Mount Unzen
In the early 1990s, Voight performed volcanic hazard assessments at Cotopaxi in Ecuador and at Nevado del Huila in Colombia, where his research was impeded by guerrilla factions and drug cartel operations. He also assisted with assessment activity at Mount Pinatubo in the Philippines, Mount Redoubt in the United States, Mount Bandai, Mount Unzen, and Mount Ontake in Japan, and Bezymianny and Shiveluch in the Kamchatka Peninsula, Russia.