Currently Active Research Projects
GMG-4 (2018) - Understanding conditions for stable/unstable fault slip induced by fluid injections
Experimental plan:
- Use the existing codes to model a field experiment on fluid injection.
- Develop codes for coupling between evolving compaction/dilation of the fault gouge and fluid flow.
Larochelle, S., Lapusta, N., Ampuero, J.-P., & Cappa, F. (2021). Constraining fault friction and stability with fluid-injection field experiments. Geophysical Research Letters, 48, e2020GL091188. https://doi.org/10.1029/2020GL091188. [PDF] *GMGPUB2
Heimisson, Elías Rafn and Rudnicki, John and Lapusta, Nadia (2021) Dilatancy and Compaction of a Rate-and-State Fault in a Poroelastic Medium: Linearized Stability Analysis. Journal of Geophysical Research. Solid Earth, 126 (8). Art. No. e2021JB022071. ISSN 2169-9313. doi:10.1029/2021jb022071. [PDF] *GMGPUB9
GMG-6 (2018) - Experimental investigation of the interaction between fluids and failure of rock faults in shear
Experimental plan:
- Conduct controlled and highly instrumented laboratory experiments with fluid injection into a pre-existing fault to study evolution in friction/pore pressure and triggering of fast/slow slip under various conditions.
- Measure slip, slip rate, and shear stress evolution along the fault during the injection process.
- Compare measurements with existing theories on the stability of fault slip.
Gori, Marcello and Rubino, Vito and Rosakis, Ares J. et al. (2021) Dynamic rupture initiation and propagation in a fluid-injection laboratory setup with diagnostics across multiple temporal scales. Proceedings of the National Academy of Sciences of the United States of America, 118 (51). Art. No. e2023433118. ISSN 0027-8424. doi:10.1073/pnas.2023433118. [PDF] [SUP] *GMGPUB8
GMG-9 (2018) - Application of DAS in monitoring microseismicity and subsurface structure changes
Experimental plan:
- Use the DAS instrument contributed by OptaSense through GMG to collect data in the Pasadena area.
- Analyze the DAS data and develop new methods in microseismicity detection, and structure monitoring.
- Optimize the data collection and processing procedures to improve the monitoring accuracy and efficiency.
Wang, Xin and Williams, Ethan F. and Karrenbach, Martin et al. (2020) Rose Parade Seismology: Signatures of Floats and Bands on Optical Fiber. Seismological Research Letters. ISSN 0895-0695. (In Press) https://resolver.caltech.edu/CaltechAUTHORS:20200506-105533707
Zhan, Zhongwen (2020) Distributed Acoustic Sensing Turns Fiber‐Optic Cables into Sensitive Seismic Antennas. Seismological Research Letters, 91 (1). pp. 1-15. ISSN 0895-0695. https://resolver.caltech.edu/CaltechAUTHORS:20200116-083302517
GMG-11 (2022) - Forecast and control of injection-induced seismicity
Experimental plan:
- WP1: Develop and test a probabilistic method to disentangle direct and indirect triggering of injection induced earthquakes. The method will provide an estimate of the probability that any particular earthquake was caused by an injection or a previous earthquake.
- WP2: Test the method on a selection of examples of injection-induced seismicity, in particular from Oklahoma or the Montney Basin (British Columbia).
- WP3: Compare the empirical spatio-temporal kernel functions with predictions from stress-based simulations (combining poroelastic stress calculation an earthquake nucleation based on rate-and-state friction). Assess the possibility of seismicity control through numerical experiments.
Kim, T., & Avouac, J.-P. (2023). Stress-based and convolutional forecasting of injection-induced seismicity: Application to the Otaniemi geothermal reservoir stimulation. Journal of Geophysical Research: Solid Earth, 128, e2022JB024960. https://doi.org/10.1029/2022JB024960. [PDF]
GMG-12 (2022) - A vertically-integrated multiphase reservoir model to enable real-time forecasting of seismicity during carbon storage operation
Experimental plan:
- Task 1: Incorporate real thermodynamic properties of CO2 into single-phase flow model to understand how initial temperature and in-situ pressure variations impact pressure diffusion in the Gronnigen site
- Task 2: Implement the vertically-integrated two-phase flow framework proposed by Jenkins et al 2019 to simulate two-phase injection into a single aquifer laye uniform thickness
- Task 3: Extend the model to consider two-phase injection into a single aquifer layer of variable thickness, hydraulic and elastic properties.Test this model using parameters from the Gronnigen site.
