Professor Dr. Christine Thomas
Professor Dr. Christine Thomas

Professur für Geophysik (Prof. Thomas)

Corrensstr. 24, Room 310
48149 Münster

Phone: +49 251 83 33591
  • Research Areas

    • Seismology, Geophysics
  • CV


    PhD (Univ. Göttingen)
    Undergraduate studies (Univ. Marburg (Pre-Diploma), Univ. Erlangen-Nürnberg (Diploma))


    Lecturer/Senior Lecturer (Univ. Liverpool)
    Postdoc (Univ. Leeds)
    visiting scientist, Univ. Cambridge and British Antarctic survey, UK
  • Projects

    • Deep Earth Rotational Seismology ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: AB 887/1-1
    • Physical properties of deep subducted lithosphere ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/11-3
    • HYPO-TZ - Generation and assessment of hypothetical seismic mantle transition zone structures ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/21-1
    • 3G-GWD: Third Generation Gravitational Wave Telescope. Subproject 6 ( - )
      Participation in BMBF-joint project: Federal Ministry of Education and Research | Project Number: 05A20PM3
    • MISS - Minderung der Störwirkung von Windenergieanlagen auf seismologischen Stationen ( - )
      Participation in other joint projects: EC - European Regional Development Fund | Project Number: EFRE-0801044/KEE-2-002E
    • Untersuchung der Anisotropie der Mantelübergangszone mit PP und SS Vorläufern ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/10-2
    • Phase transitions, Microstructures and their seismic signals from the Earth's mantle ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/18-1; SA 2585/3-1
    • SPP 2017: Gebirgsbildungsprozesse in 4-Dimensionen (4D-MB) - Teilprojekt: UNIBRA/DSEBRA - der deutsche seismologische Beitrag zu AlpArray ( - )
      Subproject in DFG-joint project hosted outside WWU: DFG - Priority Programme | Project Number: TH 1530/15-1
    • Untersuchung des Einflusses von Mantelstrukturen auf Beobachtungen des Erdkerns ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/16-1
    • CREEP - Complex RhEologies in Earth dynamics and industrial Processes ( - )
      EU-project hosted outside WWU: EC H2020 - Marie Skłodowska-Curie Actions - Innovative Training Network | Project Number: 642029
    • Physical properties of deep subducted lithosphere ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/11-1
    • Investigation of the anisotropy of the mantle transition zone using PP and SS precursors ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/10-1
    • Array study of the Reunion hotspot region from the mantle transition zone to the core-mantle boundary ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/9-1
    • RHUM-RUM - RHUM-RUM (Reunion Hotspot and Upper Mantle & Reunions Unterer Mantel): Seismological imaging of a mantle plume under La Reunion, western Indian Ocean) ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH1530/7-1
    • Investigation of Island uplift of the Azores Island region ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/6
    • Deep seismic structures beneath India and South Atlantic ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: TH 1530/5-1
    • Hochauflösende Untersuchungen der oberen Manteldiskontinuitäten ( - )
      Individual project: DFG - Individual Grants Programme | Project Number: 574345
    • SAMPLE - SPP 1375: South Atlantic Margin Processes and Links with onshore Evolution - SP: Seismic heterogeneities beneath the Atlantic and Africa - thermal or chemical? ( - )
      Subproject in DFG-joint project hosted outside WWU: DFG - Priority Programme | Project Number: TH 1530/3-1
    • DAAD Austauschprogramm: PPP Frankreich - PROCOPE ( - )
      Participation in other joint projects: German Academic Exchange Service | Project Number: 50088873
  • Publications

    • Rochira, F., Thomas, C. . ‘Mapping the edge of subducted slabs in the lower mantle beneath India.’ Geophysical Journal International 2022.
    • Hiemer, V; Thomas, C. . ‘Generation of reflections and PKP precursors from a scattering layer in D".’ Geophysical Research Letters 2022.
    • Saki, M., Thomas, C., Abreu, R. . ‘Detection and modelling of strong topography of mid-mantle structures beneath the North Atlantic.’ Geophysical Journal International 2022.
