Volcanic eruptions, prediction, hazard assessment, remote sensing, and societal implications

In volcanology, the period 1991–1994 was very busy, with many active volcanoes keeping pace with the higher-than-average frequency of eruptions (about 60–70 per year) recorded during the late 1970's to the late 1980's (Simkin, 1993). Some large and violent eruptions occurred in well populated areas but these passed without the higher death tolls caused by eruptions in the previous decade, a reflection perhaps of increased volcanic hazard awareness, improved prediction and monitoring, and better communication between volcanologists and public officials (Peterson and Tilling, 1993). The loss of human life was limited to a little over 1000, with perhaps ∼750 of these attributable to the Mount Pinatubo eruption on Luzon in the Philippines. Many were killed by post-eruption phenomena, such as mudflows, and by disease in the displaced populations. This large eruption, which had a world-wide atmospheric impact, dominates the picture of volcanism in the early 1990's. However, significant eruptions also occurred at Hudson, Unzen, Spurr, Redoubt, Hekla, Mayon, Galeras, Rabaul, Kliuchevskoi, Etna (the most voluminous lava outpourings this century), and many other volcanoes. Here we assess the current state of volcano monitoring and hazard awareness against a backdrop of the eruptions of the past four years, and take a look at future developments, stressing new techniques in the field of remote sensing.