Forecasts and predictions of eruptive activity at Mount St. Helens, USA: 1975–1984

In the citing paper

“messaging about the possibility of a lateral blast (e.g., Decker 1981) was not emphasized based on its assumed low likelihood.”

In the citing paper

“Scientists realized that scenario statements needed to be repeated with each revised prediction unless there was a strong reason not to do so (Swanson et al. 1985).”

In the citing paper

“The first medium-term forecasts (over the duration of the ongoing crisis) were given on 25-27 March and 1 April 1980 and stated that the eruptive behavior would fall somewhere within the range of long-term behavior that had been previously determined from the geologic record (Swanson et al. 1985), and hazards could extend in all directions from the volcano.”

In the citing paper

“During this time, it was discovered that increasing rates of seismicity, gas emission, and deformation repeatedly preceded dome extrusion and explosive eruptions (Swanson et al. 1983;Malone et al. 1983), leading to successful forecasts before all but two dome-building eruptions (although some small explosions were not preceded by the same signals and were therefore also not successfully forecasted”

In the citing paper

“Although forecasts of the total eruptive episode duration remained elusive, a gradual decrease in sulfur dioxide emission rates between 1980 and 1982, and an increase in crystallinity of dome rocks through time, suggested progressive degassing of magma, consistent with waning eruptive activity and declining likelihood for strong explosions (Casadevall et al. 1983;Swanson et al. 1985).”