Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile
Abstract Like earthquakes, slow slip events release elastic energy stored on faults. Yet, the mechanisms behind slow slip instability and its relationship with seismicity are debated. Here, we use a seismo‐geodetic deployment to document a shallow slow slip event (SSE) in 2023 on the Chile subductio...
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| Format: | Article |
| Language: | English |
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Wiley
2025-04-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2024GL113953 |
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| author | Jannes Münchmeyer Diego Molina‐Ormazabal Mathilde Radiguet David Marsan Juan‐Carlos Baez Francisco Ortega‐Culaciati Andres Tassara Marcos Moreno Anne Socquet |
| author_facet | Jannes Münchmeyer Diego Molina‐Ormazabal Mathilde Radiguet David Marsan Juan‐Carlos Baez Francisco Ortega‐Culaciati Andres Tassara Marcos Moreno Anne Socquet |
| author_sort | Jannes Münchmeyer |
| collection | DOAJ |
| description | Abstract Like earthquakes, slow slip events release elastic energy stored on faults. Yet, the mechanisms behind slow slip instability and its relationship with seismicity are debated. Here, we use a seismo‐geodetic deployment to document a shallow slow slip event (SSE) in 2023 on the Chile subduction. We observe dense, migrating seismic swarms accompanying the SSE, comprised of interface activity and upper plate splay faulting. Our observations suggest that the slow slip initiation is driven by structurally confined fluid overpressure in the fluid‐rich surroundings of a subducted seamount. The fluid pressure migration interacts with the slow shear deformation increasing the interface permeability and facilitating a large‐scale SSE migration. Historical earthquake swarms highlight the persistent structural control and recurrent nature of such slow slip events. Our observations provide insight into the interactions between slow slip and seismicity, suggesting they are controlled by creep on a fluid‐infiltrated fault with fractally distributed asperities. |
| format | Article |
| id | doaj-art-1c98ae96d72a4095b6b743bbc84853dc |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2025-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-1c98ae96d72a4095b6b743bbc84853dc2025-08-20T02:56:34ZengWileyGeophysical Research Letters0094-82761944-80072025-04-01528n/an/a10.1029/2024GL113953Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern ChileJannes Münchmeyer0Diego Molina‐Ormazabal1Mathilde Radiguet2David Marsan3Juan‐Carlos Baez4Francisco Ortega‐Culaciati5Andres Tassara6Marcos Moreno7Anne Socquet8Université Grenoble Alpes Université Savoie Mont Blanc CNRS IRD Université Gustave Eiffel ISTerre Grenoble FranceUniversité Grenoble Alpes Université Savoie Mont Blanc CNRS IRD Université Gustave Eiffel ISTerre Grenoble FranceUniversité Grenoble Alpes Université Savoie Mont Blanc CNRS IRD Université Gustave Eiffel ISTerre Grenoble FranceUniversité Grenoble Alpes Université Savoie Mont Blanc CNRS IRD Université Gustave Eiffel ISTerre Grenoble FranceNational Seismological Center University of Chile Santiago ChileDepartment of Geophysics Faculty of Physical and Mathematical Sciences University of Chile Santiago ChileDepartamento Ciencias de la Tierra Facultad de Ciencias Químicas Universidad de Concepción Concepción ChileDepartment of Structural and Geotechnical Engineering Pontificia Universidad Católica de Chile Santiago ChileUniversité Grenoble Alpes Université Savoie Mont Blanc CNRS IRD Université Gustave Eiffel ISTerre Grenoble FranceAbstract Like earthquakes, slow slip events release elastic energy stored on faults. Yet, the mechanisms behind slow slip instability and its relationship with seismicity are debated. Here, we use a seismo‐geodetic deployment to document a shallow slow slip event (SSE) in 2023 on the Chile subduction. We observe dense, migrating seismic swarms accompanying the SSE, comprised of interface activity and upper plate splay faulting. Our observations suggest that the slow slip initiation is driven by structurally confined fluid overpressure in the fluid‐rich surroundings of a subducted seamount. The fluid pressure migration interacts with the slow shear deformation increasing the interface permeability and facilitating a large‐scale SSE migration. Historical earthquake swarms highlight the persistent structural control and recurrent nature of such slow slip events. Our observations provide insight into the interactions between slow slip and seismicity, suggesting they are controlled by creep on a fluid‐infiltrated fault with fractally distributed asperities.https://doi.org/10.1029/2024GL113953slow slip eventsseismic swarmsseamountsfluid overpressuresubduction |
| spellingShingle | Jannes Münchmeyer Diego Molina‐Ormazabal Mathilde Radiguet David Marsan Juan‐Carlos Baez Francisco Ortega‐Culaciati Andres Tassara Marcos Moreno Anne Socquet Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile Geophysical Research Letters slow slip events seismic swarms seamounts fluid overpressure subduction |
| title | Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile |
| title_full | Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile |
| title_fullStr | Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile |
| title_full_unstemmed | Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile |
| title_short | Seismic Swarms Unveil the Mechanisms Driving Shallow Slow Slip Dynamics in the Copiapó Ridge, Northern Chile |
| title_sort | seismic swarms unveil the mechanisms driving shallow slow slip dynamics in the copiapo ridge northern chile |
| topic | slow slip events seismic swarms seamounts fluid overpressure subduction |
| url | https://doi.org/10.1029/2024GL113953 |
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