For FoaLab news, please follow our Twitter feed Friday 7th May 2021
FoaLab is reluctantly on Twitter. Please see https://twitter.com/foa_lab
Dan Spencer passes viva examination with minor corrections Monday 22nd March 2021
Dan Spencer's viva voce exam took place today and lasted for 3.25 hours. The examiners, Prof Jon Blundy and Dr. Jerome Neufeld, were satisfied with the work and awarded Dan a pass with minor corrections. The main content of Dan's thesis is published in three papers. Dan is going on to a job as Sagentia. Congratulations Dr. Spencer!
Yuan Li joins FoaLab as PDRA on the RIFT-O-MAT project Thursday 2nd July 2020
Dr. Yuan Li has joined the FoaLab to be part of the RIFT-O-MAT team, funded by an ERC Consolidator Grant. Li is an expert in analytical and computational fluid mechanics. He has worked on flows dominated by rotation and surface tension, with recent publications on spin disk atmomisation. He has help previous positions at Oxford, Brighton and Birmingham. Welcome Yuan!
Dan Spencer wins Guralp Prize Thursday 2nd July 2020
Congratulations to Dan Spencer on winning the Guralp Prize, which is awarded to a second or third-year DPhil student for excellence in research. Dan's research concerns the role of magmatism in transporting heat and chemistry in Io. In recent work recognized by the Prize committee, he has shown that magmatic segregation balances tidal dissipation in Io, and that magmatic emplacement at the base of the crust is a key control on crustal thickness. A well-deserved honour!
Adina Pusok returns to the FoaLab as ERC postdoc Saturday 6th July 2019
Dr. Adina Pusok has returned to the FoaLab group after a PhD at the University of Mainz and a postdoctoral fellowship at the Scripps Institution, UC San Diego. Adina was an Oxford undergraduate who completed her MSc thesis in the group in 2013. Her position is funded by the RIFT-O-MAT grant from the European Research Council. Her project involves the development and analysis of models of continental and oceanic rifting. In particular, Adina will be looking at how magmatism affects the dynamics and morphology of these tectonic boundaries, using theory of two-phase flow is visco-elastic plastic media. Welcome Adina!
Hanwen Zhang joins FoaLab for summer research Sunday 30th June 2019
Hanwen Zhang has joined the FoaLab for the summer of 2019 for a research experience. Hanwen is an undergraduate student of Theoretical and Applied Mechanics at Peking University. His project will analyse reactive flow in a porous matrix undergoing shear. The project seeks to address a question raised by geological observations of tabular dunite bodies in mantle ophiolites: does large-scale mantle deformation lead to tabular reactive flow channels instead of the tubular ones (that are predicted by theory without shear)? The project joins together two linearised stability analyses that have previously only been studied separately. Welcome Hanwen!
Two FoaLab alumni become lecturers in Scotland! Friday 7th December 2018
Drs. Tobias Keller and David Rees Jones have both accepted faculty positions to start in 2019. Keller will join Earth Sciences at the University of Glasgow; Rees Jones will join the Vortex Dynamics group in the School of Mathematics and Statistics at St. Andrew. Both of these rising stars of mathematical geoscience were postdocs in the FoaLab. The FoaLab wishes them all the best in their new jobs!
Parker Liautaud visits for summer research Monday 9th July 2018
Parker is a PhD student at Harvard, working under the supervision of Prof. Peter Huybers. His interests surround the coupling between the solid Earth and the climate system. In Oxford, Parker is working to develop a simple model of magmatic focusing at mid-ocean ridges that can be used to refine estimates of their variable carbon flux. Welcome Parker!
David Liu joins for summer research Monday 9th July 2018
Zhen Ning David Liu joins the FoaLab for a NERC Research Experience Placement summer position. David will be developing and writing end-of-chapter exercises for a textbook on two-phase magma dynamics. David brings hard-won problems-solving skills in fluid dynamics from the Mathematics Tripos in Cambridge, where he is achieving first-class results. David plans to start Part III of the Tripos this Autumn. Welcome David!