    • Krug M, Saki M, Ledoux E, Gay JP, Chantel J, Pakhomova A, Husband R, Rohrbach A, Klemme S, Thomas C, Merkel S, Sanchez-Valle C. . ‘Textures induced by the coesite-stishovite transition and implications for the visibility of the X-discontinuity.’ Geochemistry, Geophysics, Geosystems 23, No. 10: e2022GC010544. doi:
    • Creasy, N., Pisconti, A. Long, M., Thomas, C. . ‘Modeling of seismic anisotropy observations reveals plausible lowermost mantle flow directions beneath Siberia.’ Geochemistry, Geohysics, Geosystems 2021.
    • Varghese, J., van Alen, C.M., Fujarski, M., Warnecke ,T., Thomas, C. . ‘Sensor Validation and Diagnostic Potential of Smartwatches in Movement Disorders.’ Sensors 2021.
    • Jackson., J.M., Thomas, C. . Seismic and mineral physics constraints on the D" layer. [online first]
    • Ma, X., Thomas, C. . ‘Small-scale scattering heterogeneities in the lowermost mantle from a global analysis of PKP precursors.’ Journal of Geophysical Research 125.
    • Panero, W.R., C. Thomas, R. Myhill, J.S. Pigott. . ‘Dehydration Melting Below the Undersaturated Transition Zone.’ Gcubed 21.
    • Pisconti, A., Plenkers, K., Philipp, J., Thomas, C. . ‘Mapping Lithological Boundaries in Mines with Array Seismology and In-situ AE monitoring.’ Geophysical Journal International 220: 59–70.
    • Rein, T., Spieker, K., Hannemann, K., Thomas, C., Korn, M. . ‘Location and Characteristics of the X-Discontinuity beneath SW Morocco and the adjacent shelf area using P-wave Receiver Functions.’ Geophysical Journal International 2020. doi: 10.1093/gji/ggaa379.
    • van Tent, R., Deuss, A., Kaneshima, S., Thomas, C. . ‘The signal of outermost-core stratification in body-wave and normal-mode data.’ Geophysical Journal International 223.
    • Rein, T, Hannemann, K, Thomas, C, Korn, M. . ‘Location and characteristics of the X-discontinuity beneath SW Morocco and the adjacent shelf area using P-wave receiver functions.’ Geophysical Journal International 223 (3). doi: 10.1093/gji/ggaa379.
    • Durand, S., Thomas, C., Jackson, J.M. . ‘New constraints on D” beneath the North Atlantic region from P and S travel times and amplitudes.’ Geophysical Journal International 216: 1132–1144.
    • Ma, X., Sun, X., Thomas, C. . ‘Localized ultra-low velocity zones at the eastern boundary of Pacific LLSVP.’ Earth and Planetary Science Letters 507: 40–49.
    • Saki, M., Thomas, C., Cobden, L., Abreu, R., Buchen, J. . ‘Investigating the cause for polarity reversals of PP precursors beneath the Atlantic.’ Physics of teh Earth and Planetary Interior 286: 1132–1144.
    • Creasy, N., Pisconti, A., Long, M.D., Thomas, C., Wookey, J. . ‘Constraining lowermost mantle anisotropy with body waves: A synthetic modeling study.’ Geophysical Journal International 2017: 766–783.
    • Pisconti, A., Thomas, C., Wookey, J. . ‘Constraining D" anisotropy with reflections and splitting.’ Journal of Geophysical Research 2019.
    • Wolf, J., Creasy, N, Pisconti, A., Long, MD, Thomas, C. . ‘An investigation of seismic anisotropy in the lowermost mantle beneath Iceland.’ Geophysical Journal International 219: S152–S166.
    • Stockmann, F., Cobden, L., Deschamps, F., Fichtner, A., Thomas, C. . ‘Investigating the seismic structure and visibility of dynamic plume models with seismic array methods.’ Geophysical Journal International 2019: S167-S194.
    • Langrand, C., Andrault, D., Durand, S. Konopkova, Z., Hilairet, N., Thomas, C., Merkel S. . ‘Kinetics and detectability of the bridgmanite to post-perovskite transformation in the Earth's D" layer.’ Nature Communications 10. doi: 10.1038/s41467-019-13482-x.
