Hi Iain, Good news, Shishaldin is monitored 24/7. We at the Alaska Volcano Observatory monitor Shishaldin with local seismic and infrasound sensors, web cameras, and a geodetic network. In addition, we also use nearby geophysical networks, regional infrasound, and satellite data to detect eruptions. Thank you, AVO This Shishaldin Volcano needs 24/7 monitoring due to recently events. This volcano can cause a major eurputng because its Younger volcano (like kids been naughty ) this volcano needs watch at all times. Volcanos such This one needs monitored for life time