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    Small Earthquake Science @ the University of Oregon

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    Small Earthquake Science @ the University of Oregon

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    Small Earthquake Science @ the University of Oregon

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    Small Earthquake Science @ the University of Oregon

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    Small Earthquake Science @ the University of Oregon

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    Small Earthquake Science @ the University of Oregon


We are a group of earthquake seismologists and active tectonicists interested in the physical properties of faults, seismotectonics, crustal deformation, and the mechanics of earthquakes and faulting. We use a variety of tools, such as moment tensor inversion, waveform modeling, analysis of seismicity catalogs, and numerical models of fault friction to approach research questions. We reside in the Department of Earth Sciences at the University of Oregon. Active research projects and interests include

  • Earthquake source physics
  • Rheology of deep fault zones
  • Fluids and faulting
  • Seismotectonics of northern California and the Pacific Northwest
  • Nodal seismic deployments
  • Machine Learning
  • Earthquake hazards
  • Volcano Seismology

What we do

company 4
company 1
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Amanda Thomas


Cyril Journeau

Postdoctoral Researcher

Loic Bachelot

Data Scientist

Avery Conner

PhD Student

Brenton Hirao

PhD Student

Yu-sheng Sun

PhD Student

Renee Nassif

PhD Student


Motivational Speaker



Tyler Newton

Scientist @ Epitel

Tim Lin

Postdoc @ LLNL

Khurram Aslam

Scientist @ Air Worldwide

Jonathan Delph

Assistant Prof. @ Purdue

Quentin Bletery

IRD à Géoazur

Geena Littel

PhD Student @ UBC

Alex Babb

Whereabouts Unknown


Exxon Mobil


  1. Thomas, A. M., D. Melgar, S. N. Dybing, and J. Searcy (2023) Deep learning for denoising High-Rate Global Navigation Satellite System data. In production in Seismica.
  2. Delph, J., A. M. Thomas, A. C. Stanciu, K. Aslam, A. Chatterjee, V. Sassard (2023) SCENTAR: A high-density nodal array to study the structure and seismogenic behavior of the southern Cascadia forearc. Seismological Research Letters. doi: 10.1785/0220220251.
  3. Dumont, S., S. Custódio, S. Petrosino, A. M. Thomas, G.Sottili (2022) A Tidal Journey Through Earth’s History Chapter 17: Tides, Earthquakes and Volcanic eruptions. Elsevier. doi: 10.1016/C2020-0-02539-9.
  4. Zhang, H., M. Glasgow, B. Schmandt, W. A. Thelen, S. C. Moran, and A. M. Thomas (2022) Revisiting the depth distribution of seismicity before and after the 2004–2008 eruption of Mount St. Helens. Journal of Volcanology and Geothermal Research. doi: 10.1016/j.jvolgeores.2022.107629.
  5. Melgar, D. V. Sahakian, and A. M. Thomas (2022) Deep Coseismic Slip in the Cascadia Megathrust can be Consistent with Coastal Subsidence. Geophysical Research Letters. doi: 10.1029/2021GL097404. [PDF]
  6. Inbal, A., A. M. Thomas, T. J. Newton, and R. Burgmann (2021) Complex Migration of Tremor near Cholame, CA, Resolved by Seismic Array Analysis. JGR-Solid Earth. doi: 10.1029/2021JB022174. [PDF]
  7. Aslam, K., A. M. Thomas, and D. Melgar (2021) The effect of Fore-arc Deformation on Shallow Earthquake Rupture behavior in the Cascadia Subduction Zone. Geophysical Research Letters. doi: 10.1029/2021GL093941. [PDF]
  8. Lin, J.-T., D. Melgar, A. M. Thomas, and J. Searcy (2021) Early warning for great earthquakes from characterization of crustal deformation patterns with deep learning. JGR-Solid Earth. doi: 10.1029/2021JB022703. [PDF]
  9. Ramos, M., Y. Huang, T. Ulrich, D. Li., A.-A. Gabriel, and A. M. Thomas (2021) Assessing Margin-Wide Rupture Behaviors along the Cascadia Megathrust with 3-D Dynamic Rupture Simulations. JGR-Solid Earth. doi: 10.1029/2021JB022005. [PDF]