Katz awarded ERC Consolidator grant Wednesday 7th March 2018
Katz has been awarded an ERC consolidator grant to start in Autumn of 2018 and run for five years. The project, called RIFT-O-MAT, will investigate the magma-assisted tectonics of mid-ocean ridges and continental rifts. The overarching goal is to obtain a quantitative understanding of how magmatism promotes and shapes rifts. This will be pursued using new theoretical/computational models that are built upon the two-phase physics of magma/rock interaction. Dr. David May is already involved as the lead software architect; Dr. Tobias Keller will participate as a co-investigator. One additional postdoctoral position will be advertised for a flexible start date in 2019; one PhD studentship will be advertised for a start date in Autumn 2019. The project will support summer internships for students from AIMS.
Jonathan Burley's thesis approved after viva Wednesday 6th December 2017
Jonathan Burley (now Dr. Burley) passed his viva voce examination on Friday 10 November with minor corrections. The examiners were Profs. Chris Ballentine and David Battisti. The exam lasted over three hours and the participants were unanimous in calling it a stimulating and interesting discussion. Congratulations Dr. Burley!
New FoaLab publication Sunday 29th October 2017
Subduction zones are host to abundant magmatism and volcanism and yet thermal models of subduction zones almost invariably neglect magma. A new publication by David Rees Jones et al. shows that the canonical thermal structure calculation is missing an important heat-transport mechanism. They show that magma can transport heat vertically, increasing the temperature beneath arc volcanoes by up to 300 K. This temperature difference brings models into closer alignment with heat flow and metamorphic P-T measurements.
Marianne Haseloff joins FoaLab as PDRA Sunday 24th September 2017
Marianne Haseloff has joined the FoaLab as a postdoctoral research associated, funded by a joint NERC/NSF grant to Katz, Ian Hewitt, and collaborators Neal Iverson (Iowas State) and Luke Zoet (Wisconsin). Haseloff joins this collaboration after a postdoc at Princeton, where she worked with Olga Sergienko, and a PhD at University of British Columbia supervised by Christian Schoof. Marianne's PhD focused on the thermal and mechanical behaviour of temperate ice stream margins. She developed models of shear heating and basal sliding to investigate the potential for stream margin migration. The project at Oxford will extend those models to consider a two-phase theory for temperate ice. This will enable models of meltwater production and drainage to the bed. Welcome Marianne!
Tong Bo joins FoaLab for summer research Thursday 20th July 2017
Tong Bo has joined the FoaLab for the summer of 2017 for a research experience. Tong is an undergraduate student of Theoretical and Applied Mechanics at Peking University. He has had a long interest in quantitative geoscience. His project will analyse one-dimensional, melting-column models of trace-element transport. The underlying question is: under what conditions are trace-element heterogeneities in the source mantle expressed in the magma that reaches the crust? Welcome Tong!
Nestor Cerpa joins FoaLab as PDRA Tuesday 9th May 2017
Nestor Cerpa Gilvonio has joined the FoaLab as a postdoctoral research associate, funded by the ERC grant ISMAGiC. Nestor moved from Minnesota, where he worked with Ikuko Wada on models of two-phase flow with grain-size variations in subduction zones. He obtained his PhD from University of Nice – Sophia Antipolis, France where he studied lithosphere--asthenosphere interaction in 3D models of subduction. At Oxford, Nestor will focus on using two-phase models of volatile enriched magmatism at MORs to quantify the effect of sea-level variations on volatile degassing.
New FoaLab publication Friday 10th March 2017
The recently published models of Keller & Katz (JPet 2016) demonstrated that small concentrations of volatiles may have a large effect on the style of melt transport. So what are the implications for our understanding of melt transport at mid-ocean ridges? A new paper by Keller, Katz & collaborator Marc Hirschmann published in EPSL addresses this. Channelisation is evident the models, but doesn't have an important effect on melt focusing. An important finding is that of the volatiles mobilised by melting and melt transport, only about 50% are focused to the ridge axis; the rest metasomatise the lithosphere, creating volatile-rich heterogeneity that may freeze into the plate. Simulation movies are on YouTube.
