David Shelly

I use seismic waveforms, typically recorded at or near the surface, to infer physical processes associated with active faulting.  Recent interests include earthquake swarms (and associated fluid-faulting interactions) and tectonic tremor.  To gain insight into these processes, I have worked to develop new techniques for earthquake detection, source location, and focal mechanism determination.


I earned my Ph.D. from Stanford University in 2007, focused on understanding the mechanism of "non-volcanic tremor" in the Nankai subudction zone.  After finishing my Ph.D., I was a Miller Postdoctoral Fellow at UC Berkeley and a Mendenhall Postdoctoral Fellow in the USGS Earthquake Science Center. I am now a member of the USGS Volcano Science Center in Menlo Park.

In general, I'm working maximize the information we can obtain from seismic records of faulting processes, which are combined with other available constraints (e.g. geodetic, geologic, geochemical) to understand what these seismic signals can tell us about physical (tectonic, hydrothermal, and/or magmatic) processes in the subsurface.

Download CV (last updated in 2015)



Shelly, D. R. (2017), A 15-year catalog of more than 1 million low-frequency earthquakes: tracking tremor and slip along the deep San Andreas Fault, J. Geophys. Res. Solid Earth, 122, doi:10.1002/2017JB014047.

Shelly, D. R., J. L. Hardebeck, W. L. Ellsworth, and D. P. Hill (2016), A new strategy for earthquake focal mechanisms using waveform-correlation-derived relative polarities and cluster analysis: Application to the 2014 Long Valley Caldera earthquake swarm, J. Geophys. Res. Solid Earth, 121, doi:10.1002/2016JB013437.

Shelly, D. R., W. L. Ellsworth, and D. P. Hill (2016), Fluid-faulting evolution in high definition: connecting fault structure and frequency-magnitude variations during the 2014 Long Valley Caldera, California earthquake swarmJ. Geophys. Res. Solid Earth, 121, 1776-1795, doi:10.1002/2015JB012719.  [Supplemental Movie S1Movie S2Movie S3]

Hardebeck, J. L., & D. R. Shelly (2016). Aftershocks of the 2014 South Napa, California, Earthquake: Complex Faulting on Secondary FaultsBulletin of the Seismological Society of America,doi:10.1785/0120150169.

van der Elst, N. J., A. A. Delorey, D. R. Shelly, and P. A. Johnson (2016), Fortnightly modulation of San Andreas tremor and low-frequency earthquakes, PNAS, 113(31), 8601-8605. 

Zeng, X., C. H. Thurber, D. R. Shelly, R. M. Harrington, E. S. Cochran, N. L. Bennington, D. Peterson, B. Guo, and K. McClement (2016) Three-dimensional P- and S-wave velocity structure and low-frequency earthquake locations in the Parkfield, California region, Geophys. J. Int., 206(3), 1574-1585 doi: 10.1093/gji/ggw217. 

Hauksson, E., J. Andrews, A. Plesch, J.H. Shaw, and D. R. Shelly (2016). The 2015 Fillmore Earthquake Swarm and Possible Crustal Deformation Mechanisms near the Bottom of the Eastern Ventura Basin, California. Seismological Research Lettersdoi: 10.1785/0220160020.

Thomas, A. M., G. C. Beroza, and D. R. Shelly (2016), Constraints on the Source Parameters of Low-Frequency Earthquakes on the San Andreas FaultGeophys. Res. Lett., 43, doi:10.1002/2015GL067173

Shelly, D. R., T.’a. Taira, S. G. Prejean, D. P. Hill, and D. S. Dreger (2015), Fluid-faulting interactions: Fracture-mesh and fault- valve behavior in the February 2014 Mammoth Mountain, California, earthquake swarmGeophys. Res. Lett., 42, doi:10.1002/ 2015GL064325. [Supplemental Movie S1]

Shelly, D. R. (2015), Complexity of the deep San Andreas Fault zone defined by cascading tremorNature Geoscience, doi:10/1038/ngeo2335.

Ingebritsen, S. E.D. R. Shelly, P. A. Hsieh, L. E. Clor, P. H. Seward, and W. C. Evans (2015), Hydrothermal response to a volcano-tectonic earthquake swarm, Lassen, CaliforniaGeophys. Res. Lett., 42, doi:10.1002/2015GL065826.

Peng, Z.D. R. Shelly, and W. L. Ellsworth (2015), Delayed Dynamic Triggering of Deep tremor along the Parkfield-Cholame Section of the San Andreas Fault Following the 2014 M6.0 South Napa earthquakeGeophys. Res. Lett., 42, doi:10.1002/2015GL065277.

