I am an applied mathematician; I use mathematical models to investigate a range of scientific problems. Much of my research relates to geoscience, with a particular focus on glaciers and ice sheets and their interaction with the climate system. I have developed models and parameterisations for subglacial hydrology, glacier sliding, ice-sheet thermodynamics, grounding-line dynamics, and glacial geomorphology. I also work on other continuum mechanics problems, with interests in fluid and solid mechanics, porous media flows, and problems that couple dynamics with phase change. Mathematically, my work exploits a mixture of asymptotic and numerical techniques.

A list of publications is here.

I supervise undergraduate research projects, MSc and DPhil (PhD) theses, and postdoctoral research assistants. If you are interested in any of these, please contact me. Information about graduate study in the Mathematical Institute at Oxford is here, and another route to funding a DPhil could be the NERC DTP in Environmental Research, here.

I aspire to foster an academic community that is welcoming and supportive, in which we all listen to and learn from each other, and in which everyone is valued for their diverse experiences and ideas. I am keen to expand the representation of women and ethnic minorities in my research area, and particularly encourage applications for graduate studies from these groups.

MHFA England

I have Mental Health First Aid training, and have an open door for anyone wanting to talk about their mental health - you are not alone! (Please send me an email or just find me in my office if you'd like to talk). There are useful resources available on the University's welfare page, here. If you are a student at Trinity College you might also look here. If you are employed by the University you can also seek independent support, including counselling, from the Employee Assistance Programme, here.


University of Oxford
  • MSc Mathematical Modelling (Michaelmas 2013-2016)
  • B5.4 Waves and Compressible Flow (Hilary 2014-2017) [pdf]
  • C5.11 Mathematical Geoscience (Michaelmas 2016-2020) [pdf]
  • C5.6 Applied Complex Variables (Hilary 2018-2021) [pdf]
  • Introduction to University Mathematics (Michaelmas 2021) [pdf]
  • Oxford course materials are here.
Trinity College, Oxford
  • College tutorial teaching for most first and second year applied maths courses, including: Introductory Calculus, Geometry, Multivariable Calculus, Dynamics, Fourier series & PDEs, Constructive Maths, Differential Equations, Complex Analysis, Integral Transforms, Quantum Theory, Fluid Dynamics & Waves, Special Relativity, Mathematical Biology.
  • Lecture notes and problem sheets are here. Lecture lists are here.
  • Exam information is here, including an archive of past papers here.
Karthaus summer school
  • Slides for lectures on continuum mechanics [pdf], sliding [pdf], hydrology [pdf] and geomorphology [pdf].
  • Continuum mechanics notes are here. Exercises are here and solutions are here.
  • Some older slides on rheology [pdf] and thermodynamics [pdf].
University of British Columbia
  • Math 253: Multivariable Calculus (Fall 2012)
  • Math 307: Applied Linear Algebra (Spring 2012)
  • Math 257: Partial differential equations (Spring 2010, Fall 2010)

Research Interests
  • Fluid dynamics
  • Glaciers and Ice Sheets
  • Volcanology
  • Viscoplastic fluids
  • Industrial mathematics
  • Fluid-structure interactions
  • Multiphase problems
  • Asymptotic analysis
  • Free-boundary problems


2022- Professor of Applied Mathematics, University of Oxford
2013-2022 Associate Professor, Mathematical Institute, University of Oxford
2013- Fellow & Tutor in Mathematics, Trinity College Oxford
2010-2012 Killam Postdoctoral Fellow, University of British Columbia (supervised by Neil Balmforth)
2006-2009 DPhil Mathematics, University of Oxford (supervised by Andrew Fowler)
2002-2006 MMath Mathematics, University of Oxford
1997-2002 Queen Elizabeth High School, Hexham

A pdf of my CV is here (like all of this page, this has potential to be out of date).


