Make no mistake: lahars are often the deadliest part of a volcanic eruption. The November 1985 eruption of Colombia’s Nevado del Ruiz demonstrated this with grim clarity.
Back then, scientists repeatedly warned the local authorities of the danger of the eruption and its subsequent lahars. They were ignored, and as a result, 23,000 people died.
The Indonesian authorities have ordered the evacuation of a record-breaking number of people living around Mount Agung, determined that they won’t encounter a similar fate – particularly as it's rainy season right now.
At this point, it has to be said that predicting when a volcano erupts is notoriously difficult. The less frequently it erupts, the less certain volcanologists can be as to when the climactic moment will arrive. The best they can do is monitor it, compare their data with past eruption data – if available – and give as much warning as possible without causing unnecessary panic.
In this sense, then, signs point toward a major paroxysm within the near-future. As always, there’s a chance Agung will calm down again and we’ll be left waiting with bated breath once more.
Similar signs were in place back in September, but that activity represented the opening salvo of the recent volcanological activity. Plenty were evacuated at the time but were ultimately never really in any danger.
Now everyone’s hoping they don’t ignore the warnings this time around, thinking it’ll be another false alarm. If they do, it could be the last mistake they ever make. Let's hope the volcano ultimatley decides to calm down again.