There saying 36,000 feet.
I showed SSQ the picture you'd posted. He said "Whoa!" We're fascinated with volcanos. One of the 'educational' channels, I think it was the History Channel, had a dramatization of the eruption of Vesuvius on a couple of weeks ago. It was fascinating because they took almost verbatim, the account of Pliny the Younger, and created a drama from it.
Along with that they used information discovered when they finally did the excavations in the early part of the century and found the impressions of the bodies of all the people from the town of Herculaneum, at the foot of Vesuvius. It was originally thought that they had escaped the danger, because there were no bodies in the town, but what they'd done was go down to the beach, and stay in the boathouses, hoping for rescue from the sea. They'd seen the boats of the Navy, led by Pliny the Elder, who had come from across the bay, but the boats were not able to put in at the shore because of the wind and smoke. These people were in the boathouses and on the beach when the pyroclastic flows from Vesuvius came down and engulfed them. Their forms, cast in the ash, were found when the excavations were done.
Later that same day that Pompeii and the other town were destroyed, Pliny the Elder was down on the beach on another part of the bay when a gas cloud from Vesuvius came over him and killed him. It was quite fascinating.