Seismic hazard analysis for central-western Argentina

Gregori, Salvador Daniel; Christiansen, Rodolfo

doi:10.1016/j.geog.2017.07.006

Cited by 14 publications

(8 citation statements)

References 13 publications

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“…Regional late Miocene–Pliocene cooling ages consistently postdate the emplacement of magmatic or hydrothermal systems by at least several million years and point to a major episode of tectonic exhumation and surface uplift that affected the Andean hinterland from ~30°S to 35°S (Farías et al, 2008; Maksaev et al, 2009; Maydagán et al, 2020; Piquer et al, 2017; Rodríguez et al, 2018). At 32°S, seismicity beneath the hinterland and retroarc domains suggests contractional deformation is still active at depth (<10–20 km; Ammirati et al, 2015; Gregori & Christiansen, 2018; Marot et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

Andean Mountain Building and Foreland Basin Evolution During Thin‐ and Thick‐Skinned Neogene Deformation (32–33°S)

Mackaman‐Lofland

Horton

Fuentes³

et al. 2020

Tectonics

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The southern Central Andes recorded retroarc shortening, basin evolution, and magmatic arc migration during Neogene changes in subduction. At 31-33°S, above the modern flat-slab segment, spatial and temporal linkages between thin-and thick-skinned foreland shortening, basement-involved exhumation of the main Cordillera, and lower-crustal hinterland thickening remain poorly resolved. We integrate new geochronological and thermochronological data for thrust sheets and Neogene foreland basin fill with structural, sedimentological, and passive seismic results to reconstruct the exhumation history and evaluate potential geometric linkages across structural domains. 40 Ar/ 39 Ar ages for volcanic horizons and zircon U-Pb ages for synorogenic clastic deposits in the Manantiales Basin constrain the minimum duration of synorogenic sedimentation to~22-14 Ma. Detrital zircon age distributions record sequential unroofing of hinterland thrust sheets until~15 Ma, followed by eastward (cratonward) advance of the deformation front, shutoff of western sediment sources, and a shift from fluvial to alluvial fan deposition at 14 Ma. Apatite (U-Th)/He cooling ages confirm rapid exhumation of basement-involved structural blocks and basin partitioning by~14-5 Ma, consistent with the timing of the Manantiales facies and provenance shifts and a coeval (~12-9 Ma) pulse of thin-skinned shortening and exhumation previously identified in the eastern foreland. Late Miocene-Pliocene (~8-2 Ma) cooling ages along the Chile-Argentina border point to hinterland uplift during the latest stage of Andean orogenesis. Finally, geophysical constraints on crustal architecture and low-temperature thermochronometry results are compatible with a hybrid thin-and thick-skinned décollement spanning retroarc domains.

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Section: Discussionmentioning

confidence: 99%

Andean Mountain Building and Foreland Basin Evolution During Thin‐ and Thick‐Skinned Neogene Deformation (32–33°S)

Mackaman‐Lofland

Horton

Fuentes³

et al. 2020

Tectonics

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“…A distinct geodynamic feature of the subduction margin is a change in subduction angle of the NP between 33°S and 35°S from the Chilean‐Pampean flat‐slab zone (<5° dip, 27°–33°S) to a steeper sector south of 35°S (∼30° dip; Figure 1). The SCA are one of the most seismically active regions along the South American convergent margin, where past seismic events had devastating impacts on humans, with loss of life and far‐reaching economic repercussions (Alvarado & Beck, 2006; Alvarado, Barrientos, et al., 2009; Ammirati et al., 2019; Gregori & Christiansen, 2018; Ruiz & Madariaga, 2018). So far, seismological research in the SCA focused on understanding the causative dynamics of the recorded seismicity within the oceanic plate and along the subduction interface (e.g., Anderson et al., 2007; Cloos & Shreve, 1996; Hackney et al., 2006; Linkimer et al., 2020; Moreno et al., 2010, 2014; Wagner et al., 2020; Weiss et al., 2019), while less attention has been paid to the mechanisms controlling upper‐plate seismicity (Alvarado et al., 2005; Alvarado, Barrientos, et al., 2009; Alvarado, Pardo, et al., 2009; Ammirati et al., 2019; Nacif et al., 2017; Smalley & Isacks, 1990; Smalley et al., 1993).…”

Section: Introductionmentioning

confidence: 99%

Long‐Term Lithospheric Strength and Upper‐Plate Seismicity in the Southern Central Andes, 29°–39°S

Piceda

Scheck‐Wenderoth

Cacace

et al. 2022

Geochem Geophys Geosyst

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We examined the relationship between the mechanical strength of the lithosphere and the distribution of seismicity within the overriding continental plate of the southern Central Andes (SCA, 29°–39°S), where the oceanic Nazca Plate changes its subduction angle between 33°S and 35°S, from subhorizontal in the north (<5°) to steep in the south (∼30°). We computed the long‐term lithospheric strength based on an existing 3D model describing variations in thickness, density, and temperature of the main geological units forming the lithosphere of the SCA and adjacent forearc and foreland regions. The comparison between our results and seismicity within the overriding plate (upper‐plate seismicity) shows that most of the events occur within the modeled brittle domain of the lithosphere. The depth where the deformation mode switches from brittle frictional to thermally activated ductile creep provides a conservative lower bound to the seismogenic zone in the overriding plate of the study area. We also found that the majority of upper‐plate earthquakes occurs within the realm of first‐order contrasts in integrated strength (12.7–13.3 log Pam in the Andean orogen vs. 13.5–13.9 log Pam in the forearc and the foreland). Specific conditions characterize the mechanically strong northern foreland of the Andes, where seismicity is likely explained by the effects of slab steepening.

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“…This statement, often known as the law of attenuation, connects magnitude, distance, and seismic intensity. The impact of the earthquake's size will be lessened by the larger the distance between the rupture area and the location where the risk is assessed [22]. Usually, empirical attenuation relationships, in other words Ground Motion Prediction Equations (GMPE), constrain how PGA values reduce with distance.…”

Section: Earthquake Data and Seismic Source Zonesmentioning

confidence: 99%

Probabilistic Seismic Hazard Analysis of Burdur City

Alpyürür

2023

International Journal of Engineering and Applied Sciences

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The aim of this study is to assess seismic hazard for Burdur City (SW Turkey) using a probabilistic approach. A new earthquake catalog for Burdur City and its vicinity, with unified moment magnitude scale, was prepared in the scope of the study. Seismicity of the area was evaluated by the Gutenberg-Richter recurrence relationship. For hazard computation, R-CRISIS (v18) software was used. New Generation Attenuation models were used for analyses. Seismic hazard maps were developed for peak ground acceleration and for bedrock with hazard levels of 2% and 10% probability of exceedance in 50 years. Results of the study show that peak ground acceleration values on bedrock with hazard levels of 2% and 10% probability of exceedance in 50 years change between 0.70-0.75 g and 0.44-0.48 g, respectively.

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Seismic hazard analysis for central-western Argentina

Cited by 14 publications

References 13 publications

Andean Mountain Building and Foreland Basin Evolution During Thin‐ and Thick‐Skinned Neogene Deformation (32–33°S)

Andean Mountain Building and Foreland Basin Evolution During Thin‐ and Thick‐Skinned Neogene Deformation (32–33°S)

Long‐Term Lithospheric Strength and Upper‐Plate Seismicity in the Southern Central Andes, 29°–39°S

Probabilistic Seismic Hazard Analysis of Burdur City

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