Effective Elastic Thickness in Northern South America

The strength of the lithosphere plays an important role in understanding the deformation process of the Earth. In northern South America, the convergence of three tectonic plates has resulted in a zone of active deformation. The effective elastic thickness (Te) is a parameter that serves as a proxy for the lithospheric strength. This study determined the spatial variations of Te across northern South America through a joint inversion of admittance and coherence using Bouguer gravity anomaly and topography data. The inversion reveals that Te ranges from 15 to 60 km, with high Te (>50 km) corresponding to stable cratons, whereas low Te (<20 km) is displayed in areas close to continental margins. The Colombian Andes exhibit an intermediate Te value, ranging from 20 to 40 km. The subsurface-to-surface ratio (F) indicates dominant surface loading in the region. Furthermore, a correlation was observed between Te and other proxies for lithospheric structure, such as seismic velocity.