Overview
- Monitoring networks report continued shallow seismic swarms and elevated thermal signals into early 2026.
- UNAM documents crater‑lake shifts toward sulfate‑ and silica‑rich waters and the formation of hollow native‑sulfur spheres from liquid sulfur measured near 118°C.
- Gas sampling shows increased hydrogen sulfide and carbon dioxide near the crater that pose localized health risks in low‑lying areas.
- Authorities keep the Semáforo Volcánico at Yellow (Fase 1–2), reinforce seismic, geochemical, thermal and remote monitoring, and restrict crater access to accredited researchers.
- Agencies note the absence of deformation, deep seismicity or magmatic gas signatures and describe present hazards as hydrothermal with potential for minor steam‑driven events.