  10. Thomas, A. M., A. Inbal, J. Searcy, D. R. Shelly, and R. Burgmann (2021) Identification of low-frequency earthquakes on the San Andreas fault with deep learning. Geophysical Research Letters. doi: 10.1029/2021GL093157. [PDF]
  11. Hughes, L., C. J. Chamberlain, J. Townend, and A. M. Thomas (2021) A Repeating Earthquake Catalog from 2003 to 2020 for the Raukumara Peninsula, Northern Hikurangi Subduction Margin, New Zealand. G-Cubed. doi: 10.1029/2021GC009670. [PDF]
  12. Klimasewski, A., V. J. Sahakian, and A. M. Thomas (2021) Comparing artificial neural networks with traditional ground-motion models for small-magnitude earthquakes in Southern California. Bulletin of the Seismological Society of America. doi: 10.1785/0120200200. [PDF]
  13. Delph, J., A. M. Thomas, and A. Levander (2021) Subcretionary tectonics: Linking variability in the expression of subduction along the Cascadia forearc. Earth and Planetary Science Letters. doi: 10.1016/j.epsl.2020.116724. [PDF]
  14. Dunham, E. M., A. M. Thomas, T. Becker, et al. (2020) Modeling Collaboratory for Subduction RCN Megathrust Modeling Workshop Report. doi: 10.31223/X5730M. [PDF]
  15. Newton, T. J. and A. M. Thomas (2020) Stress orientations in the Nankai Trough constrained using seismic and aseismic slip. JGR-Solid Earth. doi: 10.1029/2020JB019841. [PDF]
  16. Lin, J.-T., K. Aslam, A. M. Thomas, and D. Melgar (2020) Overlapping regions of coseismic and transient slow slip on the Hawaiian décollement. Earth and Planetary Science Letters. doi: 10.1016/j.epsl.2020.116353. [PDF]
  17. Wech, A. G., W. A. Thelen, and A. M. Thomas (2020) Deep long-period earthquakes generated by second boiling beneath Mauna Kea volcano. Science. doi: 10.1126/science.aba4798. [PDF]
  18. Thomas, A. M., Z. Spica, M. Bodmer, W. H. Schultz, and J. R. Roering (2020) Using a dense seismic array to determine resonances and structure of the Two Towers earthflow in Northern California. Seismological Research Letters. doi: 10.1785/0220190206. [PDF]
  19. Goldberg, D. E., D. Melgar, V. J. Sahakian, A. M. Thomas, X. Xu, J. Geng, and B. W. Crowell (2020) Complex Rupture of an Immature Fault Zone: A Simultaneous Kinematic Model of the 2019 Ridgecrest, CA Earthquakes. Geophysical Research Letters. doi:10.1029/2019GL086382. [PDF]
  20. Lin, J.-T., W. Chang, D. Melgar, A. M. Thomas, and C. Chiu (2019) Quick Determination of Earthquake Source Parameters from GPS Measurements: Cases of Taiwan Earthquakes. Geophysical Journal International. doi: 10.1093/gji/ggz359. [PDF]
  21. Hawthorne, J. C., A. M. Thomas, and J.-P. Ampuero (2019) The rupture extent of low frequency earthquakes near Parkfield, CA. Geophysical Journal International. doi: 10.1093/gji/ggy429. [PDF]
  22. Littel, G., A. M. Thomas, and A. S. Baltay (2018) Using tectonic tremor to constrain seismic-wave attenuation in Cascadia. Geophysical Research Letters.doi: 10.1029/2018GL079344. [PDF]
  23. Parker, L., C. H. Thurber, X. Zeng, P. Li, N. Lord, D. Fratta, H. F. Wang, M. Robertson, A. M. Thomas, M.Karplus, A. Nayak, and K. L. Feigl (2018) Active-Source Seismic Tomography at the Brady Geothermal Field, Nevada, with Dense Nodal and Fiber-Optic Seismic Arrays. Seismological Research Letters. doi: 10.1785/0220180085. [PDF]
  24. Beeler, N. M., A. M. Thomas, R. Burgmann, and D. R. Shelly (2018) Constraints on friction, dilatancy, diffusivity, and effective stress from low-frequency earthquake rates on the deep San Andreas Fault. JGR-Solid Earth. doi: 10.1002/2017JB015052. [PDF]
  25. Thomas, A. M., N. M. Beeler, Q. Bletery, R. Burgmann, and D. R. Shelly (2018) Using low frequency earthquake families on the San Andreas fault as deep creepmeters. JGR-Solid Earth.doi: 10.1002/2017JB014404. [PDF]
  26. Bletery, Q., A. M. Thomas, A. W. Rempel, and J. L. Hardebeck (2017) Imaging shear strength along subduction faults. Geophysical Research Letters. doi: 10.1002/2017GL075501. [PDF]
