Staff profile

2003 – 2013 — Senior Researcher, Istituto Nazionale di Geofsica e Vulcanologia (INGV), Dpt. of Seismology and Tectonophysics.

2009 — Invited professor, Ecole Normale Supérieure de Paris (Laboratoire de Géologie du Département géosciences

2000 – 2002 — Researcher, Istituto Nazionale di Geofsica e Vulcanologia (INGV), Dpt. of Seismology and Tectonophysics. Detached to the University of Napoli Federico II, Dpt. Scienze Fisiche.

1997 – 1999 — Research Associate at University of California, Santa Barbara (Physics Dpt. and Institute for Crustal Studies).

1996 – 1997 — Marie Curie postdoctoral grant of the European Community, Dpt. of Geophysics and Volcanology, University of Napoli Federico II, Italy.

1994 – 1996 — Post-doctoral fellow of the SCEC (Southern California Earthquake Center, U.S.C.), at Institute of Geophysics and Planetary Physics, University of California, Los Angeles.

1990 – 1993 — PhD, Institut de Physique du Globe de Paris

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Career Research Highlights

My central interest is in dynamics of earthquake rupture. I am exploring the rupture process using tools like laboratory experiments, numerical modeling and field geology. One of the main questions I am trying to answer is what is the frictional behavior of faults during the fast and short earthquake slip episodes? How can it affect the rupture propagation and hazardous seismic radiation? I order to shed light on these questions I started to work several years ago with scientists from different backgrounds. We created an international group with specialties ranging from field structural geology and microstructures of faults, laboratory methods to deform rocks at high speed and analytical/numerical methods to help upscale the results from the small scale of the lab (rock samples of a few cm) to the large scale (natural seismic fault dimensions can reach tens of kilometers).

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Committee and Society Service

2011 — Member of the International Earth Science Olympiad comitate 5th edition (IESO 2011)

2010 — Reviewer for ANR (Agence Nationale de la Recherche)

2010 — JSPS (Japan Society for the Promotion of Science) - Review College

2012 — Czech Science Foundation (GACR) Review College

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Fellowships

1996 — Marie Curie European Fellowship

1994 — SCEC (Southern California Earthquake Center) Fellowship , postdoctoral grant

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Invited Talks

2011 — Experimental and field constraints on seismic source models – Invited talk. S. Nielsen, The second QUEST Workshop, Hveragerdi, Iceland 

2010 — Reconstructing features of earthquake dynamics from field and experimental observations – Invited talk. Nielsen, Stefan; Griffith, W Ashley; Di Toro, Giulio; Niemeijer, Andre; Smith, Steven A F. Annual meeting of the Geological Society of America (2010)

2010 — Photo-acoustic study of supershear ruptures in the laboratory – Invited talk. Nielsen, S, Schubnel, A , Taddeucci, J, Vinciguerra, S and Rao, S. 7th ACES International Workshop, OTARU, Japan

2010 — Creating earthquake avatars in the laboratory – Invited talk. Nielsen, S. Albert Tarantola Homage Workshop, Muséum National d’Histoire Naturelle, Paris

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Recent and Current Grants

2011 – 2012 — Program GALILEO: Experimental study on propagation of earthquake rupture – INGV Co-ordinator for project, with collaborators at Ecole Normale Supérieure de Paris

2008 – 2013 — USEMS project: Uncovering the Secrets of an Earthquake, a Multidisciplinary Study – INGV Research Co-ordinator

2003 – 2005 — Towards a unified vision of geophysical phenomena – Research Co-ordinator, P.I.: A. Piersanti, INGV

2005 — Progetto di studio della sorgente sismica a partire da affioramenti di faglie fossili (Study of seismic sources from exhumed fault zones) – Co-PI