Journal articles
  1. I. J. Hewitt & A. C. Fowler 2008 Partial melting in an upwelling mantle column. Proceedings of the Royal Society A 464, 2467-2491 doi:10.1098/rspa.2008.0045 [link], [pdf]
  2. I. J. Hewitt & A. C. Fowler 2008 Seasonal waves on glaciers. Hydrological Processes 22, 3919-3930 doi:10.1002/hyp.7029 [link], [pdf]
  3. I. J. Hewitt & A. C. Fowler 2009 Melt channelization in ascending mantle. Journal of Geophysical Research 114 B06210 doi:10.1029/2008JB006185 [link], [pdf]
  4. I. J. Hewitt 2010 Modelling melting rates in upwelling mantle. Earth and Planetary Science Research Letters 300, 264-274 doi:10.1016/j.epsl.2010.10.010 [link], [pdf]
  5. I. J. Hewitt 2011 Modelling distributed and channelized subglacial drainage: the spacing of channels. Journal of Glaciology 57, 302-314 doi:10.3189/002214311796405951 [link], [pdf]
  6. I. J. Hewitt, N. J. Balmforth & J. N. McElwaine 2011 Continual skipping on water. Journal of Fluid Mechanics 669, 328-353 doi:10.1017/S0022112010005057 [link], [pdf]
  7. I. J. Hewitt, H. Scolan & N. J. Balmforth 2011 Flow-destabilized seiche modes in a reservoir with a movable dam. Journal of Fluid Mechanics 678, 294-316 doi:10.1017/jfm.2011.113 [link], [pdf]
  8. I. J. Hewitt, N. J. Balmforth & J. N. McElwaine 2011 Granular and Fluid washboards. Journal of Fluid Mechanics 692, 446-463 doi:10.1017/jfm.2011.523 [link], [pdf]
  9. I. J. Hewitt & N. J. Balmforth 2012 Viscoplastic lubrication theory with application to bearings and the washboard instability of a planing plate Journal of Non-Newtonian Fluid Mechanics 169-170, 74-90 doi:10.1016/j.jnnfm.2011.11.008 [link], [pdf]
  10. C. Schoof, I. J. Hewitt & M. A. Werder 2012 Flotation and open water flow in a model for subglacial drainage. Part I: Linked Cavities. Journal of Fluid Mechanics 702, 126-156 doi:10.1017/jfm.2012.165 [link], [pdf]
  11. I. J. Hewitt, C. Schoof & M. A. Werder 2012 Flotation and open water flow in a model for subglacial drainage. Part II: Channel flow. Journal of Fluid Mechanics 702, 157-187 doi:10.1017/jfm.2012.166 [link], [pdf]
  12. N. J. Balmforth & I. J. Hewitt 2013 Viscoplastic sheets and threads. Journal of Non-Newtonian Fluid Mechanics 193, 28-42 doi:10.1016/j.jnnfm.2012.05.007 [link], [pdf]
  13. C. Schoof & I. J. Hewitt 2013 Ice-Sheet Dynamics. Annual Reviews of Fluid Mechanics 45, 217-239 doi:10.1146/annurev-fluid-011212-140632 [link], [pdf]
  14. I. J. Hewitt 2013 Seasonal Changes in Ice Sheet Motion due to Meltwater Lubrication. Earth and Planetary Science Research Letters 371-372, 16-25 doi:10.1016/j.epsl.2013.04.022 [link], [pdf]
  15. M. A. Werder, I. J. Hewitt, C. Schoof & G. E. Flowers 2013 Modeling chanelized and distributed subglacial drainage in two dimensions. J. Geophys. Res. 118, 1-19 doi:10.1002/jgrf.20146 [link], [pdf]
  16. N. S. Hall Taylor, I. J. Hewitt, J. R. Ockendon & T. P. Witelski 2014 A new model for disturbance waves. Int. J. Multiphase Flow 66, 38-45 doi:10.1016/j.ijmultiphaseflow.2014.06.004 [link], [pdf]
  17. M. C. Dallaston & I. J. Hewitt 2014 Free-boundary models of a meltwater conduit. Phys. Fluids 26, 083101 doi:10.1063/1.4892389 [link], [pdf]
  18. N. J. Balmforth, R. V. Craster & I. J. Hewitt 2014 The speed of an inclined ruck. Proc. R. Soc. A 471,20140740. doi:10.1098/rspa.2014.0740 [link], [pdf]
  19. I. J. Hewitt, N. J. Balmforth & J. R. de Bruyn 2015 Elastic-plated gravity currents. Euro. J. App. Math. 26, 1-31, doi:10.1017/S0956792514000291 [link], [pdf]
  20. M. C. Dallaston, I. J. Hewitt & A. J. Wells 2015 Channelization of plumes beneath ice shelves. Journal of Fluid Mechanics 785 109-134 doi: 10.1017/jfm.2015.609 [link], [pdf]
  21. I. J. Hewitt, A. A. Lacey & R. I. Todd 2015 A Mathematical Model for Flash Sintering. Mathematical Modelling of Natural Phenomena 10(6),77-89 doi: 10.1051/mmnp/201510607 [link], [pdf]