New FoaLab publication Monday 18th July 2016
It has long been understood that the very small content of volatile elements (especially water and CO2) in the mantle drastically lower the melting temperature. This creates a broad region of incipient, low-degree partial melting deep beneath mid-ocean ridges. Now a new publication by Keller & Katz has shown that these deep melts can drastically alter the style of melt transport, leading to channelisation of melt flow near the onset of anhydrous melting. The study, published in the Journal of Petrology, uses a newly-developed thermodynamic calculator called the Reactive Disequilibrium Multi-Component model, or (R_DMC, "run dee em see"), based on ideal solution theory and linear kinetics. A Matlab implementation of the calculator is available here https://bitbucket.org/tokeller/r_dmc.
Check out our new YouTube channel! Monday 18th July 2016
The FoaLab has a YouTube channel! We'll be broadcasting new movies with all your favourite stars: magma, the mantle, fluid dynamics, melting, and more. Stay tuned kids! https://www.youtube.com/channel/UCB1EJ7pMnF9bbWGmosRcRAQ
Jonathan Burley wins Guralp Prize Sunday 26th June 2016
Congratulations to Jonathan Burley on winning the Guralp Prize, which is awarded to a second or third-year DPhil student for excellence in research. Jonathan's research concerns the coupling between ice ages and volcanism. In recent work recognized by the Prize committee, he has shown that variations in sea level could modulate the emission rate of CO2 from mid-ocean ridges. A well-deserved honour!
Katz co-author on comment regarding sea-level and volcanism Tuesday 21st June 2016
Peter Huybers (Harvard) and co-authors including Richard Katz commented on the paper of Olive et al (2016, 10.1126/science.aad0715) in Science. Olive et al argued that the bathymetric fabric of the sea floor is dominated by normal faulting, and that the Milankovitch signal observed by Crowley et al (2015) at the AAD is unrelated to magmatic variations in the mantle. Huybers et al (10.1126/science.aae0451) commented that there are many examples of large constructional topography on the sea floor and that while there is no doubt that normal faults are important, the Milankovitch fingerprint is not fortuitous. They went on to show that at the ridge segment used by Olive et al to exemplify their arguments, the Milankovitch signal is found near the segment end, and seems to show a change in frequency content before 700ka, consistent with the shift in the dominant period of ice ages. Both Huybers et al and the reply from Olive et al et al agree that more research is needed to understand the interaction between magmatism and faulting at mid-ocean ridges.
Burley wins OGG McKarrow Cup Monday 29th February 2016
Jonathan Burley has won the 2016 McKerrow Cup/Young Geoscientist of the Year prize of the Oxford Geology Group. The prize recognises excellence in communicating geoscience to a non-specialist audience and carries an award of £400. Congratulations Jonathan!
Two new FoaLab publications Saturday 7th November 2015
The theory of anisotropic viscosity of partially molten rocks is the subject of two new papers co-authored by Richard Katz. One of them describes laboratory experiments conducted by Chao Qi and David Kohlstedt at the University of Minnesota and comparison of the results of those experiments with predictions for theoretical/computational models. The experiments are conducted in a torsion apparatus on partially molten olivine+basalt aggregates. They show radially-inward melt migration with progressive strain -- also known as base-state segregation. Such segregation is consistent with anisotropic viscosity theory but inconsistent with isotropic viscosity (even non-Newtonian). This striking agreement provides support for the validity of the theory. In the second study, Takei and Katz revisit the question of how dynamic anisotropy modifies the predictions of their earlier work on static anisotropy. The paper uses linearised stability analysis to provide a detailed explanation for why viscous anisotropy that evolves dynamically with the stress state leads to lower-angle bands than static anisotropy. Together, these two papers represent the state-of-the-art in understanding melt segregation in laboratory experiments -- but important discrepancies between experiment and theory remain and point to deficiencies of the theory that will be the subject of future work.
FoaLab at Fall AGU meeting 2015 Thursday 5th November 2015
Members of the FoaLab and collaborators will be presenting our work at American Geophysical Union Fall Meeting this year. Please find us at our poster or talk and discuss the results.
Monday V11B-3062 (invited poster) Grain Size as a Control for Melt Focusing Beneath Mid-Ocean Ridges. A Turner, RF Katz, M Behn. Moscone South, 8:00–12:20.
Tuesday V24A-01 (invited talk) SeaVOICE: Sea-going Experiments to Test Potential Linkages among Sea Level Change, Ocean Ridge Volcanism, and Hydrothermal Activity. C Langmuir et al. Moscone South 102, 16:00–16:15.
