Characterization and segmentation of subduction process along the Southamerica and Caribbean margin plates

Abstract:

Subduction surface in South America and the Caribbean represent a complex process of driving and resisting forces as part of region geodynamics, where dynamics is promoted from ridge push through potential energy toward trenches (Faccena, 2014). Energy produced is associated with the main source for building of mountain ranges, volcanic expressions and large earthquakes on the past few centuries, as detailed several authors although previous rupture descriptions and historical explanations of several of these events occurred before of 1900s related to subduction processes (Bilek, 2009; Stein and Wysession, 2013).

Determination of along-strike dip and along-dip variations have been a relevant target through different analysis for correlating them with orientation of tension axis, seismicity rate, volcanism, depth of seismicity, magnitude earthquakes, thermal structure, etc. (Gutcher et al., 2000; Chen et al., 2001; Bilek, 2009; Shellart & Rawlinson, 2013). Records of GPS measurements and Seismotectonic Deformation (STD) estimations show that movement of the slivers parallel to the subduction trench are controlled by the angle of convergence and are associated with the features of the Andes Range and seismic/aseismic zones (Holt et al., 1991; Corredor, 2003; Teza et al., 2008; Vergolle et al., 2010; Nocquet et al., 2014), also previous works which have used empirical approaches between magnitude and frequency of seismicity based on the Gutenberg-Richter (GR) law (Gutenberg & Richter, 1944). 

Nowadays and based on a larger seismic hazard due to overpopulated cities along this geotectonic feature, it is necessary to identify better subduction zone segments potentiality dominated by relatively long recurrence times and related to giant earthquakes (Müller and Landgrebe, 2012). In this work, we will present the main results obtained from an analysis done along Caribbean and South American margin plates, in order to improve the knowledge of seismic sources along subduction zones. We will support this segmentation on subduction angles, tectonic moment rates from GPS measurements, Seismic Moment Rates and mapping of the b-values.