  27. Bletery, Q., A. M. Thomas,, J. C. Hawthorne, R. M. Skarbek, A. W. Rempel, and R. D. Krogstad (2017) Characteristics of secondary slip fronts associated with slow earthquakes in Cascadia. Earth and Planetary Science Letters doi:10.1016/j.epsl.2017.01.046. [PDF]
  28. Bostock, M. G., A. M. Thomas, A. M. Rubin, and N. I. Christensen (2017) On corner frequencies, attenuation, and low-frequency earthquakes. JGR-Solid Earth. doi:10.1002/2016JB013405. [PDF]
  29. Hawthorne, J. C., M. G. Bostock, A. Royer, and A. M. Thomas (2016) Variations in slow slip moment rate associated with rapid tremor reversals in Cascadia. G-Cubed. doi:10.1002/2016GC006489. [PDF]
  30. Bletery, Q., A. M. Thomas, A. W. Rempel, L. Karlstrom, A. Sladen and L. De Barros (2016) Mega-earthquakes rupture flat megathrusts. Science. doi:10.1126/science.aag0482. [PDF]
  31. Thomas, A. M., G. C. Beroza and D. R. Shelly (2016) Constraints on the Source Parameters of Low-Frequency Earthquakes on the San Andreas Fault. Geophysical Research Letters. doi:10.1002/2015GL067173. [PDF]
  32. Beeler, N. M., G. H. Hirth, A. M. Thomas, and R. Burgmann (2016) Effective stress, friction and deep crustal faulting. JGR-Solid Earth. doi:10.1002/2015JB012115. [PDF]
  33. Bostock, M. G., A. M. Thomas, G. Savard, L. Chuang, and A. Rubin (2015) Magnitudes and moment-duration scaling of low-frequency earthquakes beneath southern Vancouver Island. JGR-Solid Earth. doi:10.1002/2015JB012195. [PDF]
  34. Thomas, A. M. and M. G. Bostock (2015) Identifying low-frequency earthquakes in central Cascadia using cross-station correlation. Tectonophysics. doi:10.1016/j.tecto.2015.07.013. [PDF]
  35. Kyriakopoulos, C., A. V. Newman, A. M. Thomas, M. Moore-Driskell, and G. T. Farmer (2015) A new seismically constrained subduction interface model for Central America. JGR-Solid Earth. doi:10.1002/2014JB011859. [PDF]
  36. Plourde, A., M. G. Bostock, P. Audet, and A. M. Thomas (2015) Low-frequency earthquakes at the southern Cascadia margin. Geophysical Research Letters. doi:10.1002/2015GL064363. [PDF]
  37. Royer, A., A. M. Thomas, and M. G. Bostock (2014) Tidal Modulation of Low Frequency Earthquakes and triggering of secondary events in Northern Cascadia. JGR-Solid Earth. doi:10.1002/2014JB011430. [PDF]
  38. Thurber, C. H., X. Zeng, A. M. Thomas and P. Audet (2014) Phase-Weighted Stacking Applied to Low-Frequency Earthquakes. Bulletin of the Seismological Society of America. doi:10.1785/0120140077. [PDF]
  39. Culha, C., A. Hayes, M. Manga, and A. M. Thomas (2014) Double ridges on Europa accommodate some of the missing surface contraction. JGR-Planets. doi:10.1002/2013JE004526. [PDF]
  40. Beeler, N. M., A. M. Thomas, R. Burgmann, and D. R. Shelly (2013) Inferring fault rheology from low frequency earthquakes on the San Andreas fault. JGR-Solid Earth. doi:10.1002/2013JB010118. [PDF]
  41. Thomas, A. M., R. Burgmann, and D. S. Dreger (2013) Incipient faulting near Lake Pillsbury, CA and the role of accessory faults in plate boundary evolution. Geology. doi:10.1130/G34588.1 [PDF]
  42. Thomas, A. M. (2013) Fact or friction: Inferring rheology from low-frequency earthquakes on the San Andreas fault. UC-Berkeley PhD Dissertation.
  43. McLaskey, G. C., A. M. Thomas, S. D. Glaser, R. M. Nadeau (2012) Fault healing promotes high frequency earthquakes in the laboratory and on natural faults. Nature. doi:10.1038/nature11512. [PDF]
  44. Thomas, A. M., R. Burgmann, D. R. Shelly, N. M. Beeler, and M. L. Rudolph (2012) Tidal sensitivity of low frequency earthquakes near Parkfield, CA: implications for fault mechanics within the brittle-ductile transition. JGR-Solid Earth. doi:10.1029/2011JB009036 [PDF]
  45. Thomas, A.M., R. M. Nadeau, and R. Burgmann (2009) Tremor-tide correlations and near-lithostatic pore pressure on the deep San Andreas fault. Nature. doi:10.1038/nature08654 [PDF]
  46. Ghosh, A., A. V. Newman, A. M. Thomas, and G. T. Farmer (2008) Interface locking along the subduction megathrust from b-value mapping near Nicoya Peninsula, Costa Rica. Geophysical Research Letters. doi:10.1029/2007GL031617 [PDF]