Tuesday V24A-02 (invited talk) Variations in Mid-Ocean Ridge Magmatism and Carbon Emissions Driven by Glacial Cycles. RF Katz, J Burley, P Huybers, C Langmuir, S-H Park. Moscone South 102, 16:15–16:30.
Wednesday DI31B-2578 (poster) Constraints on the rheology of the partially molten mantle from numerical models of laboratory experiments. J Rudge, L Alisic-Jewell, S Rhebergen, RF Katz, G Wells. Moscone South, 8:00–12:00.
Friday DI51C-01 (invited talk) Melting and Reactive Flow of Carbonated Peridotite Beneath Mid-Ocean Ridges. T Keller, RF Katz. Moscone South 303, 8:00–8:15.
Friday V53A-3124 (poster) A Climactic Feedback? Variations in Mid-Ocean Ridge CO2 Emissions Driven by Glacial Cycles. J Burley, RF Katz, P Huybers. Moscone South, 13:40–18:00.
New FoaLab publication Thursday 5th November 2015
There is a long-standing question about whether porous flow of magma is fast enough to explain the geochemical evidence for rapid melt transport (in the form of measured uranium-series disequilibria), or whether flow through cracks or dikes must be involved. A new publication by FoaLab alumnus Sam Weatherley and Richard Katz uses computational models of magma segregation from a chemically heterogeneous mantle to predict distributions of melt travel times and speeds. Fertile heterogeneities in the model are associated with channelised flow and rapid transport. But the paper shows that these melts don't always have the shorted travel time -- because they are produced by first melting much deeper in the mantle and remain trapped within their enriched enclave until later melting provides a pathway toward the surface. There is little correlation between fertility of the source and rate of magma ascent. Intermediate compositions, however, lead to melt extraction that is rapid enough to preserve thorium disequilibrium and, in some cases, also radium.
Katz is now Professor of Geodynamics Monday 20th July 2015
The University of Oxford has awarded Richard Katz full professorship with the title Professor of Geodynamics. Katz chose the title in homage to the textbook that, when he first read it in 1998, inspired him to become an Earth Scientist: Geodynamics by Turcotte and Schubert.
New FoaLab publication Thursday 16th July 2015
The mantle contains about 10000 times as much carbon as the atmosphere and ocean combined. Mid-ocean ridges vent that carbon from the mantle into the climate system. Previous work from the FoaLab modelled and documented changes in mid-ocean ridge magmatism with changing sea level. Could the flux of carbon from mid-ocean ridges also change with sea level? This is the question that is addressed by Burley & Katz in the new paper Variations in mid-ocean ridge CO2 emissions driven by glacial cycles published online in EPSL today. Models developed in this work suggest that variations in sea level could cause up to 10% variation in the global flux of CO2 from the mantle. This is sensitive to assumptions about the permeability of the mantle, which is poorly constrained. Burley and Katz are collaborating with Peter Huybers of Harvard to understand the climate implications of this carbon. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement 279925 (ISMAGiC).
New FoaLab publication Thursday 2nd April 2015
Grain size in the mantle is an important control on viscosity and permeability, but it has received relatively little attention from geodynamicists. In "Grain-size dynamics beneath mid-ocean ridges: Implications for permeability and melt extraction" by Turner, Katz, and Behn (G-cubed doi:10.1002/2014GC005692), we have used a model of grain-size growth and reduction coupled to a single-phase model of mantle flow with composite viscosity to predict the distribution of grain size beneath a mid-ocean ridge. This distribution has a structure that leads us to predict a new mode of melt focusing, along a "soft" permeability barrier caused by grain-size variation. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement 279925 (ISMAGiC).
Crowley et at published in Science Thursday 5th February 2015
Science Express published Crowley et al.'s paper entitled Glacial cycles drive variations in the production of oceanic crust today. The paper presents models of how sea-level changes associated with glacial cycles can drive variations in magmatism and the production of oceanic crust at mid-ocean ridges. The work finds the signature of Milankovitch cycles in the ocean floor at the Australian-Antarctic ridge, lending strong support to the hypothesis. News coverage of the paper includes Science, Nature, LiveScience. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement 279925 (ISMAGiC).