  22. J-B. Gorce, I. J. Hewitt & D. Vella 2016 Capillary Imbibition into Converging Tubes: Beating Washburn's Law and the Optimal Imbibition of Liquids. Langmuir 32,1560-1567 doi: 10.1021/acs.langmuir.5b04495 [link], [pdf]
  23. C. Schoof & I. J. Hewitt 2016 A model for polythermal ice incorporating gravity-driven moisture transport. Journal of Fluid Mechanics. 797,504-535 doi: 10.1017/jfm.2016.251 [link], [pdf]
  24. D. P. Hewett & I. J. Hewitt 2016 Homogenized boundary conditions and resonance effects in Faraday cages. Proc. R. Soc. A 472 doi: 10.1098/rspa.2016.0062 [link], [pdf], [errata]
  25. A. Banwell, I. J. Hewitt, I. Willis & N. Arnold 2016 Moulin density controls drainage development beneath the Greenland ice sheet J. Geophys. Res. Earth Surf. 121, doi:10.1002/2015JF003801 [link], [pdf]
  26. I. J. Hewitt & C. Schoof 2017 Models for polythermal ice sheets and glaciers The Crysophere 11, 541-551, doi: 10.5194/tc-11-541-2017 [link], [pdf]
  27. R. Drews, F. Pattyn, I.J. Hewitt, F.S.L. Ng, S. Berger , K. Matsuoka, V. Helm, N. Bergeot, L. Favier & N. Neckel 2017 Actively evolving subglacial conduits and eskers initiate ice shelf channels at an Antarctic grounding line. Nature Communications 121, doi:10.1038/ncomms15228 [link], [pdf], [SI]
  28. K. J. Burns, N. J. Balmforth & I. J. Hewitt 2017 Rolling resistance of shallow granular deformation. Proc. R. Soc. A 473, doi:10.1098/rspa.2017.0375 [link], [pdf]
  29. C. R. Meyer & I. J. Hewitt 2017 A continuum model for meltwater flow through compacting snow. The Cryosphere 11, 2799-2813 doi:10.5194/tc-11-2799-2017 [link], [pdf]
  30. G. P. Benham, A.A. Casterjon-Pita, I. J. Hewitt, C. P. Please, R. W. Style & P. A. D. Bird 2018 Turbulent shear layers in confining channels J. Turbulence 11, 2799-2813 doi:10.1080/14685248.2018.1459630 [link], [pdf]
  31. L. A. Stevens, I. J. Hewitt, S. B. Das & M. D. Behn 2018 Relationship between Greenland Ice Sheet surface speed and modeled effective pressure. J. Geophys. Res. Earth Surf. 123, 2258-2278 doi:10.1029/2017JF004581 [link], [pdf], [SI]
  32. G. P. Benham, I. J. Hewitt, C. P. Please & P. A. D. Bird 2018 Optimal control of diffuser shapes for non-uniform flow J. Eng. Math. 113, 65-92 doi:10.1007/s10665-018-9974-6 [link], [pdf]
  33. A. T. Bradley, F. Box, I. J. Hewitt & D. Vella 2019 Wettability-Independent Droplet Transport by Bendotaxis Phys. Rev. Lett. 122, 074503 doi:10.1103/PhysRevLett.122.074503 [link], [pdf]
  34. T. V. Ball, N. J. Balmforth & I. J. Hewitt 2019 Indentation into a plastic fluid layer Proc. Roy. Soc. A 475, doi:10.1098/rspa.2018.0747 [link], [pdf]
  35. I. J. Hewitt & T. T. Creyts 2019 A model for the formation of eskers Geophys. Res. Lett. 46, doi:10.1029/2019GL082304 [link], [pdf], [SI]
  36. D. I. Benn, A. C. Fowler, I. J. Hewitt & H. Sevestre 2019 A general theory of glacier surges. J. Glaciol., doi:10.1017/jog.2019.62 [link], [pdf]
  37. D. I. Benn, R. L. Jones, A. Luckman, J. J. Furst, I. J. Hewitt & C. Sommer 2019 Mass and enthalpy budget evolution during the surge of a polythermal glacier: a test of theory. J. Glaciol., doi:10.1017/jog.2019.63 [link], [pdf]
  38. M. Haseloff, I. J. Hewitt & R. F. Katz 2019 Englacial Pore Water Localises Shear in Temperate Ice Stream Margins J. Geophys. Res. 124, doi:10.1029/2019JF005399 [link], [pdf]
  39. I. J. Hewitt 2020 Subglacial Plumes. Annual Reviews of Fluid Mechanics. 52,145-169 doi:10.1146/annurev-fluid-010719-060252 [link], [preprint], [SI]
  40. M. O. Dalwadi, S. L. Waters, H. M. Bryne & I. J. Hewitt 2020 A Mathematical Framework for developing Freezing Protocols in the Cryopreservation of Cells SIAM J. App. Math. 80,657--689 doi:10.1137/19M1275875 [link], [pdf], [SI]
  41. E. A. Wilson, A. J. Wells, I. J. Hewitt & C. Cenedese 2020 The dynamics of a subglacial salt wedge. Journal of Fluid Mechanics 895 doi:10.1017/jfm.2020.308 [link], [pdf]
