MILESTONE

1. Test, compare and calibrate machine learning based techniques for seismic phase picking and association, integrating them into an automatized workflow of seismicity catalog generation
2. Apply this workflow to three or four different subduction zone segments where data from longer-term dense deployments are available; retrieval of “deep” catalogs with low completeness magnitude
3. Conduct analysis that utilizes these catalogs as input, such as local earthquake tomography, analysis of b-values or aftershock productivity
4. Combination of these results with evidence from GNSS/InSAR (to characterize the plate interface) or theoretical petrology/geodynamic modeling (to characterize slab processes)
5. Being able to locate and analyze along-strike and/or temporal changes inside one subduction zone segment as well as systematic differences between different segments

MILESTONE is composed of five work packages as follows:

• • • WP1: Earthquake catalog generation: building “deep” earthquake catalogs using novel machine learning based techniques
    • WP2: Tomographic Inversion: using the obtained phase picks to construct highly resolved tomographic images of subduction zones
    • WP3: Statistics and Imaging: statistical seismology using the “deep” catalogs, supported by receiver function analysis
    • WP4: Plate Interface Processes: Combining seismicity and GNSS/InSAR constraints to try to define asperities and their properties
    • WP5: Petrophysical and Thermal Models: Evaluation of intraslab processes with a combination of seismological and petrological analysis as well as modeling

2023:

• Hormazabal, J., Moreno, M. Ortega-Culaciati, F., Baez, J.C., Pena, C., Sippl, C., Gonzalez-Vidal, D., Ruiz, J., Metzger, S., Yoshioka, S. (2023), Fast relocking and aftershock-seismicity evolution following the 2015 Mw 8.3 Illapel earthquake in Chile, Scientific Reports, 13, 19511., https://doi.org/10.1038/s41598-023-45369-9
• González-Vidal, D., Moreno, M., Sippl, C., Baez, J. C., Ortega-Culaciati, F., Lange, D., et al. (2023). Relation between oceanic plate structure, patterns of interplate locking and microseismicity in the 1922 Atacama seismic gap. Geophysical Research Letters, 50, e2023GL103565. https://doi.org/10.1029/2023GL103565
• Sippl, C., Schurr, B., Münchmeyer, J., Barrientos, S., Oncken, O. (2023), The Northern Chile forearc constrained by 15 years of permanent seismic monitoring, Journal of South American Earth Sciences, 126, 104326, https://doi.org/10.1016/j.jsames.2023.104326

2022:

• Sippl, C., Dielforder, A., John, T., & Schmalholz, S. M. (2022). Global constraints on intermediate-depth intraslab stresses from slab geometries and mechanisms of double seismic zone earthquakes. Geochemistry, Geophysics, Geosystems, 23, e2022GC010498. https://doi.org/10.1029/2022GC010498
• Geersen, J., Sippl, C., Harmon, N. (2022). Impact of bending-related faulting and oceanic-plate topography on slab hydration and intermediate-depth seismicity. Geosphere, 18 (2), 562–584. https://doi.org/10.1130/GES02367.1
• Morales-Yáñez, C., Bustamante, L., Benavente, R. , Sippl, C., Moreno, M. (2022), B-value variations in the Central Chile seismic gap assessed by a Bayesian transdimensional approach. Scientific Reports, 12, 21710. https://doi.org/10.1038/s41598-022-25338-4

2021:

• Sippl, C., Moreno, M., Benavente, R. (2021). Microseismicity appears to outline highly coupled regions on the Central Chile megathrust. Journal of Geophysical Research, 126, e2021JB022252. https://doi.org/10.1029/2021JB022252

Links to Datasets (seismicity catalogs. slab geometries) produced within the framework of the project will be provided here.
Published seismicity catalogs:

• IPOC catalog for Northern Chile (2007-2021)
• Seismicity catalog for Central Chile (2014-2018)