Colombia has been rattled by a wave of seismic activity in recent weeks, and experts say it comes from two distinct sources. The first is an ongoing series of aftershocks following the magnitude 7.4 earthquake that struck western Colombia on August 10. The second is a separate “earthquake swarm” — a cluster of smaller, closely spaced tremors — recently detected in the department of Tolima, especially around the towns of Chaparral and Roncesvalles.
Mónica Arcila, director of Geohazards at Colombia’s Geological Survey (Servicio Geológico Colombiano, or SGC), says both phenomena are tied to the country’s unusually complex tectonic setting. Colombia sits in the northwestern corner of South America, a location where several tectonic plates meet and grind against one another, including the Nazca, South American, and Caribbean plates. That collision zone makes the country prone to frequent earthquakes, though Arcila notes that aftershock sequences and swarms are different processes: aftershocks fade gradually after a major quake, while swarms are clusters of similarly sized tremors without one dominant event.
Arcila emphasizes that this level of activity, while intense, falls within the range of normal behavior for a tectonically active country like Colombia, and that residents should expect continued minor tremors as the earth’s crust settles.
For the full interview, check out the original story on El Tiempo’s website.
Source: Secuencia de réplicas y enjambres: ¿es normal que esté temblando tanto en Colombia? Experta del SGC explica (eltiempo.com).
Image: Dvortygirl, BY-SA 2.0 (via Openverse).