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CV


Ethan F. Williams

Ph.D. Candidate in Geophysics
Seismological Laboratory
California Institute of Technology
Office:
    358 South Mudd
Mail:
    M/S 252-21
    1200 E. California Blvd.
    Pasadena, CA 91125
Email:
    efwillia (at) caltech.edu
Google Scholar

Journal Articles:

  1. Williams, E.F., T.H. Heaton, Z. Zhan, and V.R. Lambert (2022) Variability in the natural frequencies of a nine-story concrete building from seconds to decades. The Seismic Record 2 (4), pp. 237-247.
  2. Fang, J., Y. Yang, Z. Shen, E. Biondi, X. Wang, E.F. Williams, M.W. Becker, D. Eslamian, and Z. Zhan (2022) Directional sensitivity of DAS and its effect on Rayleigh-wave tomography: A case study in Oxnard, California. Seismological Research Letters, in press.
  3. Biondi, E., X. Wang, E.F. Williams, and Z. Zhan (2022) Geolocalization of large-scale DAS channels using a GPS-tracked moving vehicle. Seismological Research Letters, in press.
  4. Williams, E.F., Z. Zhan, H.F. Martins, M.R. Fernandez-Ruiz, S. Martin-Lopez, M. Gonzalez-Herraez, and J. Callies (2022) Surface gravity wave interferometry and ocean current monitoring with ocean-bottom DAS. Journal of Geophysical Research: Oceans, 127 (5), e2021JC018375.
  5. Yang, Y., J.W. Atterholt, Z. Shen, J.B. Muir, E.F. Williams, and Z. Zhan (2022) Sub-kilometer correlation between near-surface structure and ground motion measured with distributed acoustic sensing. Geophysical Research Letters, 49, e2021GL096503.
  6. Wang, X., Z. Zhan, E.F. Williams, M. Gonzalez-Herraez, H.F. Martins, and M. Karrenbach (2021) Ground vibrations recorded by fiber-optic cables reveal traffic response to COVID-19 lockdown measures in Pasadena, California. Communications Earth & Environment 2 (160).
  7. Williams, E.F., M.R. Fernandez-Ruiz, R. Magalhaes, R. Vanthillo, Z. Zhan, M. Gonzalez-Herraez, and H.F. Martins (2021) Scholte wave inversion and passive source imaging with ocean-bottom DAS. The Leading Edge 40 (8), pp. 576-583.
  8. Li, Z., Z. Shen, Y. Yang, E.F. Williams, X. Wang, and Z. Zhan (2021) Rapid response to the 2019 Ridgecrest earthquake with distributed acoustic sensing. AGU Advances 2, e2021AV000395.
  9. Wang, X., E.F. Williams, M. Karrenbach, M. Gonzalez-Herraez, H.F. Martins, and Z. Zhan (2020) Rose Parade seismology: Signatures of floats and bands on optical fiber. Seismological Research Letters 91, pp. 2395-2398.
  10. Williams, E.F., M.R. Fernandez-Ruiz, R. Magalhaes, R. Vanthillo, Z. Zhan, M. Gonzalez-Herraez, and H.F. Martins (2019) Distributed sensing of microseisms and teleseisms with submarine dark fibers. Nature Communications 10 (5778). [EarthArXiv]
  11. Gurnis, M., H. Van Avendonk, S.P.S. Gulick, J.M. Stock, R. Sutherland, E. Hightower, B. Shuck, J. Patel, E.F. Williams, D. Kardell, E. Herzig, B. Idini, K. Graham, J. Estep, and L. Carrington (2019) Incipient subduction at the contact with stretched continental crust: the Puysegur Trench. Earth and Planetary Science Letters 520, pp. 212-219.
  12. Williams, E.F., C.M. Castillo, S.L. Klemperer, N. Raineault, and L. Gee (2018) Sycamore Knoll: A wave-planed pop-up structure in a sinistral-oblique thrust system, Southern California Continental Borderland. Deep Sea Research, Part II: Topical Studies in Oceanography 150, pp. 132-145.