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• My central interests are earthquakes, fault mechanics, and near-surface geophysics.
• I investigate fault mechanics and the earthquake rupture process for natural and induced seismicity using tools like:
• -Laboratory experimentrs (Rock Mechanics, Rotary shear friction)
• -Field geology on exhumed seismic faults
• -Numerical and analog modeling
• -Mathematical analysis
• -Machine Learning techniques and Neural Networks
• One of the main questions I am trying to answer is what is the frictional behavior of faults during the fast and short earthquake slip episodes? How can it affect the rupture propagation and hazardous seismic radiation? I order to shed light on these questions I started to work several years ago with scientists from different backgrounds. I co-founded an international group with specialties ranging from field structural geology and microstructures of faults, laboratory methods to deform rocks at high speed and analytical/numerical methods to help upscale the results from the small scale of the lab (rock samples of a few cm) to the large scale (natural seismic fault dimensions can reach tens of kilometers).
• I use Near-Surface GeophysicsI to investigate environmental, structural and archaeological problems , in particular, Electrical Resistivity Tomography, GPR, seismic refraction.

Journal Article

• Lazari, F., Castagna, A., Nielsen, S., Griffith, A., Pennacchioni, G., Gomila, R., …Di Toro, G. (2023). Frictional power dissipation in a seismic ancient fault. Earth and Planetary Science Letters, 607, Article 118057. https://doi.org/10.1016/j.epsl.2023.118057
• Marty, S., Schubnel, A., Bhat, H. S., Aubry, J., Fukuyama, E., Latour, S., …Madariaga, R. (2023). Nucleation of Laboratory Earthquakes: Quantitative Analysis and Scalings. Journal of Geophysical Research. Solid Earth, 128(3), Article e2022JB026294. https://doi.org/10.1029/2022jb026294
• Cocco, M., Aretusini, S., Cornelio, C., Nielsen, S. B., Spagnuolo, E., Tinti, E., & Di Toro, G. (2023). Fracture Energy and Breakdown Work During Earthquakes. Annual Review of Earth and Planetary Sciences, 51(1), 217-252. https://doi.org/10.1146/annurev-earth-071822-100304
• Cornelio, C., Spagnuolo, E., Aretusini, S., Nielsen, S., Passelègue, F., Violay, M., …Di Toro, G. (2022). Determination of Parameters Characteristic of Dynamic Weakening Mechanisms During Seismic Faulting in Cohesive Rocks. Journal of Geophysical Research. Solid Earth, 127(7), https://doi.org/10.1029/2022jb024356
• Pozzi, G., De Paola, N., Nielsen, S., Holdsworth, R., Tesei, T., Thieme, M., & Demouchy, S. (2021). Coseismic fault lubrication by viscous deformation. Nature Geoscience, 14(6), 437-442. https://doi.org/10.1038/s41561-021-00747-8
• Nielsen, S., Spagnuolo, E., Violay, M., & Di Toro, G. (2021). Thermal weakening friction during seismic slip experiments and models with heat sources and sinks. Journal of Geophysical Research. Solid Earth, 126(5), Article e2020JB020652. https://doi.org/10.1029/2020jb020652
• Ferrand, T. P., Nielsen, S., Labrousse, L., & Schubnel, A. (2021). Scaling Seismic Fault Thickness From the Laboratory to the Field. Journal of Geophysical Research. Solid Earth, 126(3), Article e2020JB020694. https://doi.org/10.1029/2020jb020694
• Killingback, Z., Holdsworth, R., Walker, R., Nielsen, S., Dempsey, E., & Hardman, K. (2020). A bigger splat: The catastrophic geology of a 1.2-b.y.-old terrestrial megaclast, northwest Scotland. Geology, 49(2), 180-184. https://doi.org/10.1130/g48079.1
