Pyroclastic flow (volcanic) ~ it's too late to run (how did the photographer survive?) It's superheated gasses and liquid rock as hot as 1000 Fahrenheit and moving at speads of up to 450 mph It instantly vaporizes everything in it's path.
This area in New Mexico owes its remarkable geology to layers of volcanic rock and ash deposited by pyroclastic flow from a volcanic explosion. Over time weathering and erosion of these layers has created canyons and tent rocks. The tent rocks themselves are cones of soft pumice and tuff beneath harder caprocks, and vary in height from a few feet to 90 feet.
Mt. Pinatubo Eruption. Photo by Albert Garcia taken on June 15, 1991 // A volcano's deadly pyroclastic flow - the same thing that buried Pompeii. You can't outrun it: it travels at 700 km/h (450 mph) and you can't weather it in anything but highly specialized shelters: it's over 1,000 °C (1,830 °F). Once you see that in your rear view mirror, you're either already out of reach or you're not.
Herculaneum/ Herculaneum (in modern Italian Ercolano) was an ancient Roman town destroyed by volcanic pyroclastic flows AD 79, located in the territory of the current commune of Ercolano, in the Italian region of Campania in the shadow of Mt. Vesuvius. It is most famous for having been lost, along with Pompeii, Stabiae and Oplontis, in the eruption of Mount Vesuvius beginning on August 24, AD 79,