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Chalumeau C, Agurto-Detzel H, Rietbrock A, Frietsch M, Oncken O, Segovia M, Galve A. Seismological evidence for a multifault network at the subduction interface. Nature 2024; 628:558-562. [PMID: 38632482 PMCID: PMC11023936 DOI: 10.1038/s41586-024-07245-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/27/2024] [Indexed: 04/19/2024]
Abstract
Subduction zones generate the largest earthquakes on Earth, yet their detailed structure, and its influence on seismic and aseismic slip, remains poorly understood. Geological studies of fossil subduction zones characterize the seismogenic interface as a 100 m-1 km thick zone1-3 in which deformation occurs mostly on metres-thick faults1,3-6. Conversely, seismological studies, with their larger spatial coverage and temporal resolution but lower spatial resolution, often image the seismogenic interface as a kilometres-wide band of seismicity7. Thus, how and when these metre-scale structures are active at the seismic-cycle timescale, and what influence they have on deformation is not known. Here we detect these metres-thick faults with seismicity and show their influence on afterslip propagation. Using a local three-dimensional velocity model and dense observations of more than 1,500 double-difference relocated earthquakes in Ecuador, we obtain an exceptionally detailed image of seismicity, showing that earthquakes occur sometimes on a single plane and sometimes on several metres-thick simultaneously active subparallel planes within the plate interface zone. This geometrical complexity affects afterslip propagation, demonstrating the influence of fault continuity and structure on slip at the seismogenic interface. Our findings can therefore help to create more realistic models of earthquake rupture, aseismic slip and earthquake hazard in subduction zones.
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Affiliation(s)
| | | | | | | | - Onno Oncken
- GeoForschungsZentrum (GFZ), Potsdam, Germany
| | - Monica Segovia
- Institute of Geophysics, Escuela Politecnica Nacional, Quito, Ecuador
| | - Audrey Galve
- Université Côte d'Azur, CNRS, Observatoire de la Côte d'Azur, IRD, Géoazur, Valbonne, France
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Bedford JR, Moreno M, Deng Z, Oncken O, Schurr B, John T, Báez JC, Bevis M. Months-long thousand-kilometre-scale wobbling before great subduction earthquakes. Nature 2020; 580:628-635. [PMID: 32350476 DOI: 10.1038/s41586-020-2212-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 02/05/2020] [Indexed: 11/10/2022]
Abstract
Megathrust earthquakes are responsible for some of the most devastating natural disasters1. To better understand the physical mechanisms of earthquake generation, subduction zones worldwide are continuously monitored with geophysical instrumentation. One key strategy is to install stations that record signals from Global Navigation Satellite Systems2,3 (GNSS), enabling us to track the non-steady surface motion of the subducting and overriding plates before, during and after the largest events4-6. Here we use a recently developed trajectory modelling approach7 that is designed to isolate secular tectonic motions from the daily GNSS time series to show that the 2010 Maule, Chile (moment magnitude 8.8) and 2011 Tohoku-oki, Japan (moment magnitude 9.0) earthquakes were preceded by reversals of 4-8 millimetres in surface displacement that lasted several months and spanned thousands of kilometres. Modelling of the surface displacement reversal that occurred before the Tohoku-oki earthquake suggests an initial slow slip followed by a sudden pulldown of the Philippine Sea slab so rapid that it caused a viscoelastic rebound across the whole of Japan. Therefore, to understand better when large earthquakes are imminent, we must consider not only the evolution of plate interface frictional processes but also the dynamic boundary conditions from deeper subduction processes, such as sudden densification of metastable slab.