• Gluyas, J., De-Paola, N., Imber, J., Jezierski, T., Jones, R., Jordan, P., …Moors, A. (2020). The Humbly Grove, Herriard and Hester’s Copse Fields, UK onshore. Memoirs, 52, 74-81. https://doi.org/10.1144/m52-2018-78
• Mathias, S. A., Nielsen, S., & Ward, R. L. (2019). Storage Coefficients and Permeability Functions for Coal-Bed Methane Production Under Uniaxial Strain Conditions. Transport in Porous Media, 130(2), 627-636. https://doi.org/10.1007/s11242-019-01331-w
• Pozzi, G., De Paola, N., Holdsworth, R. E., Bowen, L., Nielsen, S. B., & Dempsey, E. D. (2019). Coseismic ultramylonites: An investigation of nanoscale viscous flow and fault weakening during seismic slip. Earth and Planetary Science Letters, 516, 164-175. https://doi.org/10.1016/j.epsl.2019.03.042
• Cornelio, C., Spagnuolo, E., Di Toro, G., Nielsen, S., & Violay, M. (2019). Mechanical behaviour of fluid-lubricated faults. Nature Communications, 10, Article 1274. https://doi.org/10.1038/s41467-019-09293-9
• Jayeoba, A., Mathias, S. A., Nielsen, S., Vilarrasa, V., & Bjørnarå, T. I. (2019). Closed-form equation for subsidence due to fluid production from a cylindrical confined aquifer. Journal of Hydrology, 573, 964-969. https://doi.org/10.1016/j.jhydrol.2019.03.041
• Pozzi, G., De Paola, N., Nielsen, S., Holdsworth, R., & Bowen, L. (2018). A new interpretation for the nature and significance of mirror-like surfaces in experimental carbonate-hosted seismic faults. Geology, 46(7), 583-586. https://doi.org/10.1130/g40197.1
• Murphy, S., Di Toro, G., Romano, F., Scala, A., Lorito, S., Spagnuolo, E., …Nielsen, S. (2018). Tsunamigenic earthquake simulations using experimentally derived friction laws. Earth and Planetary Science Letters, 486, 155-165. https://doi.org/10.1016/j.epsl.2018.01.011
• Guérin‐Marthe, S., Nielsen, S., Bird, R., Giani, S., & Di Toro, G. (2018). Earthquake Nucleation Size: Evidence of Loading Rate Dependence in Laboratory Faults. Journal of Geophysical Research. Solid Earth, 124(1), 689-708. https://doi.org/10.1029/2018jb016803
• Vannucchi, P., Spagnuolo, E., Aretusini, S., Di Toro, G., Ujiie, K., Tsutsumi, A., & Nielsen, S. (2017). Past seismic slip-to-the-trench recorded in Central America megathrust. Nature Geoscience, 10(12), 935-940. https://doi.org/10.1038/s41561-017-0013-4
• Harbord, C. W., Nielsen, S. B., De Paola, N., & Holdsworth, R. E. (2017). Earthquake nucleation on rough faults. Geology, 45(10), 931-934. https://doi.org/10.1130/g39181.1
• Nielsen, S. (2017). From slow to fast faulting: recent challenges in earthquake fault mechanics. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 375(2103), Article 20160016. https://doi.org/10.1098/rsta.2016.0016
• Malone, D. H., Craddock, J. P., Schmitz, M. D., Kenderes, S., Kraushaar, B., Murphey, C. J., …Mitchell, T. M. (2017). Volcanic Initiation of the Eocene Heart Mountain Slide, Wyoming, USA. The Journal of Geology, 125(4), 439-457. https://doi.org/10.1086/692328
• Kaneko, Y., Carpenter, B., & Nielsen, S. (2017). Nucleation process of magnitude 2 repeating earthquakes on the San Andreas Fault predicted by rate-and-state fault models with SAFOD drill core data. Geophysical Research Letters, 44(1), 162-173. https://doi.org/10.1002/2016gl071569
• Beeler, N., Di Toro, G., & Nielsen, S. (2016). Earthquake Source Properties from Pseudotachylite. Bulletin of the Seismological Society of America, 106(6), 2764-2776. https://doi.org/10.1785/0120150344
