Overview
- Argentina’s Segemar and Chile’s Sernageomin raised the technical alert to yellow after at least five pyroclastic pulses and minor ash emissions from the Nicanor crater were recorded on Monday.
- Chilean authorities declared a preventive alert for nearby communes and set a roughly 1-kilometre hazard zone around the active crater while stopping short of wide evacuations.
- Technical teams report signs of new magma input beneath the Las Termas subcomplex and sustained fluid-related seismicity that make low-magnitude explosions and localized ballistic ejecta possible in the near term.
- Argentine agencies including the VAAC and SMN say no ash has been detected over Argentina so far and they are maintaining 24/7 cross-border monitoring and coordination with Chilean observatories.
- The complex is one of Chile’s most monitored volcanoes with a recent eruptive cycle from 2015–2022 that previously sent ash across the Andes, so authorities warn residents to follow official channels and be prepared for localized disruption to roads, air traffic notices, or short-term ash fall.