MontgomeryBrown, E. K., C. Wicks, P. Cervelli, J. O. Langbein, J. Svarc, D. R. Shelly, D. P. Hill, and M. Lisowski (2015), Renewed inflation of Long Valley Caldera, California (2011 to 2014)Geophysical Research Lettersdoi: 10.1002/2015GL064338

Wu, C., R. Guyer, D. R. Shelly, D. Trugman, W. Frank, J. Gomberg, and P. Johnson (2015), Spatial-temporal variation of low-frequency earthquake bursts near Parkfield, CaliforniaGeophysical Journal International202(2), 914-919.

Brocher, T.M., A. S. Baltay, J. L. Hardebeck, F. F. Pollitz, J. R. Murray, A. L. Llenos, D. P. Schwartz, J. L. Blair, D. J. Ponti, J. J. Lienkaemper, V. E. Langenheim, T. E. Dawson, K. W. Hudnut, D. R. Shelly, D. Dreger, J. Boatwright, B. T. Aagaard, D. J. Wald, R. M. Allen, W. D. Barnhart, K. L. Knudsen, B. A. Brooks, and K. M. Scharer, (2015), The M6.0 24 August 2014 South Napa EarthquakeSeism. Res. Lett., 86 (2A), 309-326.

Chamberlain, C. J.D. R. Shelly, J. Townend, and T. A. Stern (2014), Low-frequency earthquakes reveal punctuated slow slip on the deep extent of the Alpine Fault, New Zealand, Geochem. Geophys. Geosyst., 15, 2984–2999, doi:10.1002/2014GC005436.

Lewicki, J. L., G. E. Hilley, D. R. Shelly, J. C. King, J. P. McGeehin, M. Mangan, and W. C Evans (2014), Crustal migration of CO2-rich magmatic fluids recorded by tree-ring radiocarbon and seismicity at Mammoth Mountain, CA, USAEarth and Planetary Science Letters, doi:10.1016/j.epsl.2013.00.832.

Shelly, D. R., D. P. Hill, F. Massin, J. Farrell, R. B. Smith, and T. Taira (2013), A fluid-driven earthquake swarm on the margin of the Yellowstone calderaJ. Geophys. Res. Solid Earth, 118, 4872-4886, doi:10.1002/jgrb.50362.  [Research Highlight in Nature Geoscience]

Shelly, D. R., S. C. Moran, and W. A. Thelen (2013), Evidence for fluid-triggered slip in the 2009 Mount Rainier, Washington earthquake swarmGeophys. Res. Lett., 40, 1506-1512, doi:10.1002/grl.50354.

Beeler, N. M., A. Thomas, R. Bürgmann, and D. R. Shelly (2013), Inferring fault rheology from low-frequency earthquakes on the San Andreas, J. Geophys. Res. Solid Earth, 118, 5976–5990, doi:10.1002/2013JB010118.

Wu, C., D. R. Shelly, J. Gomberg, Z. Peng, and P. Johnson (2013), Long-term changes of inter-event times for regular and low-frequency earthquakes in central CaliforniaEarth and Planetary Science Letters, 368, 144-150, doi:10.1016/j.epsl.2013.03.007.

Johnson, K. M., D. R. Shelly, and A. M. Bradley (2013), Simulations of tremor-related creep reveal a weak crustal root of the San Andreas FaultGeophys. Res. Lett., doi:10.1002/grl.50216.

Hill, D. P., Z. Peng, D. R. Shelly, and C. Aiken (2013), S-wave triggering of tremor beneath the Parkfield, CA, section of the San Andreas Fault by the 2011 Tohoku Japan earthquake: observations and theoryBull. Seismol. Soc. Am., doi:10.1785/0120120114, 103, 1541-1550.

Thomas, A. M., R. Bürgmann, D. R. Shelly, N. M. Beeler, and M. L. Rudolph (2012), Tidal triggering of low frequency earthquakes near Parkfield, California: Implications for fault mechanics within the brittle-ductile transitionJ. Geophys. Res., 117, B05301, doi:10.1029/2011JB009036.

Peng, Z., C. Aiken, D. Kilb, D. R. Shelly, B. Enescu (2012), Listening to the 2011 magnitude 9.0 Tohoku-Oki, Japan earthquakeSeismol. Res. Lett., 83(2), 287-293, doi: 10.1785/gssrl.83.2.287.

Shelly, D. R. and D. P. Hill (2011), Migrating swarms of brittle-failure earthquakes in the lower crust beneath Mammoth Mountain, CaliforniaGeophys. Res. Lett., 38, L20307, doi:10.1029/2011GL049336.

Shelly, D. R. and K. M. Johnson (2011), Tremor reveals stress shadowing, deep postseismic creep, and depth-dependent slip recurrence on the lower-crustal San Andreas fault near Parkfield,Geophys. Res. Lett., L13312, doi:10.1029/2011GL047863.

Shelly, D. R., Z. Peng, D. P. Hill, and C. Aiken (2011), Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakesNature Geoscience,doi:10.1038/NGEO1141.