• Nielsen, S., Spagnuolo, E., Violay, M., Smith, S., Toro, G., & Bistacchi, A. (2016). G: Fracture energy, friction and dissipation in earthquakes. Journal of Seismology, 20(4), 1187-1205. https://doi.org/10.1007/s10950-016-9560-1
• Kaneko, Y., Nielsen, S., & Carpenter, B. (2016). The onset of laboratory earthquakes explained by nucleating rupture on a rate-and-state fault. Journal of Geophysical Research. Solid Earth, 121(8), 6071-6091. https://doi.org/10.1002/2016jb013143
• Passelègue, F. X., Schubnel, A., Nielsen, S., Bhat, H. S., Deldicque, D., & Madariaga, R. (2016). Dynamic rupture processes inferred from laboratory microearthquakes. Journal of Geophysical Research. Solid Earth, 121(6), 4343-4365. https://doi.org/10.1002/2015jb012694
• Spagnuolo, E., Nielsen, S., Violay, M., & Di Toro, G. (2016). An empirically based steady state friction law and implications for fault stability. Geophysical Research Letters, 43(7), 3263-3271. https://doi.org/10.1002/2016gl067881
• Nielsen, S., Spagnuolo, E., Smith, S., Violay, M., Di Toro, G., & Bistacchi, A. (2016). Scaling in natural and laboratory earthquakes. Geophysical Research Letters, 43(4), 1504-1510. https://doi.org/10.1002/2015gl067490
• Violay, M., Di Toro, G., Nielsen, S., Spagnuolo, E., & Burg, J. (2015). Thermo-mechanical pressurization of experimental faults in cohesive rocks during seismic slip. Earth and Planetary Science Letters, 429, 1-10. https://doi.org/10.1016/j.epsl.2015.07.054
• Smith, S., Nielsen, S., & Di Toro, G. (2015). Strain localization and the onset of dynamic weakening in calcite fault gouge. Earth and Planetary Science Letters, 413, 25-36. https://doi.org/10.1016/j.epsl.2014.12.043
• Mitchell, T. M., Smith, S., Anders, M., Di Toro, G., Nielsen, S., Cavallo, A., & Beard, A. (2015). Catastrophic emplacement of giant landslides aided by thermal decomposition: Heart Mountain, Wyoming. Earth and Planetary Science Letters, 411, 199-207. https://doi.org/10.1016/j.epsl.2014.10.051
• Violay, M., Di Toro, G., Gibert, B., Nielsen, S., Spagnuolo, E., Del Gaudio, P., …Scarlato, P. (2014). Effect of glass on the frictional behavior of basalts at seismic slip rates. Geophysical Research Letters, 41(2), 348-355. https://doi.org/10.1002/2013gl058601
• Passelègue, F., Schubnel, A., Nielsen, S., Bhat, H., & Madariaga, R. (2013). From Sub-Rayleigh to Supershear Ruptures During Stick-Slip Experiments on Crustal Rocks. Science, 340(6137), 1208-1211. https://doi.org/10.1126/science.1235637
• Violay, M., Nielsen, S., Spagnuolo, E., Cinti, D., Di Toro, G., & Di Stefano, G. (2013). Pore fluid in experimental calcite-bearing faults: Abrupt weakening and geochemical signature of co-seismic processes. Earth and Planetary Science Letters, 361, 74-84. https://doi.org/10.1016/j.epsl.2012.11.021
• Smith, S., Di Toro, G., Kim, S., Ree, J., Nielsen, S., Billi, A., & Spiess, R. (2013). Coseismic recrystallization during shallow earthquake slip. Geology, 41(1), 63-66. https://doi.org/10.1130/g33588.1
• Niemeijer, A., Di Toro, G., Griffith, W., Bistacchi, A., Smith, S., & Nielsen, S. (2012). Inferring earthquake physics and chemistry using an integrated field and laboratory approach. Journal of Structural Geology, 39, 2-36. https://doi.org/10.1016/j.jsg.2012.02.018
• Bestmann, M., Pennacchioni, G., Nielsen, S., Göken, M., & de Wall, H. (2012). Deformation and ultrafine dynamic recrystallization of quartz in pseudotachylyte-bearing brittle faults: A matter of a few seconds. Journal of Structural Geology, 38, 21 - 38. https://doi.org/10.1016/j.jsg.2011.10.001