    • Durand S., R. Abreu, C. Thomas. . ‘SeisTomoPy: Fast visualization, comparison and calculations in global tomographic models.’ Seismological Reasearch Letters 300. doi: 10.1785/0220170142.
    • Abreu R., C. Thomas, S. Durand. . ‘Effect of observed micropolar motions on wave propagation in deep Earth minerals.’ Physics of the Earth and Planetary Interiors 276: 215–225. doi: 10.1016/j.pepi.2017.04.006.
    • Saki M., Thomas C., Merkel S., Wookey J. . ‘Detecting seismic anisotropy above the 410 km discontinuity using reflection coefficients of underside reflections.’ Physics of the Earth and Planetary Interiors 274, No. null: 170–183. doi: 10.1016/j.pepi.2017.12.001.
    • Schumacher L, Thomas C, Abreu R. . ‘Out-of-Plane Seismic Reflections Beneath the Pacific and Their Geophysical Implications.’ Journal of Geophysical Research: Solid Earth 123, No. 3: 2286–2302. doi: 10.1002/2017JB014728.
    • Heteny, G., Molinari, I, Clinton, J, and AlpArray Working Group. . ‘The AlpArray Seismic Network - a large-scale European experiment to image the Alpine orogeny.’ Surveys in Geophysics 39: 1–25.
    • Schneider S., C. Thomas, R.M.H. Dokht, Y.J. Gu, Y. Chen. . ‘Resolution Improvement and Reconstruction of Global Seismic Data using fk-Methods.’ Geophysical Journal International 212: 1288–1301.
    • Spieker, K., Rondenay, S., Ramalho, R., Thomas, C., Helffrich, G. . ‘Constraints on the structure of the crust and lithosphere beneath the Azores Islands from teleseismic receiver functions.’ Geophysical Journal International 213: 824–835.
    • Schumacher, L., Thomas C. Abreu, R. . ‘Out-of-Plane Seismic Reflections Beneath the Pacific and Their Geophysical Implications.’ Journal of Geophysical Research 123: 2286–2302.
    • Abreu, R., Durand, S., Thomas, C. . ‘The asymmetric seismic moment tensor in micropolar media.’ Bulletin of the Seismological Society of America 108: 1160–1170.
    • Attanayake, J., Thomas, C., Cormier, V.F., Miller, M.S., Koper, K. . ‘Irregular Transition Layer Beneath the Earth's Inner Core Boundary from Observations of Antipodal PKIKP and PKIIKP Waves.’ Gcubed 19. doi: 10.1029/2018GC007562.
    • Reiß, A-S, Thomas, C., Lecocq, T. . ‘Using SP precursor waves to detect upper mantle discontinuities.’ Geophys. Journal International 215: 1914-1929.
    • Borleanu F., De Siena L., Thomas C., Popa M., Radulian M. . ‘Seismic scattering and absorption mapping from intermediate-depth earthquakes reveals complex tectonic interactions acting in the Vrancea region and surroundings (Romania).’ Tectonophysics null, No. null: 129–142. doi: 10.1016/j.tecto.2017.04.013.
    • Ramalho R., Helffrich G., Madeira J., Cosca M., Thomas C., Quartau R., Hipólito A., Rovere A., Hearty P., Ávila S. . ‘Emergence and evolution of Santa Maria Island (azores)- The conundrum of uplifted islands revisited.’ Geological Society of America Bulletin 129, No. null: 372–391. doi: 10.1130/B31538.1.
    • Reiss A., Thomas C., van Driel J., Heyn B. . ‘A hot midmantle anomaly in the area of the Indian Ocean Geoid Low.’ Geophysical Research Letters 44, No. 13: 6702–6711. doi: 10.1002/2017GL073440.
    • Ballmer M., Schumacher L., Lekic V., Thomas C., Ito G. . ‘Compositional layering within the large low shear-wave velocity provinces in the lower mantle.’ Geochemistry, Geophysics, Geosystems 17, No. 12: 5056–5077. doi: 10.1002/2016GC006605.
