The Servicio Geológico Colombiano (SGC, Colombian Geological Survey) described it as the strongest earthquake to hit Colombia in a decade. Earthquake magnitude measures the total energy released at the source; USGS calculated this event at 7.4 on the moment magnitude scale, the modern standard that replaced the older Richter scale for large earthquakes. Monday’s earthquake originated roughly 110 kilometers down, a category seismologists call an “intermediate-depth” earthquake (any quake between 70 and 300 kilometers deep). That is why residents felt Monday’s earthquake as far as Bogotá and across three neighboring countries, even though the shaking was most intense closer to the Chocó-Valle del Cauca border. Finance Colombia asked Isabella Casasbuenas, a mining engineer from Colombia’s Universidad Nacional (National University), whether Monday’s earthquake and Puracé’s unrest are connected.