The Romeral Fault System is a broad, long-lived zone of faults running north to south for hundreds of kilometres through the central Colombian Andes, roughly between the Central and Western Cordilleras. It marks an ancient suture where oceanic terranes were welded onto the South American continent and it remains active under the compressive stress of ongoing plate convergence.
Today it behaves largely as a right-lateral strike-slip system with a component of compression, accommodating part of the complex interaction among the Nazca, Caribbean and South American plates. Because it threads through the densely populated Andean valleys near cities such as Medellín, Manizales and Pereira, even moderate ruptures pose serious hazard.
The system is linked to damaging earthquakes in Colombia's coffee region, and it lies within the tectonic setting that produced the deadly 1999 Armenia (Quindío) earthquake (magnitude 6.2), which killed around a thousand people. Its combination of activity and dense population makes Romeral a key focus of Colombian seismic-hazard studies.