If you're trying to decide which graduate school you'd like to attend, here are some reasons why you should choose the University of Oregon in Eugene.

Earthquake Seismology @ UO

My group works on problems in seismology, fault mechanics, active tectonics, etc. Additionally, our department hosts one of the largest geophysics programs in the country. If you're interested in attending graduate school in earthquake seismology at UO please send me an email with a copy of your CV and a statement of why you're interested in working with me. I'm particularly interested in taking students that have ideas of what they'd like to work on and why we'd be a good fit.

Earth Sciences @ UO

The University of Oregon's Department of Earth Sciences is among the top geoscience programs in the world. Our faculty members are nationally and internationally recognized leaders in their fields. We're a big department, but we're not too big. You'll still have regular meetings with your advisor(s), have the chance to interact with all faculty members, and there's a healthy graduate community to support you in your research endeavors. Recent graduates go on to postdoctoral positions, faculty jobs, and the private sector.


Eugene is a big-small town centered around the University of Oregon. With a population of approximately 150,000 it has all the conveniences of a larger city (e.g. restaurants, airport, etc.) without the traffic or the crowds. After living here for a few years my observations are that it sometimes rains, the softball leagues are very competitive, and some parts of town (and the people that live in them) are stuck in the 1970s. Also, the views of the Cascades, especially the Three Sisters volcanoes, do not get old.


Oregon is wild, beautiful, and unspoiled. An hour drive west of Eugene is the breathtaking Oregon coast where you can fish, surf, and eat local all in a day trip. You'll likely have whatever beach you choose to visit to yourself. An hour to the east are the Oregon Cascades. Both downhill and cross country skiing are slightly over an hour away. Two hours north, you'll find Portland, OR. A beer and hipster mecca, you'll need to make a pilgrimage north at some point, if not for Portland itself, to ski above the clouds at Mt. Hood or tour the spectacular waterfalls of the Columbia River Gorge. Two plus hours south is Crater Lake National Park.



Amanda M. Thomas
Associate Professor
Department of Earth Sciences
1272 University of Oregon
Eugene, OR 97403
Office: Cascade 210C
Email: amt.seismo@gmail.com