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Affiliation(s)
- Jonathan R Bedford
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany.
| | - Marcos Moreno
- Departamento de Geofísica, Universidad de Concepción, Concepción, Chile
| | - Zhiguo Deng
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
| | - Onno Oncken
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany.,Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Bernd Schurr
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
| | - Timm John
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Juan Carlos Báez
- University of Chile, National Seismological Centre, Santiago, Chile
| | - Michael Bevis
- School of Earth Sciences, Ohio State University, Columbus, OH, USA
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Schurr B, Asch G, Hainzl S, Bedford J, Hoechner A, Palo M, Wang R, Moreno M, Bartsch M, Zhang Y, Oncken O, Tilmann F, Dahm T, Victor P, Barrientos S, Vilotte JP. Gradual unlocking of plate boundary controlled initiation of the 2014 Iquique earthquake. Nature 2014; 512:299-302. [PMID: 25119049 DOI: 10.1038/nature13681] [Citation(s) in RCA: 230] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 07/14/2014] [Indexed: 11/09/2022]
Abstract
On 1 April 2014, Northern Chile was struck by a magnitude 8.1 earthquake following a protracted series of foreshocks. The Integrated Plate Boundary Observatory Chile monitored the entire sequence of events, providing unprecedented resolution of the build-up to the main event and its rupture evolution. Here we show that the Iquique earthquake broke a central fraction of the so-called northern Chile seismic gap, the last major segment of the South American plate boundary that had not ruptured in the past century. Since July 2013 three seismic clusters, each lasting a few weeks, hit this part of the plate boundary with earthquakes of increasing peak magnitudes. Starting with the second cluster, geodetic observations show surface displacements that can be associated with slip on the plate interface. These seismic clusters and their slip transients occupied a part of the plate interface that was transitional between a fully locked and a creeping portion. Leading up to this earthquake, the b value of the foreshocks gradually decreased during the years before the earthquake, reversing its trend a few days before the Iquique earthquake. The mainshock finally nucleated at the northern end of the foreshock area, which skirted a locked patch, and ruptured mainly downdip towards higher locking. Peak slip was attained immediately downdip of the foreshock region and at the margin of the locked patch. We conclude that gradual weakening of the central part of the seismic gap accentuated by the foreshock activity in a zone of intermediate seismic coupling was instrumental in causing final failure, distinguishing the Iquique earthquake from most great earthquakes. Finally, only one-third of the gap was broken and the remaining locked segments now pose a significant, increased seismic hazard with the potential to host an earthquake with a magnitude of >8.5.
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Affiliation(s)
- Bernd Schurr
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Günter Asch
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Sebastian Hainzl
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Jonathan Bedford
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Andreas Hoechner
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Mauro Palo
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Rongjiang Wang
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Marcos Moreno
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Mitja Bartsch
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Yong Zhang
- School of Earth and Space Sciences, Peking University, Beijing 100871, China
| | - Onno Oncken
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Frederik Tilmann
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Torsten Dahm
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Pia Victor
- GFZ Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
| | - Sergio Barrientos
- Centro Sismológico National, Universidad de Chile, Facultad de Ciencias Físicas y Matemáticas, Blanco Encalada 2002, Santiago, Chile
| | - Jean-Pierre Vilotte
- Institut de Physique du Globe de Paris, 1, rue Jussieu, 75238 Paris cedex 05, France
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Moreno M, Rosenau M, Oncken O. 2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone. Nature 2010; 467:198-202. [PMID: 20829792 DOI: 10.1038/nature09349] [Citation(s) in RCA: 323] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 07/09/2010] [Indexed: 11/09/2022]
Abstract
The magnitude-8.8 Maule (Chile) earthquake of 27 February 2010 ruptured a segment of the Andean subduction zone megathrust that has been suspected to be of high seismic potential. It is the largest earthquake to rupture a mature seismic gap in a subduction zone that has been monitored with a dense space-geodetic network before the event. This provides an image of the pre-seismically locked state of the plate interface of unprecedentedly high resolution, allowing for an assessment of the spatial correlation of interseismic locking with coseismic slip. Pre-seismic locking might be used to anticipate future ruptures in many seismic gaps, given the fundamental assumption that locking and slip are similar. This hypothesis, however, could not be tested without the occurrence of the first gap-filling earthquake. Here we show evidence that the 2010 Maule earthquake slip distribution correlates closely with the patchwork of interseismic locking distribution as derived by inversion of global positioning system (GPS) observations during the previous decade. The earthquake nucleated in a region of high locking gradient and released most of the stresses accumulated in the area since the last major event in 1835. Two regions of high seismic slip (asperities) appeared to be nearly fully locked before the earthquake. Between these asperities, the rupture bridged a zone that was creeping interseismically with consistently low coseismic slip. The rupture stopped in areas that were highly locked before the earthquake but where pre-stress had been significantly reduced by overlapping twentieth-century earthquakes. Our work suggests that coseismic slip heterogeneity at the scale of single asperities should indicate the seismic potential of future great earthquakes, which thus might be anticipated by geodetic observations.
