A geological transect across the suture separating northwestern South America from the Panama Arc helps document the provenance and thermal history of both crustal domains and the suture zone. During middle Miocene, strata were being accumulated over the suture zone between the Panama Arc and the continental margin. Integrated provenance analyses of those middle Miocene strata show the presence of mixed sources that includes material derived from the two major crustal domains: the old northwestern South American orogens and the younger Panama Arc. Coeval moderately rapid exhumation of Upper Cretaceous to Paleogene sediments forming the reference continental margin is suggested from our inverse thermal modeling. Strata within the suture zone are intruded by ~12 Ma magmatic arc‐related plutons, marking the transition from a collisional orogen to a subduction‐related one. Renewed late Miocene to Pliocene acceleration of the exhumation rates is the consequence of a second tectonic pulse, which is likely to be triggered by the onset of a flat‐slab subduction of the Nazca plate underneath the northernmost Andes of Colombia, suggesting that late Miocene to Pliocene orogeny in the Northern Andes is controlled by at least two different tectonic mechanisms.

The Eastern Cordillera of Colombia, in the northern Andes, is an example of an orogen in which Mesozoic basins were compressed during the Cenozoic, forming a ~2,500‐m‐high plateau in its northern portion. Significant shortening and crustal thickening have contributed to the construction of the present topography and elevation. In this contribution, we combine the use of teleseismic receiver functions, Hf isotopes, whole‐rock geochemistry, and U‐Pb dating to help elucidate the main mechanisms that played a role in the crustal thickening and uplift of the cordillera. Receiver functions calculated for three stations on top of the plateau are consistent with the presence of thrusts that converge into major crustal interfaces at upper‐middle crustal depths; they also suggest the existence of two crustal anisotropic layers beneath the western flank of the cordillera, which we interpret to have formed as a result of shearing. In the northern portion of the plateau, in the area where two Mio‐Pliocene volcanic domes and their related deposits outcrop, a lower crustal high seismic velocity layer is suggested by the receiver functions; we propose magmatic underplating for the origin of this layer. The geochemical characteristics of the volcanic rocks in the area are consistent with partial melt in a mantle influenced by slab‐related fluids; this magma could have been added to the crust and portions of it ascended and reached the surface, experiencing assimilation and differentiation during the process. We hypothesize that this Mio‐Pliocene volcanism was related to flattening of the Nazca subducting slab.

This study presents a seismic risk assessment and a set of earthquake scenarios for the residential building stock of the three largest metropolitan centers of Colombia: Bogotá, Medellín and Cali (with 8.0, 2.5, and 2.4 million inhabitants, respectively). A uniform methodology was followed for the development of the seismic hazard, vulnerability, and exposure models, thus allowing a direct comparison between the seismic risk of the different cities. Risk metrics such as exceedance probability curves and average annual losses were computed for each city. The earthquake scenarios were selected considering events whose direct economic impact is similar to the aggregated loss for a probability of exceedance of 10% in 50 years. Results show a higher mean aggregate loss ratio for Cali and similar mean aggregate loss ratios for Bogotá and Medellín. All of the models used in this study are openly accessible, enabling risk modelers, engineers, and stakeholders to explore them for disaster risk management.

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