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11- 15 december 2023: ANR INSeis represented at the AGU (San Francisco)
P. Dublanchet and Ph. Danré are co-chairing a session at the AGU, the most followed international conferences in Earth Sciences. This session is about: "Physical Controls of Earthquake Swarm Evolution".
They also present 3 communications within the ANR INSeis:
- Ph. Danré, D. Garagash, L.De Barros, F. Cappa, and J.-P. Ampuero, Propagation of a fluid-induced aseismic crack leads to earthquake swarm migration controlled by fluid volume,
- Ph. Danré, L.De Barros, F. Cappa, and L. Passarelli,Slow slips and fluid-induced seismicity swarms : a tale across scales.
- G. Gerardi, P. Dublanchet, L.Jeannin, A. Kazantsev, L.Duboeuf, I. Ramadhan, H. Azis, N. Ganefianto and I. Agoes Nugroho, S53F-0336Geomechanical Modeling of Injection-induced Seismicity: the Case Study of the Muara Laboh Geothermal Plant
Great job, thanks to them!
1st october 2023: Ph. Danré as new postdoc in the ANR INSeis
Having successfully defended his PHD, Philippe starts a new 2-years project within the WP1 of ANR INSeis, within the supervision of O. Lengliné and L. De Barros. His goal is to derive an improved catalog of the seismicty in the Corinth rift using up-to-date methods (detection by deep learning and template-matching and double-difference relocation) in order to refine the analysis of the swarms in this area and to study their long-term behavior.
Happy to keep Philippe within the ANR INSeis, and good luck!
27 September 2023: Brand New Doctor Ph. Danré
Philippe Danré successfully and brilliantly defend his PhD thesis at Géoazur, « Analyse multi-échelles et multi-objets du couplage entre les fluides et la sismicité ». The panel was composed of D. Marsan, P. Bernard, F. Courboulex, J. Albaric and P. Poli, plus his supervisors L.De Barros and F. Cappa.
The abstract of this exeptionnal work, linking swarms and induced seismicity is:
"Earthquake swarms are seismic sequences with moderate magnitudes (below 4) and without a clear mainshock. They occur in a wide diversity of tectonic contexts where fluids are expected to be present like for instance volcanic regions, along the subduction interface or in the vicinity of transform or rifting faults zones. Fluid injection at depth, for geothermal, wastewater storage or CO2 sequestration purposes also leads to such swarms. Despite an overall moderate seismicity, some of those sequences can present magnitudes above 3, putting at risk injection activities or even endangering populations. Improving our knowledge of seismogenic processes is a necessary condition, for instance, for the access to geothermal energy, or to anticipate the evolution of swarms towards large, potentially damaging, earthquakes. Experiments as well as numerical and theoretical developments suggest that aseismic deformation would play a key role in earthquake swarms dynamics, whether they are natural or injection-induced. This work aims at improving our understanding of the coupling between fluids, seismicity and aseismic deformation. For that, I study in detail many earthquake swarms from a diversity of tectonic contexts or from different injection operations. First, through the study of aseismic slip release, I show that natural and injection-induced earthquake swarms behave in a similar way. Then, I explore the link between injection properties (volume, pressure) and seismicity (magnitude, number of events). I propose and validate two new empirical laws relating injected fluid volume to seismicity and aseismic deformation, based on observations made on injection-induced sequences. This allows me to reconstruct fluid volume circulating during natural earthquake swarms. In order to explain seismicity migration, which is observed during most of the swarms, and to constrain physical parameters controlling seismic and aseismic slip, I apply a mechanical model to two sequences associated with geothermal activities (Basel, Switzerland and Soultz-sous-Forêts, France). New observations linking hypocenter migration and injected fluid volume allow me to reconstruct accurately temporal evolution of fluid volume circulating during those two sequences, and to apply it to natural earthquake swarms. In a last part, I study global scaling laws, which are commonly used in seismology, to discriminate swarm driving processes. Taking into account aseismic slip release, this allows me to differentiate two behaviors within swarms : one associated with fluid circulation at depth and the other triggered by slow slip episodes. Inferred scaling relations lead to a simple and efficient tool to determine the driving process of earthquake swarms."
Congratulations, Doctor Phil!
16 & 17 february 2023 - Kick-Off Meeting
Two days of scientific discussions about swarms and induced seismicity gathered about 20 researchers in Geoazur. After presentation of the main goals and objectives of the ANR INSeis project, we have nice talks and chats about 1) Swarms in the Corinth rift, 2) induced seismicity in geothermal fields, shale gas reservoirs and decametric experiments and 3) other very interesting swarms and analysis (Maurienne, Ubaye, Mt Blanc, Apenines), 4) the large scientific possibilities that offers numerical modelling to better understand the observations and 4) the scaling relationships between these different objects that allow us to identify generic properties of swarms. Very good scientific ideas emerge from the discussion, helped by a glass of port-wine, and numerous working paths are identified.
Thanks to all the speakers (M. Baques, Q. Blétery, P. Briole, F. Cappa, L. De Barros, Ph. Danré, P. Dublanchet, M. Godano, A. Helmstteter, O. Lengliné, H. Lyon-Caen, R. Minetto, L. Xiang) and all participants, for this constructive and enjoyable days.
Let's concretize all this positive emulation!
