Fig. 1

Tectonic map of the study area in and around the CTJ. The inset shows the location of the study area as a red boxed area within South America (SA). The blue dashed rectangle delineates the model region and the two blue orthogonal arrows indicate the \(+x\) and \(+y\) axis directions, respectively. The thick black lines delineate the plate boundaries at the Earth’s surface (Bird 2003), and the thin black lines indicate the depth (in km) of the upper surface of the oceanic plate geometry model used in this numerical simulation. The pink dashed line is the approximate boundary of the slab window at a depth of 50 km (Russo et al. 2010). Yellow lines show the current age of the NZ and AN plates (Seton et al. 2020). The colored circles represent the depths and epicenters of all tectonic tremors that occurred from January 2005 to February 2007 (Ide 2012). The light blue dashed line indicates the tectonic tremor-generating area used in Figs. 5 and 6. The volcanoes are represented by solid red triangles. The purple and orange arrows are the convergence rate vectors of the NZ and AN plates, respectively, with respect to the SA plate, calculated using ITRF2014 (Altamimi et al. 2016). The bathymetry and topography data are taken from ETOPO1 (Amante and Eakins 2009)