My research focuses on the mechanics of fault slip. We seek to understand why some faults slip at a steady rate near plate rate, others slip in large earthquakes, and still other faults slip in a series of slow earthquakes. And we want to understand how these processes work. For instance, how does an earthquake nucleate and grow, and what physical processes stop some faults from accelerating to seismogenic speeds?
Large populations around the world live near faults that host large and small earthquakes. As we improve our understanding of seismic and aseismic slip, we seek to incorporate more physical modeling into estimating and mitigating seismic hazard, so that we can better interpret what has happened on faults in the past in terms of what might happen in the future.
I use three primary tools in investigating earthquakes and seismic slip on faults: seismology, geodesy, and frictional modeling. Much of my work focuses on finding the most effective ways to test models of fault slip with laboratory results and geophysical observations. We are always trying to organize the numerous seismic and geodetic data from small slip events in ways that can validate or disprove specific model hypotheses.
View Selected Publications
- J. R. Williams and J. C. Hawthorne, Stress drops on the Blanco oceanic transform fault from interstation phase coherence, Bull. Seis. Soc. Amer., in press, doi: 10.1785/ 0120180319, 2019.
- M. A. Alwahedi and J. C. Hawthorne, Intermediate-magnitude postseismic slip follows intermediate-magnitude (M 4 to 5) earthquakes in California, Geophys. Res. Lett., 46, 3676-3687, doi: 10.1029/ 2018GL081001, 2019.
- C. Tape, S. Holtkamp, V. Silwal, J. Hawthorne, Y. Kaneko, J.-P. Ampuero, N. Ruppert, K. Smith, and M. West, Slow-to-fast earthquake nucleation in the lower crust of central Alaska. Nature Geoscience, 11, 536-541, doi: 10.1038/ s41561-018-0144-2, 2018.
- J. C. Hawthorne and N. M. Bartlow. Observing and modeling the spectrum of a slow slip event. J. Geophys. Res., 123, 5, 4243-4265, doi: 10.1029/ 2017JB015124, 2018.
- Q. Bletery, A M. Thomas, J. C. Hawthorne, R. M. Skarbek, A. W. Rempel, and R. D. Krogstad, Charac- teristics of secondary slip fronts associated with slow earthquakes in Cascadia. Earth. Plan. Sci. Lett., 463, 212-220, doi: 10.1016/ j.epsl.2017.01.046, 2017.
- J. C. Hawthorne and J.-P. Ampuero. A phase coherence approach to identifying co-located earthquakes and tremor. Geophys. J. Intl., 209, 623-642, doi: 10.1093/ gji/ ggx012, 2017.
- J. C. Hawthorne, J.-P. Ampuero, and M. Simons. A method for calibration of local magnitude scale based on relative spectral amplitudes, and application to the San Juan Bautista, CA area. Bull. Seis. Soc. Amer., 107, 85-96, doi: 10.1785/ 0120160141, 2017.
- J. C. Hawthorne, M. G. Bostock, A. A. Royer, and A. M. Thomas. Variations in slow slip moment rate associated with rapid tremor reversals in Cascadia. Geochem., Geophys., Geosyst., 17, 4899-4919, doi: 10.1002/ 2016GC006489, 2016.
- J. C. Hawthorne, M. Simons, and J.-P. Ampuero. Estimates of the magnitude of aseismic slip associated with small earthquakes near San Juan Bautista, CA. J. Geophys. Res., doi: 10.1002/ 2016JB013120, 2016.
- J. C. Hawthorne and A. M. Rubin. Laterally propagating slow slip events in a rate and state friction model with a velocity-weakening to velocity-strengthening transition. J. Geophys. Res., 118, 3785-3808, doi: 10.1002/ jgrb.50261, 2013.
- J. C. Hawthorne and A. M. Rubin. Short-time scale correlation between slow slip and tremor in Cascadia. J. Geophys. Res., 118, 1316-1329, doi: 10.1002/ jgrb.50103, 2013.
- J. C. Hawthorne and A. M. Rubin. Tidal modulation and back-propagating fronts in slow slip events simulated with a velocity-weakening to velocity-strengthening friction law. J. Geophys. Res., 118, 1216-1239, doi: 10.1002/ jgrb.50107, 2013.
- S. Long, N. McQuarrie, T. Tobgay, and J. Hawthorne. Quantifying internal strain and deformation temperature in the eastern Himalaya, Bhutan: Implications for the evolution of strain in thrust sheets. J. Structural Geology, 33, 579-608, doi: 10.1016/ j.jsg.2010.12.011, 2011.
- J. C. Hawthorne and A. M. Rubin. Tidal modulation of slow slip in Cascadia. J. Geophys. Res., 115, B09406, doi: 10.1029/ 2010JB007502, 2010.
- F. J. Simons, J. C. Hawthorne, and C. D. Beggan. E cient analysis and representation of geophysical processes using localized spherical basis functions. Proc. of SPIE, 7446, doi: 10.1117/ 12.825730, 2009.
- Hoink, C.-T. A. Lee, J. C. Hawthorne, and A. Lenardic. Paleo-viscometry of magma bodies. Earth and Planetary Science Letters, 267, 100-106, doi: 10.1016/ j.epsl.2007.11.046, 2008.