Welcome!

I am the GPS Chair’s Prize Postdoctoral Fellow at the California Institute of Technology. I completed my PhD in Geophysics at Géoazur, Université Côte d’Azur, in May 2019.

My research aims at better understanding the deformation of the shallow parts of the Earth on multiple temporal and spatial scales, from the displacement induced a few seconds to days before, during and after an earthquake to the long-term interaction of fault networks. I am particularly interested in modeling or simulating earthquakes and faults behavior.
These last few years, I focused on source estimation problems, using probabilistic approaches to decipher the robust characteristics, or the uncertainties, of our models. I also use stochastic methods to study recent large earthquakes. Finally, I am also interested in how faults interact with each other and how their geometry impacts the deformation.

You can find me in my office in the Seismological Laboratory building:
Office 262 | South Mudd building
Caltech Seismo Lab | GPS Division
1200 E. California Blvd., 252-21 | Pasadena, CA 91125, USA

You can also reach me via:
tragon (at) caltech.edu

Latest News

• December 2021: Our AGU session on the earthquake source has been amazing! Many thanks to the presenters and many attendees, both online and in person, that made it possible! Recordings are available on the AGU website until February 2022. If you cannot access a presentation, please reach out to me, another convener or the presenter.

• November 2021: Our paper on the evolution of the northern Turkana Depression (EARS), as seen from the interpretation of seismic reflection and field analyses, is now published in EPSL! Key result: we show that a regional-scale migration of the locus of brittle deformation promotes the concomitant development of post-tectonic (sag) and syn-tectonic deformations.

• November 2021: My recent seminar at Isterre, Grenoble, has been recorded: video is here, with the first few minutes missing

• September 2021: Glad to have given the first seminar of the year at the geological lab of ENS Paris!

• June 2021: Our session proposal for AGU 2021 has been accepted! Please consider submitting abstracts to S023- State-of-the-art observations and modeling of earthquake source processes, convened with Alice Gabriel, Elisa Tinti and Yoshihiro Kaneko.

• June 2021: I am participating to the Pylith 2021 Hackathon!

• March 2021: I gave a Mardi Séisme seminar at Géoazur, Nice. You can find the recording of my talk on their youtube chanel: How to hamper the effect of Earth’s structure approximations on on-fault deformation estimates?

• January 2021: Our work on uncertainties in fault geometry is amongst the 14 most cited articles of GJI in 2020!

• December 2020: Our Bayesian analysis of the 2020 Elazığ Mw6.8 earthquake (Turkey) based on geodetic data is now published in GRL! Free access link

• December 2020: Our AGU20 session is live! Live Modeling and imaging complex earthquake ruptures session is Saturday, 12 December from 4 to 6:30pm PST. Presentations are available online:
  • S042 oral presentations on numerical simulations
  • S043 oral session on observation-based modeling
  • S036 posters on numerical simulations
  • S037 posters on observation-based modeling

  Questions and discussions, during and following the meeting, are encouraged in the slack workspace dedicated to the session - if interested, ask for the link!

• November 2020: Our work on Accounting for uncertain 3D elastic structure in fault slip estimates is now out in GJI.

• November 2020: A. Nutz’s work on the Plio-Pleistocene sedimentation in West Turkana (Kenya, EARS): Paleolake fluctuations, paleolandscapes and controlling factors is now out in Earth Science Reviews.

• October 2020: Alexis Nutz will present Plio-pleistocene paleoenvironments in West Turkana (East African Rift System, Kenya) at the GSA Meeting - 10/29 at 7:15pm.

• September 2020: Our work on the stochastic view of the 2020 Elazığ Mw 6.8 earthquake (Turkey) is available as a Preprint

• August 2020: Our work on Bayesian estimate of interseismic slip deficit of the East and North Anatolian faults (Turkey) is now published in GRL

• July 2020: Our work on the impact of topography on slip estimates is now published in Tectonophysics. We notably show that topography can largely affect slip models even when using geodetic data only, and that zeroth-order corrections are not sufficient to account for induced biases. Link to journal

• June 2020: Our session proposal for AGU 2020 has been accepted! Please consider submitting abstracts to S016 - Modeling and imaging complex earthquake ruptures, co-convened with Ryo Okuwaki, Wenyuan Fan and Dara Goldberg.

• March 2020: Q. Bletery et al. propose a Bayesian estimate of interseismic slip deficit of the East and North Anatolian faults (Turkey). Preprint available!

• February 2020: Our work on topography is now available as a preprint! Check it out: Impact of topography on static slip estimates Free access link

• December 2019: Our work at the 2019 AGU Fall meeting:
  • Don’t miss our session on Resolving the Complexity of Earthquake Processes convened with Kurama Okubo, Ryo Okuwaki, Wenyuan Fan and Harsha Bhat. Oral session on Thursday morning 10:20 - 12:20, and posters on Friday morning!
  • I will present how early afterslip impacts our co-seismic and post-seismic models in the session T13D. Come have a look at my poster the Monday afternoon!
  • Leah Langer will present our work about the impact of topography on static slip estimates, in the same poster session.
• October 2019: Alexis Nutz presented our work about the rifting of the northern Turkana Depression (Kenya, EARS), at the French Association of Sedimentologists annual meeting.