M. Sc. Luc Illien
M. Sc. Luc Illien4.6 Geomorphology
Building F, Room 423
Function and Responsibilities:
- Project manager and scientist for the European Horizon MSCA Doctoral Network EnvSeis
- The impact of earthquakes on the mechanical properties of the shallow subsurface (Non-linear Elasticity and Slow Dynamics)
- Groundwater dynamics and recharge in steep landscapes
- ... and any interactions between these subjects !
My current focus consists in estimating and constraining seismic velocity evolution in various systems and tackle these subjects:
For more information about me: lucillien.com
Since September 2022: Project manager and scientist for the European Horizon Doctoral Network EnvSeis
2018 - 2022: PhD Researcher at the German Research Center for Geosciences (GFZ) under the supervision of Prof. Niels Hovius (Section 4.6 Geomorphology) and Dr. Christoph Sens-Schönfelder (Section 2.4 Seismology)
Research Assistant/Intern positions :
University College London (January 2018 - June 2018), Seismological Laboratory
University College London (January 2017 - August 2017), Seismological Laboratory
GFZ Potsdam (March 2016 - December 2016), Geomorphology SectionGeosciences Rennes (Summer 2015), Quantitative Geomorphology Team
2018: M. Sc. in Geophysics (Solid Earth Speciality), Institut Physique du Globe de Paris (IPGP).
2018: Graduate Diploma in Geosciences from Ecole Normale Superieure de Paris (ENS Paris).
2015: B. Sc. in Earth Sciences, Ecole Normale Superieure de Paris (ENS Paris).
CauSE: Constraining Seismic velocity Evolution in the critical zone:
The first shallow layers of the Earth are at the interplay of many physical processes, some
being driven by atmospheric forcing (precipitation, temperature...) whereas others take their origin
at depth, for instance ground shaking due to seismic activity. These forcing cause the subsurface to
continuously change its mechanical properties, therefore impacting how our societies settle, rely
and evolve on the shallowest layers of the Earth. This portion of the subsurface where life and rocks
meet is known as the critical zone. One way to investigate the everchanging time-dependent
properties of this layer is through the use of seismic interferometry. This technique is based on
cross-correlations of the ambient seismic noise wavefield recorded by seismometers and allows for
the continuous monitoring of seismic wave velocities. My project aims to monitor and constrain
seismic velocity changes that are caused by hydrological changes and ground shaking-induced
damage after earthquakes to better mitigate postseismic hazards and predict water availability. I
analyse seismic dataset in a range of field settings that spans several climatic conditions (wet to arid
climate) in various seismic-prone areas. I also constrain our results using simple physical models
and independent dataset. The first part of the project was conducted in the Nepal Himalayas where
we estimated seismic velocity changes to reveal detailed insights on groundwater dynamics during
three monsoon seasons. I also investigated the effect of damage caused of the 2015 Gorkha
earthquake on ground properties. Motivated by this work, I am currently working on the time-
dependent evolution of subsurface rock properties following earthquakes.
I am also part of the PRESSurE project.