• Schubnel, A., Nielsen, S., Taddeucci, J., Vinciguerra, S., & Rao, S. (2011). Photo-acoustic study of subshear and supershear ruptures in the laboratory. Earth and Planetary Science Letters, 308(3-4), 424-432. https://doi.org/10.1016/j.epsl.2011.06.013
• Bistacchi, A., Griffith, W., Smith, S., Di Toro, G., Jones, R., & Nielsen, S. (2011). Fault Roughness at Seismogenic Depths from LIDAR and Photogrammetric Analysis. Pure and Applied Geophysics, 168, 2345-2363. https://doi.org/10.1007/s00024-011-0301-7
• Di Toro, G., Han, R., Hirose, T., De Paola, N., Nielsen, N., Mizoguchi, K., …Shimamoto, T. (2011). Fault lubrication during earthquakes. Nature, 471(7339), 494-498. https://doi.org/10.1038/nature09838
• Niemeijer, A., Di Toro, G., Nielsen, S., & Di Felice, F. (2011). Frictional melting of gabbro under extreme experimental conditions of normal stress, acceleration and sliding velocity. Journal of Geophysical Research, 116, https://doi.org/10.1029/2010jb008181
• Malagnini, L., Nielsen, S., Mayeda, K., & Boschi, E. (2010). Energy radiation from intermediate- to large-magnitude earthquakes: Implications for dynamic fault weakening. Journal of Geophysical Research, 115, https://doi.org/10.1029/2009jb006786
• Nielsen, S., Di Toro, G., & Griffith, W. (2010). Friction and Roughness of a Melting Rock Surface. Geophysical Journal International, 182, 299-310. https://doi.org/10.1111/j.1365-246x.2010.04607.x
• Nielsen, S., Mosca, P., Giberti, G., Di Toro, G., Hirose, T., & Shimamoto, T. (2010). On the transient behavior of frictional melt during seismic slip. Journal of Geophysical Research, 115, https://doi.org/10.1029/2009jb007020
• Griffith, W., Nielsen, S., Di Toro, G., & Smith, F. (2010). Rough Faults, Distributed Weakening, and Off-Fault Deformation. Journal of Geophysical Research, 115, https://doi.org/10.1029/2009jb006925
• Nielsen, S., Taddeucci, J., & Vinciguerra, S. (2010). Experimental observation of stick-slip instability fronts. Geophysical Journal International, 180, 697-702. https://doi.org/10.1111/j.1365-246x.2009.04444.x
• Di Toro, G., Niemeijer, A., Tripoli, A., Nielsen, S., Di Felice, F., Scarlato, P., …Mariano, S. (2010). From field geology to earthquake simulation: a new state-of-the-art tool to investigate rock friction during the seismic cycle (SHIVA). Rendiconti Lincei. Scienze Fisiche e Naturali, 21, 95-114. https://doi.org/10.1007/s12210-010-0097-x
• Murphy, S., & Nielsen, S. (2009). Estimating Earthquake Magnitude with Early Arrivals: A Test Using Dynamic and Kinematic Models. Bulletin of the Seismological Society of America, 99(1), 1-23. https://doi.org/10.1785/0120070246
• Del Gaudio, P., Di Toro, G., Han, R., Hirose, T., Nielsen, S., Shimamoto, T., & Cavallo, A. (2009). Frictional melting of peridotite and seismic slip. Journal of Geophysical Research, 114, https://doi.org/10.1029/2008jb005990
• Griffith, W., Di Toro, G., Pennacchioni, G., Pollard, D., & Nielsen, S. (2009). Static stress drop associated with brittle slip events on exhumed faults. Journal of Geophysical Research, 114, https://doi.org/10.1029/2008jb005879
• Nielsen, S., Di Toro, G., Hirose, T., & Shimamoto, T. (2008). Frictional melt and seismic slip. Journal of Geophysical Research. Solid Earth, 113(B1), Article B01308. https://doi.org/10.1029/2007jb005122
• Nisii, V., Saccorotti, G., & Nielsen, S. (2007). Detailed analysis of wave propagation beneath the Campi Flegrei Caldera, Italy. Bulletin of the Seismological Society of America, 97, 440-456. https://doi.org/10.1785/0120050207