    • De Siena L., Calvet M., Watson K., Jonkers A., Thomas C. . ‘Seismic scattering and absorption mapping of debris flows, feeding paths, and tectonic units at Mount St. Helens volcano.’ Earth and Planetary Science Letters 442, No. null: 21–31. doi: 10.1016/j.epsl.2016.02.026.
    • Mancinelli N., Shearer P., Thomas C. . ‘On the frequency dependence and spatial coherence of PKP precursor amplitudes.’ Journal of Geophysical Research B: Solid Earth 121, No. 3: 1873–1889. doi: 10.1002/2015JB012768.
    • Schlaphorst D., Thomas C., Holme R., Abreu R. . ‘Investigation of core-mantle boundary topography and lowermost mantle with P4KP waves.’ Geophysical Journal International 204, No. 2: 1060–1071. doi: 10.1093/gji/ggv496.
    • Schumacher L., Thomas C. . ‘Detecting lower-mantle slabs beneath Asia and the Aleutians.’ Geophysical Journal International 205, No. 3: 1512–1524. doi: 10.1093/gji/ggw098.
    • Schumacher L, Thomas C. . ‘Detecting Lower-Mantle Slabs beneath Asia and the Aleutians.’ Geophysical Journal International 205, No. 3: 1512–1524. doi: 10.1093/gji/ggw098.
    • Thomas, C, Laske, G. . ‘D" observations in the Pacific from PLUME Ocean Bottom Seismometer recordings.’ Geophysical Journal International 200: 851–862. doi: 10.1093/gji/ggu441.
    • Lessing S., Thomas C., Saki M., Schmerr N., Vanacore E. . ‘On the difficulties of detecting PP precursors.’ Geophysical Journal International 201, No. 3: 1666–1681. doi: 10.1093/gji/ggv105.
    • Saki M., Thomas C., Nippress S., Lessing S. . ‘Topography of upper mantle seismic discontinuities beneath the North Atlantic: The Azores, Canary and Cape Verde plumes.’ Earth and Planetary Science Letters 409, No. null: 193–202. doi: 10.1016/j.epsl.2014.10.052.
    • Cobden L., Thomas C., Trampert J. . ‘Seismic detection of post-perovskite inside the earth.’ In The Earth's Heterogeneous Mantle: A Geophysical, Geodynamical, and Geochemical Perspective, edited by Springer, 391–440. Springer International Publishing. doi: 10.1007/978-3-319-15627-9_13.
    • Gassner A., Thomas C., Krüger F., Weber M. . ‘Probing the core-mantle boundary beneath Europe and Western Eurasia: A detailed study using PcP.’ Physics of the Earth and Planetary Interiors 246, No. null: 9–24. doi: 10.1016/j.pepi.2015.06.007.
    • Waszek L., Thomas C., Deuss A. . ‘PKP precursors: Implications for global scatterers.’ Geophysical Research Letters 42, No. 10: 3829–3838. doi: 10.1002/2015GL063869.
    • Poli P., Thomas C., Campillo M., Pedersen H. . ‘Imaging the D″ reflector with noise correlations.’ Geophysical Research Letters 42, No. 1: 60–65. doi: 10.1002/2014GL062198.
    • Miller M., O'Driscoll L., Butcher A., Thomas C. . ‘Imaging Canary Island hotspot material beneath the lithosphere of Morocco and southern Spain.’ Earth and Planetary Science Letters 431, No. null: 186–194. doi: 10.1016/j.epsl.2015.09.026.
    • De Siena, L.; Thomas, C.; Aster, R. . ‘Multi-scale reasonable attenuation tomography analysis (MuRAT): An imaging algorithm designed for volcanic regions.’ Journal of Volcanology and Geothermal Research 277: 35. doi: 10.1016/j.jvolgeores.2014.03.009.
    • Lessing, S.; Thomas, C.; Rost, S.; Cobden, L.J.; Dobson, D.P. . ‘Mantle transition zone structure beneath India and Western China from migration of PP and SS precursors.’ Geophysical Journal International 197, No. 1: 413. doi: 10.1093/gji/ggt511.
