Charles Sammis

Professor Emeritus of Earth Sciences


  • Ph.D. Geophysics, California Institute of Technology, 6/1971
  • B.S. Physics, Brown University, 1/1965
    • NATO Postdoctoral Fellow, University of Bristol England, 1974-1975
  • Tenure Track Appointments

    • Associate Professor, Pennsylvania State University, 1972 – 1977

    PostDoctoral Appointments

    • NATO Postdoctoral Fellow, Bristol University England, 1971 – 1972

    Visiting and Temporary Appointments

    • Thomas Brody Visiting Professor of Physics, UNAM Mexico City, 1999
    • Visiting Professor, Institut de Phusique du Globe de Paris,
    • NERC Visiting Scientist, Cambridge University , 1983-1984
  • Summary Statement of Research Interests

    Professor Sammis researches fractal fragmentation of the crust; frictional instabilities in granular fault zones; and application of non-linear mechanics to the spatial and temporal patterns of regional seismicity. He also studies mechanical and tectonic interpretation of fracture patterns on the volcanic plains of Venus. Other areas of interests are high-temperature, high-pressure rheology applicable to the constitution and dynamics of planetary interior, as well as low-temperature, low-pressure rheology applicable to shallow crustal problems associated with energy extraction and earthquake prediction. Professor Sammis’ current research focus on the application of fracture mechanics and fractal geometry to the problem of earthquake instabilities.

  • Book

    • Ben-Zion, Y. (2011). Brittle deformation of solid and granular materials with applications to mechanics of earthquakes and faults. Basel: Birkhauser Press.
    • Ben-Zion, Y., Sammis, C. G. (2010). Mechanics, Structure and Evolution of Fault Zones. Basel: Birkhauser Press.

    Book Chapters

    • Sammis, C. G., Kositsky, A. (2008). Accelerating Moment Release Before Large Earthquakes. Acoustic Emissions and Critical Phenomena: From Structural Mechanics to Geophysics/A. A. Balkema Publishers.
    • Biegel, R. L., Sammis, C. G. (2004). Relating Earthquakes and Fault Zone Structure. (Vol. 66-111) Advances In Geophysics, Volume 47/Elsevier.

    Journal Article

    • Bhat, H. S., Sammis, C. G., Rosakis, A. J. (2011). The micromechanics of Westerly granite at large compressive loads. Pure and Applied Geophysics. Vol. 168, pp. 2181-2198.
    • Sammis, C. G., Lockner, D. A., Reches, Z. (2011). The role of adsorbed water on the friction of a layer of submicron particles. Pure and Applied Geophysics. Vol. 168, pp. 2325-2334.
    • Biegel, R. L., Bhat, H. S., Sammis, C. G., Rosakis, A. J. (2010). The Effect of Asymmetric Damage on Dynamic Shear RupturePropagation I: No Mismatch in Bulk Elasticity. Tectonophysics. Vol. 493, pp. 254-262.
    • Bhat, H. S., Biegel, R. L., Rosakis, A. J., Samms, C. G. (2010). The Effect of Asymmetric Damage on Dynamic Shear Rupture Propagation II: With Mismatch in Bulk Elasticity. Tectonophysics.
    • Sammis, C. G., Rosakis, A. J., Bhat, H. S. (2009). Effects of Off-Fault Damage on Earthquake Rupture Propagation: Experimental Studies. Pure and Applied Geophysics. Vol. 166, pp. 1629-1648.
    • Fischer, A. D., Sammis, C. G. (2009). Dynamic driving of small shallow events during strong motion. Bull. Seismol. Soc. Am. Vol. 99, pp. 1720-1729.
    • Sammis, C. G., Ben-Zion, Y. (2008). The Mechanics of Grain-Size Reduction in Fault Zones. Journal of Geophysical Research. Vol. 113 PubMed Web Address
    • Fischer, A. D., Peng, Z., Sammis, C. G. (2008). Dynamic triggering of high-frequency bursts by strong motions during the 2004 Parkfield earthquake sequence. Geophys. Res. Lett. Vol. 35, pp. L12305. PubMed Web Address
    • Fischer, A. D., Sammis, C. G., Chen, Y., Teng, T. L. (2008). Dynamic triggering by strong motion P- and S-waves: Evidence from the 1999 Chi-Chi, Taiwan earthquake. Bull. Seismol. Soc. Am.. Vol. 98, pp. 580-592.
    • Frost, E., Dolan, J. A., Sammis, C. G. (2008). Progressive strain localization in a major strike-slip fault exhumed from mid-seismogenic depths: Structural observations from the SEMP fault system, Austria. Journal of Geophysical Research.
    • Sammis, C. G., King, G. C. (2007). Mechanical origin of power law scaling in fault zone rock. Geophys. Res. Lett.. Vol. 34, pp. L04312. PubMed Web Address
    • Biegel, R. L., Sammis, C. G., Rosakis, A. J. (2007). Interaction of a dynamic rupture on a fault plane with Short Frictionless Fault Branches. Pure and Applied Geophysics. Vol. 164, pp. 1881-1904. PubMed Web Address
    • Dolan, J. L., Bowman, D. D., Sammis, C. G. (2007). Long-range and long-term fault interactions in southern California. Geology. Vol. 35, pp. 855-858. PubMed Web Address
    • Biegel, R. L., Sammis, C. G., Rosakis, A. J. (2007). An experimental study of the effect of off-fault damage on the velocity of a slip pulse. Journal of Geophysical Research. Vol. 113, pp. B04302. PubMed Web Address


    • Chen, Y., Sammis, C. G. (2006). View of the 1999 Chi-Chi Taiwan Earthquake source rupture and fault mechanics, Bull. Seism. pp. p.807-820.
    • Sammis, C. G. (2005). Off-fault secondary failure induced by a dynamic slip pulse,. pp. p.95.
    • Fellow (or Equivalent) of National Society in Discipline, Fellow of the American Geophysical Union, 2007/01/01
    • USC or School/Dept Award for Teaching, General Education Teaching Award, 2004-2005
    • USC Associates Award For Creativity In Research And Scholarship, 2002
    • USC Associates Award For Excellence In Teaching, 1994
    • Burlington Resources Foundation Faculty Achievement Award for Outstanding Scholar, 1991
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