Daub, E. G., D. R. Shelly, R. A. Guyer, and P. A. Johnson (2011), Brittle and ductile friction and the physics of tectonic tremorGeophys. Res. Lett., doi:10.1029/2011GL046866.

Shelly, D. R.  and J. L. Hardebeck (2010), Precise tremor source locations and amplitude variations along the lower-crustal central San Andreas FaultGeophys. Res. Lett.,  37, L14301, doi:10.1029/2010GL043672.

Shelly, D. R. (2010)Periodic, chaotic, and doubled earthquake recurrence intervals on the deep San Andreas FaultScience, 328, 1385-1388, doi:10.1126/science.1189741. [Full text] [PDF]

Shelly, D. R. (2010), Migrating tremors illuminate deformation beneath the seismogenic San Andreas faultNature, 463, 648-652. doi:10.1038/nature0875.

Peng, Z., D. P. Hill, D. R. Shelly and C. Aiken (2010), Remotely triggered microearthquakes and tremor in central California following the 2010 Mw 8.8 Chile earthquakeGeophys. Res. Lett., 37, L24312.

Rubinstein, J. R., D. R. Shelly, and W. L. Ellsworth (2010), Non-Volcanic Tremor: A Window into the Roots of Fault Zones, in New Frontiers in Integrated Solid Earth Sciences, Springer.

Ryberg, R., Ch. Haberland, G. S. Fuis, W. L. Ellsworth, and D. R. Shelly (2010), Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique,Geophys. J. Int., 183, 1485-1500.

Shelly D. R. (2009), Possible deep fault slip preceding the 2004 Parkfield earthquake, inferred from detailed observations of tectonic tremorGeophys. Res. Lett., 36, L17318, doi:10.1029/2009GL039589.

Shelly, D. R., W. L. Ellsworth, T. Ryberg, C. Haberland, G. S. Fuis, J. Murphy, R. M. Nadeau, and R. Bürgmann (2009), Precise location of San Andreas Fault tremors near Cholame, California using seismometer clusters: Slip on the deep extension of the fault?Geophys. Res. Lett., 36, L01303, doi:10.1029/2008GL036367.

Brown, J. R., G. C. Beroza, S. Ide, K. Ohta, D. R. Shelly, S. Y. Schwartz, W. Rabbel, M. Thorwart, and H. Kao (2009), Deep low-frequency earthquakes in tremor localize to the plate interface in multiple subduction zonesGeophys. Res. Lett., doi:10.1029/2009GL040027.

Brown, J. R., G. C. Beroza, and D. R. Shelly (2008), An autocorrelation method to detect low frequency earthquakes within tremorGeophys. Res. Lett., 35, L16305, doi:10.1029/2008GL034560.

Ide, S., K. Imanishi, Y. Yoshida, G. C. Beroza, and D. R. Shelly (2008), Bridging the gap between seismically and geodetically detected slow earthquakesGeophys. Res. Lett., 35, L10305, doi:10.1029/2008GL034014.

Shelly, D. R., G. C. Beroza, and S. Ide (2007), Complex evolution of transient slip derived from precise tremor locations in western Shikoku, JapanGeochem. Geophys. Geosyst., 8, Q10014, doi:10.1029/2007GC001640.

Shelly, D. R., G. C. Beroza, and S. Ide (2007), Non-Volcanic Tremor and Low Frequency Earthquake SwarmsNature, 446, 305-307, doi:10.1038/nature05666

Ide, S., G. C. Beroza, D. R. Shelly, and T. Uchide (2007), A scaling law for slow earthquakesNature, 447, 76-79, doi:10.1038/nature05780.

Ide, S., D. R. Shelly, and G. C. Beroza (2007), Mechanism of deep low frequency earthquakes: Further evidence that deep non-volcanic tremor is generated by shear slip on the plate interface,Geophys. Res. Lett.34, L03308, doi:10.1029/2006GL028890.

Shelly, D. R., G. C. Beroza, S. Ide, and S. Nakamula (2006), Low-frequency earthquakes in Shikoku, Japan and their relationship to episodic tremor and slipNature, 442, 188-191, doi:10.1038/nature04931.

Shelly, D. R., G.C. Beroza, H. Zhang, C.H. Thurber, S. Ide (2006), High-Resolution Subduction Zone Seismicity and Velocity Structure in Ibaraki, JapanJ. Geophys. Res., 111, B06311, doi:10.1029/2005JB004081.

Segall, P.,  E. K. Desmarais, D. R. Shelly, A. Miklius, and P. Cervelli (2006), Earthquakes triggered by silent slip events on Kilauea volcano, HawaiiNature, 442,  71-74, doi:10.1038/nature04938.

Zhang, H., C. H. Thurber, D. R. Shelly, S. Ide, G. C. Beroza, and A. Hasegawa (2004), High-resolution subducting slab structure beneath Northern Honshu, Japan, revealed by double-difference tomographyGeology, 32, 361-364, doi: 10.1130/G20261.2.