Collision versus sliver transport in the hanging wall at the Middle America subduction zone: Constraints from background seismicity in central Costa Rica

Lewis, Jonathan C.; Boozer, Adam C.; López, A. M.; Montero, Walter

doi:10.1029/2007gc001711

Cited by 21 publications

(21 citation statements)

References 56 publications

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“…The trailing edge may be expressed as a zone of lithospheric extension. Lewis et al [2008] indicate that the trailing edge of this system is located in central Costa Rica on the basis of an analysis of background seismicity. The leading edge maybe expressed as a zone of convergence.…”

Section: Modelingmentioning

confidence: 98%

Fore‐arc motion and Cocos Ridge collision in Central America

LaFemina

Dixon

Govers

et al. 2009

Geochem Geophys Geosyst

187

179

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[1] We present the first regional surface velocity field for Central America, showing crustal response to interaction of the Cocos and Caribbean plates. Elastic half-space models for interseismic strain accumulation on the dipping subduction plate boundary fit the GPS data well and show strain accumulation offshore and beneath the Nicoya and Osa peninsulas in Costa Rica but not in Nicaragua. Since large subduction zone earthquakes occur in Nicaragua, we suggest that interseismic locking in Nicaragua and some other parts of Central America occurs but is mainly shallow, <20 km depth, too far offshore to be detected by our on-land GPS measurements. Our data also show significant trench-parallel motion for most of the region, generally interpreted as due to oblique convergence and strong mechanical coupling between subducting and overriding plates. However, trench-parallel motion is also observed in central Costa Rica, where plate convergence is normal to the trench, and in the Nicaraguan fore arc, where trench-parallel motion is fast, up to 9 mm a À1 , but mechanical coupling is low. A finite element model of collision (as opposed to subduction) involving the aseismic Cocos Ridge also fits the GPS surface velocity field, most significantly reproducing the pattern of trench-parallel motion. We infer that buoyant, thickened CNS-2-Cocos Ridge crust resists normal subduction and instead acts as an indenter to the Caribbean plate, driving crustal shortening in southern Costa Rica and contributing to trench-parallel fore-arc motion in Costa Rica and perhaps Nicaragua as a type of tectonic escape.

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Section: Modelingmentioning

confidence: 98%

Fore‐arc motion and Cocos Ridge collision in Central America

LaFemina

Dixon

Govers

et al. 2009

Geochem Geophys Geosyst

187

179

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“…Southern Costa Rica and Panama are located on the Panama Microplate [ Adamek et al , 1988], which is underthrust by the Caribbean Plate at its northern boundary in the North Panama Deformed Belt. The northwestern boundary of the Panama block is situated along a diffuse fault system in central Costa Rica, the Central Costa Rica Deformed Belt (CCRDB) [ Lewis et al , 2008; Marshall et al , 2000], located along the onshore continuation of the North Panama Deformed Belt. Underneath Panama and further into South America, the Nazca Plate subducts nearly perpendicularly to the Middle and South American Trench.…”

Section: Regional Backgroundmentioning

confidence: 99%

Imaging crustal structure in south central Costa Rica with receiver functions

Dzierma

Thorwart

Rabbel

et al. 2010

Geochem Geophys Geosyst

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[1] An array of broadband seismometers transecting the Talamanca Range in southern Costa Rica was operated from 2005 until 2007. In combination with data from a short-period network near Quepos in central Costa Rica, this data is analyzed by the receiver function method to image the crustal structure in south-central Costa Rica. Two strong positive signals are seen in the migrated images, interpreted as the Moho (at around 35 km depth) and an intra-crustal discontinuity (15 km depth). A relatively flat crustal and Moho interface underneath the north-east flank of the Talamanca Range can be followed for a lateral distance of about 50 km parallel to the trench, with only slight changes in the overall geometry. Closer to the coast, the topography of the discontinuities shows several features, most notably a deeper Moho underneath the Talamanca Mountain Range and volcanic arc. Under the highest part of the mountain ranges, the Moho reaches a depth of about 50 km, which indicates that the mountain ranges are approximately isostatically compensated. Local deviations from the crustal thickness expected for isostatic equilibrium occur under the active volcanic arc and in south Costa Rica. In the transition region between the active volcanic arc and the Talamanca Range, both the Moho and intracrustal discontinuity appear distorted, possibly related to the southern edge of the active volcanic zone and deformation within the southern part of the Central Costa Rica Deformed Belt. Near the volcanoes Irazu and Turrialba, a shallow converter occurs, correlating with a low-velocity, low-density body seen in tomography and gravimetry. Applying a grid search for the crustal interface depth and vp/vs ratio cannot constrain vp/vs values well, but points to generally low values (<1.7) in the upper crust. This is consistent with quartz-rich rocks forming the mountain range.

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“…1; LaFemina et al, 2009;Feng et al, 2012). La zona de estudio se localiza en el sector trasero de la zona de escape tectónico del anterior bloque (Lewis et al, 2008;Montero et al, 2013).…”

Section: Marco Tectónicounclassified

“…Destacan los trabajos de Güendel et al (1990), Barquero et al (1991b), Rojas & Barquero (1991), Fernández (1995) y Fernández & Pacheco (1998). A partir de los mecanismos focales obtenidos a partir de algunos de los anteriores autores, Lewis et al (2008) obtuvieron una dirección sub-horizontal de alargamiento de dirección ENE-WSW. Asimismo, Quintero & Güendel (2000) obtuvieron, un esfuerzo máximo (16°/23°) y uno mínimo (276°/20°), ambos subhorizontales.…”

Section: Introduccionunclassified

Las fallas Purires y Picagres, y su relación con la secuencia sísmica del Puriscal de 1990

Montero

Rojas

2014

Rev. Geol. Amér. Central

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New morphotectonic, structural, and seismological interpretations have allowed us to define the neotectonics of the region located between the northwestern border of the Talamanca cordillera and the southern flanks of Aguacate Mounts, along the central-western sector of the Central Costa Rican Deformed Belt. The principal tectonic structures identified in this study are the Purires, Zapote, Jaris, Bajos de Jorco and Picagres faults. They constitute a set of northwest dextral-slip faults, traversing for more than 45 km the previous mountains ranges. Transtensive and transpressive structures were identified along these faults. Another recognized structure is the Junquillo fault, a predominantly east-west sinistral fault that lies between the Purires and Picagres faults.

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Collision versus sliver transport in the hanging wall at the Middle America subduction zone: Constraints from background seismicity in central Costa Rica

Cited by 21 publications

References 56 publications

Fore‐arc motion and Cocos Ridge collision in Central America

Fore‐arc motion and Cocos Ridge collision in Central America

Imaging crustal structure in south central Costa Rica with receiver functions

Las fallas Purires y Picagres, y su relación con la secuencia sísmica del Puriscal de 1990

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