  42. B. Hankin, I. J. Hewitt, G. Sander, F. Danieli, G. Formetta, A. Kamilova, A. Kretzschmar, K. Kiradjiev, C. Wong, S. Pegler, R. Lamb 2020 A risk-based network analysis of distributed in-stream leaky barriers for flood risk management. Nat. Hazards Earth Syst. Sci. 20, 2567-2584, doi:10.5194/nhess-20-2567-2020 [link], [pdf]
  43. D. C. Spencer, R. F. Katz & I. J. Hewitt 2020 Magmatic intrusions control Io's crustal thickness J. Geophys. Res. doi:10.1029/2020JE006443 [link], [pdf]
  44. D. C. Spencer, R. F. Katz, I. J. Hewitt, D. A. May & L. P. Keszthelyi 2020 Compositional layering in Io driven by magmatic segregation and volcanism J. Geophys. Res. doi:10.1029/2020JE006604 [link], [pdf]
  45. I. J. Hewitt & N. J. Balmforth 2020 Viscoelastic ribbons. J. Fluid Mech. 908, doi:10.1017/jfm.2020.870 [link], [pdf]
  46. R. Philip, I. J. Hewitt & P. D. Howell 2021 Modelling the effect of surfactant on droplet breakup in a turbulent flow SIAM J. Appl. Math. 81 doi:10.1137/20M1321851 [link], [pdf]
  47. D. C. Spencer, R. F. Katz & I. J. Hewitt 2021 Tidal controls on the lithospheric thickness and topography of Io from magmatic segregation and volcanism modelling Icarus 359 doi:10.1016/j.icarus.2021.114352 [link], [pdf]
  48. N. Karlsson, A. Solgaard, K. Mankoff, F. Gillet-Chaulet, J. MacGregor, J. Box, M. Citterio, W. Colgan, S. Larsen, K. Kjeldsen, N. Korsgaard, D. Benn, I. J. Hewitt & R. Fausto 2021 A First Constraint on Basal Melt-water Production of the Greenland Ice Sheet Nature Communications doi:10.1038/s41467-021-23739-z [link], [pdf]
  49. A. T. Bradley, F. Box, I. J. Hewitt & D. Vella 2021 Droplet trapping in bendotaxis caused by contact angle hysteresis. Phys. Rev. Fluids 6, 114003 doi:10.1103/PhysRevFluids.6.114003 [link], [pdf]
  50. G. Gonzalez de Diego, P. E. Farrell & I. J. Hewitt 2022 Numerical approximation of viscous contact problems applied to glacial sliding J. Fluid Mech. 938, A21 doi:10.1017/jfm.2022.178 [link], [pdf]
  51. D. Stevens, J. C. Ely, S. J. Livingstone, C. D. Clark, F. E. G. Butcher, I. J. Hewitt 2022 Effects of basal topography and ice-sheet surface slope in a subglacial glaciofluvial deposition model. J. Glaciology doi:10.1017/jog.2022.71 [link], [pdf]
  52. L. A. Stevens, M. Nettles, J. L. Davis, T. T. Creyts, J. Kingslake, I. J. Hewitt & A. Stubblefield 2022 Tidewater-glacier response to supraglacial lake drainage. Nature Communications 13,6065 doi:10.1038/s41467-022-33763-2 [link], [pdf]
  53. A. T. Bradley, I. J. Hewitt & D. Vella 2023 Bendocapillary instability of liquid in a flexible-walled channel. J. Fluid Mech. 955, A26 doi:10.1017/jfm.2022.1025 [link], [pdf]
  54. G. Gonzalez de Diego, P. E. Farrell & I. J. Hewitt 2023 On the finite element approximation of a semicoercive Stokes variational inequality arising in glaciology SIAM J. Numerical Analysis 61,1-25 doi:10.1137/21M1437640 [link], [pdf]
  55. T. Woods & I. J. Hewitt 2023 A model of the weathering crust and microbial activity on an ice-sheet surface. The Cryosphere. 17, 1967--1987 doi:10.5194/tc-17-1967-2023 [link], [pdf]
  56. D. I. Benn, I. J. Hewitt & A. Luckman 2023 Enthalpy balance theory unifies diverse glacier surge behaviour. Ann. Glaciol., doi:10.1017/aog.2023.23 [link], [pdf]
  1. I. J. Hewitt 2008 Continual skipping - getting a kick from water. Proceedings of the 50th GFD Summer School, Woods Hole Oceanographic Institute [pdf]
  2. I. J. Hewitt 2009 Mathematical Modelling of Geophysical Melt Drainage. DPhil thesis, University of Oxford [pdf]
  3. I. J. Hewitt 2020 Modelling the spread of coronavirus. (Some thoughts on the coronavirus epidemic from March 2020 when the UK government were delaying the initial lockdown) [pdf]
  4. I. J. Hewitt 2021 Slow viscous flow. In 'Glaciers and Ice Sheets in the Climate System', ed. A. C. Fowler & F. Ng, Springer [pdf]