Mauro Prosperi’s run through the Sahara desert was going well. The Marathon des Sables is a notorious foot race – 250km in extreme heat across terrain that ranges from dunes three storeys high to stony outcrops. Prosperi, a former Olympian, was among the fastest competitors. But, as he began to pass through a section of the race that was dominated by small dunes, the sand around him started to lift and swirl. “Small dunes, unlike large ones, walk,” he says. The swirling resembled a dance, rhythmic and mesmerising at first, but the rhythm became insistent and before he knew what was happening, Prosperi faced a yellow wall. “I couldn’t see anything. The wind blew so violently, the sand hurt.”
At the start, the organisers had given a talk and advised runners to take shelter in the event of a sandstorm. If lost, they should walk towards the clouds that gather at sunset. But, as Prosperi says, “There aren’t many shelters in the desert. In the middle of the dunes, it’s hard to find a place that will defend you.”