- Task 4: Incorporate the new model into the seismicity forecasting framework at GMG (Smieth et al. 2022).
GMG-13 (2023) - A Discrete Fault Network model to forecast induced earthquakes, creep and tremors
Project Description:
The project aims at the development of a new modeling capability to simulate fault reactivation (seismic slip, aseismic and tremors) due to a fluid injection for a network of faults. The faults will be assumed to have known geometry and governed by rate-and-state friction. The model will allow taking into account pore pressure diffusion, poro-elastic and thermos-elastic stress changes. The model will make use of the lumped-mass method. This approximation speeds up the computation time making it possible to model a 3-D fault network with non-planar geometries. The model will be benchmarked against dynamic simulations done with the Boundary Integral Method and compared with simple simulations amenable to analytical approximations.
Work plan:
- WP1: Benchmarking with simulations run with the Boundary Integral Method.
- WP2: Comparison with semi-analytical approximations (cf, Segall and Lu, 2016).
- WP3: Comparison with case examples of injection induced seismicity (Coso, Otaniemi).
Kyungjae Im Jean-Philippe Avouac, Cascading foreshocks, aftershocks and earthquake swarms in a discrete fault network, Geophysical Journal International, Volume 235, Issue 1, October 2023, Pages 831–852. https://doi.org/10.1093/gji/ggad278
GMG-14 (2023) - CO2 emissions along faults in geothermal fields
Project Description:
This new project will conduct surveys of CO2 flux using soil accumulation chambers on profiles across known and suspected faults around the Salton Sea and in the Brawley Geothermal Field. Dense measurements in a few fault zones will reveal the width of the zone of CO2 emission associated with active faults. Repeat surveys will provide an assessment of changes with time, compared to the seismic swarms detected during the one-year project. These field measurements can be used to plan the appropriate scale and repeat times for future land, aerial, or drone surveys of CO2 emissions over a larger area.
Work plan:
- WP1: Initial field surveys to obtain CO2 degassing profiles across several active faults in the Brawley and Salton Sea geothermal fields. Analysis of observations to establish whether density or locations of survey points need to be modified. If so, adjust and improve data collection sesign during WP1.
- WP2: Repeat field surveys at the same locations to assess temporal changes.
- WP3: Comparison of results from WP1 and WP2 and assessment of linkages to micro seismicity and swarm behavior detected by the Southern California seismic network over the same region and time interval.
GMG-15 (2023) - Efficient non-ergodic ground motion models using physics-based simulations and machine learning: Methodology and application for hazard assessment at the Groningen O&G field
Project Description:
We propose to develop a computationally efficient methodology for non-ergodic ground motion models (NGMMs) tailored to induced earthquake characteristics. Using ground motion observations and geophysical data from O&G fields (for example, Groningen), the proposed methodology will model tepeatable effects related to the source, path and site, and remove them from the GMM aleatory variability, leading to better characterized site-specific hazard estimation. The proposed framework will also be transferable to regional natural earthquakes, leading to better constrainded ground motion predictions and risk assessment for site-specific and for city-scale applications.
Experimental plan:
- Use the database of ground motion recordings1 at Groningen to identify repeatable effects of induced and natural earthquake source, path and site effects.
- Combine high resolution subsurface characerization2 with wave-propagation simulations of simulated induced event catalog to better identify repeatable path effects.
- Remove the repeatable effects from established GMMs for O&G field3, compute reduction aleatory variability, quantify the epistemic uncertainty in the non-ergodic effects, and evaluate impact in site-specific probabilistic seismic hazard analysis.
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