Expanded Abstracts:

  1. Karrenbach, M., Z. Shen, Z. Li, S. Cole, E.F. Williams, A. Klesh, X. Wang, Z. Zhan, L. LaFlame, V. Yartsev, and V. Bogdanov (2020) Rapid deployment of distributed acoustic sensing systems to track earthquake activity. SEG Technical Program Expanded Abstracts 2020, p. 490-494.
  2. Fernandez-Ruiz, M.R., E.F. Williams, R. Magalhaes, R. Vanthillo, L. Costa, Z. Zhan, S. Martin-Lopez, M. Gonzalez-Herraez, and H.F. Martins (2019) Teleseism monitoring using chirped-pulse ΦOTDR. Seventh European Workshop on Optical Fibre Sensors 1119921.
  3. Martins, H.F., M.R. Fernandez-Ruiz, L. Costa, E.F. Williams, Z. Zhan, S. Martin-Lopez, and M. Gonzalez-Herraez (2019) Monitoring of remote seismic events in metropolitan area fibers using distributed acoustic sensing (DAS) and spatiotemporal signal processing. Optical Fiber Communication Conference M2J.1.

Review Papers:

  1. Fernandez-Ruiz, M.R., H.F. Martins, E.F. Williams, C. Becerril, R. Magalhaes, L.D. Costa, S. Martin-Lopez, S. Jia, Z. Zhan, and M. Gonzalez-Herraez (2022) Seismic monitoring with distributed acoustic sensing from the near-surface to the deep oceans. Journal of Lightwave Technology 40 (5), pp. 1453-1463.
  2. Fernandez-Ruiz, M.R., M.A. Soto, E.F. Williams, S. Martin-Lopez, Z. Zhan, M. Gonzalez-Herraez, and H.F. Martins (2020) Distributed acoustic sensing for seismic activity monitoring. APL Photonics 5 (3), 030901.

Other Publications:

  1. Williams, E.F. (2022) Listening to the seafloor through optical fibers. Physics Today 75 (10), pp. 70-71.
  2. Williams, E.F. and E.R. Martin (2016) Detection and removal of coherent anthropogenic noise from passive seismic data. SEP Report 165, pp. 153-164.

Invited Talks:

  1. 2022-10 "Large-N and large-T seismology with structural vibrations." Caltech Seismo Lab Seminar
  2. 2022-09 "Large-N and large-T seismology with structural vibrations." USGS Earthquake Science Center seminar
  3. 2021-10 "Applications of ocean-bottom DAS for offshore engineering and hazard analysis." NHERI@UTexas Workshop on DAS for Infrastructure Engineering and Subsurface Imaging

Conference Presentations:

