Tungurahua began erupting in 1999 and has continued ever since. Damaging lahars and pyroclastic flows have hit major population centres around the volcano, and ash emissions have frequently affected surrounding areas, extending as far as Guayaquil international airport on several occasions. Tungurahua is very well monitored by Instituto Geofisico Escuela Politecnica Nacional de Ecuador (IG-EPN) whose scientists have a well-established set of empirical indices based on seismic, gas and deformation data, which allow them to forecast changes in activity on timescales of hours to weeks. Local communities are embedded in the monitoring process, with a network of ‘vigias' (lookouts) in all of the affected communities around the volcano.