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Affiliation(s)
- Marcos Moreno
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam 14473, Germany
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Bachmann R, Oncken O, Glodny J, Seifert W, Georgieva V, Sudo M. Exposed plate interface in the European Alps reveals fabric styles and gradients related to an ancient seismogenic coupling zone. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jb005927] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Rosenau M, Lohrmann J, Oncken O. Shocks in a box: An analogue model of subduction earthquake cycles with application to seismotectonic forearc evolution. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jb005665] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Matthias Rosenau
- GeoForschungsZentrum Potsdam; Department of Geodynamics; Telegrafenberg, Potsdam Germany
| | - Jo Lohrmann
- GeoForschungsZentrum Potsdam; Department of Geodynamics; Telegrafenberg, Potsdam Germany
| | - Onno Oncken
- GeoForschungsZentrum Potsdam; Department of Geodynamics; Telegrafenberg, Potsdam Germany
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Oncken O, Asch G, Haberland C, Metchie J, Sobolev S, Stiller M, Yuan X, Brasse H, Buske S, Giese P, Görze HJ, Lueth S, Scheuber E, Shapiro S, Wigger P, Yoon MK, Bravo P, Vieytes H, Chong G, Gonzales G, Wilke HG, Lüschen E, Martinez E, Rössling R, Ricaldi E, Rietbrock A. Seismic imaging of a convergent continental margin and plateau in the central Andes (Andean Continental Research Project 1996 (ANCORP'96)). ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb001771] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- O. Oncken
- GeoForschungsZentrum Potsdam; Potsdam Germany
| | - G. Asch
- GeoForschungsZentrum Potsdam; Potsdam Germany
| | | | - J. Metchie
- GeoForschungsZentrum Potsdam; Potsdam Germany
| | - S. Sobolev
- GeoForschungsZentrum Potsdam; Potsdam Germany
| | - M. Stiller
- GeoForschungsZentrum Potsdam; Potsdam Germany
| | - X. Yuan
- GeoForschungsZentrum Potsdam; Potsdam Germany
| | - H. Brasse
- Freie Universität Berlin; Berlin Germany
| | - S. Buske
- Freie Universität Berlin; Berlin Germany
| | - P. Giese
- Freie Universität Berlin; Berlin Germany
| | | | - S. Lueth
- Freie Universität Berlin; Berlin Germany
| | | | - S. Shapiro
- Freie Universität Berlin; Berlin Germany
| | - P. Wigger
- Freie Universität Berlin; Berlin Germany
| | - M.-K. Yoon
- Freie Universität Berlin; Berlin Germany
| | - P. Bravo
- ENAP-Empresa Nacional Del Petróleo; Punta Arenas Chile
| | - H. Vieytes
- ENAP-Empresa Nacional Del Petróleo; Punta Arenas Chile
| | - G. Chong
- Universidad Católica del Norte; Antofagasta Chile
| | - G. Gonzales
- Universidad Católica del Norte; Antofagasta Chile
| | - H.-G. Wilke
- Universidad Católica del Norte; Antofagasta Chile
| | - E. Lüschen
- Universität München (LMU); München Germany
| | | | | | - E. Ricaldi
- Universidad Mayor de San Andres; La Paz Bolivia
| | - A. Rietbrock
- Institute of Geosciences, University of Potsdam; Potsdam Germany
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8
