Earthquake Swarm Rattles Sipí and Istmina, Reactivating Chocó Alert Five Weeks After M7.4 Quake

Colombia's National Seismological Network recorded at least seven tremors on September 14 (magnitude 3.2–4.9, depths 39–120 km) centered on Sipí and Istmina in Chocó's San Juan region, felt as far as Valle del Cauca, Risaralda, Antioquia and Tolima with more than 2,000 'did you feel it' reports by mid-afternoon. Network coordinator Freddy Tovar classified the activity as a genuine 'earthquake swarm' — a sequence lacking a single mainshock from which aftershocks progressively decrease — rather than standard aftershocks of the August 10 M7.4 quake. More than 1,340 tremors have been registered in the area since August 10, reviving anxiety in communities still housed in temporary shelters more than a month after the disaster.