  1. (Invited) Williams, E.F., T.H. Heaton, Z. Zhan, and V. Lambert (2022) Continuous seismic monitoring of a building over 20 years. Talk, SSA Annual Meeting, April 2022.
  2. (Invited) Williams, E.F. and Z. Zhan (2022) Understanding and exploiting ocean waves in DAS data. Talk, SSA Annual Meeting, April 2022.
  3. Biondi, E., W. Zhu, E.F. Williams, J. Li, and Z. Zhan (2022) High-resolution eikonal traveltime tomography of the Long Valley Caldera using distributed acoustic sensing. Talk, SSA Annual Meeting, April 2022.
  4. Fang, J., Y. Yang, Z. Shen, E. Biondi, X. Wang, E.F. Williams, M. Becker, D. Eslamian, and Z. Zhan (2022) Directional sensitivity of DAS and its effect on Rayleigh wave tomography. Poster, SSA Annual Meeting, April 2022.
  5. Li, J., Z. Zhan, E. Biondi, and E.F. Williams (2022) Back-projection imaging of the 2021 Antelope Valley M6.0 earthquake using distributed acoustic sensing. Talk, SSA Annual Meeting, April 2022.
  6. Yang, Y., J. Atterholt, Z. Shen, J.B. Muir, E.F. Williams, and Z. Zhan (2021) Urban seismic hazard mapping with distributed acoustic sensing. Poster, AGU Fall Meeting, December 2021.
  7. Fang, J., Y. Yang, Z. Shen, E. Biondi, X. Wang, E.F. Williams, M. Becker, D. Eslamian, and Z. Zhan (2021) Imaging the shallow subsurface underneath the City of Oxnard with telecom cables. Talk, AGU Fall Meeting, December 2021.
  8. Shen, Z., Z. Zhan, Y. Yang, and E.F. Williams (2021) High-resolution seismic velocity response to subsurface hydrology with distributed acoustic sensing. Talk, AGU Fall Meeting, December 2021.
  9. Williams, E.F., H.F. Martins, M.R. Fernandez-Ruiz, Z. Shen, S. Martin-Lopez, M. Gonzalez-Herraez, and Z. Zhan (2020) Ocean surface gravity wave interferometry with seafloor DAS. Poster, AGU Fall Meeting, December 2020.
  10. Shen, Z., Z. Li, Z. Zhan, X. Wang, E.F. Williams, and M. Karrenbach (2020) High-resolution foreshock evolution of the 2020 Mw5.8 Owens Lake earthquake illuminated with Olancha DAS array. Poster, AGU Fall Meeting, December 2020.
  11. Williams, E.F., Z. Zhan, V. Lambert, and Y. Zhang (2019) Time-lapse shear-wave velocity profiling in urban pasadena with a fiber seismic network. Talk, AGU Fall Meeting, December 2019.
  12. Robo, E.T., C.R. Labedz, E.F. Williams, A. Klesh, M.P. Panning, A. Marandi, and Z. Zhan (2019) DAS on Ice: insights gained from deploying several kilometers of fiber optic cable on Taku Glacier, Alaska. Poster, AGU Fall Meetings, December 2019.
  13. Li, Z., Z. Zhan, E.F. Williams, and A. Klesh (2019) Monitoring aftershocks of the 2019 Ridgecrest earthquakes with DAS arrays. Poster, AGU Fall Meeting, December 2019.
  14. Williams, E.F., Z. Zhan, Z. Li, M. Karrenbach, T. Coleman, A. Klesh, S. Cole, L. LaFlame, and V. Yartsev (2019) Aftershocks of the Ridgecrest earthquake sequence on four dense fiber seismic arrays. Poster, SCEC Annual Meeting, September 2019.
  15. Zhang, Y., E.F. Williams, V.R. Lambert, and Z. Zhan (2019) Updating the Caltech Millikan Shaker for time-lapse seismic imaging in Southern California. Poster, SCEC Annual Meeting, September 2019.
  16. Williams, E.F., M.R. Fernandez-Ruiz, H.F. Martins, Z. Zhan, M. Gonzalez-Herraez, R. Vanthillo, and R. Magalhaes (2019) Teleseisms and microseism generation observed by an ocean-bottom distributed acoustic sensing array offshore Belgium. Talk, SSA Annual Meeting, April 2019.
  17. Williams, E.F., Z. Zhan, M. Karrenbach, S. Cole, L. LaFlame, H.F. Martins, and M. Gonzalez-Herraez (2019) High-resolution mapping and monitoring of shallow shear-wave velocity in urban Pasadena with Distributed Acoustic Sensing Poster, SSA Annual Meeting, April 2019.
  18. Williams, E.F., Z. Zhan, M. Karrenbach, S. Cole, and L. LaFlame (2018) Dense mapping of shallow velocity structure in the Raymond Basin using the Pasadena Distributed Acoustic Sensing Array. Poster, SCEC Annual Meeting, September 2018.
  19. Williams, E.F., C.M. Castillo, S.L. Klemperer, N. Raineault, and L. Gee (2017) A new estimate of latest Quaternary slip on the Anacapa-Dume Fault at Sycamore Knoll, Southern California Continental Borderland. Poster, SCEC Annual Meeting, September 2017.
  20. Williams, E.F., E.R. Martin, B. Biondi, N.J. Lindsey, J.B. Ajo-Franklin, A.M. Wagner, K.L. Bjella, T.M. Daley, S. Dou, B.M. Freifeld, M. Robertson, and C. Ulrich (2016) Quality of Green's functions improved by automatic detection and removal of coherent anthropogenic noise. Poster, AGU Fall Meeting, December 2016.
  21. Castillo, C.M., S.L. Klemperer, E.F. Williams, M.R. Legg, and R.D. Francis (2015) Tsunamogenic landslides and marine paleoseismology: applications of the submerged marine terrace record, Santa Catalina Island, Southern California Borderland. Talk, AGU Fall Meeting, December 2015.
  22. Williams, E.F., C.M. Castillo, S.L. Klemperer, K.M. Maher, R.D. Francis, and M. Legg (2015) Preliminary results of marine paleoseismology from MCS, CHIRP, and coring off Catalina Island. Poster, SCEC Annual Meeting, September 2015.