1In 1999, two volcanoes regarded as “explosive” erupted in Ecuador. The first one was a few kilometres outside Quito, a city of two million residents whose airport is vital for the country’s economy, but the second volcano, Tungurahua, caused most concern. It overlooked a small town with a population of 15,000 and was particularly dangerous. In fact, it is likely to produce pyroclastic flows, glowing ash clouds moving down the flanks of volcanoes at high velocity. Field teams initiated research in an attempt to determine the frequency and magnitude of eruptions, as well as the vulnerability of populations and surrounding facilities.

Eruption of the Tungurahua volcano in 1999, Ecuador.

2For good reason: in contrast to those of Hawaii or Mount Etna, Ecuador’s volcanoes produce a highly viscous lava. Rich in silica, it flows a little like toothpaste squeezed out of a tube – by forming a lava dome which rises towards the sky and explodes under pressure from the gas trapped underneath. In 2006 in Tungurahua, a very powerful eruption generated pyroclastic flows, killing six people… The death toll remained low thanks to the local geophysical institute which involves volcanologists and authorities in charge of the safety of civilian populations. Local residents were warned in advance; the six casualties were people who returned to the red zone during the eruption and paid the ultimate price.

3This example illustrates the need to adjust warning systems to the characteristics of volcanoes but also to the culture and psychology of local populations, to ensure people do not refuse to evacuate, and to avoid premature returns in the event of a crisis. The perception of risk is as important as the risk itself. Hence the relevance of the transdisciplinary approach, rooted in the field and over the long term.

Consequences of the eruption of the Tungurahua volcano, Ecuador.

“Our cooperation with IRD on volcanology has proven to be very successful in determining the past behaviour of certain volcanoes (recurrence and power of eruptions, chemical properties of magma, associated hazards) and monitoring the activity of certain dangerous active volcanoes, such as Tungurahua, Reventador or Cotopaxi. In addition to publications and training, for example via the SVAN LMI, this collaboration is therefore a success with shared benefit.” 
Silvana Hidalgo, director of the Geophysical Institute, Quito National Polytechnic School, Ecuador