heavy metal pollution. Marine Pollution Bulletin, 64(5): 1039-1048.

Jones, A., Rogerson, M., Greenway, G., Potter, H. and Mayes, W., 2013. Mine water geochemistry and metal flux in a major historic Pb-Zn-F orefield, the Yorkshire Pennines, UK. Environmental Science and Pollution Research: 1-12.

Rogerson, M., Rohling, E.J., Bigg, G.R. and Ramirez, J., 2012a. North Atlantic Density gradients since the Last Glacial Maximum. . Climate Dynamics, 39: 589–598.

Rogerson, M., Rohling, E.J., Bigg, G.R. and Ramirez, J., 2012b. Palaeoceanography of the Atlantic-Mediterranean Exchange: Overview and first quantitative assessment of climatic forcing. . Reviews of Geophysics, 50: DOI: 8755-1209/12/2011RG000376.

Rogerson, M., J. Schönfeld, and M. Leng, Qualitative and quantitative approaches in palaeohydrography: A case study from core-top parameters in the Gulf of Cadiz. Marine Geology, 2011. 280: p. 150-167.

Rogerson, M., Rohling, E.J., Bigg, G.R. and Ramirez, J., 2012. North Atlantic Density gradients since the Last Glacial Maximum. Climate Dynamics, 39: 589–598.

Rogerson, M., et al., What Mechanisms Underlie Palaeoceanographic Changes in the Mediterranean Outflow? Geo-Temas, 2010. 7: p. 141-142.

Rogerson, M., et al., Enhanced Mediterranean-Atlantic Exchange During Atlantic Freshening Phases. . Geochemistry Geophysics Geosystems, 2010. 11: p. doi:10.1029/2009GC002931.

Pedley, H.M. and M. Rogerson, eds. Speleothems and Tufas: Unravelling Physical and Biological controls. Geological Society Special Publication, ed. J. Gregory. Vol. 336. 2010, Geological Society of London: London.

Pedley, H.M. and M. Rogerson, In vitro investigations of the impact of different temperature and flow velocity conditions on tufa microfabric. , in Speleothems and Tufas: Unravelling Physical and Biological controls, H.M. Pedley and M. Rogerson, Editors. 2010, Geological Society of London: London. p. 193-210.

Hoffmann, D.L., et al., A speleothem record of the ’Mediterranean monsoon’ during MIS 3 in Northern Libya, in 3rd Workshop of Daphne Working Group, A. Mangini and C. Spötl, Editors. 2010: Kranebitterhof, Innsbruck. p. 46.

Rogerson, M., H.M. Pedley, and R. Middleton, Microbial Influence on Macroenvironment Chemical Conditions in Alkaline (Tufa) Streams; Perspectives from In Vitro Experiments, in Speleothems and Tufas: Unravelling Physical and Biological controls, H.M. Pedley and M. Rogerson, Editors. 2010, Geological Society of London: London. p. 65-81.

Pedley, H.M., M. Rogerson, and R. Middleton, The growth and morphology of freshwater calcite precipitates from in Vitro Mesocosm flume experiments; the case for biomediation. Sedimentology, 2009. 56, : p. 511-527.

Jimenez-Espejo, F.J., et al., Climate and oceanographic variability in the westernmost Mediterranean since the Last Glacial Maximum: detrital input and productivity fluctuations. Geochemistry Geophysics Geosystems, 2008. 9(11): p. doi: 10.1029/2008GC002096.

Rogerson, M., et al., A Dynamic Explanation For The Origin Of The Western Mediterranean Organic Rich Layers. Geochemistry Geophysics Geosystems, 2008. 9(Q07U01): p. doi:10.1029/2007GC001936.

Osborne, A., et al., A humid corridor across the Sahara for the migration of early modern humans out of Africa 120,000 years ago. Proceedings of the National Academy of Sciences of the United States of America, 2008: p. doi_10.1073_pnas.0804472105.

Rogerson, M., et al., New Insights into Biological Influence on the Geochemistry of Freshwater Carbonate Deposits. Geochimica et Cosmochimica Acta, 2008. 72: p. 4976-4987.

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