Satellite, Air and Ground Observations of Volcanic Clouds over Islands of the Southwest Pacific

Volcanic ash is dangerous to aircraft. In response to this, a warning system has been created: the International Airways Volcano Watch. Many of the world's active volcanoes are in relatively underresourced regions of the southwest Pacific and eastern Indian Ocean. We show here examples of recent eruptions in the southwest Pacific and Indonesia, including major eruptions at Rabaul (NewBritain, Papua New Guinea), Merapi (Java, Indonesia), and Ruang (Sangihe Islands, Indonesia). We examine the effectiveness of satellite, air, and ground observations. There is a great variation in reported eruption heights between different observations, and we explore some of the reasons for this. There are particular difficulties with the under-reporting of eruption heights from the ground. More funding and development of ground-based observations will improve the overall effectiveness of the warning system.