On the interaction of the North Andes plate with the Caribbean and South American plates in northwestern South America from GPS geodesy and seismic data

Authors

Omar J. Pérez, Simón Bolivar University, Caracas
Steven G. Wesnousky, University of Nevada, Reno
Roberto De La Rosa, Simón Bolivar University, Caracas
Julio Márquez, Simón Bolivar University, Caracas
Redescal Uzcátegui, Simón Bolivar University, Caracas
Christian Quintero, Simón Bolivar University, Caracas
Luis Liberal, Central University of Venezuela, Caracas
Héctor Mora-Páez, Colombian Geological Survey, Bogota
Walter Szeliga, Central Washington University

Document Type

Article

Department or Administrative Unit

Geological Sciences

Publication Date

9-1-2018

Abstract

We examine the hypocentral distribution of seismicity and a series of geodetic velocity vectors obtained from Global Positioning System observations between 1994 and 2015 both offshore and mainland northwestern South America (66°W–77°W; 8°N–14°N). Our analysis, that includes a kinematic block modelling, shows that east of the Caribbean–South American–North Andes plates’ triple junction at ∼68°W; 10.7°N, right-lateral easterly oriented shear motion (∼19.6 ± 2.0 mm yr⁻¹) between the Caribbean and South America plates is split along two easterly striking, right-lateral strike-slip subparallel fault zones: the San Sebastián fault that runs off-shore the Venezuelan coast and slips about 17.0±0.5mm yr⁻¹ and the La Victoria fault, located on-shore to the south, which is accumulating strain equivalent to 2.6 ± 0.4 mm yr⁻¹.West of the triple junction, relative right-lateral motion between the Caribbean and South American plates is mostly divided between the Morrocoy and Boconó fault systems that strike northwest and southwest from the triple junction, respectively, and bound the intervening North Andes plate that shows an easterly oriented geodetic slip of 15.0 ± 1.0 mm yr⁻¹ relative to the South American plate. Slip on the Morrocoy fault is right-lateral and transtensional. Motion across the Boconó fault is also right-lateral but instead transpressional, divided between ∼9 and 11 mm yr⁻¹ of right-slip on the Bocon´o fault and 2–5 mm yr⁻¹ of convergence across adjacent and subparallel thrust faults. Farther west of the triple junction, ∼800 km away in northern Colombia, the Caribbean plate subducts to the southeast beneath the North Andes plate at a geodetically estimated rate of ∼5–7 mm yr⁻¹.

Comments

This article has been accepted for publication in Geophysical Journal International ©: 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. The full-text article from the publisher can be found here.

Recommended Citation

Omar J Pérez, Steven G Wesnousky, Roberto De La Rosa, Julio Márquez, Redescal Uzcátegui, Christian Quintero, Luis Liberal, Héctor Mora-Páez, Walter Szeliga, On the interaction of the North Andes plate with the Caribbean and South American plates in northwestern South America from GPS geodesy and seismic data, Geophysical Journal International, Volume 214, Issue 3, 1 September 2018, Pages 1986–2001, https://doi.org/10.1093/gji/ggy230

Journal

Geophysical Journal International

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Rights

© The Author(s) 2018.