Study of Receptor Functions of the Cortical Structure of the Southern Sector of the Merida Andes

Abstract

13 temporary broadband seismological stations were installed as part of the GIAME (Integral Geoscience of the Merida Andes) and CARMA (CARibbean Merida Andes) projects (2015-2018) along a NW-SE profile, perpendicular to the axis of the Mérida Andes mountain range. P-wave receiver functions analyses were conducted on teleseismic events recordings with epicentral distances of 30º to 95º and magnitudes greater than 5.5. The data was sourced from the GEM Catalog of the International Seismological Center (ISC, 2019), encompassing 228 earthquakes recorded during the operational period of the stations. These analyses identified two prominent discontinuities: the Moho discontinuity, exhibiting depths between 35-50 km, with its greatest depth located northwest of the mountain range axis; and an intracortical discontinuity within the upper crust at depths ranging from 10-15 km. The Moho deptht determined in this study (∼50 km) is consistent with previous studies based on deep seismic and gravimetric data (Rondón, 2016; Medina, 2017).