    • Bonnin, M.; Nolet G.; Villaseñor, A.; Gallart, J.; Thomas, C. . ‘Multiple-frequency tomography of the upper mantle beneath the African/Iberian collision zone.’ Geophysical Journal International 198, No. 3: 1473. doi: 10.1093/gji/ggu214.
    • Spieker, K.; Wölbern, I.; Thomas, C.; Harnafi, M.; El Moudnib, L. . ‘Crustal and upper-mantle structure beneath the western Atlas Mountains in SW Morocco derived from receiver functions.’ Geophysical Journal International 198, No. 3: 1485. doi: 10.1093/gji/ggu216.
    • De Siena L, Thomas C, Waite GP, Moran SC, Klemme S. . ‘Attenuation and scattering tomography of the deep plumbing system of Mount St. Helens.’ Journal of Geophysical Research - Solid Earth 119: 8223–8238. doi: 10.1002/2014JB011372.
    • Jacobeit E, Thomas C, Vernon F. . ‘Influence of station topography and Moho depth on the mislocation vectors for the Kyrgyz Broadband Seismic Network (KNET).’ Geophysical Journal International 193, No. 2: 949–959. doi: 10.1093/gji/ggt014.
    • Cobden L., Thomas C. . ‘The origin of D" reflections: A systematic study of seismic array data sets.’ Geophysical Journal International 194, No. 2: 1091–1118. doi: 10.1093/gji/ggt152.
    • De Siena L., Del Pezzo E., Thomas C., Curtis A., Margerin L. . ‘Seismic energy envelopes in volcanic media: In need of boundary conditions.’ Geophysical Journal International 195, No. 2: 1102–1119. doi: 10.1093/gji/ggt273.
    • Earle PS, Rost S, Shearer PM, Thomas C. . ‘Scattered P′ P′ waves observed at short distances.’ Bulletin of the Seismological Society of America 101, No. 6: 2843–2854. doi: 10.1785/0120110157.
    • Schmerr N, Thomas C. . ‘Subducted lithosphere beneath the Kuriles from migration of PP precursors.’ Earth and Planetary Science Letters . doi: 10.1016/j.epsl.2011.09.002.
    • Thomas C, Wookey J, Brodholt J, Fieseler T. . ‘Anisotropy as cause for polarity reversals of D′ reflections.’ Earth and Planetary Science Letters 307, No. 3-4: 369–376. doi: 10.1016/j.epsl.2011.05.011.
    • Rost S, Thomas C. . ‘High resolution CMB imaging from migration of short-period core reflected phases.’ Physics of the Earth and Planetary Interiors 183, No. 1-2: 143–150. doi: 10.1016/j.pepi.2010.04.005.
    • Caracas R, Mainprice D, Thomas C. . ‘Is the spin transition in Fe2+-bearing perovskite visible in seismology?Geophysical Research Letters 37.
    • Chaloner JW, Thomas C, Rietbrock A. . ‘P- and S-wave reflectors in D ' beneath southeast Asia.’ Geophysical Journal International 179, No. 2: 1080–1092. doi: 10.1111/j.1365-246X.2009.04328.x.
    • Rost S, Thomas C. . ‘Improving Seismic Resolution Through Array Processing Techniques.’ Surveys in Geophysics 30, No. 4-5: 271–299. doi: 10.1007/s10712-009-9070-6.
    • Thomas C, Kendall JM, Helffrich G. . ‘Probing two low-velocity regions with PKP b-caustic amplitudes and scattering.’ Geophysical Journal International 178, No. 1: 503–512. doi: 10.1111/j.1365-246X.2009.04189.x.
    • Thomas C, Billen MI. . ‘Mantle transition zone structure along a profile in the SW Pacific: thermal and compositional variations.’ Geophysical Journal International 176, No. 1: 113–125. doi: 10.1111/j.1365-246X.2008.03934.x.
    • Kito T, Thomas C, Rietbrock A, Garnero EJ, Nippress SEJ, Heath AE. . ‘Seismic evidence for a sharp lithospheric base persisting to the lowermost mantle beneath the Caribbean.’ Geophysical Journal International 174, No. 3: 1019–1028. doi: 10.1111/j.1365-246X.2008.03880.x.