• Zollo, A., Lancieri, M., & Nielsen, S. (2007). Reply to comment by P. Rydelek et al. on ``Earthquake magnitude estimation from peak amplitudes of very early seismic signals on strong motion records''. Geophysical Research Letters, 34, https://doi.org/10.1029/2007gl030560
• Zollo, A., Lancieri, M., & Nielsen, S. (2006). Earthquake magnitude estimation from peak amplitudes of very early seismic signals on strong motion records. Geophysical Research Letters, 33, https://doi.org/10.1029/2006gl027795
• Di Toro, G., Hirose, T., Nielsen, S., Pennacchioni, G., & Shimamoto, T. (2006). Natural and Experimental Evidence of Melt Lubrication of Faults During Earthquakes. Science, 311, 647-649. https://doi.org/10.1126/science.1121012
• Di Toro, G., Nielsen, S., & Pennacchioni, G. (2005). Earthquake rupture dynamics frozen in exhumed ancient faults. Nature Cell Biology, 436, 1009-1012. https://doi.org/10.1038/nature03910
• Nielsen, S., & Madariaga, R. (2003). On the self-healing fracture mode. Bulletin of the Seismological Society of America, 93(6), 2375-2388. https://doi.org/10.1785/0120020090
• Festa, G., & Nielsen, S. (2003). PML absorbing boundaries. Bulletin of the Seismological Society of America, 93, 891-903. https://doi.org/10.1785/0120020098
• Nielsen, S., & Carlson, J. (2000). Rupture Pulse Characterization: Self-Healing, Self-Similar, Expanding Solutions in a Continuum Model of Fault Dynamics. Bulletin of the Seismological Society of America, 90(6), 1480-1497. https://doi.org/10.1785/0120000021
• Oglesby, D., Archuleta, R., & Nielsen, S. (2000). The Three-dimensional Dynamics of Dipping Faults. Bulletin of the Seismological Society of America, 90, 616-628. https://doi.org/10.1785/0119990113
• Nielsen, S., Carlson, J., & Olsen, K. (2000). Influence of friction and fault geometry on earthquake rupture. Journal of Geophysical Research, 105, 6069-6088. https://doi.org/10.1029/1999jb900350
• Oglesby, D., Archuleta, R., & Nielsen, S. (2000). Dynamics of dip-slip faulting; explorations in two dimensions. Journal of Geophysical Research, 105, 13,643-13,653. https://doi.org/10.1029/2000jb900055
• Nielsen, S., & Olsen, K. (2000). Constraints on stress and friction from dynamic rupture models of the 1994 Northridge, California, earthquake
• Maillot, B., Nielsen, S., & Main, I. (1999). Numerical simulation of seismicity due to fluid injection in a brittle poroelastic medium. Geophysical Journal International, 139, 263-272. https://doi.org/10.1046/j.1365-246x.1999.00933.x
• Nielsen, S., & Knopoff, L. (1998). The equivalent strength of geometrical barriers to earthquakes. Journal of Geophysical Research, 103(B5), 9953-9965. https://doi.org/10.1029/97jb03293
• Oglesby, D., Archuleta, R., & Nielsen, S. (1998). Earthquakes on dipping faults: the effects of broken symmetry. Science, 280, 1055-1059
• Nielsen, S. (1998). Free surface effects on the propagation of dynamic rupture. Geophysical Research Letters, 25(1), 125-128. https://doi.org/10.1029/97gl03445
• Nielsen, S., Knopoff, L., & Tarantola, A. (1995). Model of Earthquake Recurrence: Role of Elastic Wave Radiation, Relaxation of Friction and Inhomogeneity. Journal of Geophysical Research, 100(7), 12,423-12,430. https://doi.org/10.1029/95jb00714
• Nielsen, S., & Tarantola, A. (1992). Numerical Model of Seismic Rupture. Journal of Geophysical Research, 97, 15291-15295. https://doi.org/10.1029/92jb00205