The destruction wrought by the 1985 eruption was partially due to the fact that many scientists did not say whether or not to evacuate the area. A group of scientists informed them that they faced imminent and almost certain death. The people in Armero thought that because the volcano had not erupted in 100 years, it had no reason to erupt. Scientists later looked back to the hours before the eruption and noticed that several long period earthquakes had occurred. Long-period earthquakes are those which start out strong and then die down very slowly. Volcanologist Bernard Chouet said that these earthquakes occur in the final hours before an eruption. According to Chouet, "the volcano was screaming 'I'm about to explode'," but scientists at the time doubted his theory.