    • Thomas, C. . ‘Array Signal Processing.’ In Handbook of Signal Processing, edited by Havelock, D., Kuwano, S. Vorländer, M., 1655–1665. Springer Verlag.
    • Kito T, Rietbrock A, Thomas C. . ‘Slowness-backazimuth weighted migration: A new array approach to a high-resolution image.’ Geophysical Journal International 169, No. 3: 1201–1209. doi: 10.1111/j.1365-246X.2007.03379.x.
    • Kito T, Rost S, Thomas C, Garnero EJ. . ‘New insights into the P- and S-wave velocity structure of the D '' discontinuity beneath the Cocos plate.’ Geophysical Journal International 169, No. 2: 631–645. doi: 10.1111/j.1365-246X.2007.03350.x.
    • Thomas C, Wookey J, Simpson M. . ‘D '' anisotropy beneath Southeast Asia.’ Geophysical Research Letters 34, No. 4.
    • Wallace M, Thomas C. . ‘Investigating D '' structure beneath the North Atlantic.’ Physics of the Earth and Planetary Interiors 151, No. 1-2: 115–127.
    • Hernlund JW, Thomas C, Tackley PJ. . ‘A doubling of the post-perovskite phase boundary and structure of the Earth's lowermost mantle.’ Nature 434, No. 7035: 882–886. doi: 10.1038/nature03472.
    • Thomas C, Kendall JM, Lowman J. . ‘Lower-mantle seismic discontinuities and the thermal morphology of subducted slabs.’ Earth and Planetary Science Letters 225, No. 1-2: 105–113. doi: 10.1016/j.epsl.2004.05.038.
    • Thomas C, Garnero EJ, Lay T. . ‘High-resolution imaging of lowermost mantle structure under the Cocos plate.’ Journal of Geophysical Research 109, No. B8.
    • Thomas C, Livermore R, Pollitz F. . ‘Motion of the Scotia Sea plates.’ Geophysical Journal International 155, No. 3: 789–804. doi: 10.1111/j.1365-246X.2003.02069.x.
    • Rost S, Thomas C. . ‘Array seismology: Methods and applications.’ Reviews of Geophysics 40, No. 3.
    • Thomas C, Heesom T, Kendall JM. . ‘Investigating the heterogeneity of the D '' region beneath the northern Pacific using a seismic array.’ Journal of Geophysical Research 107, No. B11.
    • Thomas C, Kendall JM, Weber M. . ‘The lowermost mantle beneath northern Asia - I. Multi-azimuth studies of a D '' heterogeneity.’ Geophysical Journal International 151, No. 1: 279–295. doi: 10.1046/j.1365-246X.2002.01759.x.
    • Thomas C, Kendall JM. . ‘The lowermost mantle beneath northern Asia - II. Evidence for lower-mantle anisotropy.’ Geophysical Journal International 151, No. 1: 296–308. doi: 10.1046/j.1365-246X.2002.01760.x.
    • Thomas C, Igel H, Weber M, Scherbaum F. . ‘Acoustic simulation of P-wave propagation in a heterogeneous spherical earth: numerical method and application to precursor waves to PKPdf.’ Geophysical Journal International 141, No. 2: 307–320. doi: 10.1046/j.1365-246x.2000.00079.x.
    • Thomas C, Weber M, Wicks CW, Scherbaum F. . ‘Small scatterers in the lower mantle observed at German broadband arrays.’ Journal of Geophysical Research 104, No. B7: 15073–15088. doi: 10.1029/1999JB900128.
    • Thomas Ch, Weber M. . ‘P velocity heterogeneities in the lower mantle determined with the German Regional Seismic Network: Improvement of previous models and results of 2D modelling.’ Physics of the Earth and Planetary Interiors 101, No. 1-2: 105–117. doi: 10.1016/S0031-9201(96)03245-1.
    • Weber, M, J.P. Davis, C. Thomas, F. Krüger, F. Scherbaum, J. Schlittenhardt, M. Körnig. . ‘The structure of the lowermost mantle as determined from using seismic arrays.’ In Seismic Modelling of the Earth's structure, edited by E. Boschi, G. Ekström, A Morelli, 399–442. Roma: Selbstverlag / Eigenverlag / Self-publishing.