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Yuan X, Sobolev SV, Kind R, Oncken O, Bock G, Asch G, Schurr B, Graeber F, Rudloff A, Hanka W, Wylegalla K, Tibi R, Haberland C, Rietbrock A, Giese P, Wigger P, Röwer P, Zandt G, Beck S, Wallace T, Pardo M, Comte D. Subduction and collision processes in the Central Andes constrained by converted seismic phases. Nature 2000; 408:958-61. [PMID: 11140679 DOI: 10.1038/35050073] [Citation(s) in RCA: 305] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Central Andes are the Earth's highest mountain belt formed by ocean-continent collision. Most of this uplift is thought to have occurred in the past 20 Myr, owing mainly to thickening of the continental crust, dominated by tectonic shortening. Here we use P-to-S (compressional-to-shear) converted teleseismic waves observed on several temporary networks in the Central Andes to image the deep structure associated with these tectonic processes. We find that the Moho (the Mohorovicić discontinuity--generally thought to separate crust from mantle) ranges from a depth of 75 km under the Altiplano plateau to 50 km beneath the 4-km-high Puna plateau. This relatively thin crust below such a high-elevation region indicates that thinning of the lithospheric mantle may have contributed to the uplift of the Puna plateau. We have also imaged the subducted crust of the Nazca oceanic plate down to 120 km depth, where it becomes invisible to converted teleseismic waves, probably owing to completion of the gabbro-eclogite transformation; this is direct evidence for the presence of kinetically delayed metamorphic reactions in subducting plates. Most of the intermediate-depth seismicity in the subducting plate stops at 120 km depth as well, suggesting a relation with this transformation. We see an intracrustal low-velocity zone, 10-20 km thick, below the entire Altiplano and Puna plateaux, which we interpret as a zone of continuing metamorphism and partial melting that decouples upper-crustal imbrication from lower-crustal thickening.
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Affiliation(s)
- X Yuan
- GeoForschungsZentrum Potsdam, Telegrafenberg, Germany
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Tanner DC, Behrmann JH, Oncken O, Weber K. Three-dimensional retro-modelling of transpression on a linked fault system: the Upper Cretaceous deformation on the western border of the Bohemian Massif, Germany. ACTA ACUST UNITED AC 1998. [DOI: 10.1144/gsl.sp.1998.135.01.18] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Oncken O. Transformation of a magmatic arc and an orogenic root during oblique collision and its consequences for the evolution of the European Variscides (Mid-German Crystalline Rise). ACTA ACUST UNITED AC 1997. [DOI: 10.1007/s005310050118] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Berzin R, Oncken O, Knapp JH, Pérez-Estaún A, Hismatulin T, Yunusov N, Lipilin A. Orogenic Evolution of the Ural Mountains: Results from an Integrated Seismic Experiment. Science 1996. [DOI: 10.1126/science.274.5285.220] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- R. Berzin
- R. Berzin, Spetsgeofisika, Moscow, 107140 Russia
| | - O. Oncken
- O. Oncken, GeoForschungsZentrum, D-14473 Potsdam, Germany
| | - J. H. Knapp
- J. H. Knapp, Institute for the Study of the Continents, Cornell University, Ithaca, NY 14853, USA
| | - A. Pérez-Estaún
- A. Pérez-Estaún, Instituto de Ciencias de la Tierra, Consejo Superior de Investigaciones Cientificas-Barcelona, 08028 Spain
| | - T. Hismatulin
- T. Hismatulin, Bazhenov Geophysical Expedition, Scheelite, 624051 Russia
| | - N. Yunusov
- N. Yunusov, Bashneftegeofizika, Ufa, 450000 Russia
| | - A. Lipilin
- A. Lipilin, ROSCOMNEDRA (Committee on Geology and Use of Mineral Resources of the Russian Federation), Moscow, 107140 Russia
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Zulauf G, Kleinschmidt G, Oncken O. Brittle deformation and graphitic cataclasites in the pilot research well KTB-VB (Oberpfalz, FRG). ACTA ACUST UNITED AC 1990. [DOI: 10.1144/gsl.sp.1990.054.01.10] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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